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CarexInternational Information System on Occupational

Exposure to Carcinogens

OCCUPATIONAL EXPOSURE TO CARCINOGENSIN THE EUROPEAN UNION IN 1990-93

Timo Kauppinen, Jouni Toikkanen, David Pedersen, Randy Young,Manolis Kogevinas, Wolfgang Ahrens, Paolo Boffetta, JohnniHansen, Hans Kromhout, Jeronimo Maqueda Blasco, Dario Mirabelli,Victoria de la Orden-Rivera, Nils Plato, Brian Pannett, Anja Savela,Hendrik Veulemans and Raymond Vincent

Finnish Institute of Occupational Health, Helsinki 1998

Carex report of EU Summary •• 2

Contents

SUMMARY 4

INTRODUCTION 5

MATERIAL AND METHODS 7

Overview of the assessment method and data included 7

Agents and occupational exposure 8Agents covered 8Characterisation of agents 9Definition of occupational exposure 9Period covered 9

Industry specific estimation procedure 10Characterisation of industry and labour force 10Estimation procedure 10Estimates of low confidence 11Estimates of low level of exposure 11Estimates of multiple exposure 12

Exposure measurements and descriptions 13Exposure measurements included 13Exposure by occupation and gender 13

Estimation procedure in different countries 14Reference countries 14The countries of the European Union 16

RESULTS 20The European Union 20Austria 20Belgium 21Denmark 21Finland 21France 21Germany 21Great Britain 22Greece 22Ireland 22Italy 22Luxembourg 22The Netherlands 23Portugal 23Spain 23


Sweden 23

DISCUSSION 24

REFERENCES 28

APPENDICES 30


Summary

CAREX is an international information system on occupational exposure toknown and suspected carcinogens. The CAREX (CARcinogen EXposure)database, constructed with support from the Europe Against Cancer program ofthe European Union (EU), provides selected exposure data and documentedestimates of the number of exposed workers by country, carcinogen, andindustry. CAREX includes data on 139 agents evaluated by the InternationalAgency for Research on Cancer (all agents in Groups 1 and 2A, and selectedagents in Group 2B), displayed across the 55 industrial classes of the UnitedNations system (ISIC Revision 2). The 1990-93 occupational exposure to thesecarcinogens was estimated for the fifteen countries of the EU in two phases.First, estimates were generated automatically by the CAREX system on thebasis of national workforce data and exposure prevalence estimates from tworeference countries (the United States and Finland) which had the mostcomprehensive data available on exposures to these agents. These estimates areadjusted for the economic structure (workforce distribution) of each countryindividually, but do not take into account country-specific exposure patternswhich may deviate from those of the reference countries. For selected countries,these estimates were then refined by national experts in view ofsimilarity/dissimilarity to the perceived exposure patterns in their owncountries.

According to the results, there were about 32 million workers (23 % of theemployed) in the 15 countries of the EU exposed to the IARC agents covered byCAREX in 1990-93. The estimated numbers of exposed workers by countrywere: Austria 800 000, Belgium 700 000, Denmark 700 000, Finland 500 000,France 4.9 million, Germany 8.2 million, Great Britain 5.0 million, Greece900 000, Ireland 300 000, Italy 4.2 million, Luxembourg 50 000, theNetherlands 1.1 million, Portugal 1.0 million, Spain 3.1 million, and Sweden800 000. These workers had altogether about 42 million exposures (1.3exposures/exposed worker on average). The most common exposures were solarradiation (9.1 million workers exposed at least 75% of working time),environmental tobacco smoke (7.5 million workers exposed at least 75% ofworking time), crystalline silica (3.2 million exposed), diesel exhaust (3.1million), radon (2.7 million), wood dust (2.6 million), lead and inorganic leadcompounds (1.5 million), and benzene (1.4 million).

The numbers of workers exposed to known or suspected carcinogens generatedby the CAREX system and the network of national experts are the firstestimates published for the EU and most of the member countries. Theseestimates should be considered preliminary, because many of them do not yetaccurately account for specific national exposure patterns. Continuation of theestimation work by the CAREX network of experts would probably increase thevalidity of national estimates as the basic information needed to create andimplement effective policies intended to control and eliminate occupationalcancer in Europe.

Carex report of EU Introduction •• 5

Introduction

The 'Europe Against Cancer' program of the European Union (EU) prompted aproject on the estimation of the burden of occupational cancer in Europe, whichincludes a component on occupational exposure to carcinogens. This substudy isaimed at estimating the number of workers exposed to major known andsuspected carcinogens in the EU by specific carcinogen, country and industry.

The review of available literature, including the Monographs of theInternational Agency for Research on Cancer (IARC), indicated that directestimates on numbers of exposed workers were usually not available. Therefore,it was obvious that most of the estimates would have to be derived indirectly byprofessional judgement, on the basis of available published and unpublishedinformation on workers exposed to carcinogens.

An international group of experts on carcinogen exposure was summoned to ameeting to plan the estimation procedure. After the initial meeting, a firstversion of exposure information system called CAREX (from CarcinogenExposure) was constructed by the Finnish Institute of Occupational Health(FIOH) to support the estimation process. CAREX was tested and furtherdeveloped in another meeting of experts. Because knowledge on nationalexposures is essential in the estimation process, additional experts fromdifferent countries were identified and called to participate to the project. Thefollowing scientists have contributed significantly to the planning, systemdesign, data collection or assessment of exposure in the CAREX system:

Dr Manolis Kogevinas Greece, Spain leader of the project, planning

Dr Timo Kauppinen Finland coordinator, planning, assessment

Mr Jouni Toikkanen Finland planning, system design

Dr David Pedersen USA planning, US data, conversions

Mr Randy Young USA US data , computing

Ms Anja Savela Finland Finnish data, computing

Dr Hans Kromhout the Netherlands planning, assessment

Dr Jeronimo MaquedaBlasco

Spain planning, assessment

Dr Victoria de laOrden-Rivera

Spain assessment

Dr Wolfgang Ahrens Germany planning, assessment

Dr Dario Mirabelli Italy planning, assessment

Carex report of EU Introduction •• 6

Mr Raymond Vincent France planning, assessment

Dr Nils Plato Sweden planning, assessment

Mr Brian Pannett United Kingdom planning, assessment

Dr Johnni Hansen Denmark assessment

Dr Hendrik Veulemans Belgium assessment

Dr Paolo Boffetta IARC planning

Contact information of the participants is presented in the end of this report(Appendix 51).

This report describes the adopted methodology of the assessment and presentsthe European results. A corresponding report will be prepared also for eachmember country of the EU. Only a small part of the CAREX documentation(which includes definitions, subindustrial estimates, descriptive information,results of exposure measurements, labour force data, and bibliographicreferences) could be included in this reports.

A diskette copy of CAREX is available from FIOH upon request. It is plannedto make the CAREX data available also on the Internet.

This project was partially financed by the EU from the 'Europe Against Cancer'program.

Carex report of EU Material and methods •• 7

Material and methods

Overview of the assessment method and dataincluded

The assessment procedure included several main phases which are described inmore detail in the following sections:

- definition of agents and occupational exposure- definition of industries and collection of labour force data- collection of exposure measurement data and descriptive exposure data- generation of default estimates of exposures by the CAREX system- generation of final estimates of exposures by national experts- estimation of multiple exposures

The majority of agents were assessed according to a detailed industry-specific('long') procedure which involves stratification by industry. The assessment ofa few agents followed a country-specific ('short') procedure which providesonly one figure of the exposed workers per country. For example, some medicaltreatments were assessed according to this procedure. Carcinogenic 'exposurecircumstances' evaluated by IARC were only briefly described. For example,'occupational exposure as a painter' was described by providing the number ofpainters in the country supplemented by descriptive information. Noassessment was appropriate or feasible for some of the agents (betel quid, someviruses, salted fish, etc) exposure to which is not primarily occupational. Theywere included in the database but the number of occupationally exposedworkers was assumed to be zero or unknown. Only results from the industry-specific estimations are presented in this report because data from otherprocedures was very incomplete.

