Research ArticleAtmospheric Pollution and Hospitalization for Cardiovascularand Respiratory Diseases in the City of Manaus from 2008 to 2012

Daniel S Sacramento1 Lourdes C Martins2 Marcos A Arbex3

and Ysabely de A P Pamplona 2

1Manaus Municipal Health Secretariat Manaus 69057-001 Brazil2Department of Public Health Catholic University of Santos Santos 11015-008 Brazil3Department of Medicine University of Araraquara Araraquara 14801-340 Brazil

Correspondence should be addressed to Ysabely de A P Pamplona ysabelypontesgmailcom

Received 21 October 2019 Revised 16 January 2020 Accepted 4 February 2020 Published 31 March 2020

Academic Editor Aggelos Avramopoulos

Copyright copy 2020 Daniel S Sacramento et al is is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Introduction Air pollution has been identified as a serious public health problem in the worldrsquos major metropolises Recent studieshave shown that airborne particle concentrations are associated with a wide range of effects on human health including increasedhospital admissions for respiratory disease enhanced asthma episodes decreased lung function and increased mortalityObjective To relate the levels of air pollution and hospital admissions for cardiovascular and respiratory diseases in the city ofManaus in Brazil from 2008 to 2012 Method is is an ecological time-series study among children (under 5 years of age) andelderly (above 60 years of age) Data on the daily number of hospitalizations for cardiovascular and respiratory diseases pollutants(PM25) temperature and humidity were used Poisson generalized additive models were used to estimate the association betweenvariables Increases in hospitalizations for cardiovascular and respiratory diseases were estimated for the interquartile range (IQR)daily mean level of each variable studied with a confidence interval of 95 Results Respiratory diseases and children minus040(95 CI minus111 030) 059 (95 CI minus035 152) and 047 (95 CI minus328 421) for PM25 temperature and humidityrespectively Respiratory diseases and elderly 019 (95 CI minus093 131) minus010 (95 CI minus185 165) and minus617 (95 CIminus1308 074) for PM25 temperature and humidity respectively Cardiovascular diseases and elderly minus018 (95 CI minus086050) minus004 (95 CI minus110 103) and minus337 (95 CI minus759 085) for PM25 temperature and humidity respectivelyConclusions e time-series study found no significant association between PM25 temperature humidity and hospitalizationunlike the evidences provided by the present academic literature Since there is no air quality monitoring network in Manaus andthe option available in the present study was to reproduce some information obtained from remote sensing there is a need forimplementation of ground monitoring stations for health and environmental studies in the region

1 Introduction

e interaction between men and the surrounding envi-ronment has promoted the exposure to several aggressorseither natural or resulting from anthropogenic activityAlthough the effects of pollution have been reported sinceantiquity pollution affects population in large proportionssolely from the beginning of the industrial revolution [1]Exposure to air pollutants may influence humansrsquo healthsince intrauterine life Studies have shown that pollutants

have deleterious effects even at exposure levels below theacceptable standard limitsemost affected and susceptibleage groups are children and the elderly [2ndash4]

In the Brazilian Amazon urbanization has been a rapidprocess e Brazilian Amazon covers the states of AcreAmapa Amazonas Para Rondonia Roraima TocantinsMato Grosso and part of Maranhatildeo and hosts 128 of thenational population e fast process of urbanization cou-pled with significant changes in the pattern of exploitation ofnatural resources has caused many types of environmental

Hindawie Scientific World JournalVolume 2020 Article ID 8458359 8 pageshttpsdoiorg10115520208458359

impacts including loss of biodiversity reduction of theproductive potential of soils erosion river pollution de-forestation and forest fires ese impacts have altered therelationship between urban and rural spaces resulting in theemergence of new territorialities with positive andor neg-ative configurations [5] Urban air pollution producedmainly by forest fires and increased vehicular fleet as well asthe installation of industries in the region (especially theIndustrial Pole of Manaus) constitutes one of the negativeconfigurations that these new territorialities can assume

Currently air quality monitoring is an object of researchin several developed or developing countries In the Ama-zon environmental information databases in several areasare affected by the lack of spatial and environmental cov-erage In turn the lack of data for continuous air qualitymonitoring and forecasting can translate into consequencesfor public health [6] Studies on the effects of air pollution inthe Amazon have mostly focused on the analysis of theeffects of biomass burning on outpatient care and thenumber of hospitalizations for respiratory diseases mainlyasthma [7]

As exposure to pollution and weather conditions occursimultaneously it is important to seek to understand notonly their isolated effect but also their interaction investi-gating whether they modify the effect of each other ecombination of risks may follow simple or complex patternsand may vary among different geographic regions echaracterization of such a combination of factors may clarifymany questions through the description of more realisticestimates of risk and the establishment of new guidelines inpublic health

Estimating the health risks caused by air pollution in thepopulation is a first step for the planning and imple-mentation of actions aimed at a healthier environment eproduction of this type of knowledge is fundamental for theformulation of public policies that promote socioeconomicdevelopment and that consider environmental issues andpeoplersquos quality of life us the objective of this study wasto relate levels of air pollution to hospital admissions forcardiovascular and respiratory diseases in the city of Manausfrom 2008 to 2012

e present study is structured into five sections besidesthe introductory one Section 2 presents the literature reviewabout air pollution and health risks Section 3 presents thematerials and methods Section 4 presents the resultsSection 5 presents the discussion Finally the conclusionsare presented

2 Literature Review

Air pollution is recognized as a major risk factor for pop-ulation health [8] Exposure to air pollution represents thelargest and greatest health risk from the environment and isamong the nine major modifiable risk factors ahead of othercommon factors such as physical inactivity high cholesteroland drug use Its presence is still associated with a significantreduction in life expectancy and productivity [9]

Particulate matter (PM) is the most common pollutantassociated with adverse health effects [10] PM is composed

of carbonaceous particles associated with reactive and or-ganic metals including nitrates sulphates polycyclic aro-matic hydrocarbons endotoxins and metals such as ironcopper zinc nickel and vanadium [11] Its compositionvaries depending on the geographical location in eachcountry the type of industry existing and the amount offossil fuel burned for heating and transport [12]

e concentration of particulate matter present inpollution influences the disease and where it will accumulatein the human body upon inhalation PM25 lodges in thelungs and smallest airways PM10 tends to deposit in theupper respiratory tract and upper airways Particle size alsoinfluences the adverse effects of its exposure Smaller particlesizes have a greater impact on health due to their ability toreach smaller airways epidemiological studies have focusedon the effects of PM25 and PM10 [13] PM25 has differenthealth effects than PM10 because of its size and surface area[14]

Elderly children pregnant women those with chronicdiseases and those with low immunity represent the mostvulnerable group due to the presence and variation of airpollution [10 15ndash17] Exposure to air pollution is a cause ofcardiovascular disease with a high association of particulatematter [9] Cardiovascular diseases are a major public healthtopic accounting for nearly 30 of worldwide mortality[18]

Research involving emerging countries is still very in-cipient [19 20] Although environmental pollution is aserious environmental problem in developing countries fewstudies investigate the effects of PM25‒10 particulate matterdue to PM25 monitoring constraints [13] Given the highlevels of PM25 pollution in Asia Africa and theMiddle Eastair pollution in Latin America receives little attentionHowever between 1990 and 2013 annual averages of PM25showed a high upward trend in parts of South America [21]

3 Materials and Methods

is is an ecological time-series study of hospital admissionsfor respiratory and cardiovascular diseases among children(5 years of age and under) and elderly (60 years of age andolder) in the city of Manaus State of Amazonas Brazil from2008 to 2012 It has an area of 11474 km2 (073 of the Statearea) with a total population of 18 million people and ademographic density of 15806 inhabitants per square kil-ometres e climate of Manaus is considered humidtropical with an annual average temperature of 27degC andrelatively high air humidity e seasons are relatively welldefined regarding rain winter is very rainy and summer isrelatively dry Due to the proximity of the Equator line theheat is constant and there are no cold winter days [22] ecapital of the state of Amazonas Manaus was chosen be-cause it represents the urban centre of the Amazon markedby an intense process of urban expansion and populationgrowth since the 1970s and a total accumulated deforestationuntil 2012 of 12566 km2 equivalent to 109 of the cityarea

Data on hospital admissions for respiratory diseases ofresidents of Manaus were collected from the Hospital

2 e Scientific World Journal

Information System (HIS) for the analysed period providedby the Department of Informatics of the Unified HealthSystem (DATASUS) All hospitalizations for respiratorydiseases (ICD-10th revision J00 to J99) in children (0 to 5years) and elderly people (60 years or older) and for car-diovascular diseases (ICD-10th revision I00 to I99) in theelderly (60 years or more) in this period were selected for thisstudy Particulate matter concentrations (PM25 in μgm3)minimum temperature and relative humidity of the air wereused as exposure variables ese values were obtainedthrough the Environmental Information System Integratedwith the Environmental Health (SISAM)

Descriptive analyses of all variables of the study werecarried out by calculating the values of central tendency anddispersion To estimate the effects of the daily variation in theconcentration of pollutants on the outcomes of interestPoisson generalized linear models (GLM) were used toassess atmospheric pollution and hospitalization for car-diovascular and respiratory diseases in the city of Manaus

e independent variables were the average daily levelsof each pollutant the minimum temperature (in degC) and theaverage relative humidity (in ) To address the effect oflong-term seasonality the number of sequential days elapsed(from 1 to 1827) was used in the analysis and in the case ofshort-term seasonality the days of the week (from 1 to 7considering Sunday as the first day) were considered ecubic spline natural straightener was used for smoothinglong-term seasonality e number of inflection points orthe degrees of freedom of the straightener were chosen tominimize the sum of residual autocorrelation using theAkaike criteria [23] Weekdays were regarded as categoricalvariables with Sunday as baseline Temperature and hu-midity entered the model as continuous variables

For data with normal distribution suppressing thecovariates a distributed lag model can take the followingform [24 25]

log E Yt( 11138571113858 1113859 α + β0Xt + middot middot middot + βXtminusq + εt (1)

where Xt-q is the environmental exposure of interest forexample and air pollutants q are the days before the esti-mated event for example hospital admissions e totaleffect of environmental exposure is the sum of the estimatedeffects of subsequent q days erefore it can be written asβ0 + middot middot middot + βq However the high correlation between con-secutive days makes individual estimates unstable for eachβq

To solve this problem of the days of the lag periodanalysed a constraint factor has been imposed that causesthe βq to vary smoothly as a polynomial function ispolynomial distribution lag model has q days and d degreesof freedom (degree of polynomial) and may be restrictivedepending on the degree of the polynomial used As thecentral point of interest of this study is to estimate the effectsof air pollutants on hospitalizations for cardiovascular andrespiratory diseases and to explore the lag structure betweenexposure to these factors and the analysed outcome poly-nomial distribution lag models were used because envi-ronmental exposures may cause deleterious effects in the

case of hospitalizations for cardiovascular and respiratorydiseases on the day of exposure one day after or up toseveral days after exposure us hospitalizations that occuron a given day may be a result of exposure that occurred onthe same day but also on other preceding days To solve thisproblem the analyses included a constraint factor thatcauses the coefficients to vary smoothly as a polynomialfunction of the days of the analysed lag period e effects ofexposure to pollutants and climate variables on a seven-daylag structure were estimated using third-degree polynomialsthat allow more stable estimates than those generated bymodels without the constraint factore effects of pollutantexposures on a 7-day lag structure (exposure day and up to6 days after exposure) were estimated using third-degreepolynomials that allow flexible and more stable estimatesthan unrestricted models [25 26]

e results were presented as the increase in the numberof hospitalizations and their respective 95 confidenceintervals for each day of the lag period analysed due toincreases of one interquartile in the concentration of pol-lutants Interquartile variation can be defined as the dif-ference between the third and first quartiles of the values of agiven variable e estimated percentage increase and its95 confidence interval can be represented by

increase() eβqlowastIQV( 1113857

minus 11113874 1113875lowast100 (2)

where IQV is the interquartile variation and

CI 95 eβqlowastIQV( 1113857 plusmn 196lowastSEqlowastIQV( 1113857( 1113857

minus 11113874 1113875lowast100 (3)

where SEq is the standard error for each βqDatabases were prepared using the Statistical Package for

the Social Sciences (SPSS) for Windows version 210 (SPSSInc Chicago United States) Regression analyses wereperformed with the S-PLUS 45 software

