Exposure to Lead in Firing RangesAlf Fischbein, MD; Carol Rice, MS; Laszlo Sarkozi, PhD;

Steven H. Kon, PhD; Michael Petrocci; Irving J. Selikoff, MD

\s=b\Members of law enforcement agencies were examined for adversehealth effects caused by their activities in firing ranges and exposure to lead.Central nervous system and gastrointestinal symptoms were prominent andcorrelated with blood lead and zinc protoporphyrin levels. Half the group hadblood lead levels exceeding 40 \g=m\g/dL,and four (5%) exceeded 60 \g=m\g/dL.Environmental surveys of three firing ranges indicate that indoor facilitieswith insufficient ventilation may have considerable air lead concentrationswith levels up to 900 \g=m\g/cum or 4.5 times the current Occupational Safetyand Health Administration standard for an eight-hour shift. Evaluation of leadeffects should be taken into account in medical surveillance programs offirearms instructors. Zinc protoporphyrin determination has proved a suit-able and practical way to assess biological effects among exposed personsand should be available at medical facilities responsible for the health ofindoor firing range employees.(JAMA 241:1141-1144, 1979)

LAW enforcement agencies requiretheir personnel to be proficient andaccurate in the use of handguns, andregular training programs have re¬sulted in the increased use of indoorfiring ranges. Shooting as a recrea¬

tional activity has also contributed tothis increase. For the adequate pro¬tection of trainees, instructors, andattendants, proper ventilation is es¬sential to minimize exposure to dustand the gaseous and suspended com¬bustion products of ammunition.Compounds generated include nitro¬gen, hydrogen, carbon dioxide, nitro¬gen oxide, and complex organic com¬

pounds of nitrogen. These productsgenerate the characteristic odor ofgunpowder smoke and may produceirritation of the eyes and upper respi¬ratory tract passages. Guns also

produce lead oxide fumes by thecombustion of lead in priming com¬

pounds, by friction of the bulletsagainst the gun barrel, and by frag¬mentation of lead-containing bulletsstriking the target or backstop.Recent investigations in a number

of firing ranges have demonstratedadverse lead effects among firearminstructors,1,2 and other cases of leadpoisoning with similar exposure havebeen reported.35 The spectrum oflead-associated changes includes ef¬fects on heme synthesis,6'7 central andperipheral nervous systems,8 andfetal development.' Attention hasbeen focused on long-term low-levellead exposure, which by itself isinsufficient to cause recognizableclinical poisoning but has the poten¬tial for deleterious health effects.10New techniques have been designed toassess such abnormalities11 and topermit early detection and preventionof lead disease.We report some medical and bio¬

chemical effects of lead exposureamong firearms instructors of lawenforcement agencies in the NewYork metropolitan area and the

results of industrial hygiene surveysof three indoor firing ranges.

METHODS OF INVESTIGATIONEighty-one employees of law enforce¬

ment agencies in the New York metropoli¬tan area underwent clinical field examina¬tions. A medical history, occupationalhistory, and review of symptoms poten¬tially related to lead toxicity were taken.The review included CNS symptoms (head-

•ache, dizziness, fatigue, sleep disturbances,and irritability), gastrointestinal (GI)symptoms (anorexia, nausea, weight loss,and abdominal pain), and musculoskeletalsymptoms (muscle and joint pain andmuscle weakness). A careful occupationalhistory provided an estimate of totalrounds fired per month, enabling us toclassify the firearms instructors as pri¬marily indoor or outdoor. Twenty-threepersons were examined on two separateoccasions, giving us the opportunity toevaluate the effect of indoor trainingduring the winter season.Blood lead determinations were per¬

formed by atomic absorption spectropho-tometry. The effect of lead on the hemato-poietic system was investigated by zincprotoporphyrin (ZPP) determinations; thiswas done with a hematofluorometer.Personal and air samples were collected on0.8-/i pore size cellulose ester membranefilters, using standard, commerciallyavailable, battery-operated pumps cali¬brated to 2 L/min. Samples were digestedwith concentrated nitric acid and analyzedby atomic absorption spectrophotometry.Lead concentrations in air were deter¬mined before firing (background) andduring firing both at the firing booths andat the instructor stations.