To support the estimation and to document the basis for estimates, a CAREXexposure information system was designed and constructed. It is based on theMicrosoft Access 2 database which can be run on personal computers.Summarised results of published and unpublished exposure measurements anddescriptions of exposure were entered in CAREX to facilitate the assessment oflevels of exposure in different industries and jobs.

Our preference was to use original national estimates on carcinogenicexposures, but their poor availability forced us to adopt an approach where mostfigures were derived indirectly on the basis of information from two referencecountries with reasonably comprehensive data (Finland and the United States).The calculation of these first estimates started from direct exposure data


retrieved from the Finnish SUTKEA (Anttila et al 1992), FINJEM (Kauppinenet al, in press) and ASA databases (Kauppinen et al 1990), and from US NOESdatabase (Greife et al 1995, Seta et al 1988, Sieber 1990). After conversion ofthe Finnish and US industrial classifications to ISIC Rev 2 of UN (1968)format, the numbers of workers exposed to agents under study were listed byindustry. The absolute figures were converted to exposure frequencies(prevalences) by dividing them by the employed labour force of the industryconcerned. The prevalence considered to be most valid, which was often themean of the US and Finnish prevalences, was then multiplied by the the numberof employed in the industry of the country to be assessed. The resulting estimategenerated by the CAREX system was used as the first (preliminary) estimate ofthe numbers of the exposed workers.

The first estimates were not directly valid for other countries because theindustrial substructure, use pattern of agents, and temporal factors may differsignificantly across countries. Therefore:

1) National experts refined the first estimates and documented in the databasetheir changes. This resulted in 'final' estimates.

2) National data were then collected and cumulated in the CAREX informationsystem for reporting.

The degree of multiple exposure to agents covered is needed when data aresummed to obtain the total number of the exposed workers in an industry or in acountry. Multiple exposure to agents was estimated in Finland and calculatedFinnish values were applied also to other countries unless individual nationalexperts modified them.

Agents and occupational exposure

Agents covered

The selection of agents was carried out by the project group in its first meetingin March 1995. CAREX includes all agents, groups of agents and mixtureswhich the International Agency for Research on Cancer (IARC) had classifiedto group 1 (carcinogenic to humans) and group 2A (probably carcinogenic tohumans) as of February 1995. Selected agents from group 2B (possiblycarcinogenic to humans) were also included. In addition, ionising radiation wasincluded because, although not evaluated by IARC, there is sufficient evidenceof its carcinogenicity to humans. Appendix 3 of this report lists the agentswhich were assessed according to the industry-specific procedure.

Some of the group 1 or 2A agents are chemically polycyclic aromatichydrocarbons (PAHs) or their mixtures, and they were merged under that title.PAHs include coal-tar pitches, coal-tars, untreated and mildly-treated mineraloils, shale-oils, soots and creosotes, as well as benzo(a)pyrene and otherprobably carcinogenic PAH-compounds. The reason for this regrouping is thatPAHs almost always occur in occupational setting as complex mixtures andexposure to a single PAH is impossible to distinguish. However, tobacco smoke(passive exposure at work) and diesel exhaust, while recognised also as complexmixtures containing PAHs, were assessed separately.

Carcinogenic 'exposure circumstances' in IARC groups 1 and 2A were alsocovered but only at national levels by providing a single estimate of workers, ifavailable.


Characterisation of agents

The agents were described in CAREX by:

- IARC name- abbreviated name- 2-4 letter code- commonly used synonyms- Chemical Abstracts System (CAS) number- IARC evaluation group:- main occurrence:- unit in which the measurement results of CAREX were provided- Occupational exposure limits (from ECDIN database)- estimation procedure used in CAREX

Definition of occupational exposure

The definition of exposure provides the relevant routes of exposure (inhalatory,dermal or both of them) and the nonoccupational background level, which isused as the minimum criterion of occupational exposure. If the backgroundlevel is assumed to be negligible, it is not reported numerically. If a CAREXagent is a group or otherwise unspecific, the definition may list the mostcommon agents included. The definition may also note inclusions or exclusionsof 'borderline' exposures and national deviations from the general definition.

Period covered

The CAREX estimations cover the early 1990s, and available workforcestatistics during the construction of CAREX. The mean workforce by industrywas calculated for the years 1990-93 and the national assessors were advised toaddress the average exposure situation during these years.


Industry specific estimation procedure

Characterisation of industry and labour force

The numbers of exposures in CAREX were estimated mainly for industrialclasses (CAREX industries) at the 3-digit level of United Nations ISICRevision 2 (1968). For some non-manufacturing sectors, 1- or 2-digit levelswere used as the assessment level.

Labour force information was necessary for the estimation of exposed workersThe number of employed persons used in the calculation was the mean numberof employed in 1990-93. As far as possible, we tried to include all employed inthe industry covering salaried workers, self-employed, working family membersand part-time workers. However, labour force information in the EU countrieswas heterogeneous and incomplete.

The major source of labour force data was Organisation for Economic Co-operation and Development (OECD) which has collected industrial structureand workforce statistics uniformly according to the ISIC Rev 2 classificationsince the late 1960s. The manufacturing industry and mining are divided upinto 76 sectors at the 3-digit level. Selected industries data are also at the 4-digitlevel, if available. Non-manufacturing sectors are reported only at the 1-digitlevel in the OECD statistics which was not accurate enough for the CAREXpurposes. Therefore, workforce data by Nomenclature Général des ActivitésEconomiques dans les Communautés Européennes (NACE) Revision 1 (1993)of EUROSTAT, which are available at the 2-digit level (60 classes) andavailable national statistics were also used to derive the 1- or 2-digit levelworkforce figures needed for the non-industrial ISIC-sectors of CAREX.National experts surveyed, corrected, and completed data from various sourcesavailable to them.

Selected information on the distribution of labour force by gender and crudeoccupational group (professional, administrative, clerical etc) in 1-digitindustrial classes from ILO statistics was also provided for each country to helpfor the estimation process. The percentages of clerical/administrative workersby 3-digit industrial class were available for several countries, and Finnish andUK data were included in CAREX.

Estimation procedure

CAREX includes internal routines which calculated some guiding figures onthe basis of the labour force structure of the country and exposure prevalencesin the reference countries. CAREX provided the national assessors severalfigures to choose from:

1) a figure based on exposure prevalence in Finland (FIN)

2) a figure based on exposure prevalence in the United States (USA)

3) a figure based on the mean prevalence of Finland and the United States(AVERAGE)

4) own national estimate (OWN), designated by the national assessor

5) the number of exposed is zero (ZERO)

One of the values was set as DEFAULT VALUE. The logic in the selection ofdefault value was that the AVERAGE value was preferred. If either the Finnishor the US value was flagged with a warning (indicating low validity), the other


was proposed as the default value. Beacause the US NOES Survey did not coverall agents included in CAREX, the Finnish value was proposed if the US valuewas missing. If both Finnish and US values were flagged, the AVERAGE valuewas used as the default value because most often the US prevalence wassuspected to be too high and the Finnish value too low. The following tablesummarises the default values in CAREX:

FINNISH VALUE

no flag flagged zero

US no flag AVE USA AVE

VALUE flagged FIN AVE ZERO

missing FIN OWN ZERO

zero AVE ZERO ZERO

Estimates of low confidence

The confidence of many estimates in the reference countries was consideredlow. In Finland, the following criteria to flag estimates of low confidence wereused (intuitively):

1) The order of magnitude of the estimate may be wrong. This concerns mainlylow figures.

2) The absolute error may exceed 0.1% of the national workforce (about 2000exposed workers in Finland). This concerns mainly high figures.

The premises for the US low confidence flags were different. By generalsurvey/statistical design, NOES was intended to produce 'defensible estimates'of the number of workers exposed to specific agents at the 2-digit US SIC level.According to the Standard Error Tables, any NOES estimate of less than 8000exposed workers is associated with a standard error of 25% or more. Thereforeall such subindustrial estimates were marked as 'low confidence'. This resultedin earmarking a majority of US subindustrial estimates in CAREX whichincluded exposure information at the 4-digit SIC level.