4 Results and Discussion

During the analysed period 501493 hospital admissionsoccurred in the city of Manaus Of this total 50278 werebecause of respiratory diseases and 34582 due to cardio-vascular diseases representing 101 and 69 of the totalnumber of hospitalizations respectively Among the hos-pitalizations for respiratory diseases 29582 (589) were ofchildren and 6274 (125) of elderly patients Among thehospitalizations for cardiovascular disease 17778 (514)occurred in elderly people

Table 1 presents the descriptive parameters on hospi-talization level of PM25 minimum temperature and av-erage humidity It is observed that for PM25 both the 25percentile and the 50 percentile have the same valueshowing inaccuracies in the measurement of this pollutantas well as in the measurement of minimum temperaturewhich presented a minimum value of 15degC which is im-possible in a hot region such as the Amazon

Table 2 presents the Spearman correlation matrix be-tween PM25 temperature humidity and hospitalizations forrespiratory diseases in under-five children and

e Scientific World Journal 3

cardiovascular and respiratory diseases in patients over 60years of age

e bivariate exploratory analysis of the correlationsperformed through the correlation matrix (Table 2) showedthat no significant statistical correlations were observedbetween respiratory and cardiovascular diseases in patientsover 60 years of age and respiratory diseases in under-fivechildren and PM25 temperature and air relative humidity

In the statistical modeling with the GLM model theestimated effects were not statistically significant in the caseof respiratory diseases in under-five children Oneinterquartile range increase of daily mean level representedan increase in hospitalizations of minus040 (95 CI minus111030) 059 (95 CI minus035 152) and 047 (95 CIminus328 421) for PM25 temperature and humidity respec-tively as observed in Figure 1

In the case of respiratory diseases in patients with 60years of age and over the estimated effects were not sta-tistically significant in the model One interquartile rangeincrease of daily mean level represented an increase ofhospitalizations of 019 (95 CI minus093 131) minus010 (95CI minus185 165) and -617 (95 CI minus1308 074) for PM25temperature and humidity respectively as shown inFigure 2

For cardiovascular diseases and elderly the estimatedeffects were not statistically significant One interquartilerange increase of daily mean level represented an increase ofhospitalizations of minus018 (95 CI minus086 050) minus004(95 CI minus110 103) and minus337 (95 CI minus759 085) forPM25 temperature and humidity respectively as observedin Figure 3

e time series did not find a significant associationbetween PM25 concentrations minimum temperature orrelative humidity and hospitalizations for respiratory

diseases in under-five children and respiratory and car-diovascular diseases in patients over 60 years of age

e first possible explanation for the inconsistenciesfound in the results is the way PM25 levels are measuredesatellite measurements provided by SISAM showed the samevalue (10 μgm3) for 70 of the studied days It was alsoobserved that that for PM25 both the 25 percentile and the50 percentile had the same value thus indicating inac-curacies in the measurement of this pollutant e samehappened with temperature which presented a minimumvalue of 15degC which is impossible in a hot region such as theAmazon ese possible measurement errors representshortcomings in the time series that prevented the statisticalmodel to find correlations between exposure to pollutionand the diseases analysed in this study

e results in the present study differ from other studiesthat showed the relationship between PM25 and the in-creased risk of hospitalization for cardiovascular disease inpeople over 60 years e adverse effects of PM on hospi-talizations for cardiovascular disease were correlated withthe same day of pollutant increase (lag 0) and decreased therisk on subsequent days [27ndash30]

e present study also differs from the academic liter-ature that shows an association between PM25 and theincrease in hospitalization for cardiorespiratory diseases[31ndash33]e literature shows that for children an increase inthe PM25 level increased the number of hospitalizations forrespiratory diseases [34ndash37]

e academic literature also shows that the modificationof the effects of PM25 by high temperatures on human healthmay be related to the direct or indirect response of the bodyto heat stress [38] Body thermoregulation is directly linkedto the circulatory regulation of an individual Hot days canoverload the bodyrsquos temperature regulation system and alter

Table 1 Basic descriptive parameters in Manaus Amazonas Brazil from 2008 to 2012

Respiratory diseases Cardiovascular diseases PM25 Temperature HumidityChildren Elderly Elderly

Mean 133 32 90 135 227 800Standard deviation 81 21 40 91 40 151Minimum 00 00 00 100 15 186Maximum 500 130 300 1174 373 99225th 110 30 90 100 231 67850th 110 30 90 100 238 85775th 170 40 120 137 245 923PM25 particulate matter (PM25 in μgm3)

Table 2 Spearman correlation matrix for the variables in the study

PM25 Minimum temperature Humidity RDle 5 years RDge 60 years CDge 60 yearsPM25 1000Minimum temperature minus0082 1000Humidity minus0550 minus0116 1000RDle 5 years 0060 minus0086 0003 1000RDge 60 years 0006 minus0025 minus0007 0148 1000CDge 60 years 0004 0012 0030 0159 0237 1000PM25 particulate matter (μgm3) RD respiratory diseases CD cardiovascular diseases

4 e Scientific World Journal

the physiological response to toxic agents increasing indi-vidual vulnerability [30]

We could not find any scientific articles that couldsupport our findings In fact the lack of air quality moni-toring seems to be a major element preventing a broaderanalysis of environmental and health conditions Howeveras there is no air quality monitoring network in Manaus weused the data provided by SISAM that comes from remotesensing (satellite) ose who research the effects of airpollution on health know that well-conducted studies andair quality monitoring programs require not only adequatemethodology but also quality data on local pollutionweather conditions and health information [39]

ere are evidences that hospital admissions of childrendue to respiratory diseases in Manaus are more related tometeorological conditions and humidity than to exposure to

smoke from the fires and to PM25 concentrations in theregion It is possible that the environmental characteristicsinherent to the rainy season in the region play an importantrole in increased hospitalization rates of children due torespiratory diseases ere is a predominance of naturalbiogenic particulate emissions during the rainy seasoncaused by the intense activity of biological organisms in theforest which include fragments of plants and insects pollengrains fungi algae and fungal spores [40] e presence of aground monitoring system could provide more reliable datato confirm such hypothesis

In any case air pollution is pointed out by its systemicimportance in urban environments because it has a syn-ergic effect when allied to other exposure factors

0 1 2 3 4 5 6

ndash15

ndash05

05

15

ndash100

ndash050

000

050

100

150

200

ndash200

ndash100

000

100

200

300

400

PM25

Temperature

Humidity

Figure 1 One interquartile range increase of daily mean level ofPM25 using polynomial distribution for hospitalizations due torespiratory diseases in children under 5 years in Manaus (AM)from 2008 to 2012

Temperature

Humidity

0 1 2 3 4 5 6

ndash200

ndash100

000

100

200

ndash200

ndash150

ndash100

ndash050

000

050

100

150

200

ndash1500

ndash1000

ndash500

000

500

1000

PM25

Figure 2 One interquartile range increase of daily mean level ofPM25 for hospitalizations due to respiratory diseases in patientsover 60 years of age in Manaus (AM) from 2008 to 2012

e Scientific World Journal 5

potentiating the risks for respiratory or cardiovasculardiseases About the modernization process of urbanizationwe must consider the relevance of the growth of the fleet ofvehicles as emitters of atmospheric pollutants which add toemissions of the operating thermoelectric plants and to thefires in the peripheral areas of Manaus us we highlightthe possibility that the exposure of the population of Manausto air pollutants has increased From 2007 to 2011 the fleetof cars in the city increased by 65 is is the highest rateamong the ten most populous capitals It is impossiblehowever to quantify the seriousness of the situation due tothe nonexistence of an atmospheric quality monitoringnetwork in the city different from other regions of Brazil

About the hospitalization data we only used the hospitaladmission authorizations (HAA) registered in DATASUSand comprised the information obtained in the hospitals

linked to the Brazilian Unified Health System (SUS) It isworth noting that the HIS uses the HAA and not the sickindividual as the unit of analysis As the same individual canbe hospitalized more than once or even not be hospitalizeddespite being ill due to limitations in the hospital structurethe use of hospitalizations as a proxy of the number of casesof illness is considered as fragility However HAA has beenpointed out as one of the best information systems for healthresearch [41] We used data on hospitalizations in the SUSconsidering that hospitalization is the final stage of severalvisits to the emergency room and several inhalations be-cause people only seek the emergency service and arehospitalized when their lung function is altered On theother hand the participation of the supplementary healthsystem in the Amazon is not relevant in the regionere arecities where SUS is responsible for 100 of outpatient andhospital care which indicates that the data used in this studyhave good population coverage

Regarding the age groups selected for the study severalauthors sustain that the most sensitive to exposure to airpollutants are under-five children and the elderly as well aspeople with respiratory or cardiac diseases [42 43] How-ever other risk factors linked to sociological-sanitary con-ditions are also associated with the development ofchildhood respiratory diseases especially in the first year oflife [44 45] Of the two sensitive groups included in thepresent study most of the groups with the highest preva-lence of hospitalizations due to respiratory diseases occurredin the municipalities belonging to the ldquoArch of Deforesta-tionrdquo composed of municipalities that extend from the stateof Acre to the south of Maranhatildeo and are characterized byextensive deforested areas and large concentrations of forestfires [46]

When time-series studies are used to assess the effects ofpollution on health they consider only the short-termimpacts A longer time series with more consistent infor-mation would enable the detection of small short-term ef-fects on public health caused by exposure to air pollution[47] Considering that the city of Manaus may be chronicallypolluted the present results may underestimate the realdamages

As it is well known epidemiological studies only provideindications of the associations between pollutants and hu-man health Based on the premises of this study we hopethat researchers are prompted to examine this subject planresearch that can provide more conclusive results

5 Conclusions

e present study found no significant association betweenPM25 concentrations minimum temperature relative hu-midity and hospitalizations for respiratory diseases inchildren under 5 years and respiratory and cardiovasculardiseases in those over 60 years

Studies of the impact of air pollution on health usingtime series can contribute to obtain short-term effects of airpollution on respiratory and cardiovascular morbiditysupporting the control and warn actions to health serviceswhen pollution peaks occur e realization of such studies

0 1 2 3 4 5 6

Humidity

ndash050

000

050

100

ndash100

ndash050

000

050

100

ndash1000

ndash500

000

500

Temperature

PM25

Figure 3 One interquartile range increase of daily mean level ofPM25 for hospitalizations due to cardiovascular diseases in pa-tients over 60 years of age in Manaus (AM) from 2008 to 2012

6 e Scientific World Journal

depends on the continuous collection and availability ofquality data In this sense efforts must be made to ensure thecontinuous collection of data and expansion of the airquality monitoring network in the northern region of thecountry

It should be emphasized that the measurement of cli-matic variables is also essential in all seasons to properly fitmodels and improve the results On the other hand effortsmust also be undertaken by the health sector in the ac-quisition and systematization of all information on hospitalmorbidity Considering the seriousness of the situation of airpollution in the city of Manaus the implementation of acomputerized registry of outpatient clinics especially chil-dren and older people and improving the quality of data onair pollution are recommended to create possibilities forother research routes

Remote sensing techniques are used as a complementarytool to surface measurements because they are indirect mea-surements which explain the importance of long-term ter-restrial-monitoring stations for integrated studies in the region

We stress that it is a great challenge to describe con-ditions and trends in terms of environmental situations andexposures to which the population of Manaus is subjectede results of this research can be used to evaluate theimprovement of the quality of hospitalization and air pol-lution data On the one hand we must deal with the poorproduction of environmental indicators and on the otherhand we must research the most different sources anddocuments for the description of these aspects in a city inwhich the municipal level follows the logic of production ofinformation within the peculiarities of the municipalityespecially for relatively new themes

Data Availability

All the data reported in this manuscript have been depositedat Mendeley Data Copies of this data can be obtained free ofcharge from httpsdatamendeleycom

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

References

[1] M A Arbex U D P Santos L C Martins P H N SaldivaL A A Pereira and A L F Braga ldquoA poluiccedilatildeo do ar e osistema respiratoriordquo Jornal Brasileiro de Pneumologiavol 38 no 5 pp 643ndash655 2012

[2] C T Amancio L F C Nascimento and T T AmancioldquoPoluentes ambientais e chance de internaccedilotildees por asma emcrianccedilasmdashSatildeo Jose dos Campos Brasil nos anos 2004-2005rdquoJournal of Human Growth and Development vol 22 no 2pp 202ndash208 2012

[3] S M C Bakonyi I M Danni-Oliveira L C Martins andA L F Braga ldquoPoluiccedilatildeo atmosferica e doenccedilas respiratoriasem crianccedilas na cidade de Curitiba PRrdquo Revista de SaudePublica vol 38 no 5 pp 695ndash700 2004