POPULATIONThe persons examined were divided into

three different occupational categories: 43instructors, full-time firearm instructorsof the police force personnel; 23 policeofficers, with some instruction activitiesbut to lesser degrees than instructors; and15 members of law enforcement agencieswith only sporadic episodes of shooting

From the Environmental Sciences Laboratory,Department of Community Medicine (Drs Fisch-bein and Selikoff, Ms Rice, and Mr Petrocci) andthe Department of Chemistry (Drs Sarkozi andKon), Mount Sinai School of Medicine of the CityUniversity of New York, New York.Reprint requests to Environmental Sciences

Laboratory, Mount Sinai Medical Center, 1Gustave L. Levy PI, New York, NY 10029 (DrFischbein).

activities. The mean age was 40.3+8.4years. Duration of employment is summa¬rized as follows: 31 men (38%) hadbetween one and five years, 23 (28% ) hadfive to ten years, and 12 (15%) had morethan 15 years. The mean duration ofemployment was 6.6+5.9 years.

RESULTSClinical Symptoms

Central nervous system symptoms,eg, headache, dizziness, fatigue, weak¬ness, nervousness, hyperirritability,and sleep disturbances (sleeplessnessor somnolence), were explored. Suchsymptoms were reported by 21 (26%)of the examined persons, and whenpresent, they were oftenmultiple. Theassociation between CNS symptomsand duration of employment indi¬cated that the proportion of sympto¬matic persons increases with dura¬tion of employment; however, CNSsymptoms were also reported withappreciable frequency (22%) by per¬sons with shorter periods of employ¬ment (one to five years) (Table 1). Theprevalence of CNS symptoms alsoincreased with elevated blood leadlevels, as shown in Table 2. This trendwas noticeable at both examinationsand particularly when the blood leadlevel exceeded 50 pg/dL; three of fourpersons with levels exceeding 50pg/dh reported CNS complaints. Cen¬tral nervous system symptoms like¬wise showed a sharp increase withelevated ZPP levels, especially at thesecond examination (Table 2). Of 56persons with ZPP levels of less than80 Mg/dL, only four (7%) reportedCNS symptoms, while five (62%) ofthose with ZPP levels exceeding 80pg/dL were symptomatic.Gastrointestinal symptoms were

also prominent, ranging from loss ofappetite and weight loss to abdominaldiscomfort and pain. Such symptoms,reported by 13 persons (16%), alsotended to increase with longer dura¬tion of employment: five (28%) ofthose with more than ten years of

Table 1.—CNS Symptoms andDuration of Employment

CNS SymptomsDuration, Total Present,yr_No. (%)_No.(%)<1 9(11.1) Ô1Ô11-4.9 31 (38.3) 7(22.5)

5.0-9.9 23(28.4) 5(21.7)10.0-14.9 6(7.4) 3(50.0)>15 12(14.8) 6(50.0)Total 81(100) 21

_

Table 2.—CNS Symptoms and Distribution of BloodLead and ZPP in Firearms Instructors*

Level, fig'dLTotal Examined,

No.(%)CNS Symptoms Present,

No.(%)Blood leadExamination 1<40 34(85.0) 10(29.4)40-49 2(5.0) 1 (50.0)>50 4(10.0) 3(75.0)

Examination 2<40 31 (48.4) 3(9.7)40-49 21(32.8) 3(14.3)>50 12(18.8) 7(58.3)

ZPPExamination 1<80 36(90.0) 12(33.3)>80 4(10.0) 2(50.0)

Examination 2

<80_>80

56(87.5)8(12.5)

4(7.1)5(62.5)

"Abbreviation ZPP indicates zinc protoporphyrin.