Estimates of low level of exposure

If the level of exposure was considered to be close to background, the estimatewas marked as such. In Finland, the nonoccupational annual dose was used as aguideline. However, the background exposure may vary quite a lot and is oftensubjective. Many low exposures in Finnish data involved handling of smallamounts of carcinogens in laboratories, pharmacies or hospitals. Volatility,dustiness and, in some cases, skin contact were used as criteria to make thedecision of existence or lack of occupational exposure.

The premises for the US low level flags were different. NOES did not classifyexposures by level and therefore 'low exposures' could not be systematicallyidentified. The Finnish estimates which were judged to be close to thebackground level were used as one basis to mark NOES estimates. However, noNOES data were discarded on this basis which resulted in tagging of someexposures in laboratories as 'low level' in the USA when similar exposures werenot considered to entail exposure (exceeding the background level) in Finland.Similarly, exposure to many impurities in polymeric materials and metal alloyswere considered as 'low exposure' in the USA and as being below the minimumcriterion of exposure in Finland. Another criterion to assign a 'low exposure'flag to NOES data was discrepancy with the Finnish data without an evidentreason. For example, if there were over 10 000 exposed workers in a CAREX


industry in NOES and none in Finland, it was assumed that most of the USexposures were of low level. In addition, some very small figures wereconsidered to reflect low exposure.

Estimates of multiple exposure

If one worker is exposed to two agents, the number of exposed workers is one,but the number of exposures is two. The concept 'exposure' does not refer to thenumber of exposure events (eg 5 times/year) but to the qualitative occurrence ofexposure of a worker.

The reason for distinguishing between exposure and exposed worker relates tothe calculation of exposed workers in a CAREX-industry, or in a country. If weadd up all exposures within an industry, we may be counting the same workersseveral times (in cases of multiple exposure) and end up with an overestimate.The CAREX estimation procedure addresses exposures (number of workersexposed to a specified agent). The number of exposures and that of the exposedworkers is the same if there is only one carcinogenic exposure/worker withinthe CAREX-industry. The estimation of exposed workers in multiple exposuresituation required the development of industry-specific factors (multipliers),which convert the numbers of exposures to those of the exposed workers. These'multiple exposure factor' were derived in CAREX for the Finnish data only.They are based on the assessment of additivity of exposed subgroups. The USNOES data did not us allow to derive multiple exposure factors by CAREXindustry.

The approach where primarily exposures are estimated can also be defended byarguing that under the assumption of independent effect of the agents, thenumber of cases of cancers caused by them depends on the number ofexposures, not on the number of exposed workers. However, because of'multiple exposure factors' CAREX is able to provide estimates to bothexposures and exposed workers. The numbers of exposures and those of theexposed workers are equal (except the sum of all agents) in tables where dataare shown by agent (eg, Appendix 3).


Exposure measurements and descriptions

Exposure measurements included

In order to identify worker groups at high risk, information on the level ofexposure is important. A valid estimation of the level would require that thelevels (eg, high and low) are accurately defined and enough knowledge onexposure circumstances from different countries are available. Industrialhygienic data are available for many agents but their representativeness andgeneralisation across countries are debatable. It was considered too laboriousand uncertain to estimate exposures by level in each of the countries. However,CAREX includes agent- and industry-specific measurement data to enable theuser of the database to make his/her own estimations and conclusions on thelevels. The descriptions of measurements also show illustrative examples ofwork tasks and operations where exposure may occur.

The industrial hygienic measurement sets are characterised by:

- country where measurements were carried out

- year(s) of measurements

- range of concentrations in standard units

- mean concentrations in standard units

- number of measurements on which the mean is based

- bibliographic reference

- brief description of the measurement site, process, representativeness etc

The measurement data was limited to data easily available from published orunpublished sources. In Finland, over 1 000 measurement sets were entered.Data were available for arsenic, asbestos, benzene, cadmium, chromium VI,diesel engine exhaust (measured as nitrogen dioxide), formaldehyde, glasswool,methylenechloride, nickel compounds, PAHs, lead, perchloroethylene, silica,styrene and wood dust. Most of the measurements are from Finland but also theIARC Monographs were used as sources of information.

Exposure by occupation and gender

CAREX includes some information about carcinogenic exposures by occupationand gender at the national level. The countries of the European Union haveadopted the ISCO 88 (COM) classification of occupations. The workforce dataare available at the 3-digit level, but EUROSTAT has emphasised thatcomparability of figures across countries is poor because of non uniformdefinitions and data collection practises. Therefore, occupation was not used asa basic variable in CAREX. Instead, descriptive information of the distributionof exposures by occupation was provided for the reference countries (Finlandand the United States). These data do not allow systematic calculation ofexposure prevalences by occupation, but help to identify the occupations atpotential risk.

Detailed workforce statistics of OECD were not separately available for menand women (except for some countries). Gender could therefore not be used as abasic variable in CAREX. The reference countries had some exposureinformation available for men and women separately and descriptiveinformation was included in CAREX.


Estimation procedure in different countries

Reference countries

Finland

Finnish estimates were generated and documented as accurately as possible atsubindustrial level. The major source of Finnish data were the reports of acomprehensive estimation survey (SUTKEA project) carried out by industrialhygienists of the Finnish Institute of Occupational Health (FIOH) in the late1980s and early 1990s. SUTKEA summarised the exposure data and experienceof FIOH on the situation in Finland. It was not a systematic field survey but wasbased on industrial hygienic data collected for separate research projects, or forcompliance testing. Much of the exposure data collected for SUTKEA isincluded in CAREX as background data to indicate crudely the level ofexposure in different work tasks. Because the measurements were partiallycarried out for compliance testing purposes, they can not be generalised directlyto all exposed workers in addressed industries. The numbers of exposed workersare estimates generated by individual Finnish experts responsible for theSUTKEA reports.

Another basic source of information was the national register of workersexposed to carcinogens (ASA Register) kept by FIOH since 1979. ASA data arebased on empoyers' annual notifications on exposed workers and use ofcarcinogens. The ASA notifications are obligatory and they cover all salariedworkers in Finland. However, the coverage of ASA is incomplete for manycarcinogenic exposures, because occasional low level exposures are often notreported, and there are also employers who are not aware of exposures or whoneglect the notification duty. ASA estimates, subjectively adjusted forincompleteness, were used in CAREX when SUTKEA did not provide anestimate of exposed workers. If neither SUTKEA nor ASA provided estimates,other available sources were used as the basis of estimation.

CONCEPT OF EXPOSURE: The basic criterion for assigning occupationalexposure in Finland was that the annual exposure dose at work exceeded thenonoccupational dose. This was also the proposed criterion used to assessexposure in other countries in CAREX. If the dose due to occupational exposurewas close to the background level and it was unclear if exposure was compatiblewith the definition of exposure, decisions on inclusion and exclusion weremade. These decisions were documented in the CAREX system.

WARNING FLAGS: One weakness of Finnish estimation procedure was that itwas not based on a systematic survey and it may have discarded many smallgroups of exposed workers, especially when exposure was infrequent or at a lowlevel. If omission of small groups was suspected, a warning flag (red questionmark in the CAREX application) was attached to all estimates proposed byCAREX for other countries. On the other hand, this estimation procedure isable to pick up some exposures which may have been missed by a sample-basedfield survey. A warning flag was used also to indicate that exposure may occurin other countries although it does not exist in Finland because there is no suchindustry (eg, coal mining, oil drilling) or activity (manufacture of carcinogen X)at all in Finland. The person reponsible for the Finnish data and estimates wasDr Timo Kauppinen (FIOH, Helsinki) who collaborated with many Finnishindustrial hygienists and other experts.