[4] J E D Canccedilado A Braga L A A Pereira M A ArbexP H N Saldiva and U D P Santos ldquoRepercussotildees clınicasda exposiccedilatildeo a poluiccedilatildeo atmosfericardquo Jornal Brasileiro dePneumologia vol 32 no 2 pp S5ndashS11 2006

[5] K D S Gonccedilalves A S P Siqueira H A D Castro andS D S Hacon ldquoIndicador de vulnerabilidade socioambientalna Amazonia Ocidental O caso do municıpio de Porto VelhoRondonia Brasilrdquo Ciencia amp Saude Coletiva vol 19 no 9pp 3809ndash3818 2014

[6] A F Duarte R M da Cunha and W da Silva Lima ldquoAnecessidade de otimizaccedilatildeo das informaccedilotildees meteorologicas naamazonica ocidentalrdquo Boletim da Sociedade Brasileira deMeteorologia no 1 pp 21ndash31 2006

[7] K D S Gonccedilalves H A D Castro and S D S Hacon ldquoAsqueimadas na regiatildeo amazonica e o adoecimento respira-toriordquo Ciencia amp Saude Coletiva vol 17 no 6 pp 1523ndash15322012

[8] H Broslashnnum-Hansen A M Bender Z J Andersen et alldquoAssessment of impact of traffic-related air pollution onmorbidity and mortality in Copenhagen Municipality and thehealth gain of reduced exposurerdquo Environment Internationalvol 121 pp 973ndash980 2018

[9] R B Hamanaka and G M Mutlu ldquoParticulate matter airpollution effects on the cardiovascular systemrdquo Frontiers inEndocrinology vol 9 2018

[10] D E RWarburton S S D Bredin E M Shellington et al ldquoAsystematic review of the short-term health effects of airpollution in persons living with coronary heart diseaserdquoJournal of Clinical Medicine vol 8 no 2 p 274 2019

[11] M T Chin ldquoBasic mechanisms for adverse cardiovascularevents associated with air pollutionrdquo Heart vol 101 no 4pp 253ndash256 2015

[12] J-H Kim I-H Oh J-H Park and H-K Cheong ldquoPre-mature deaths attributable to long-term exposure to ambientfine particulate matter in the Republic of Koreardquo Journal ofKorean Medical Science vol 33 2018

[13] R Chen P Yin X Meng et al ldquoAssociations between coarseparticulate matter air pollution and cause-specific mortality anationwide analysis in 272 Chinese citiesrdquo EnvironmentalHealth Perspectives vol 127 Article ID 017008 2019

[14] L Bai S Weichenthal J C Kwong et al ldquoAssociations oflong-term exposure to ultrafine particles and nitrogen dioxidewith increased incidence of congestive heart failure and acutemyocardial infarctionrdquo American Journal of Epidemiologyvol 188 no 1 pp 151ndash159 2018

[15] N Berglind T Bellander F Forastiere et al ldquoAmbient airpollution and daily mortality among survivors of myocardialinfarctionrdquo Epidemiology vol 20 no 1 pp 110ndash118 2009

[16] H-J Kwon S-H Cho F Nyberg and G Pershagen ldquoEffectsof ambient air pollution on daily mortality in a cohort ofpatients with congestive heart failurerdquo Epidemiology vol 12no 4 pp 413ndash419 2001

[17] T F Bateson and J Schwartz ldquoWho is sensitive to the effectsof particulate air pollution on mortalityrdquo Epidemiologyvol 15 no 2 pp 143ndash149 2004

[18] X Liu and S Bertazzon ldquoExploratory temporal and spatialanalysis of myocardial infarction hospitalizations in CalgaryCanadardquo International Journal of Environmental Researchand Public Health vol 14 p 1555 2017

[19] H Liu Y Tian J Song et al ldquoEffect of ambient air pollutionon hospitalization for heart failure in 26 of Chinarsquos largestcitiesrdquo gte American Journal of Cardiology vol 121 no 5pp 628ndash633 2018

e Scientific World Journal 7

Information System (HIS) for the analysed period providedby the Department of Informatics of the Unified HealthSystem (DATASUS) All hospitalizations for respiratorydiseases (ICD-10th revision J00 to J99) in children (0 to 5years) and elderly people (60 years or older) and for car-diovascular diseases (ICD-10th revision I00 to I99) in theelderly (60 years or more) in this period were selected for thisstudy Particulate matter concentrations (PM25 in μgm3)minimum temperature and relative humidity of the air wereused as exposure variables ese values were obtainedthrough the Environmental Information System Integratedwith the Environmental Health (SISAM)

Descriptive analyses of all variables of the study werecarried out by calculating the values of central tendency anddispersion To estimate the effects of the daily variation in theconcentration of pollutants on the outcomes of interestPoisson generalized linear models (GLM) were used toassess atmospheric pollution and hospitalization for car-diovascular and respiratory diseases in the city of Manaus

e independent variables were the average daily levelsof each pollutant the minimum temperature (in degC) and theaverage relative humidity (in ) To address the effect oflong-term seasonality the number of sequential days elapsed(from 1 to 1827) was used in the analysis and in the case ofshort-term seasonality the days of the week (from 1 to 7considering Sunday as the first day) were considered ecubic spline natural straightener was used for smoothinglong-term seasonality e number of inflection points orthe degrees of freedom of the straightener were chosen tominimize the sum of residual autocorrelation using theAkaike criteria [23] Weekdays were regarded as categoricalvariables with Sunday as baseline Temperature and hu-midity entered the model as continuous variables

For data with normal distribution suppressing thecovariates a distributed lag model can take the followingform [24 25]

log E Yt( 11138571113858 1113859 α + β0Xt + middot middot middot + βXtminusq + εt (1)

where Xt-q is the environmental exposure of interest forexample and air pollutants q are the days before the esti-mated event for example hospital admissions e totaleffect of environmental exposure is the sum of the estimatedeffects of subsequent q days erefore it can be written asβ0 + middot middot middot + βq However the high correlation between con-secutive days makes individual estimates unstable for eachβq

To solve this problem of the days of the lag periodanalysed a constraint factor has been imposed that causesthe βq to vary smoothly as a polynomial function ispolynomial distribution lag model has q days and d degreesof freedom (degree of polynomial) and may be restrictivedepending on the degree of the polynomial used As thecentral point of interest of this study is to estimate the effectsof air pollutants on hospitalizations for cardiovascular andrespiratory diseases and to explore the lag structure betweenexposure to these factors and the analysed outcome poly-nomial distribution lag models were used because envi-ronmental exposures may cause deleterious effects in the

case of hospitalizations for cardiovascular and respiratorydiseases on the day of exposure one day after or up toseveral days after exposure us hospitalizations that occuron a given day may be a result of exposure that occurred onthe same day but also on other preceding days To solve thisproblem the analyses included a constraint factor thatcauses the coefficients to vary smoothly as a polynomialfunction of the days of the analysed lag period e effects ofexposure to pollutants and climate variables on a seven-daylag structure were estimated using third-degree polynomialsthat allow more stable estimates than those generated bymodels without the constraint factore effects of pollutantexposures on a 7-day lag structure (exposure day and up to6 days after exposure) were estimated using third-degreepolynomials that allow flexible and more stable estimatesthan unrestricted models [25 26]

e results were presented as the increase in the numberof hospitalizations and their respective 95 confidenceintervals for each day of the lag period analysed due toincreases of one interquartile in the concentration of pol-lutants Interquartile variation can be defined as the dif-ference between the third and first quartiles of the values of agiven variable e estimated percentage increase and its95 confidence interval can be represented by

increase() eβqlowastIQV( 1113857

minus 11113874 1113875lowast100 (2)

where IQV is the interquartile variation and

CI 95 eβqlowastIQV( 1113857 plusmn 196lowastSEqlowastIQV( 1113857( 1113857

minus 11113874 1113875lowast100 (3)

where SEq is the standard error for each βqDatabases were prepared using the Statistical Package for

the Social Sciences (SPSS) for Windows version 210 (SPSSInc Chicago United States) Regression analyses wereperformed with the S-PLUS 45 software

4 Results and Discussion

During the analysed period 501493 hospital admissionsoccurred in the city of Manaus Of this total 50278 werebecause of respiratory diseases and 34582 due to cardio-vascular diseases representing 101 and 69 of the totalnumber of hospitalizations respectively Among the hos-pitalizations for respiratory diseases 29582 (589) were ofchildren and 6274 (125) of elderly patients Among thehospitalizations for cardiovascular disease 17778 (514)occurred in elderly people

Table 1 presents the descriptive parameters on hospi-talization level of PM25 minimum temperature and av-erage humidity It is observed that for PM25 both the 25percentile and the 50 percentile have the same valueshowing inaccuracies in the measurement of this pollutantas well as in the measurement of minimum temperaturewhich presented a minimum value of 15degC which is im-possible in a hot region such as the Amazon

Table 2 presents the Spearman correlation matrix be-tween PM25 temperature humidity and hospitalizations forrespiratory diseases in under-five children and

e Scientific World Journal 3

cardiovascular and respiratory diseases in patients over 60years of age

e bivariate exploratory analysis of the correlationsperformed through the correlation matrix (Table 2) showedthat no significant statistical correlations were observedbetween respiratory and cardiovascular diseases in patientsover 60 years of age and respiratory diseases in under-fivechildren and PM25 temperature and air relative humidity

In the statistical modeling with the GLM model theestimated effects were not statistically significant in the caseof respiratory diseases in under-five children Oneinterquartile range increase of daily mean level representedan increase in hospitalizations of minus040 (95 CI minus111030) 059 (95 CI minus035 152) and 047 (95 CIminus328 421) for PM25 temperature and humidity respec-tively as observed in Figure 1

In the case of respiratory diseases in patients with 60years of age and over the estimated effects were not sta-tistically significant in the model One interquartile rangeincrease of daily mean level represented an increase ofhospitalizations of 019 (95 CI minus093 131) minus010 (95CI minus185 165) and -617 (95 CI minus1308 074) for PM25temperature and humidity respectively as shown inFigure 2

For cardiovascular diseases and elderly the estimatedeffects were not statistically significant One interquartilerange increase of daily mean level represented an increase ofhospitalizations of minus018 (95 CI minus086 050) minus004(95 CI minus110 103) and minus337 (95 CI minus759 085) forPM25 temperature and humidity respectively as observedin Figure 3

e time series did not find a significant associationbetween PM25 concentrations minimum temperature orrelative humidity and hospitalizations for respiratory

diseases in under-five children and respiratory and car-diovascular diseases in patients over 60 years of age

e first possible explanation for the inconsistenciesfound in the results is the way PM25 levels are measuredesatellite measurements provided by SISAM showed the samevalue (10 μgm3) for 70 of the studied days It was alsoobserved that that for PM25 both the 25 percentile and the50 percentile had the same value thus indicating inac-curacies in the measurement of this pollutant e samehappened with temperature which presented a minimumvalue of 15degC which is impossible in a hot region such as theAmazon ese possible measurement errors representshortcomings in the time series that prevented the statisticalmodel to find correlations between exposure to pollutionand the diseases analysed in this study

e results in the present study differ from other studiesthat showed the relationship between PM25 and the in-creased risk of hospitalization for cardiovascular disease inpeople over 60 years e adverse effects of PM on hospi-talizations for cardiovascular disease were correlated withthe same day of pollutant increase (lag 0) and decreased therisk on subsequent days [27ndash30]

e present study also differs from the academic liter-ature that shows an association between PM25 and theincrease in hospitalization for cardiorespiratory diseases[31ndash33]e literature shows that for children an increase inthe PM25 level increased the number of hospitalizations forrespiratory diseases [34ndash37]

e academic literature also shows that the modificationof the effects of PM25 by high temperatures on human healthmay be related to the direct or indirect response of the bodyto heat stress [38] Body thermoregulation is directly linkedto the circulatory regulation of an individual Hot days canoverload the bodyrsquos temperature regulation system and alter

Table 1 Basic descriptive parameters in Manaus Amazonas Brazil from 2008 to 2012

Respiratory diseases Cardiovascular diseases PM25 Temperature HumidityChildren Elderly Elderly

Mean 133 32 90 135 227 800Standard deviation 81 21 40 91 40 151Minimum 00 00 00 100 15 186Maximum 500 130 300 1174 373 99225th 110 30 90 100 231 67850th 110 30 90 100 238 85775th 170 40 120 137 245 923PM25 particulate matter (PM25 in μgm3)