employment compared with eight(13% ) of those with shorter duration.Gastrointestinal symptoms were alsocommonly reported by persons withelevated blood lead levels. Even morestriking was the prevalence of GIsymptoms with increased ZPP levels;only four (6%) of the persons withZPP levels less than 80 pg/dL had a

history of GI complaints, while allthree persons with ZPP levels exceed¬ing 160 pg/dL were symptomatic.None gave a history of typical leadcolic.There were six instructors who

reported both CNS and GI symptoms.All but one were full-time instructorsassigned to indoor ranges. These fiveall had elevated blood lead and ZPPlevels, with median values of 63.5 and153.5 pg/dL, respectively. They alsohad a rather long duration of employ¬ment, with a median of 13.5 years.Further analysis of the association

of reported CNS and GI symptomswith blood lead and ZPP levels indi¬cates differences in mean blood levelsbetween those who gave a history ofsuch symptoms and those who didnot. These differences were particu¬larly noted after the indoor trainingperiod. The respective mean bloodlead levels were 47.6+12.8 and 37.6±11.1 pg/dL (i=-3.17, #=67, P=.002),while the corresponding mean ZPPlevels were 72.2±49.1 and 38.0±20.9pg/dL (i—-8.92, #=62, P=.007).

Laboratory FindingsThe blood lead levels of the exam¬

ined men are shown in Table 2. More

Table 3.—Blood Lead Levelsof Firearms Instructors Before andAfter Indoor Training (n=23)'

Blood Lead, Before, After,Mg/dL_No.(%) No.(%)<20 1 (4.3) 1 (4.3)20-39 19(82.6) 12(52.2)40-59 2(8.7) 8(34.8)

_Í60_1(4.3)_2(8.7)•x'=25.62, df=9, P=.002.

than half (52%) had blood lead levelsexceeding 40 pg/dL, while 14% hadblood lead levels between 50 and 59Pg/dL at the second examination,which took place after the indoorwinter season; in three cases (5%),the blood lead level exceeded 60Pg/dL. The highest recorded level was87 pg/dL.The ZPP levels are shown in Table

2. Four persons (10%) of the firstgroup and eight (13%) of the secondgroup had ZPP levels exceeding 80Pg/dL. Three instructors (4%) of thetotal group had sharply elevated ZPPlevels, ie, exceeding 160 pg/dL; teninstructors (12%) had ZPP levelsexceeding 80 pg/dL.Twenty-three firearms instructors

participated in two field surveys; thefirst was conducted immediately aftera four-month outdoor training periodand the second one immediatelysubsequent to a four-month indoortraining period. Among these were 16full-time instructors (70%), nine po¬lice officers (26%), and one person(4%) with only sporadic shootingactivities. Before indoor training, 20(87%) of the instructors had blood

Fig 1.—Schematic diagram of indoor police firing range showingairborne lead particulate concentrations at five firing stations andthree instructor positions. Numbers in parentheses refer to after¬noon practice session. Letter T indicates trainee; I, instructor.Personal monitoring lead exposure measured in mg/cu m.

Fig 2.—Ventilation pattern of police firing range (Fig 1) illustratingdirection and magnitude of airflow. Note that airflow is directedtoward two instructors' breathing zones. Fan is exhausting only15% the amount of air recommended by American Conference ofGovernmental Industrial Hygienists.

lead levels below 40 pg/dL. Afterindoor training, ten (43%) had levelsabove this value (Table 3). In 17(74%), there was a measurable in¬crease in blood lead levels after theindoor training period. The mean

blood lead level observed after theoutdoor training period (31.9 pg/dL±11.5 SD) was significantly differentfrom the mean value found after theindoor training period (41.2 pg/dL±15.9 SD); i=3.05, #=22, P=.006. Con¬trary to these findings, there was no

statistically significant change inmean ZPP levels, an interesting find¬ing, which may be explained by thedifferent kinetics of these two biologi¬cal parameters. While the blood lead

level reflects recent and current leadabsorption and may vary considera¬bly with the prevailing exposure situ¬ation, the ZPP level is a representa¬tion of biological events occurring inthe bone marrow. Since it has beenshown that ZPP remains in theerythrocyte for the lifetime of theRBC (approximately 120 days),1213variations in blood lead over a shorterperiod may therefore not be accompa¬nied by significant change in ZPPconcentration; this parameter repre¬sents rather an integrated biologicaleffect of the preceding three to fourmonths of exposure to lead. This rela¬tionship may be of considerableimportance for the medical surveil-

lance of persons with such intermit¬tent exposure, since acceptable bloodlead levels might be associated withthe simultaneously elevated ZPP lev¬el, ie, a persistent toxic effect on hemesynthesis. There was a strong correla¬tion, however, between blood lead andZPP levels of the total group; correla¬tion coefficients and P values atthe two examinations were as follows:r=.72, P=.00001, and r=.60, P=.00001,respectively.