The United States

The National Occupational Exposure Survey (NOES) conducted by the USNational Institute for Occupational Safety and Health (NIOSH) was anationwide observational survey conducted in a sample of 4,490 establishmentsfrom 1981-83. The goal of the NOES was to compile data on the kinds ofexposure agents found in the workplace, and the kinds of safety and healthprograms which had been implemented at the plant level. The sample ofestablishments included in the survey was designed to represent those segmentsof industry covered under the Occupational Safety and Health Act of 1970. Thetarget population was defined as employees working in establishments or jobsites in the US employing eight or more workers in a defined list of StandardIndustrial Classifications. Generally, these classifications emphasized coverageof construction (USSIC1972 classes 15-17), manufacturing (20-39),transportation (40-47), private and business service (72-76), and hospitalindustries (80). The NOES had little or no sampling activity in agriculture,mining, wholesale/retail trade, finance/real estate, or government operations.The NOES sample was designed to maximize the reliability of estimates of thenumber of workers with defined characteristics, and utilized a two-stagesampling strategy which considered industrial activity, facility employmentsize, and geographical location. National estimates of the numbers of workerswere obtained through the use of weighting factors assigned to sampledestablishments, based on the probability of their selection from the nationaluniverse. The inverse of the sampling probability was then used as a weightingfactor for facility-level observations, the results were subjected to ratioestimation to improve estimate precision, and then summed across sampledfacilities nationally and by industry classification for final estimates.

The computerized NOES data file of approximately 10,000 chemical, physical,and biological agents was searched for the CAREX agents. Where thedesignated agent was not a single unique agent (eg, cadmium compounds) theappropriate IARC Monograph was searched for listings of individual agents byCAS number, and these CAS numbers were used to identify agents in theNOES data base for an 'aggregate estimate'. In the case of unique agents, anestimate of the number of US workers potentially exposed to the agent inquestion was produced for the US as a whole, and for all industry classificationsat the 2-, 3-, and 4-digit US Standard Industrial Classification (SIC) levels inthe NOES sample frame. In the case of an aggregate estimate, special computerprocessing allowed the production of estimates of the number of workersestimated to be potentially exposed to one or more of the agents in a nonuniqueor 'aggregated' list, again for the US as a whole, and for those industries at the2-, 3-, and 4-digit SIC levels in the NOES sample frame.

NOES potential exposure data displayed in the CAREX system is limited tothose industries which were sampled and surveyed in the NOES. The NOES didnot provide for a sample in facilities employing less than 8 workers, or foractivity in agriculture, mining, lerge portions of wholesale/retail trade,finance/real estate, or government operations. In order to utilize the NOES datain the CAREX system, it was necessary to convert the US 1987 SIC codes to theISIC Rev2 system common outside the US. To accomplish this, a conversiontable was established and used to convert from one coding system to the other sothat data on the number of workers by industry estimated to be potentiallyexposed to carcinogens could be expressed in US SIC 1987, ISIC Rev2 notation,or ISIC Rev3 code, as desired. NOES data did not include environmental levelmeasurements, with the exception of noise level readings.

MISSING NOES DATA: Because the NOES Survey did not cover all agentsand industries in CAREX, first estimates based on NOES data could not be


generated for uncovered CAREX agents or for uncovered or incompletelycovered industries. If NOES covered a CAREX industry only partially, thenumber of exposed persons in the covered part of that industry was presented inthe database (in Subgroup Exposure fields) but prevalence was not calculatedbecause it was potentially invalid.

CONCEPT OF EXPOSURE: NOES addressed recordable potential exposure.A potential exposure had to meet two criteria to be recorded: (1) A chemical,physical or biological agent or a tradename product had to be observed insufficient proximity to an employee such that one or more physical phases ofthat agent or product were likely to enter or contact the body of the employee,and (2) The duration of the potential exposure had to meet the minimumduration guidelines (at least 30 minutes/week on an annual average, or at leastonce per week for 90% of the weeks of the work year).

The following types of potential exposure were encountered: (1) Observedpotential exposure: any potential exposure to chemical, physical, or biologicalagents observed directly by the surveyor. (2) Inferred potential exposure: Ifthere is an observable dust accumulation or other physical evidence in theworkplace which indicates that an agent is present in the workplace and if thereare persons working in the immediate area of the agent and the minimumduration guidelines were met, or secondly, if the process is not functioning atthe time of the surveyor's observation, the surveyor must, through questioning,identify and record any potential exposures which in his/her judgement, areassociated with the functioning process. For tradename products, the potentialexposure was assigned to all components of the product. Approximately 80% ofthe exposures in NOES are due to the presence of agents in the tradenameformulations, and about 80% of all NOES exposures are part-time in duration.

WARNING FLAGS: Because NOES data addressed potential (including verysmall) exposures, from 1981 to 1983, and did not cover all industries andagents in CAREX, it was considered reasonable to warn the users aboutapplying US prevalence figures too directly to other countries. These flags arereadable under the red question marks in the CAREX application. SelectedFinnish estimates were also flagged with similar warnings. The NOES surveyincluded data about part-time (or occasional) exposures and small groups ofpotentially exposed workers which were often discarded in Finnish estimates(resulting in a warning flag to some Finnish estimates). The NOES estimateswere provided for the CAREX system by Dr David Pedersen and Mr RandyYoung (NIOSH, Cincinnati, OH).

The countries of the European Union

Austria

The Austrian estimates are default (preliminary) estimates generated by theCAREX system and not modified by a national expert. These estimates areadjusted for the economic structure/workforce distribution of Austria, but theydo not take into account country-specific exposure patterns, which may deviatein Austria from those in the reference countries.

Belgium

The Belgian estimates are default (preliminary) estimates generated by theCAREX system. The Belgian contact person in the CAREX network was DrHendrik Veulemans (University of Louvain, Leuven).

Denmark

The Danish estimates were provided by Dr Johnni Hansen (Danish CancerSociety, Copenhagen). The Danish estimates are based on 1) nationawide


surveys on industrial use of carcinogens and potential carcinogens in 1983-85(Hansen 1992) and 1992 (Bjersing et al 1992), 2) a sample-based survey on theuse of organic solvents in 1000 companies in 1984 (Seedorf and Olsen 1990,Olsen, Seedorf and Laursen 1988), 3) a survey in 10% of all companies in thewood and furniture industry in 1988 (Borglum, Damgaard and Nielsen 1989),and 4) a sample-based survey including 1500 companies in 1989 (Brandorf et al1994, Brandorf et al 1995). The default estimates generated by the CAREXsystem were replaced by estimates based on Danish surveys (mainly the surveyin 1989), if available. However, since a Danish classification of industries wasused in the 1989 survey, supporting results from other surveys using the sameclassification as CAREX were used to complement information on the numbersof exposed workers. The figures were usually as rounded to one or two integers.It was also checked if agents not reported to occur in specific industries of thereference countries were actually used in Denmark. If no appropriate estimateswere available from the Danish surveys, the default estimates of the CAREXsystem were used, unless they were considered invalid for Denmark on the basisof subjective judgement. The Danish surveys did not include all CAREX agents,e.g. solar radiation, radon, diesel exhaust, wood dust outside the wood andfurniture industries, and sulphuric acid mists.

France

The French estimates were provided by Mr Raymond Vincent (INRS, Nancy)with the contribution from many of his collegues. Several data sources wereused:

-the SUMER survey (Heran Le Roy and Sandret 1996) conducted in1994 by theFrench ministry of labour,

-the INRS COLCHIC national occupational exposure measurements database ,

-employment and economic statistics issued from the Ministry of trade andindustry or INSEE ( national statistical institute).

The SUMER study was conducted in 1994 by the French Ministry of labour. Itconcerned 48190 workers who were asked by 1205 occupational physiciansabout their working conditions and chemical hazards at their workplaces. Alarge part of chemical substances included in CAREX was assessed during thissurvey. After obtaining these results, estimations were made by industry andcompany size.