Table 2 Spearman correlation matrix for the variables in the study

PM25 Minimum temperature Humidity RDle 5 years RDge 60 years CDge 60 yearsPM25 1000Minimum temperature minus0082 1000Humidity minus0550 minus0116 1000RDle 5 years 0060 minus0086 0003 1000RDge 60 years 0006 minus0025 minus0007 0148 1000CDge 60 years 0004 0012 0030 0159 0237 1000PM25 particulate matter (μgm3) RD respiratory diseases CD cardiovascular diseases

4 e Scientific World Journal

the physiological response to toxic agents increasing indi-vidual vulnerability [30]

We could not find any scientific articles that couldsupport our findings In fact the lack of air quality moni-toring seems to be a major element preventing a broaderanalysis of environmental and health conditions Howeveras there is no air quality monitoring network in Manaus weused the data provided by SISAM that comes from remotesensing (satellite) ose who research the effects of airpollution on health know that well-conducted studies andair quality monitoring programs require not only adequatemethodology but also quality data on local pollutionweather conditions and health information [39]

ere are evidences that hospital admissions of childrendue to respiratory diseases in Manaus are more related tometeorological conditions and humidity than to exposure to

smoke from the fires and to PM25 concentrations in theregion It is possible that the environmental characteristicsinherent to the rainy season in the region play an importantrole in increased hospitalization rates of children due torespiratory diseases ere is a predominance of naturalbiogenic particulate emissions during the rainy seasoncaused by the intense activity of biological organisms in theforest which include fragments of plants and insects pollengrains fungi algae and fungal spores [40] e presence of aground monitoring system could provide more reliable datato confirm such hypothesis

In any case air pollution is pointed out by its systemicimportance in urban environments because it has a syn-ergic effect when allied to other exposure factors

0 1 2 3 4 5 6

ndash15

ndash05

05

15

ndash100

ndash050

000

050

100

150

200

ndash200

ndash100

000

100

200

300

400

PM25

Temperature

Humidity

Figure 1 One interquartile range increase of daily mean level ofPM25 using polynomial distribution for hospitalizations due torespiratory diseases in children under 5 years in Manaus (AM)from 2008 to 2012

Temperature

Humidity

0 1 2 3 4 5 6

ndash200

ndash100

000

100

200

ndash200

ndash150

ndash100

ndash050

000

050

100

150

200

ndash1500

ndash1000

ndash500

000

500

1000

PM25

Figure 2 One interquartile range increase of daily mean level ofPM25 for hospitalizations due to respiratory diseases in patientsover 60 years of age in Manaus (AM) from 2008 to 2012

e Scientific World Journal 5

potentiating the risks for respiratory or cardiovasculardiseases About the modernization process of urbanizationwe must consider the relevance of the growth of the fleet ofvehicles as emitters of atmospheric pollutants which add toemissions of the operating thermoelectric plants and to thefires in the peripheral areas of Manaus us we highlightthe possibility that the exposure of the population of Manausto air pollutants has increased From 2007 to 2011 the fleetof cars in the city increased by 65 is is the highest rateamong the ten most populous capitals It is impossiblehowever to quantify the seriousness of the situation due tothe nonexistence of an atmospheric quality monitoringnetwork in the city different from other regions of Brazil

About the hospitalization data we only used the hospitaladmission authorizations (HAA) registered in DATASUSand comprised the information obtained in the hospitals

linked to the Brazilian Unified Health System (SUS) It isworth noting that the HIS uses the HAA and not the sickindividual as the unit of analysis As the same individual canbe hospitalized more than once or even not be hospitalizeddespite being ill due to limitations in the hospital structurethe use of hospitalizations as a proxy of the number of casesof illness is considered as fragility However HAA has beenpointed out as one of the best information systems for healthresearch [41] We used data on hospitalizations in the SUSconsidering that hospitalization is the final stage of severalvisits to the emergency room and several inhalations be-cause people only seek the emergency service and arehospitalized when their lung function is altered On theother hand the participation of the supplementary healthsystem in the Amazon is not relevant in the regionere arecities where SUS is responsible for 100 of outpatient andhospital care which indicates that the data used in this studyhave good population coverage

Regarding the age groups selected for the study severalauthors sustain that the most sensitive to exposure to airpollutants are under-five children and the elderly as well aspeople with respiratory or cardiac diseases [42 43] How-ever other risk factors linked to sociological-sanitary con-ditions are also associated with the development ofchildhood respiratory diseases especially in the first year oflife [44 45] Of the two sensitive groups included in thepresent study most of the groups with the highest preva-lence of hospitalizations due to respiratory diseases occurredin the municipalities belonging to the ldquoArch of Deforesta-tionrdquo composed of municipalities that extend from the stateof Acre to the south of Maranhatildeo and are characterized byextensive deforested areas and large concentrations of forestfires [46]

When time-series studies are used to assess the effects ofpollution on health they consider only the short-termimpacts A longer time series with more consistent infor-mation would enable the detection of small short-term ef-fects on public health caused by exposure to air pollution[47] Considering that the city of Manaus may be chronicallypolluted the present results may underestimate the realdamages

As it is well known epidemiological studies only provideindications of the associations between pollutants and hu-man health Based on the premises of this study we hopethat researchers are prompted to examine this subject planresearch that can provide more conclusive results

5 Conclusions

e present study found no significant association betweenPM25 concentrations minimum temperature relative hu-midity and hospitalizations for respiratory diseases inchildren under 5 years and respiratory and cardiovasculardiseases in those over 60 years

Studies of the impact of air pollution on health usingtime series can contribute to obtain short-term effects of airpollution on respiratory and cardiovascular morbiditysupporting the control and warn actions to health serviceswhen pollution peaks occur e realization of such studies

0 1 2 3 4 5 6

Humidity

ndash050

000

050

100

ndash100

ndash050

000

050

100

ndash1000

ndash500

000

500

Temperature

PM25

Figure 3 One interquartile range increase of daily mean level ofPM25 for hospitalizations due to cardiovascular diseases in pa-tients over 60 years of age in Manaus (AM) from 2008 to 2012

6 e Scientific World Journal

depends on the continuous collection and availability ofquality data In this sense efforts must be made to ensure thecontinuous collection of data and expansion of the airquality monitoring network in the northern region of thecountry

It should be emphasized that the measurement of cli-matic variables is also essential in all seasons to properly fitmodels and improve the results On the other hand effortsmust also be undertaken by the health sector in the ac-quisition and systematization of all information on hospitalmorbidity Considering the seriousness of the situation of airpollution in the city of Manaus the implementation of acomputerized registry of outpatient clinics especially chil-dren and older people and improving the quality of data onair pollution are recommended to create possibilities forother research routes

Remote sensing techniques are used as a complementarytool to surface measurements because they are indirect mea-surements which explain the importance of long-term ter-restrial-monitoring stations for integrated studies in the region

We stress that it is a great challenge to describe con-ditions and trends in terms of environmental situations andexposures to which the population of Manaus is subjectede results of this research can be used to evaluate theimprovement of the quality of hospitalization and air pol-lution data On the one hand we must deal with the poorproduction of environmental indicators and on the otherhand we must research the most different sources anddocuments for the description of these aspects in a city inwhich the municipal level follows the logic of production ofinformation within the peculiarities of the municipalityespecially for relatively new themes

Data Availability

All the data reported in this manuscript have been depositedat Mendeley Data Copies of this data can be obtained free ofcharge from httpsdatamendeleycom

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

References

[1] M A Arbex U D P Santos L C Martins P H N SaldivaL A A Pereira and A L F Braga ldquoA poluiccedilatildeo do ar e osistema respiratoriordquo Jornal Brasileiro de Pneumologiavol 38 no 5 pp 643ndash655 2012

[2] C T Amancio L F C Nascimento and T T AmancioldquoPoluentes ambientais e chance de internaccedilotildees por asma emcrianccedilasmdashSatildeo Jose dos Campos Brasil nos anos 2004-2005rdquoJournal of Human Growth and Development vol 22 no 2pp 202ndash208 2012

[3] S M C Bakonyi I M Danni-Oliveira L C Martins andA L F Braga ldquoPoluiccedilatildeo atmosferica e doenccedilas respiratoriasem crianccedilas na cidade de Curitiba PRrdquo Revista de SaudePublica vol 38 no 5 pp 695ndash700 2004

[4] J E D Canccedilado A Braga L A A Pereira M A ArbexP H N Saldiva and U D P Santos ldquoRepercussotildees clınicasda exposiccedilatildeo a poluiccedilatildeo atmosfericardquo Jornal Brasileiro dePneumologia vol 32 no 2 pp S5ndashS11 2006

[5] K D S Gonccedilalves A S P Siqueira H A D Castro andS D S Hacon ldquoIndicador de vulnerabilidade socioambientalna Amazonia Ocidental O caso do municıpio de Porto VelhoRondonia Brasilrdquo Ciencia amp Saude Coletiva vol 19 no 9pp 3809ndash3818 2014

[6] A F Duarte R M da Cunha and W da Silva Lima ldquoAnecessidade de otimizaccedilatildeo das informaccedilotildees meteorologicas naamazonica ocidentalrdquo Boletim da Sociedade Brasileira deMeteorologia no 1 pp 21ndash31 2006

[7] K D S Gonccedilalves H A D Castro and S D S Hacon ldquoAsqueimadas na regiatildeo amazonica e o adoecimento respira-toriordquo Ciencia amp Saude Coletiva vol 17 no 6 pp 1523ndash15322012

[8] H Broslashnnum-Hansen A M Bender Z J Andersen et alldquoAssessment of impact of traffic-related air pollution onmorbidity and mortality in Copenhagen Municipality and thehealth gain of reduced exposurerdquo Environment Internationalvol 121 pp 973ndash980 2018

[9] R B Hamanaka and G M Mutlu ldquoParticulate matter airpollution effects on the cardiovascular systemrdquo Frontiers inEndocrinology vol 9 2018

[10] D E RWarburton S S D Bredin E M Shellington et al ldquoAsystematic review of the short-term health effects of airpollution in persons living with coronary heart diseaserdquoJournal of Clinical Medicine vol 8 no 2 p 274 2019

[11] M T Chin ldquoBasic mechanisms for adverse cardiovascularevents associated with air pollutionrdquo Heart vol 101 no 4pp 253ndash256 2015

[12] J-H Kim I-H Oh J-H Park and H-K Cheong ldquoPre-mature deaths attributable to long-term exposure to ambientfine particulate matter in the Republic of Koreardquo Journal ofKorean Medical Science vol 33 2018

[13] R Chen P Yin X Meng et al ldquoAssociations between coarseparticulate matter air pollution and cause-specific mortality anationwide analysis in 272 Chinese citiesrdquo EnvironmentalHealth Perspectives vol 127 Article ID 017008 2019

[14] L Bai S Weichenthal J C Kwong et al ldquoAssociations oflong-term exposure to ultrafine particles and nitrogen dioxidewith increased incidence of congestive heart failure and acutemyocardial infarctionrdquo American Journal of Epidemiologyvol 188 no 1 pp 151ndash159 2018

[15] N Berglind T Bellander F Forastiere et al ldquoAmbient airpollution and daily mortality among survivors of myocardialinfarctionrdquo Epidemiology vol 20 no 1 pp 110ndash118 2009

[16] H-J Kwon S-H Cho F Nyberg and G Pershagen ldquoEffectsof ambient air pollution on daily mortality in a cohort ofpatients with congestive heart failurerdquo Epidemiology vol 12no 4 pp 413ndash419 2001

[17] T F Bateson and J Schwartz ldquoWho is sensitive to the effectsof particulate air pollution on mortalityrdquo Epidemiologyvol 15 no 2 pp 143ndash149 2004

[18] X Liu and S Bertazzon ldquoExploratory temporal and spatialanalysis of myocardial infarction hospitalizations in CalgaryCanadardquo International Journal of Environmental Researchand Public Health vol 14 p 1555 2017

[19] H Liu Y Tian J Song et al ldquoEffect of ambient air pollutionon hospitalization for heart failure in 26 of Chinarsquos largestcitiesrdquo gte American Journal of Cardiology vol 121 no 5pp 628ndash633 2018

e Scientific World Journal 7

cardiovascular and respiratory diseases in patients over 60years of age

e bivariate exploratory analysis of the correlationsperformed through the correlation matrix (Table 2) showedthat no significant statistical correlations were observedbetween respiratory and cardiovascular diseases in patientsover 60 years of age and respiratory diseases in under-fivechildren and PM25 temperature and air relative humidity