Air Sampling andVentilation Studies

Concentrations of lead in the air atfive firing stations and three instruc¬tor positions of one firing range are

Table 4.—Lead Exposures and Biological Indexes ofLead Absorption in Instructors*

Location 1 Location 2 Location 3

_Average Span Average Span Average SpanBackground, jig/cu m air 76

...

0...

25...Firing, itg/cu m air 3,750 1,850-4,910 520 296-691 210 182-261

Instruction, M/cum air_1,850 1,450-2,290 568 197-759 116 103-128Blood lead, ng/àlblood_60 53-74_56 44-77 35 29-43Zinc protoporphyrin,Mg/dLblood_186 61-280 122 76-202 48 41-56

Time-weighted average exposureof instructor, ¿tg/cu m air 900 94 45

'Data obtained from three New York City firing ranges.

shown in Fig 1. Peak airborne leadconcentrations generated during fir¬ing are high; when considered on an

eight-hour full-shift basis, the time-weighted average exposure of the twoinstructors at this facility was ap¬proximately 900 Mg/cu m or 4.5 timesthe current Occupational Safety andHealth Administration standard of200 Mg/cu m. The reason for this situ¬ation may be found in Fig 2 where thedirection and magnitude of airfloware shown. The airflow was notdirected away from the breathingzone in most locations. Furthermore,there was insufficient air exhaustedfrom this range (cu m/min). Approxi¬mately 170 eu m of air should beexhausted from this range each min¬ute, according to recommendations ofthe American Conference of Govern¬mental Industrial Hygienists.14Comparative lead exposures at

three New York City firing rangesand the instructors' biological indexesof lead exposure are shown in Table 4.Peak exposure in two ranges cause

concern. The average exposure in

location 1 is 900 pg/cu m; the expo¬sure in location 2 is 94 pg/cu m,approaching the new OccupationalSafety and Health Administrationeight-hour time-weighted average. Inlocation 3, however, the existingventilation approximated recommen¬dations of the American Conferenceof Governmental Industrial Hy¬gienists. There, the eight-hour time-weighted average was 45 pg/cu m,well within the acceptable range.

COMMENTIt appears that lead-related symp¬

toms may occur with appreciablefrequency among firearms instruc¬tors. The CNS and GI symptomscorrelated well with other biologicalindexes of lead exposure, such as

blood lead and ZPP levels. Five of sixfirearms instructors with severallead-related symptoms had clear, bio¬chemical, lead-induced abnormalities.Environmental surveys of three

firing ranges indicate that indoorfiring ranges with insufficient venti¬lation may have considerable lead

exposure for instructors. In someinstances, this may lead to clinicallyobservable lead disease.The results also illustrate that

adherence to currently recommendeddesign criteria is necessary to mini¬mize exposure to lead particulates infiring ranges and thereby to preventthe occurrence of lead disease amongfirearms instructors.1415 However,good personal hygiene, work prac¬tices, and housekeeping are likewisenecessary components of a lead pre¬vention program.On the basis of currently available

data, we suggest that evaluation oflead effects be taken into account inmedical surveillance programs offirearms instructors. The ZPP deter¬mination is a suitable and practicalway to assess important biologicaleffects among exposed persons. Thistest, combined with blood lead deter¬mination, should be available at med¬ical facilities responsible for thehealth of those employed in indoorfiring ranges.

This work was supported by National Instituteof Environmental Health Sciences grant ES00928.Aviv Associates, Lakewood, NJ, provided use

of a ZPP-meter for blood zinc protoporphyrindeterminations.Clarence G. Robinson, MD, chief police

surgeon of the New York City Police Depart¬ment, participated in this study. Drs WilliamLorimer, Edwin Holstein, and Kenneth Rosen-man participated in the clinical examinations.Mrs Frances Perez and Mrs Diane Monahanprovided technical laboratory assistance. LtFrancis J. McGee, Lt Edwin Love, New York CityPolice Department, and members of Nassau and.Suffolk Counties' police departments, New YorkCity Police Department, New York City HousingPolice, and New York City Transit Police forcesassisted in this study.

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