The results of the SUMER study were used for industry-specific estimates ofCAREX. They are documented in the CAREX database with the followingremarks:

-'results of the SUMER study' means that SUMER results were directly used inthe estimation resulting in good confidence of estimates

-'assessor's estimate based on results of the SUMER study' means that estimateswere based on results having low confidence, or on results having goodconfidence but requiring some corrections. For example, the SUMER surveyprovided a good estimate for a group of agents (eg, halogenated solvents) butnot for the CAREX substance itself. In this case, estimates were obtained byusing economic statistics or substance-specific production rates.

-'assessor's estimate' means that SUMER results of low confidence were used. Insome situations, this remark means that no data were available from theSUMER study. In these cases, the estimates are based on knowledge of differentINRS experts, or on crude estimates issued from the reference countries. If theestimate had to be based on the prevalence of exposure in the referencecountries, the estimate (Finnish, US or their average) judged to be most validfor France was selected.


The exposure measurements in the COLCHIC database of the INRS indicatedin some situations exposure in certain industries even though there were noestimates available from the SUMER survey. In those cases the estimate isbased on crude professional judgement. Selected exposure measurements fromCOLCHIC database are included in CAREX.

Germany

The German estimates are default (preliminary) estimates generated by theCAREX system. The German contact person in the CAREX network was DrWolfgang Ahrens (Institute of Medical Information, Essen).

Great Britain

The UK estimates are default (preliminary) estimates generated by the CAREXsystem. The British contact person in the CAREX network was Mr BrianPannett (Medical Research Council, Environmental Epidemiology Unit,Southampton).

Greece

The Greek estimates are default (preliminary) estimates generated by theCAREX system. The contact person for Greece in the CAREX network was DrManolis Kogevinas (IMIM, Barcelona, Spain).

Ireland

The Irish estimates are default (preliminary) estimates generated by theCAREX system.

Italy

The Italian estimates were first generated by the CAREX system and thenmodified by a national expert (Dr Dario Mirabelli, Agenzia per la ProtezioneAmbientale del Piemonte, Grucliasco). They take into account exposurepatterns in Italy to the extent the expert was able to identify them. In theabsence of a general reporting system on occupational exposure to carcinogensin Italy, and due to lack of countrywide as well as regional surveys, the assessorbased his judgements either on the evaluations received from a group of Italianindustrial hygienists who revised the occupational exposure patterns of theCAREX agents during the development of an industrial activity/exposurematrix within the framework of the PRiOR programme (an occupationalhazards surveillance programme in 1996-97 in Piedmont region), or on his ownexperiance in the surveillance of occupational exposures as a member of anOccupational Health and Safety Unit in an industrialised area close to Turin.

Luxembourg

The Luxembourgian estimates are default (preliminary) estimates generated bythe CAREX system.

The Netherlands

The Dutch estimates were first generated by the CAREX system and thenchecked by a national expert (Dr Hans Kronhout, Wageningen AgriculturalUniversity, Wageningen). They take into account exposure patterns in theNetherlands to the extent the expert was able to identify them. As a data sourcethe WAUNC database with approximately 20,000 chemical exposuremeasurements was used. Input from collegues was used to some extent.Unpublished data from the Ministry of Social Affairs and Employment on theoccurrence of exposure to carcinogens by industry and process was also takeninto account.

Portugal


The Portugese estimates are default (preliminary) estimates generated by theCAREX system.

Spain

The Spanish estimates are default (preliminary) estimates generated by theCAREX system. The Spanish contact persons in the CAREX network were DrJeronimo Maqueda Blasco and Dr Victoria de la Orden-Rivera (InstitutoNacional de Seguridad e Higiene en el Trabajo, Madrid).

Sweden

The Swedish estimates are default (preliminary) estimates generated by theCAREX system and not checked by a national expert.

Alternative estimates were produced on the basis of the Swedish national reporton exposure to carcinogens (Plato, Nise, Lundberg 1995). Because thedefinitions and estimation procedures were different from the CAREX system,the alternative Swedish estimates are reported separately. The Swedish contactperson in the CAREX network was Dr Nils Plato (Karolinska Institute,Stockholm).

The alternative Swedish figures were estimated on the basis of occupationallabour force figures, whereas CAREX used industrial labour force as thestarting point. The differences of these procedures are illustrated in thefollowing example on exposure to chromium (VI) in welding of stainless steel:

Total number of welders in Sweden was 27 145 males and 1 003 females. TheSwedish welding association estimated that 7% of welders work regularly withstainless steel which equals with 1 970 welders exposed to chromium VI. Whenindustry code 381 (metal products) is linked with occupational code 756.12(welders), there would be 9 356 welders in that industry and 655 weldersexposed to chromium VI. The comparative CAREX estimates extrapolated toSweden are 7 397 welders exposed to chromium VI, out of which 2 751 areemployed in the metal product industry. The Swedish alternative figures areonly 27% and 24% of the respective CAREX estimates. One important reasonfor the discrepancy is that CAREX estimates 20% of welders as regularly ortemporarily exposed, and that also an equivalent number bystanders areconsidered exposed.

Carex report of EU Results •• 20

Results

The detailed main results are presented in appendices of this report. The resultsfor the EU are presented first, followed by figures for the individual EUcountries in alphabetical order.

The European Union

According to the results (Appendix 1), there were about 32 million workers(23 % of the employed) in the 15 countries of the EU exposed to the agentscovered by CAREX in 1990-93. These workers had altogether about 42 millionexposures (1.3 exposures/exposed worker on average). These figures arerounded from calculatory estimates presented in Appendix 1. Because ofuncertainty of the estimates, it is reasonable to round all figures in the followingappendices to a precision of one or two integers only.

The numbers of exposed workers by country (Appendix 2) were: Austria800 000, Belgium 700 000, Denmark 700 000, Finland 500 000, France 4.9million, Germany 8.2 million, Great Britain 5.0 million, Greece 900 000,Ireland 300 000, Italy 4.2 million, Luxembourg 50 000, the Netherlands 1.1million, Portugal 1.0 million, Spain 3.1 million, and Sweden 800 000.

The total numbers of exposed workers by agent are presented in Appendix 3.The most common exposures in the EU countries (Appendix 4) were solarradiation (9.1 million workers exposed at least 75% of working time),environmental tobacco smoke (7.5 million workers exposed at least 75% ofworking time), crystalline silica (3.2 million exposed), diesel exhaust (3.1million), radon (2.7 million), wood dust (2.6 million), lead and inorganic leadcompounds (1.5 million), and benzene (1.4 million).

Austria

According to the preliminary estimates, there were ca. 800 000 workers (25% ofthe employed) exposed to the agents covered by CAREX (Appendix 5). Themost common exposures (Appendices 6-7) were solar radiation (240 000workers exposed at least 75% of working time), environmental tobacco smoke(180 000 workers exposed at least 75% of working time), crystalline silica(100 000 exposed), wood dust (80 000), diesel engine exhaust (80 000), radonand its decay products (70 000), benzene (50 000), ethylene dibromide (50 000),lead and inorganic lead compounds (40 000) and glasswool (20 000).


Belgium

According to the preliminary estimates, there were ca. 700 000 workers (21% ofthe employed) exposed to the agents covered by CAREX (Appendix 8). Themost common exposures (Appendices 9-10) were solar radiation (200 000workers exposed at least 75% of working time), environmental tobacco smoke(190 000 workers exposed at least 75% of working time), radon and its decayproducts (90 000), crystalline silica (70 000 exposed), diesel engine exhaust(70 000), wood dust (55 000), lead and inorganic lead compounds (30 000),benzene (20 000), chromium VI compounds (19 000), and glasswool (19 000).

Denmark

According to the results, there were ca. 700 000 workers (24% of the employed)exposed to the agents covered by CAREX (Appendix 11). The most commonexposures (Appendices 12-13) were solar radiation (180 000 workers exposedat least 75% of working time), environmental tobacco smoke (100 000 workersexposed at least 75% of working time), formaldehyde (90 000 exposed), dieselengine exhaust (70 000), crystalline silica (60 000), wood dust (50 000),benzene (50 000), styrene (36 000), ethylene dibromide (26 000), andchromium VI compounds (25 000).