In the statistical modeling with the GLM model theestimated effects were not statistically significant in the caseof respiratory diseases in under-five children Oneinterquartile range increase of daily mean level representedan increase in hospitalizations of minus040 (95 CI minus111030) 059 (95 CI minus035 152) and 047 (95 CIminus328 421) for PM25 temperature and humidity respec-tively as observed in Figure 1

In the case of respiratory diseases in patients with 60years of age and over the estimated effects were not sta-tistically significant in the model One interquartile rangeincrease of daily mean level represented an increase ofhospitalizations of 019 (95 CI minus093 131) minus010 (95CI minus185 165) and -617 (95 CI minus1308 074) for PM25temperature and humidity respectively as shown inFigure 2

For cardiovascular diseases and elderly the estimatedeffects were not statistically significant One interquartilerange increase of daily mean level represented an increase ofhospitalizations of minus018 (95 CI minus086 050) minus004(95 CI minus110 103) and minus337 (95 CI minus759 085) forPM25 temperature and humidity respectively as observedin Figure 3

e time series did not find a significant associationbetween PM25 concentrations minimum temperature orrelative humidity and hospitalizations for respiratory

diseases in under-five children and respiratory and car-diovascular diseases in patients over 60 years of age

e first possible explanation for the inconsistenciesfound in the results is the way PM25 levels are measuredesatellite measurements provided by SISAM showed the samevalue (10 μgm3) for 70 of the studied days It was alsoobserved that that for PM25 both the 25 percentile and the50 percentile had the same value thus indicating inac-curacies in the measurement of this pollutant e samehappened with temperature which presented a minimumvalue of 15degC which is impossible in a hot region such as theAmazon ese possible measurement errors representshortcomings in the time series that prevented the statisticalmodel to find correlations between exposure to pollutionand the diseases analysed in this study

e results in the present study differ from other studiesthat showed the relationship between PM25 and the in-creased risk of hospitalization for cardiovascular disease inpeople over 60 years e adverse effects of PM on hospi-talizations for cardiovascular disease were correlated withthe same day of pollutant increase (lag 0) and decreased therisk on subsequent days [27ndash30]

e present study also differs from the academic liter-ature that shows an association between PM25 and theincrease in hospitalization for cardiorespiratory diseases[31ndash33]e literature shows that for children an increase inthe PM25 level increased the number of hospitalizations forrespiratory diseases [34ndash37]

e academic literature also shows that the modificationof the effects of PM25 by high temperatures on human healthmay be related to the direct or indirect response of the bodyto heat stress [38] Body thermoregulation is directly linkedto the circulatory regulation of an individual Hot days canoverload the bodyrsquos temperature regulation system and alter

Table 1 Basic descriptive parameters in Manaus Amazonas Brazil from 2008 to 2012

Respiratory diseases Cardiovascular diseases PM25 Temperature HumidityChildren Elderly Elderly

Mean 133 32 90 135 227 800Standard deviation 81 21 40 91 40 151Minimum 00 00 00 100 15 186Maximum 500 130 300 1174 373 99225th 110 30 90 100 231 67850th 110 30 90 100 238 85775th 170 40 120 137 245 923PM25 particulate matter (PM25 in μgm3)

Table 2 Spearman correlation matrix for the variables in the study

PM25 Minimum temperature Humidity RDle 5 years RDge 60 years CDge 60 yearsPM25 1000Minimum temperature minus0082 1000Humidity minus0550 minus0116 1000RDle 5 years 0060 minus0086 0003 1000RDge 60 years 0006 minus0025 minus0007 0148 1000CDge 60 years 0004 0012 0030 0159 0237 1000PM25 particulate matter (μgm3) RD respiratory diseases CD cardiovascular diseases

4 e Scientific World Journal

the physiological response to toxic agents increasing indi-vidual vulnerability [30]

We could not find any scientific articles that couldsupport our findings In fact the lack of air quality moni-toring seems to be a major element preventing a broaderanalysis of environmental and health conditions Howeveras there is no air quality monitoring network in Manaus weused the data provided by SISAM that comes from remotesensing (satellite) ose who research the effects of airpollution on health know that well-conducted studies andair quality monitoring programs require not only adequatemethodology but also quality data on local pollutionweather conditions and health information [39]

ere are evidences that hospital admissions of childrendue to respiratory diseases in Manaus are more related tometeorological conditions and humidity than to exposure to

smoke from the fires and to PM25 concentrations in theregion It is possible that the environmental characteristicsinherent to the rainy season in the region play an importantrole in increased hospitalization rates of children due torespiratory diseases ere is a predominance of naturalbiogenic particulate emissions during the rainy seasoncaused by the intense activity of biological organisms in theforest which include fragments of plants and insects pollengrains fungi algae and fungal spores [40] e presence of aground monitoring system could provide more reliable datato confirm such hypothesis

In any case air pollution is pointed out by its systemicimportance in urban environments because it has a syn-ergic effect when allied to other exposure factors

0 1 2 3 4 5 6

ndash15

ndash05

05

15

ndash100

ndash050

000

050

100

150

200

ndash200

ndash100

000

100

200

300

400

PM25

Temperature

Humidity

Figure 1 One interquartile range increase of daily mean level ofPM25 using polynomial distribution for hospitalizations due torespiratory diseases in children under 5 years in Manaus (AM)from 2008 to 2012

Temperature

Humidity

0 1 2 3 4 5 6

ndash200

ndash100

000

100

200

ndash200

ndash150

ndash100

ndash050

000

050

100

150

200

ndash1500

ndash1000

ndash500

000

500

1000

PM25

Figure 2 One interquartile range increase of daily mean level ofPM25 for hospitalizations due to respiratory diseases in patientsover 60 years of age in Manaus (AM) from 2008 to 2012

e Scientific World Journal 5

potentiating the risks for respiratory or cardiovasculardiseases About the modernization process of urbanizationwe must consider the relevance of the growth of the fleet ofvehicles as emitters of atmospheric pollutants which add toemissions of the operating thermoelectric plants and to thefires in the peripheral areas of Manaus us we highlightthe possibility that the exposure of the population of Manausto air pollutants has increased From 2007 to 2011 the fleetof cars in the city increased by 65 is is the highest rateamong the ten most populous capitals It is impossiblehowever to quantify the seriousness of the situation due tothe nonexistence of an atmospheric quality monitoringnetwork in the city different from other regions of Brazil

About the hospitalization data we only used the hospitaladmission authorizations (HAA) registered in DATASUSand comprised the information obtained in the hospitals

linked to the Brazilian Unified Health System (SUS) It isworth noting that the HIS uses the HAA and not the sickindividual as the unit of analysis As the same individual canbe hospitalized more than once or even not be hospitalizeddespite being ill due to limitations in the hospital structurethe use of hospitalizations as a proxy of the number of casesof illness is considered as fragility However HAA has beenpointed out as one of the best information systems for healthresearch [41] We used data on hospitalizations in the SUSconsidering that hospitalization is the final stage of severalvisits to the emergency room and several inhalations be-cause people only seek the emergency service and arehospitalized when their lung function is altered On theother hand the participation of the supplementary healthsystem in the Amazon is not relevant in the regionere arecities where SUS is responsible for 100 of outpatient andhospital care which indicates that the data used in this studyhave good population coverage

Regarding the age groups selected for the study severalauthors sustain that the most sensitive to exposure to airpollutants are under-five children and the elderly as well aspeople with respiratory or cardiac diseases [42 43] How-ever other risk factors linked to sociological-sanitary con-ditions are also associated with the development ofchildhood respiratory diseases especially in the first year oflife [44 45] Of the two sensitive groups included in thepresent study most of the groups with the highest preva-lence of hospitalizations due to respiratory diseases occurredin the municipalities belonging to the ldquoArch of Deforesta-tionrdquo composed of municipalities that extend from the stateof Acre to the south of Maranhatildeo and are characterized byextensive deforested areas and large concentrations of forestfires [46]

When time-series studies are used to assess the effects ofpollution on health they consider only the short-termimpacts A longer time series with more consistent infor-mation would enable the detection of small short-term ef-fects on public health caused by exposure to air pollution[47] Considering that the city of Manaus may be chronicallypolluted the present results may underestimate the realdamages

As it is well known epidemiological studies only provideindications of the associations between pollutants and hu-man health Based on the premises of this study we hopethat researchers are prompted to examine this subject planresearch that can provide more conclusive results

5 Conclusions

e present study found no significant association betweenPM25 concentrations minimum temperature relative hu-midity and hospitalizations for respiratory diseases inchildren under 5 years and respiratory and cardiovasculardiseases in those over 60 years

Studies of the impact of air pollution on health usingtime series can contribute to obtain short-term effects of airpollution on respiratory and cardiovascular morbiditysupporting the control and warn actions to health serviceswhen pollution peaks occur e realization of such studies

0 1 2 3 4 5 6

Humidity

ndash050

000

050

100

ndash100

ndash050

000

050

100

ndash1000

ndash500

000

500

Temperature

PM25

Figure 3 One interquartile range increase of daily mean level ofPM25 for hospitalizations due to cardiovascular diseases in pa-tients over 60 years of age in Manaus (AM) from 2008 to 2012

6 e Scientific World Journal

depends on the continuous collection and availability ofquality data In this sense efforts must be made to ensure thecontinuous collection of data and expansion of the airquality monitoring network in the northern region of thecountry

It should be emphasized that the measurement of cli-matic variables is also essential in all seasons to properly fitmodels and improve the results On the other hand effortsmust also be undertaken by the health sector in the ac-quisition and systematization of all information on hospitalmorbidity Considering the seriousness of the situation of airpollution in the city of Manaus the implementation of acomputerized registry of outpatient clinics especially chil-dren and older people and improving the quality of data onair pollution are recommended to create possibilities forother research routes

Remote sensing techniques are used as a complementarytool to surface measurements because they are indirect mea-surements which explain the importance of long-term ter-restrial-monitoring stations for integrated studies in the region

We stress that it is a great challenge to describe con-ditions and trends in terms of environmental situations andexposures to which the population of Manaus is subjectede results of this research can be used to evaluate theimprovement of the quality of hospitalization and air pol-lution data On the one hand we must deal with the poorproduction of environmental indicators and on the otherhand we must research the most different sources anddocuments for the description of these aspects in a city inwhich the municipal level follows the logic of production ofinformation within the peculiarities of the municipalityespecially for relatively new themes

Data Availability

All the data reported in this manuscript have been depositedat Mendeley Data Copies of this data can be obtained free ofcharge from httpsdatamendeleycom

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

References

[1] M A Arbex U D P Santos L C Martins P H N SaldivaL A A Pereira and A L F Braga ldquoA poluiccedilatildeo do ar e osistema respiratoriordquo Jornal Brasileiro de Pneumologiavol 38 no 5 pp 643ndash655 2012

[2] C T Amancio L F C Nascimento and T T AmancioldquoPoluentes ambientais e chance de internaccedilotildees por asma emcrianccedilasmdashSatildeo Jose dos Campos Brasil nos anos 2004-2005rdquoJournal of Human Growth and Development vol 22 no 2pp 202ndash208 2012

[3] S M C Bakonyi I M Danni-Oliveira L C Martins andA L F Braga ldquoPoluiccedilatildeo atmosferica e doenccedilas respiratoriasem crianccedilas na cidade de Curitiba PRrdquo Revista de SaudePublica vol 38 no 5 pp 695ndash700 2004

[4] J E D Canccedilado A Braga L A A Pereira M A ArbexP H N Saldiva and U D P Santos ldquoRepercussotildees clınicasda exposiccedilatildeo a poluiccedilatildeo atmosfericardquo Jornal Brasileiro dePneumologia vol 32 no 2 pp S5ndashS11 2006

[5] K D S Gonccedilalves A S P Siqueira H A D Castro andS D S Hacon ldquoIndicador de vulnerabilidade socioambientalna Amazonia Ocidental O caso do municıpio de Porto VelhoRondonia Brasilrdquo Ciencia amp Saude Coletiva vol 19 no 9pp 3809ndash3818 2014

[6] A F Duarte R M da Cunha and W da Silva Lima ldquoAnecessidade de otimizaccedilatildeo das informaccedilotildees meteorologicas naamazonica ocidentalrdquo Boletim da Sociedade Brasileira deMeteorologia no 1 pp 21ndash31 2006

[7] K D S Gonccedilalves H A D Castro and S D S Hacon ldquoAsqueimadas na regiatildeo amazonica e o adoecimento respira-toriordquo Ciencia amp Saude Coletiva vol 17 no 6 pp 1523ndash15322012

[8] H Broslashnnum-Hansen A M Bender Z J Andersen et alldquoAssessment of impact of traffic-related air pollution onmorbidity and mortality in Copenhagen Municipality and thehealth gain of reduced exposurerdquo Environment Internationalvol 121 pp 973ndash980 2018

[9] R B Hamanaka and G M Mutlu ldquoParticulate matter airpollution effects on the cardiovascular systemrdquo Frontiers inEndocrinology vol 9 2018

[10] D E RWarburton S S D Bredin E M Shellington et al ldquoAsystematic review of the short-term health effects of airpollution in persons living with coronary heart diseaserdquoJournal of Clinical Medicine vol 8 no 2 p 274 2019

[11] M T Chin ldquoBasic mechanisms for adverse cardiovascularevents associated with air pollutionrdquo Heart vol 101 no 4pp 253ndash256 2015

[12] J-H Kim I-H Oh J-H Park and H-K Cheong ldquoPre-mature deaths attributable to long-term exposure to ambientfine particulate matter in the Republic of Koreardquo Journal ofKorean Medical Science vol 33 2018

[13] R Chen P Yin X Meng et al ldquoAssociations between coarseparticulate matter air pollution and cause-specific mortality anationwide analysis in 272 Chinese citiesrdquo EnvironmentalHealth Perspectives vol 127 Article ID 017008 2019

[14] L Bai S Weichenthal J C Kwong et al ldquoAssociations oflong-term exposure to ultrafine particles and nitrogen dioxidewith increased incidence of congestive heart failure and acutemyocardial infarctionrdquo American Journal of Epidemiologyvol 188 no 1 pp 151ndash159 2018

[15] N Berglind T Bellander F Forastiere et al ldquoAmbient airpollution and daily mortality among survivors of myocardialinfarctionrdquo Epidemiology vol 20 no 1 pp 110ndash118 2009

[16] H-J Kwon S-H Cho F Nyberg and G Pershagen ldquoEffectsof ambient air pollution on daily mortality in a cohort ofpatients with congestive heart failurerdquo Epidemiology vol 12no 4 pp 413ndash419 2001

[17] T F Bateson and J Schwartz ldquoWho is sensitive to the effectsof particulate air pollution on mortalityrdquo Epidemiologyvol 15 no 2 pp 143ndash149 2004

[18] X Liu and S Bertazzon ldquoExploratory temporal and spatialanalysis of myocardial infarction hospitalizations in CalgaryCanadardquo International Journal of Environmental Researchand Public Health vol 14 p 1555 2017

[19] H Liu Y Tian J Song et al ldquoEffect of ambient air pollutionon hospitalization for heart failure in 26 of Chinarsquos largestcitiesrdquo gte American Journal of Cardiology vol 121 no 5pp 628ndash633 2018

e Scientific World Journal 7

the physiological response to toxic agents increasing indi-vidual vulnerability [30]

We could not find any scientific articles that couldsupport our findings In fact the lack of air quality moni-toring seems to be a major element preventing a broaderanalysis of environmental and health conditions Howeveras there is no air quality monitoring network in Manaus weused the data provided by SISAM that comes from remotesensing (satellite) ose who research the effects of airpollution on health know that well-conducted studies andair quality monitoring programs require not only adequatemethodology but also quality data on local pollutionweather conditions and health information [39]

ere are evidences that hospital admissions of childrendue to respiratory diseases in Manaus are more related tometeorological conditions and humidity than to exposure to

smoke from the fires and to PM25 concentrations in theregion It is possible that the environmental characteristicsinherent to the rainy season in the region play an importantrole in increased hospitalization rates of children due torespiratory diseases ere is a predominance of naturalbiogenic particulate emissions during the rainy seasoncaused by the intense activity of biological organisms in theforest which include fragments of plants and insects pollengrains fungi algae and fungal spores [40] e presence of aground monitoring system could provide more reliable datato confirm such hypothesis

In any case air pollution is pointed out by its systemicimportance in urban environments because it has a syn-ergic effect when allied to other exposure factors

0 1 2 3 4 5 6

ndash15

ndash05

05

15

ndash100

ndash050

000

050

100

150

200

ndash200

ndash100

000

100

200

300

400

PM25

Temperature

Humidity

Figure 1 One interquartile range increase of daily mean level ofPM25 using polynomial distribution for hospitalizations due torespiratory diseases in children under 5 years in Manaus (AM)from 2008 to 2012

Temperature

Humidity

0 1 2 3 4 5 6

ndash200

ndash100

000

100

200

ndash200

ndash150

ndash100

ndash050

000

050

100

150

200

ndash1500

ndash1000

ndash500

000

500

1000

PM25

Figure 2 One interquartile range increase of daily mean level ofPM25 for hospitalizations due to respiratory diseases in patientsover 60 years of age in Manaus (AM) from 2008 to 2012

e Scientific World Journal 5

potentiating the risks for respiratory or cardiovasculardiseases About the modernization process of urbanizationwe must consider the relevance of the growth of the fleet ofvehicles as emitters of atmospheric pollutants which add toemissions of the operating thermoelectric plants and to thefires in the peripheral areas of Manaus us we highlightthe possibility that the exposure of the population of Manausto air pollutants has increased From 2007 to 2011 the fleetof cars in the city increased by 65 is is the highest rateamong the ten most populous capitals It is impossiblehowever to quantify the seriousness of the situation due tothe nonexistence of an atmospheric quality monitoringnetwork in the city different from other regions of Brazil

About the hospitalization data we only used the hospitaladmission authorizations (HAA) registered in DATASUSand comprised the information obtained in the hospitals

linked to the Brazilian Unified Health System (SUS) It isworth noting that the HIS uses the HAA and not the sickindividual as the unit of analysis As the same individual canbe hospitalized more than once or even not be hospitalizeddespite being ill due to limitations in the hospital structurethe use of hospitalizations as a proxy of the number of casesof illness is considered as fragility However HAA has beenpointed out as one of the best information systems for healthresearch [41] We used data on hospitalizations in the SUSconsidering that hospitalization is the final stage of severalvisits to the emergency room and several inhalations be-cause people only seek the emergency service and arehospitalized when their lung function is altered On theother hand the participation of the supplementary healthsystem in the Amazon is not relevant in the regionere arecities where SUS is responsible for 100 of outpatient andhospital care which indicates that the data used in this studyhave good population coverage

Regarding the age groups selected for the study severalauthors sustain that the most sensitive to exposure to airpollutants are under-five children and the elderly as well aspeople with respiratory or cardiac diseases [42 43] How-ever other risk factors linked to sociological-sanitary con-ditions are also associated with the development ofchildhood respiratory diseases especially in the first year oflife [44 45] Of the two sensitive groups included in thepresent study most of the groups with the highest preva-lence of hospitalizations due to respiratory diseases occurredin the municipalities belonging to the ldquoArch of Deforesta-tionrdquo composed of municipalities that extend from the stateof Acre to the south of Maranhatildeo and are characterized byextensive deforested areas and large concentrations of forestfires [46]

When time-series studies are used to assess the effects ofpollution on health they consider only the short-termimpacts A longer time series with more consistent infor-mation would enable the detection of small short-term ef-fects on public health caused by exposure to air pollution[47] Considering that the city of Manaus may be chronicallypolluted the present results may underestimate the realdamages

As it is well known epidemiological studies only provideindications of the associations between pollutants and hu-man health Based on the premises of this study we hopethat researchers are prompted to examine this subject planresearch that can provide more conclusive results

5 Conclusions

e present study found no significant association betweenPM25 concentrations minimum temperature relative hu-midity and hospitalizations for respiratory diseases inchildren under 5 years and respiratory and cardiovasculardiseases in those over 60 years

Studies of the impact of air pollution on health usingtime series can contribute to obtain short-term effects of airpollution on respiratory and cardiovascular morbiditysupporting the control and warn actions to health serviceswhen pollution peaks occur e realization of such studies

0 1 2 3 4 5 6

Humidity

ndash050

000

050

100

ndash100

ndash050

000

050

100

ndash1000

ndash500

000

500

Temperature

PM25

Figure 3 One interquartile range increase of daily mean level ofPM25 for hospitalizations due to cardiovascular diseases in pa-tients over 60 years of age in Manaus (AM) from 2008 to 2012

6 e Scientific World Journal

depends on the continuous collection and availability ofquality data In this sense efforts must be made to ensure thecontinuous collection of data and expansion of the airquality monitoring network in the northern region of thecountry

It should be emphasized that the measurement of cli-matic variables is also essential in all seasons to properly fitmodels and improve the results On the other hand effortsmust also be undertaken by the health sector in the ac-quisition and systematization of all information on hospitalmorbidity Considering the seriousness of the situation of airpollution in the city of Manaus the implementation of acomputerized registry of outpatient clinics especially chil-dren and older people and improving the quality of data onair pollution are recommended to create possibilities forother research routes

Remote sensing techniques are used as a complementarytool to surface measurements because they are indirect mea-surements which explain the importance of long-term ter-restrial-monitoring stations for integrated studies in the region

We stress that it is a great challenge to describe con-ditions and trends in terms of environmental situations andexposures to which the population of Manaus is subjectede results of this research can be used to evaluate theimprovement of the quality of hospitalization and air pol-lution data On the one hand we must deal with the poorproduction of environmental indicators and on the otherhand we must research the most different sources anddocuments for the description of these aspects in a city inwhich the municipal level follows the logic of production ofinformation within the peculiarities of the municipalityespecially for relatively new themes

Data Availability

All the data reported in this manuscript have been depositedat Mendeley Data Copies of this data can be obtained free ofcharge from httpsdatamendeleycom

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

References

[1] M A Arbex U D P Santos L C Martins P H N SaldivaL A A Pereira and A L F Braga ldquoA poluiccedilatildeo do ar e osistema respiratoriordquo Jornal Brasileiro de Pneumologiavol 38 no 5 pp 643ndash655 2012

[2] C T Amancio L F C Nascimento and T T AmancioldquoPoluentes ambientais e chance de internaccedilotildees por asma emcrianccedilasmdashSatildeo Jose dos Campos Brasil nos anos 2004-2005rdquoJournal of Human Growth and Development vol 22 no 2pp 202ndash208 2012

[3] S M C Bakonyi I M Danni-Oliveira L C Martins andA L F Braga ldquoPoluiccedilatildeo atmosferica e doenccedilas respiratoriasem crianccedilas na cidade de Curitiba PRrdquo Revista de SaudePublica vol 38 no 5 pp 695ndash700 2004

[4] J E D Canccedilado A Braga L A A Pereira M A ArbexP H N Saldiva and U D P Santos ldquoRepercussotildees clınicasda exposiccedilatildeo a poluiccedilatildeo atmosfericardquo Jornal Brasileiro dePneumologia vol 32 no 2 pp S5ndashS11 2006

[5] K D S Gonccedilalves A S P Siqueira H A D Castro andS D S Hacon ldquoIndicador de vulnerabilidade socioambientalna Amazonia Ocidental O caso do municıpio de Porto VelhoRondonia Brasilrdquo Ciencia amp Saude Coletiva vol 19 no 9pp 3809ndash3818 2014

[6] A F Duarte R M da Cunha and W da Silva Lima ldquoAnecessidade de otimizaccedilatildeo das informaccedilotildees meteorologicas naamazonica ocidentalrdquo Boletim da Sociedade Brasileira deMeteorologia no 1 pp 21ndash31 2006

[7] K D S Gonccedilalves H A D Castro and S D S Hacon ldquoAsqueimadas na regiatildeo amazonica e o adoecimento respira-toriordquo Ciencia amp Saude Coletiva vol 17 no 6 pp 1523ndash15322012

[8] H Broslashnnum-Hansen A M Bender Z J Andersen et alldquoAssessment of impact of traffic-related air pollution onmorbidity and mortality in Copenhagen Municipality and thehealth gain of reduced exposurerdquo Environment Internationalvol 121 pp 973ndash980 2018

[9] R B Hamanaka and G M Mutlu ldquoParticulate matter airpollution effects on the cardiovascular systemrdquo Frontiers inEndocrinology vol 9 2018

[10] D E RWarburton S S D Bredin E M Shellington et al ldquoAsystematic review of the short-term health effects of airpollution in persons living with coronary heart diseaserdquoJournal of Clinical Medicine vol 8 no 2 p 274 2019