Finland

The Finnish estimates are adjusted for the economic structure/workforcedistribution of Finland, and they take also into account country-specificexposure patterns to the extent the experts were able to identify them.According to the estimates, there were in 1990-93 ca. 500 000 workers (24 % ofthe employed) exposed to the agents covered by CAREX (Appendix 14). Themost common exposures (Appendices 15-16) were solar radiation (180 000workers exposed at least 75% of working time), environmental tobacco smoke(110 000 workers exposed at least 75% of working time), crystalline silica(80 000 exposed), wood dust (65 000), radon (50 000), diesel engine exhaust(40 000), benzene (14 000), lead and inorganic lead compounds (13 000),ethylene dibromide (12 000), and glasswool (12 000).

France

There were ca. 5 million workers (23 % of the employed) exposed to the agentscovered by CAREX (Appendix 17). The most common exposures(Appendices 18-19) were solar radiation (1.5 million workers exposed at least75% of working time), environmental tobacco smoke (1.2 million workersexposed at least 75% of working time), radon (500 000), diesel exhaust(400 000), sulphuric acid mist (400 000), formaldehyde (300 000), wood dust(180 000), tetrachloroethylene (140 000), asbestos (140 000), and lead andinorganic lead compounds (140 000).

Germany

According to the preliminary estimates, there were ca. 8 million workers (24%of the employed) exposed to the agents covered by CAREX (Appendix 20). Themost common exposures (Appendices 21-22) were solar radiation (2.4 millionworkers exposed at least 75% of working time), environmental tobacco smoke(2.0 million workers exposed at least 75% of working time), crystalline silica(1.0 million exposed), radon and its decay products (800 000), diesel engineexhaust (740 000), wood dust (670 000), benzene (470 000), lead and inorganic


lead compounds (460 000), ethylene dibromide (450 000), chromium VIcompounds (250 000), and glasswool (240 000).

Great Britain

According to the preliminary estimates, there were ca. 5 million workers (22%of the employed) exposed to the agents covered by CAREX (Appendix 23). Themost common exposures (Appendices 24-25) were environmental tobaccosmoke (1.3 million workers exposed at least 75% of working time), solarradiation (1.3 million workers exposed at least 75% of working time),crystalline silica (600 000), radon and its decay products (600 000), dieselengine exhaust (470 000), wood dust (430 000), benzene (300 000), ethylenedibromide (280 000), lead and inorganic lead compounds (250 000), glasswool(140 000), and chromium VI compounds (130 000).

Greece

According to the preliminary estimates, there were ca. 900 000 workers (27% ofthe employed) exposed to the agents covered by CAREX (Appendix 26). Themost common exposures (Appendices 27-28) were solar radiation (460 000workers exposed at least 75% of working time), environmental tobacco smoke(170 000 workers exposed at least 75% of working time), crystalline silica(90 000), diesel engine exhaust (80 000), radon and its decay products (70 000),wood dust (50 000), benzene (35 000), ethylene dibromide (33 000), lead andinorganic lead compounds (24 000), glasswool (17 000), and asbestos (15 000).

Ireland

According to the preliminary estimates, there were ca. 260 000 workers (24% ofthe employed) exposed to the agents covered by CAREX (Appendix 29). Themost common exposures (Appendices 30-31) were solar radiation (110 000workers exposed at least 75% of working time), environmental tobacco smoke(58 000 workers exposed at least 75% of working time), crystalline silica(29 000), radon and its decay products (24 000), diesel engine exhaust (21 000),wood dust (18 000), benzene (11 000), ethylene dibromide (10 000), lead andinorganic lead compounds (9 000), glasswool (6 000), and asbestos (6 000).

Italy

There were ca. 4.2 million workers (25 % of the employed) exposed to theagents covered by CAREX (Appendix 32). The most common exposures(Appendices 33-34) were environmental tobacco smoke (800 000 workersexposed at least 75% of working time), solar radiation (600 000 workersexposed at least 75% of working time), asbestos (700 000), diesel engineexhaust (600 000), PAHs (400 000), crystalline silica (300 000 exposed), wooddust (300 000), lead and inorganic lead compounds (300 000), benzene(200 000), formaldehyde (170 000) and tetrachloroethylene (180 000).

Luxembourg

According to the preliminary estimates, there were ca. 50 000 workers (25% ofthe employed) exposed to the agents covered by CAREX (Appendix 35). Themost common exposures (Appendices 36-37) were solar radiation (14 000workers exposed at least 75% of working time), environmental tobacco smoke(11 000 workers exposed at least 75% of working time), crystalline silica


(7 000), diesel engine exhaust (4 000), radon and its decay products (4 000),wood dust (4 000), lead and inorganic lead compounds (2 600), benzene(2 000), PAHs (1 700) and ethylene dibromide (1 700).

The Netherlands

According to the results corrected by a national expert, there were ca. 1.1million workers (17% of the employed) exposed to the agents covered byCAREX (Appendix 38). The most common exposures (Appendices 39-40)were environmental tobacco smoke (350 000 workers exposed at least 75% ofworking time), solar radiation (290 000 workers exposed at least 75% ofworking time), crystalline silica (170 000), diesel engine exhaust (110 000),wood dust (95 000), lead and inorganic lead compounds (48 000), benzene(43 000), glasswool (34 000), and chromium VI compounds (29 000).

Portugal

According to the preliminary estimates, there were ca. one million workers(24% of the employed) exposed to the IARC agents covered by CAREX(Appendix 41). The most common exposures (Appendices 42-43) were solarradiation (370 000 workers exposed at least 75% of working time),environmental tobacco smoke (210 000 workers exposed at least 75% ofworking time), radon and its decay products (92 000), wood dust (85 000),crystalline silica (83 000), diesel engine exhaust (73 000), benzene (43 000),ethylene dibromide (40 000), formaldehyde (36 000), lead and inorganic leadcompounds (33 000), PAHs (21 000) and tetrachloroethylene (21 000).

Spain

According to the preliminary estimates, there were ca. 3.1 million workers(25% of the employed) exposed to the IARC agents covered by CAREX(Appendix 44). The most common exposures (Appendices 45-46) were solarradiation (1 100 000 workers exposed at least 75% of working time),environmental tobacco smoke (700 000 workers exposed at least 75% ofworking time), crystalline silica (400 000 exposed), wood dust (400 000), radonand its decay products (280 000), diesel engine exhaust (270 000), lead andinorganic lead compounds (100 000), glasswool (90 000), benzene (90 000),and ethylene dibromide (80 000).

Sweden

According to the preliminary estimates, there were ca. 800 000 workers (20% ofthe employed) exposed to the IARC agents covered by CAREX (Appendix 47).The most common exposures (Appendices 48-49) were solar radiation (240 000workers exposed at least 75% of working time), environmental tobacco smoke(210 000 workers exposed at least 75% of working time), radon and its decayproducts (100 000), crystalline silica (86 000), wood dust (84 000), dieselengine exhaust (81 000), lead and inorganic lead compounds (35 000), benzene(34 000), ethylene dibromide (31 000), chromium VI compounds (21 000),glasswool (20 000) and PAHs (18 000).

The alternative estimates produced on the basis of the Swedish national reporton exposure to carcinogens (Plato, Nise, Lundberg 1995) are presented inAppendix 50.

Carex report of EU Discussion •• 24

Discussion

The numbers of workers exposed to known or suspected carcinogens generatedby the CAREX system and the network of national experts are the firstestimates published for the EU and most of the member countries. In thatrespect this new approach turned out to be feasible and successful. The resultssuggest that the number of workers exposed to carcinogenic substances andfactors was very large in 1990-93, and amounted to about 32 million workers,or about 23% of the total number of workers employed in the EU. The absolutefigures varied strongly by country and the proportion of exposed workers variedbetween 17% and 27%, as estimated by the CAREX procedure. Substantial partof all exposures originated from natural sources (ultraviolet radiation from thesun, radon from the ground) or from activities not related to work as such(environmental tobacco smoke at work). The contribution of theseenvironmental factors was 19-20 million exposures out of 42 million exposures.