[11] M T Chin ldquoBasic mechanisms for adverse cardiovascularevents associated with air pollutionrdquo Heart vol 101 no 4pp 253ndash256 2015

[12] J-H Kim I-H Oh J-H Park and H-K Cheong ldquoPre-mature deaths attributable to long-term exposure to ambientfine particulate matter in the Republic of Koreardquo Journal ofKorean Medical Science vol 33 2018

[13] R Chen P Yin X Meng et al ldquoAssociations between coarseparticulate matter air pollution and cause-specific mortality anationwide analysis in 272 Chinese citiesrdquo EnvironmentalHealth Perspectives vol 127 Article ID 017008 2019

[14] L Bai S Weichenthal J C Kwong et al ldquoAssociations oflong-term exposure to ultrafine particles and nitrogen dioxidewith increased incidence of congestive heart failure and acutemyocardial infarctionrdquo American Journal of Epidemiologyvol 188 no 1 pp 151ndash159 2018

[15] N Berglind T Bellander F Forastiere et al ldquoAmbient airpollution and daily mortality among survivors of myocardialinfarctionrdquo Epidemiology vol 20 no 1 pp 110ndash118 2009

[16] H-J Kwon S-H Cho F Nyberg and G Pershagen ldquoEffectsof ambient air pollution on daily mortality in a cohort ofpatients with congestive heart failurerdquo Epidemiology vol 12no 4 pp 413ndash419 2001

[17] T F Bateson and J Schwartz ldquoWho is sensitive to the effectsof particulate air pollution on mortalityrdquo Epidemiologyvol 15 no 2 pp 143ndash149 2004

[18] X Liu and S Bertazzon ldquoExploratory temporal and spatialanalysis of myocardial infarction hospitalizations in CalgaryCanadardquo International Journal of Environmental Researchand Public Health vol 14 p 1555 2017

[19] H Liu Y Tian J Song et al ldquoEffect of ambient air pollutionon hospitalization for heart failure in 26 of Chinarsquos largestcitiesrdquo gte American Journal of Cardiology vol 121 no 5pp 628ndash633 2018

e Scientific World Journal 7

potentiating the risks for respiratory or cardiovasculardiseases About the modernization process of urbanizationwe must consider the relevance of the growth of the fleet ofvehicles as emitters of atmospheric pollutants which add toemissions of the operating thermoelectric plants and to thefires in the peripheral areas of Manaus us we highlightthe possibility that the exposure of the population of Manausto air pollutants has increased From 2007 to 2011 the fleetof cars in the city increased by 65 is is the highest rateamong the ten most populous capitals It is impossiblehowever to quantify the seriousness of the situation due tothe nonexistence of an atmospheric quality monitoringnetwork in the city different from other regions of Brazil

About the hospitalization data we only used the hospitaladmission authorizations (HAA) registered in DATASUSand comprised the information obtained in the hospitals

linked to the Brazilian Unified Health System (SUS) It isworth noting that the HIS uses the HAA and not the sickindividual as the unit of analysis As the same individual canbe hospitalized more than once or even not be hospitalizeddespite being ill due to limitations in the hospital structurethe use of hospitalizations as a proxy of the number of casesof illness is considered as fragility However HAA has beenpointed out as one of the best information systems for healthresearch [41] We used data on hospitalizations in the SUSconsidering that hospitalization is the final stage of severalvisits to the emergency room and several inhalations be-cause people only seek the emergency service and arehospitalized when their lung function is altered On theother hand the participation of the supplementary healthsystem in the Amazon is not relevant in the regionere arecities where SUS is responsible for 100 of outpatient andhospital care which indicates that the data used in this studyhave good population coverage

Regarding the age groups selected for the study severalauthors sustain that the most sensitive to exposure to airpollutants are under-five children and the elderly as well aspeople with respiratory or cardiac diseases [42 43] How-ever other risk factors linked to sociological-sanitary con-ditions are also associated with the development ofchildhood respiratory diseases especially in the first year oflife [44 45] Of the two sensitive groups included in thepresent study most of the groups with the highest preva-lence of hospitalizations due to respiratory diseases occurredin the municipalities belonging to the ldquoArch of Deforesta-tionrdquo composed of municipalities that extend from the stateof Acre to the south of Maranhatildeo and are characterized byextensive deforested areas and large concentrations of forestfires [46]

When time-series studies are used to assess the effects ofpollution on health they consider only the short-termimpacts A longer time series with more consistent infor-mation would enable the detection of small short-term ef-fects on public health caused by exposure to air pollution[47] Considering that the city of Manaus may be chronicallypolluted the present results may underestimate the realdamages

As it is well known epidemiological studies only provideindications of the associations between pollutants and hu-man health Based on the premises of this study we hopethat researchers are prompted to examine this subject planresearch that can provide more conclusive results

5 Conclusions

e present study found no significant association betweenPM25 concentrations minimum temperature relative hu-midity and hospitalizations for respiratory diseases inchildren under 5 years and respiratory and cardiovasculardiseases in those over 60 years

Studies of the impact of air pollution on health usingtime series can contribute to obtain short-term effects of airpollution on respiratory and cardiovascular morbiditysupporting the control and warn actions to health serviceswhen pollution peaks occur e realization of such studies

0 1 2 3 4 5 6

Humidity

ndash050

000

050

100

ndash100

ndash050

000

050

100

ndash1000

ndash500

000

500

Temperature

PM25

Figure 3 One interquartile range increase of daily mean level ofPM25 for hospitalizations due to cardiovascular diseases in pa-tients over 60 years of age in Manaus (AM) from 2008 to 2012

6 e Scientific World Journal

depends on the continuous collection and availability ofquality data In this sense efforts must be made to ensure thecontinuous collection of data and expansion of the airquality monitoring network in the northern region of thecountry

It should be emphasized that the measurement of cli-matic variables is also essential in all seasons to properly fitmodels and improve the results On the other hand effortsmust also be undertaken by the health sector in the ac-quisition and systematization of all information on hospitalmorbidity Considering the seriousness of the situation of airpollution in the city of Manaus the implementation of acomputerized registry of outpatient clinics especially chil-dren and older people and improving the quality of data onair pollution are recommended to create possibilities forother research routes

Remote sensing techniques are used as a complementarytool to surface measurements because they are indirect mea-surements which explain the importance of long-term ter-restrial-monitoring stations for integrated studies in the region

We stress that it is a great challenge to describe con-ditions and trends in terms of environmental situations andexposures to which the population of Manaus is subjectede results of this research can be used to evaluate theimprovement of the quality of hospitalization and air pol-lution data On the one hand we must deal with the poorproduction of environmental indicators and on the otherhand we must research the most different sources anddocuments for the description of these aspects in a city inwhich the municipal level follows the logic of production ofinformation within the peculiarities of the municipalityespecially for relatively new themes

Data Availability

All the data reported in this manuscript have been depositedat Mendeley Data Copies of this data can be obtained free ofcharge from httpsdatamendeleycom

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

References

[1] M A Arbex U D P Santos L C Martins P H N SaldivaL A A Pereira and A L F Braga ldquoA poluiccedilatildeo do ar e osistema respiratoriordquo Jornal Brasileiro de Pneumologiavol 38 no 5 pp 643ndash655 2012

[2] C T Amancio L F C Nascimento and T T AmancioldquoPoluentes ambientais e chance de internaccedilotildees por asma emcrianccedilasmdashSatildeo Jose dos Campos Brasil nos anos 2004-2005rdquoJournal of Human Growth and Development vol 22 no 2pp 202ndash208 2012

[3] S M C Bakonyi I M Danni-Oliveira L C Martins andA L F Braga ldquoPoluiccedilatildeo atmosferica e doenccedilas respiratoriasem crianccedilas na cidade de Curitiba PRrdquo Revista de SaudePublica vol 38 no 5 pp 695ndash700 2004

[4] J E D Canccedilado A Braga L A A Pereira M A ArbexP H N Saldiva and U D P Santos ldquoRepercussotildees clınicasda exposiccedilatildeo a poluiccedilatildeo atmosfericardquo Jornal Brasileiro dePneumologia vol 32 no 2 pp S5ndashS11 2006

[5] K D S Gonccedilalves A S P Siqueira H A D Castro andS D S Hacon ldquoIndicador de vulnerabilidade socioambientalna Amazonia Ocidental O caso do municıpio de Porto VelhoRondonia Brasilrdquo Ciencia amp Saude Coletiva vol 19 no 9pp 3809ndash3818 2014

[6] A F Duarte R M da Cunha and W da Silva Lima ldquoAnecessidade de otimizaccedilatildeo das informaccedilotildees meteorologicas naamazonica ocidentalrdquo Boletim da Sociedade Brasileira deMeteorologia no 1 pp 21ndash31 2006

[7] K D S Gonccedilalves H A D Castro and S D S Hacon ldquoAsqueimadas na regiatildeo amazonica e o adoecimento respira-toriordquo Ciencia amp Saude Coletiva vol 17 no 6 pp 1523ndash15322012

[8] H Broslashnnum-Hansen A M Bender Z J Andersen et alldquoAssessment of impact of traffic-related air pollution onmorbidity and mortality in Copenhagen Municipality and thehealth gain of reduced exposurerdquo Environment Internationalvol 121 pp 973ndash980 2018

[9] R B Hamanaka and G M Mutlu ldquoParticulate matter airpollution effects on the cardiovascular systemrdquo Frontiers inEndocrinology vol 9 2018

[10] D E RWarburton S S D Bredin E M Shellington et al ldquoAsystematic review of the short-term health effects of airpollution in persons living with coronary heart diseaserdquoJournal of Clinical Medicine vol 8 no 2 p 274 2019

[11] M T Chin ldquoBasic mechanisms for adverse cardiovascularevents associated with air pollutionrdquo Heart vol 101 no 4pp 253ndash256 2015

[12] J-H Kim I-H Oh J-H Park and H-K Cheong ldquoPre-mature deaths attributable to long-term exposure to ambientfine particulate matter in the Republic of Koreardquo Journal ofKorean Medical Science vol 33 2018

[13] R Chen P Yin X Meng et al ldquoAssociations between coarseparticulate matter air pollution and cause-specific mortality anationwide analysis in 272 Chinese citiesrdquo EnvironmentalHealth Perspectives vol 127 Article ID 017008 2019

[14] L Bai S Weichenthal J C Kwong et al ldquoAssociations oflong-term exposure to ultrafine particles and nitrogen dioxidewith increased incidence of congestive heart failure and acutemyocardial infarctionrdquo American Journal of Epidemiologyvol 188 no 1 pp 151ndash159 2018

[15] N Berglind T Bellander F Forastiere et al ldquoAmbient airpollution and daily mortality among survivors of myocardialinfarctionrdquo Epidemiology vol 20 no 1 pp 110ndash118 2009

[16] H-J Kwon S-H Cho F Nyberg and G Pershagen ldquoEffectsof ambient air pollution on daily mortality in a cohort ofpatients with congestive heart failurerdquo Epidemiology vol 12no 4 pp 413ndash419 2001

[17] T F Bateson and J Schwartz ldquoWho is sensitive to the effectsof particulate air pollution on mortalityrdquo Epidemiologyvol 15 no 2 pp 143ndash149 2004

[18] X Liu and S Bertazzon ldquoExploratory temporal and spatialanalysis of myocardial infarction hospitalizations in CalgaryCanadardquo International Journal of Environmental Researchand Public Health vol 14 p 1555 2017

[19] H Liu Y Tian J Song et al ldquoEffect of ambient air pollutionon hospitalization for heart failure in 26 of Chinarsquos largestcitiesrdquo gte American Journal of Cardiology vol 121 no 5pp 628ndash633 2018

e Scientific World Journal 7

depends on the continuous collection and availability ofquality data In this sense efforts must be made to ensure thecontinuous collection of data and expansion of the airquality monitoring network in the northern region of thecountry

It should be emphasized that the measurement of cli-matic variables is also essential in all seasons to properly fitmodels and improve the results On the other hand effortsmust also be undertaken by the health sector in the ac-quisition and systematization of all information on hospitalmorbidity Considering the seriousness of the situation of airpollution in the city of Manaus the implementation of acomputerized registry of outpatient clinics especially chil-dren and older people and improving the quality of data onair pollution are recommended to create possibilities forother research routes

Remote sensing techniques are used as a complementarytool to surface measurements because they are indirect mea-surements which explain the importance of long-term ter-restrial-monitoring stations for integrated studies in the region