The strengths of the CAREX system are its systematic nature, good coverageand ease of use. CAREX applies basically the same definitions and proceduresto each country, which improves comparability and consistency of the resultsacross countries. It covers all industries in an international classification ofindustries and is able to provide national figures in addition to industry-specificestimates. Major known and suspected carcinogens occurring at work, asevaluated by IARC, are included. CAREX is easy to use in personal computers.It allows the addition of new countries, provided that reasonably accurate labourforce statistics are available. CAREX automatically calculates preliminaryestimates for a new country and produces a rather wide variety of standardreports.

Validity of the estimates was extensively discussed during the planning andconstruction of CAREX, and several solutions to improve validity and facilitatethe estimation process were adopted. First, all estimates were standardised bythe labour force structure of the country. For manufacturing industries whereexposure depends strongly on the type of industry, standardisation took place atthe 3-digit level of the classification. Second, uniform definitions of agents andof occupational exposure, with inclusions and exclusions, were used to improveconsistency. Third, preliminary estimates were in many countries checked andmodified by national experts familiar with the exposure situation in their owncountry. Fourth, exposures in the reference countries were made at'subindustrial' level where different subgroups of exposed workers could bedefined, assessed and described. The same procedure was possible for eachcountry assessed. Fifth, industrial hygiene data, description of industries andproportions of 'white-collar' and 'blue-collar' workers by industry were includedto support estimation. The premises of the estimates were documented tofacilitate their modification and quality assessment. Sixth, estimates of lowconfidence could be earmarked to identify them. Seventh, estimates entailinglow level of exposure were earmarked to allow their inclusion or exclusion since


low exposures may have a strong effect on the estimated numbers of exposed.Eight, 'warning flags' were build into CAREX to avoid the use of possiblyinvalid prevalence figures from the reference countries. The prevalence figuresused by the CAREX system in the generation of preliminary estimates for othercountries were selected to be the most valid ones on the basis of informationfrom the reference countries. In spite of these precautions and aids included inthe CAREX system, there are many validity issues which are of concern andrequire further discussion.

The inspection of data from the reference countries revealed several differencesbetween exposure estimates from Finnish and US sources. These differencesinclude: (1) National industrial processes and related use patterns forcarcinogens (2) national survey protocols (3) time frame, and (4) nationalindustrial coding systems and conversion difficulties. These points are discussedseparately below since they concern not only Finnish and US figures but alsohave consequences for estimates of other countries.

(1) Country-specific exposure patterns

Omission of country-specific exposure patterns may bias results seriously. Oneexample is exposure to radon. Exposure to radon from the ground in Finland ishigher than in most other EU countries. The ground emits significantly lessradon, e.g., in Denmark and The Netherlands, and therefore regular indoorworkers are hardly ever exposed to levels exceeding the Finnish averagebackground level in dwellings. If Finnish prevalence values are used for othercountries, the result may be an overestimate. Similar bias may concerncrystalline silica, because Finnish stone and construction materials containfrequently silica from granite. A further example would be solar radiation.Direct use of Finnish prevalence figures (prevalence of regular outdoor workers)is likely to result in underestimation for countries in Southern Europe becausethere also many part-time outdoor workers will be exposed to similar doses dueto more intense solar radiation. The industrial substructure may also differsignificantly by country depending on the type of products or processes used.This concerns exposures especially in the chemical industry.

Different legislation may lead to large variations between countries. Forexample, the use of asbestos in 1990-93 was legally prohibited or restricted inmany countries, but not in all. The same applies to passive smoking at work.Sometimes the use pattern is regulated strongly by price policy. For example,exposure to ethylene dibromide (scavenger agent in leaded gasoline) decreaseddrastically in Finland in 1990-93 when unleaded gasoline substituted for moreexpensive leaded gasoline.

Because the average prevalence of the USA and Finland (when not identified tobe unreliable) was preferred in the CAREX procedure, the preliminaryestimates inherently assume that the exposure pattern of the country is typicallybetween that of a big country (such as the USA) and that of a smaller country(such as Finland). This assumption may be rather valid for big Europeancountries (such as the UK, France, Germany, Italy and Spain) where a widerange of processes and exposures occur. However, the CAREX procedureprobably provides many rare exposures which do not occur in small countrieswith less varying economic structure (such as Luxembourg).

(2) Definition of occupational exposure

It is notable that the concept of exposure used in the reference countries differ.The Finnish protocol required in most cases that the nonoccupational exposuremeasured as annual dose had to be exceeded whereas the US protocol addressedpotential exposure. The Finnish approach sets the minimum limit generallyhigher than the US approach and results in lower estimates of exposed workers.The CAREX system compromises between these two concepts and usually


applies the average of the US and Finnish prevalences to calculate preliminaryestimates for other countries. This means that the concept of exposure inCAREX becomes unclear and is between potential exposure (as in the USA)and exposure exceeding nonoccupational background (as in Finland). Inpractise CAREX thus partially addresses exposures which are lower than thebackground. The national experts face the same problem while making theirown estimates or choosing among estimates based on US, Finnish or theiraverage figures.

(3) Estimation procedures

Another significant difference is that the US data is based on an observationalfield survey and the Finnish data on professional judgement. Both methods havetheir advantages and disadvantages. A field survey is sensitive in identifyingtypical and untypical exposures whereas professional judgement may neglectsmall exposed groups and atypical exposures. However, sometimes professionaljudgement may identify exposures which are missed in a comprehensive fieldsurvey. For example, the NOES sample did not include any nickel refineriesand did not therefore identify nickel exposure in ISIC 372 (manufacture of othermetals). The Finnish professional judgement identified nickel refineries andprovided a more reliable estimate in this case. The US procedure providedempirical values for many rare agents but was unable to address all CAREXagents. Professional judgement in Finland was extented to cover all CAREXagents. The NOES procedure was based on direct observations and inferences atwork places. The effect of subjective opinions on the results was probably rathersmall. However, inclusion or exclusion of very low or infrequent exposures maydepend on the observer. The Finnish procedure based more on experience of theexperts on occurrence and level of exposure in different industries, althoughindustrial hygiene data and labour force data were also used to the extentpossible.

Another kind of procedural difference arose when the CAREX estimates werecompared with alternative estimates from a Swedish national report. Thealternative estimates differed significantly from those generated by the CAREXsystem. Major source of difference was the definition of agent-specific exposure,and the estimation of low levels of exposure. Generally, the alternative exposureprevalences were lower than those in the CAREX. For example, CAREX wasable to take crudely into account exposures of bystanders employed inworkshops where stainless steel was welded. This is an appropriate and feasibleapproach when one bases the calculations on industry codes (as in CAREX) butvery difficult when assessment is carried out by occupations (as in the Swedishmethod). Therefore bystander exposures were neglected in the estimation ofalternative Swedish figures.

(4) Time frame

The reference data from the United States comes from 1981-83. Exposurepatterns may have changed after that in the United States and elsewhere. Forexample, the production or use of some agents may have been forbidden orstrongly restricted since then. Although CAREX does not use clearly outdatedUS figures as default values, there probably are a number of them which couldnot be identified as outdated during the CAREX project. Therefore some of theresulting CAREX estimates may be biased by the US situation in the early1980s when occupational exposure to carcinogens may have been more frequentthan in 1990-93. The Finnish estimates are for the same period (1990-93) asthose of other EU countries.

(5) National industrial coding systems and conversion difficulties

Conversions between different industrial coding systems were used in theprocessing of labour force statistics and US (NOES) exposure data. Major part


of labour force statistics came from OECD directly in the UN ISIC Revision 2coding system. However, the OECD data are not coded originally according toUN ISIC but according to national classifications which are then converted toUN ISIC. Conversions, different definitions of the employed populationsincluded, and estimations of missing values caused some inaccuracy andincomparability to the labour force statistics used in CAREX. Also the USworkforce figures and exposure data were converted from US SIC 1987 throughUN ISIC Rev 3 to UN ISIC Rev 2. The concersion was carried out at maximallevel of specificity to minimise conversion errors. In spite of conversionproblems, the order of magnitude of the labour force figures is probably correctand not a major source of error.

(6) Estimation of multiple exposures

The CAREX system applied Finnish values to other EU countries in theestimation of the degree of multiple exposure. This resulted sometimes inestimates of exposed workers which exceeded the total labour force of theindustrial class. In those cases applying the Finnish figure based on Finnishmultiple exposure patterns was clearly inappropriate. National modifications ofmultiple exposure multipliers are therefore necessary, especially if the exposurepattern within the industrial class is likely to differ significantly from theFinnish one.

The validity of the CAREX results is so far unknown. Validity testing wouldrequire well-defined and comprehensive field surveys and mesurements becausevalidity may vary quite a lot by agent, industry, and country. Such surveyswould be very labourious and expensive. However, we believe that the CAREXprocedure, especially when supplemented by assessment of national experts, hasproduced interesting estimates of at least moderate confidence. All estimates donot yet take accurately into account specific features of national exposurepatterns. Continuation of the estimation work by the CAREX network ofexperts would probably increase the validity of national estimates as the basicinformation needed to create and implement effective policies intended tocontrol and eliminate occupational cancer in Europe.

Carex report of EU References •• 28

References

Anttila A, Jaakkola J, Tossavainen A, Vainio H. Occupational exposure tochemical agents in Finland (In Finnish), Altisteet työssä 34, Työterveyslaitos jatyösuojelurahasto, Helsinki1992

Bjersing M, Hansen J, Schöller C, ThomsenP. Kraeftfremkaldende stoffer IDanmark. Forekomst, anvendelse og regulering af 240 stoffer, 1989.Kobenhavn: Arbejdsmiljoinsituttet 1992.

Borglum B, Damgaard K, Nielsen S. Trae- og mobelindustrien.Tvaersnitsundersogelse - Kemiske stoffer og materialer. Kobenhavn: At-rapport1989:1-31.

Brandorf NP, Flyvholm MA, Beck ID, Skov T, Bach E. National survey on theuse of chemicals in the working environment: estimated exposure events. OccupEnviron Med 1995;52:454-63.

Brandorf NP, Beck ID, Skov T, Flyvholm MA. Kemikalieforbruk ogeksponering I danske virksomhedet 1989. Kemikalieforbruksundersogelsen.Kobenhavn: Arbejdsmiljoinstituttet 1994.

Greife A, Young R, Carroll M, Sieber W, Pedersen D, Sundin D, Seta J.National Institute for Occupational Safety and Health general industryoccupational exposure databases: their structure, capabilities, and limitations.Appl Occup Environ Hyg 1995;10:264-9.

Hansen J. Industriel anvendelse af utvalgde kemiske stoffer og risiko for kraeft,1979-84. Delrapport II. Udarbejdelse af en eksponeringsmatrice. Kobenhavn:Arbejdsmiljoinstituttet 1992:1-116.

Heran Le Roy O, Sandret N. Enquête nationale SUMER 94, premiers résultats(National survey SUMER 94, preliminary results). Ministère du Travail et desAffaires Sociales, Paris 1996

Kauppinen T, Savela A, Vuorela R. ASA 1990 - employees exposed tocarcinogens in Finland in 1990, reviews 18, Finnish Institute of OccupationalHealth, Helsinki 1992

Kauppinen T, Toikkanen J, Pukkala E. From cross-tabulations to multipurposeexposure information systems: a new job-exposure matrix. Am J Ind Med , inpress

Olsen E, Seedorf L, Laursen B. Organiske oplosningsmidler-kartlaegning afanvendelsen og forekomsten af dampe. Kobenhavn: Arbejdstilsynet 1988:1-101.

Seedorf L, Olsen E. Exposure to organic solvents I. A survey on the use ofsolvents. Ann Occup Hyg 1990;34: 371-8.

Carex report of EU References •• 29

Seta J, Sundin D, Pedersen D. National Occupational Exposure Survey. VolumeI. Survey manual. U.S. Department of Health and Human Services, NationalInstitute for Occupational Safety and Health, Cincinnati 1988.

Sieber W. National Occupational Exposure Survey. Volume II. Samplingmethodology. U.S. Department of Health and Human Services, NationalInstitute for Occupational Safety and Health, Cincinnati 1990.

Carex report of EU Appendices •• 30

Appendices

1. Employment, exposed workers and exposures in the EU in 1990-1993

2. Exposed workers by country in the EU in 1990-93

3. Exposed workers (exposures) by agent in the EU in 1990-93

4. Most common exposures to IARC agents in the EU in 1990-1993

5. Employment, exposed workers and exposures in Austria in 1990-1993

6. Exposed workers (exposures) by agent in Austria in 1990-93

7. Most common exposures to IARC agents in Austria in 1990-1993

8. Employment, exposed workers and exposures in Belgium in 1990-1993

9. Exposed workers (exposures) by agent in Belgium in 1990-93

10. Most common exposures to IARC agents in Belgium in 1990-1993

11. Employment, exposed workers and exposures in Denmark in 1990-1993

12. Exposed workers (exposures) by agent in Denmark in 1990-93

13. Most common exposures to IARC agents in Denmark in 1990-1993

14. Employment, exposed workers and exposures in Finland in 1990-1993

15. Exposed workers (exposures) by agent in Finland in 1990-93

16. Most common exposures to IARC agents in Finland in 1990-1993

17. Employment, exposed workers and exposures in France in 1990-1993

18. Exposed workers (exposures) by agent in France in 1990-93

19. Most common exposures to IARC agents in France in 1990-1993

20. Employment, exposed workers and exposures in Germany in 1990-1993

21. Exposed workers (exposures) by agent in Germany in 1990-93

22. Most common exposures to IARC agents in Germany in 1990-1993

23. Employment, exposed workers and exposures in Great Britain in 1990-1993

24. Exposed workers (exposures) by agent in Great Britain in 1990-93

25. Most common exposures to IARC agents in Great Britain in 1990-1993

26. Employment, exposed workers and exposures in Greece in 1990-1993

27. Exposed workers (exposures) by agent in Greece in 1990-93

28. Most common exposures to IARC agents in Greece in 1990-1993

29. Employment, exposed workers and exposures in Ireland in 1990-1993

30. Exposed workers (exposures) by agent in Ireland in 1990-93

31. Most common exposures to IARC agents in Ireland in 1990-1993

32. Employment, exposed workers and exposures in Italy in 1990-1993

Carex report of EU Appendices •• 31

33. Exposed workers (exposures) by agent in Italy in 1990-93

34. Most common exposures to IARC agents in Italy in 1990-1993

35. Employment, exposed workers and exposures in Luxembourg in 1990-1993

36. Exposed workers (exposures) by agent in Luxembourg in 1990-93

37. Most common exposures to IARC agents in Luxembourg in 1990-1993

38. Employment, exposed workers and exposures in the Netherlands in 1990-93

39. Exposed workers (exposures) by agent in the Netherlands in 1990-93

40. Most common exposures to IARC agents in the Netherlands in 1990-93

41. Employment, exposed workers and exposures in Portugal in 1990-1993

42. Exposed workers (exposures) by agent in Portugal in 1990-93

43. Most common exposures to IARC agents in Portugal in 1990-1993

44. Employment, exposed workers and exposures in Spain in 1990-1993

45. Exposed workers (exposures) by agent in Spain in 1990-93

46. Most common exposures to IARC agents in Spain in 1990-1993

47. Employment, exposed workers and exposures in Sweden in 1990-1993

48. Exposed workers (exposures) by agent in Sweden in 1990-93

49. Most common exposures to IARC agents in Sweden in 1990-1993

50. Alternative Swedish estimates

51. List of participants

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