We stress that it is a great challenge to describe con-ditions and trends in terms of environmental situations andexposures to which the population of Manaus is subjectede results of this research can be used to evaluate theimprovement of the quality of hospitalization and air pol-lution data On the one hand we must deal with the poorproduction of environmental indicators and on the otherhand we must research the most different sources anddocuments for the description of these aspects in a city inwhich the municipal level follows the logic of production ofinformation within the peculiarities of the municipalityespecially for relatively new themes

Data Availability

All the data reported in this manuscript have been depositedat Mendeley Data Copies of this data can be obtained free ofcharge from httpsdatamendeleycom

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

References

[1] M A Arbex U D P Santos L C Martins P H N SaldivaL A A Pereira and A L F Braga ldquoA poluiccedilatildeo do ar e osistema respiratoriordquo Jornal Brasileiro de Pneumologiavol 38 no 5 pp 643ndash655 2012

[2] C T Amancio L F C Nascimento and T T AmancioldquoPoluentes ambientais e chance de internaccedilotildees por asma emcrianccedilasmdashSatildeo Jose dos Campos Brasil nos anos 2004-2005rdquoJournal of Human Growth and Development vol 22 no 2pp 202ndash208 2012

[3] S M C Bakonyi I M Danni-Oliveira L C Martins andA L F Braga ldquoPoluiccedilatildeo atmosferica e doenccedilas respiratoriasem crianccedilas na cidade de Curitiba PRrdquo Revista de SaudePublica vol 38 no 5 pp 695ndash700 2004

[4] J E D Canccedilado A Braga L A A Pereira M A ArbexP H N Saldiva and U D P Santos ldquoRepercussotildees clınicasda exposiccedilatildeo a poluiccedilatildeo atmosfericardquo Jornal Brasileiro dePneumologia vol 32 no 2 pp S5ndashS11 2006

[5] K D S Gonccedilalves A S P Siqueira H A D Castro andS D S Hacon ldquoIndicador de vulnerabilidade socioambientalna Amazonia Ocidental O caso do municıpio de Porto VelhoRondonia Brasilrdquo Ciencia amp Saude Coletiva vol 19 no 9pp 3809ndash3818 2014

[6] A F Duarte R M da Cunha and W da Silva Lima ldquoAnecessidade de otimizaccedilatildeo das informaccedilotildees meteorologicas naamazonica ocidentalrdquo Boletim da Sociedade Brasileira deMeteorologia no 1 pp 21ndash31 2006

[7] K D S Gonccedilalves H A D Castro and S D S Hacon ldquoAsqueimadas na regiatildeo amazonica e o adoecimento respira-toriordquo Ciencia amp Saude Coletiva vol 17 no 6 pp 1523ndash15322012

[8] H Broslashnnum-Hansen A M Bender Z J Andersen et alldquoAssessment of impact of traffic-related air pollution onmorbidity and mortality in Copenhagen Municipality and thehealth gain of reduced exposurerdquo Environment Internationalvol 121 pp 973ndash980 2018

[9] R B Hamanaka and G M Mutlu ldquoParticulate matter airpollution effects on the cardiovascular systemrdquo Frontiers inEndocrinology vol 9 2018

[10] D E RWarburton S S D Bredin E M Shellington et al ldquoAsystematic review of the short-term health effects of airpollution in persons living with coronary heart diseaserdquoJournal of Clinical Medicine vol 8 no 2 p 274 2019

[11] M T Chin ldquoBasic mechanisms for adverse cardiovascularevents associated with air pollutionrdquo Heart vol 101 no 4pp 253ndash256 2015

[12] J-H Kim I-H Oh J-H Park and H-K Cheong ldquoPre-mature deaths attributable to long-term exposure to ambientfine particulate matter in the Republic of Koreardquo Journal ofKorean Medical Science vol 33 2018

[13] R Chen P Yin X Meng et al ldquoAssociations between coarseparticulate matter air pollution and cause-specific mortality anationwide analysis in 272 Chinese citiesrdquo EnvironmentalHealth Perspectives vol 127 Article ID 017008 2019

[14] L Bai S Weichenthal J C Kwong et al ldquoAssociations oflong-term exposure to ultrafine particles and nitrogen dioxidewith increased incidence of congestive heart failure and acutemyocardial infarctionrdquo American Journal of Epidemiologyvol 188 no 1 pp 151ndash159 2018

[15] N Berglind T Bellander F Forastiere et al ldquoAmbient airpollution and daily mortality among survivors of myocardialinfarctionrdquo Epidemiology vol 20 no 1 pp 110ndash118 2009

[16] H-J Kwon S-H Cho F Nyberg and G Pershagen ldquoEffectsof ambient air pollution on daily mortality in a cohort ofpatients with congestive heart failurerdquo Epidemiology vol 12no 4 pp 413ndash419 2001

[17] T F Bateson and J Schwartz ldquoWho is sensitive to the effectsof particulate air pollution on mortalityrdquo Epidemiologyvol 15 no 2 pp 143ndash149 2004

[18] X Liu and S Bertazzon ldquoExploratory temporal and spatialanalysis of myocardial infarction hospitalizations in CalgaryCanadardquo International Journal of Environmental Researchand Public Health vol 14 p 1555 2017

[19] H Liu Y Tian J Song et al ldquoEffect of ambient air pollutionon hospitalization for heart failure in 26 of Chinarsquos largestcitiesrdquo gte American Journal of Cardiology vol 121 no 5pp 628ndash633 2018

e Scientific World Journal 7

[20] D Phung T T Hien H N Linh et al ldquoAir pollution and riskof respiratory and cardiovascular hospitalizations in the mostpopulous city in Vietnamrdquo Science of gte Total Environmentvol 557-558 pp 322ndash330 2016

[21] L Fajersztajn P Saldiva L A A Pereira V F Leite andA M Buehler ldquoShort-term effects of fine particulate matterpollution on daily health events in Latin America a systematicreview and meta-analysisrdquo International Journal of PublicHealth vol 62 no 7 pp 729ndash738 2017

[22] IBGE Characteristics of the Amazon Region Brazilian Instituteof Geography and Statistics Rio de Janeiro Brazil 2019

[23] P McCullagh Generalized Linear Models RoutledgeAbingdon UK 2018

[24] A Zanobetti and J Schwartz ldquoAir pollution and emergencyadmissions in Boston MArdquo Journal of Epidemiology ampCommunity Health vol 60 no 10 pp 890ndash895 2006

[25] L C Martins Efeitos da Poluiccedilatildeo do ar e Fatores Meter-eologicos nas Doenccedilas Cardiovasculares na Cidade de SatildeoPaulo USP Satildeo Paulo Brazil 2004

[26] A Zanobetti J Schwartz E Samoli et al ldquoe temporalpattern of mortality responses to air pollution a multicityassessment of mortality displacementrdquo Epidemiology vol 13no 1 pp 87ndash93 2002

[27] M Franchini and P M Mannucci ldquoAir pollution and car-diovascular diseaserdquo gtrombosis Research vol 129 no 3pp 230ndash234 2012

[28] A C Nardocci C U D Freitas A C M Ponce de LeonW L Junger N D C Gouveia and N D C GouveialdquoPoluiccedilatildeo do ar e doenccedilas respiratorias e cardiovascularesestudo de series temporais em Cubatatildeo Satildeo Paulo BrasilrdquoCadernos de Saude Publica vol 29 no 9 pp 1867ndash1876 2013

[29] A Luis and A Ponce ldquoMulticity study of air pollution andmortality in Latin America (the ESCALA study)rdquo ResearchReport Health Effects Institute Boston MA USA 2017

[30] P C D O Rodrigues S D L Pinheiro W Junger E Ignottiand S D S Hacon ldquoVariabilidade climatica aumenta amorbimortalidade associada ao material particuladordquo Revistade Saude Publica vol 51 p 91 2017

[31] T To S Shen E G Atenafu et al ldquoe air quality healthindex and asthma morbidity a population-based studyrdquoEnvironmental Health Perspectives vol 121 pp 46ndash52 2012

[32] M Stafoggia E Samoli E Alessandrini et al ldquoShort-termassociations between fine and coarse particulate matter andhospitalizations in Southern Europe results from the MED-PARTICLES projectrdquo Environmental Health Perspectivesvol 121 no 9 pp 1026ndash1033 2013

[33] L-F Tetreault M Doucet P Gamache et al ldquoSevere andmoderate asthma exacerbations in asthmatic children andexposure to ambient air pollutantsrdquo International Journal ofEnvironmental Research and Public Health vol 13 no 8p 771 2016

[34] P-S Yap S Gilbreath C Garcia N Jareen and B Goodrichldquoe influence of socioeconomic markers on the associationbetween fine particulate matter and hospital admissions forrespiratory conditions among childrenrdquo American Journal ofPublic Health vol 103 no 4 pp 695ndash702 2013

[35] K Chen G Glonek A Hansen et al ldquoe effects of airpollution on asthma hospital admissions in Adelaide SouthAustralia 2003‒2013 time-series and case-crossover ana-lysesrdquo Clinical amp Experimental Allergy vol 46 no 11pp 1416ndash1430 2016

[36] N V Patto L F C Nascimento K C C MantovaniL C P F S Vieira and D S Moreira ldquoExposure to fineparticulate matter and hospital admissions due to pneumonia

effects on the number of hospital admissions and its costsrdquoRevista da Associaccedilatildeo Medica Brasileira vol 62 no 4pp 342ndash346 2016

[37] H Leatildeo R O Santos N Araujo and T Oliveira ldquoA qual-idade do ar influencia as internaccedilotildees hospitalares por doenccedilasrespiratorias em crianccedilas Uma revisatildeo sistematicardquo ASSO-BRAFIR Ciencia vol 9 pp 55ndash70 2019

[38] S Roberts ldquoInteractions between particulate air pollution andtemperature in air pollution mortality time series studiesrdquoEnvironmental Research vol 96 no 3 pp 328ndash337 2004

[39] A L F Braga L A A Pereira M Procopio P A D Andreand P H D N Saldiva ldquoAssociaccedilatildeo entre poluiccedilatildeo atmos-ferica e doenccedilas respiratorias e cardiovasculares na cidade deItabira Minas Gerais Brasilrdquo Cadernos de Saude Publicavol 23 no 4 pp S570ndashS578 2007

[40] V S D Andrade Filho P Artaxo S Hacon C N D Carmoand G Cirino ldquoAerossois de queimadas e doencas respira-torias em criancas Manaus Brasilrdquo Revista de Saude Publicavol 47 no 2 pp 239ndash247 2013

[41] E D F Drumond C J Machado M D R Vasconcelos andE Franccedila ldquoUtilizaccedilatildeo de dados secundarios do SIM Sinasc eSIH na produccedilatildeo cientıfica Brasileira de 1990 a 2006rdquo RevistaBrasileira de Estudos de Populaccedilatildeo vol 26 no 1 pp 7ndash192009

[42] K Rumchev J Spickett H Brown and B Mkhweli ldquoIndoorair pollution from biomass combustion and respiratorysymptoms of women and children in a Zimbabwean villagerdquoIndoor Air vol 17 pp 468ndash474 2007

[43] M Medina-Ramon A Zanobetti and J Schwartz ldquoe effectof ozone and PM10 on hospital admissions for pneumonia andchronic obstructive pulmonary disease a national multicitystudyrdquo American Journal of Epidemiology vol 163 pp 579ndash588 2006

[44] S E C Macedo A M B Menezes E Albernaz P Post andM Knorst ldquoRisk factors for acute respiratory disease hos-pitalization in children under one year of agerdquo Revista deSaude Publica vol 41 pp 351ndash358 2007

[45] A M C D Silva I E Mattos S R Freitas K M Longo andS S Hacon ldquoParticulate matter (PM25) of biomass burningemissions and respiratory diseases in the south of the Bra-zilian Amazonrdquo Revista Brasileira de Epidemiologia vol 13pp 337ndash351 2010

[46] P R S Silva A M Rosa S S Hacon and E IgnottildquoHospitalization of children for asthma in the BrazilianAmazon trend and spatial distributionrdquo Jornal de Pediatriavol 85 no 6 pp 541ndash546 2009

[47] C N D Carmo and S D S Hacon ldquoEstudos de seriestemporais de poluiccedilatildeo atmosferica por queimadas e saudehumanardquo Ciencia amp Saude Coletiva vol 18 no 11pp 3245ndash3258 2013

8 e Scientific World Journal