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Exposure to lead in South African shooting ranges
Environmental Research 153 (2017) 93–98
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Exposure to lead in South African shooting ranges Angela Mathee
a,b,c,⁎
, Pieter de Jager
b,d
b
a,b,c
, Shan Naidoo , Nisha Naicker
crossmark
a
South African Medical Research Council (Environment & Health Research Unit), PO Box 87373, Houghton 2041, South Africa b University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050, South Africa c University of Johannesburg (Environmental Health Department, Faculty of Health Sciences), PO Box 524, Auckland Park, Johannesburg 2006, South Africa d National Health Laboratory Service (Epidemiology and Surveillance Unit, National Institute for Occupational Health), PO Box 4788, Johannesburg 2000, South Africa
A R T I C L E I N F O
A BS T RAC T
Keywords: Lead exposure Blood lead Shooting range Firearms South Africa
Introduction: Lead exposure in shooting ranges has been under scrutiny for decades, but no information in this regard is available in respect of African settings, and in South Africa specifically. The aim of this study was to determine the blood lead levels in the users of randomly selected private shooting ranges in South Africa's Gauteng province. Methods: An analytical cross sectional study was conducted, with participants recruited from four randomly selected shooting ranges and three archery ranges as a comparator group. Results: A total of 118 (87 shooters and 31 archers) were included in the analysis. Shooters had significantly higher blood lead levels (BLL) compared to archers with 36/85 (42.4%) of shooters versus 2/34 (5.9%) of archers found to have a BLL ≥10 μg/dl (p < 0.001). Conclusion: Shooting ranges may constitute an import site of elevated exposure to lead. Improved ventilation, low levels of awareness of lead hazards, poor housekeeping, and inadequate personal hygiene facilities and practices at South African shooting ranges need urgent attention.
1. Introduction Lead is associated with an array of contemporary products and activities (such as batteries, paint, the use of arms and ammunition, pottery and the crafting of fishing sinkers) and a broad range of detrimental health and social outcomes in children as well as adults (Bellinger and Needleman, 2003; Tong et al., 2000). Reductions in intelligence, shortened concentration spans, hearing loss, poor school performance, aggression and violence (Bellinger, 2008; Nevin, 2007; Schwartz and Otto, 1991) are amongst the detrimental health and social effects associated with lead exposure (Bellinger et al., 1991). In adults, lead exposure has been associated with kidney damage, hypertension, cardiac disease and lowered levels of fertility (Hu et al., 2007; Martin et al., 2006). Lead-related health effects have been demonstrated even at very low levels of exposure (around 3 µg/dl), and there is widespread consensus regarding the absence of a blood lead threshold of safety (Betts, 2012; Gilbert and Weiss, 2006). Growing recognition of the devastating personal and community consequences of lead exposure and poisoning prompted many countries to commence multi-faceted lead exposure reduction programmes in the 1970 s. Amongst the measures implemented were phasing out
the use of leaded gasoline, and controlling the use of lead in products such as paint, fishing sinkers, food cans and toys. In the United States of America (USA), where a concerted programme of action to reduce lead exposure has been underway since the 1970 s, children's blood lead levels have since declined considerably (Pirkle et al., 1994; Tong et al., 2000). In contrast to the experience in well-resourced countries, lead exposure reduction efforts have been relatively weak and piecemeal in many poorly resourced countries. In various African countries for example, studies conducted have indicated ongoing lead exposure from mining (Lo et al., 2012), paint (Mathee et al., 2007), fishing sinkers (Mathee et al., 2013), playground equipment (Mathee et al., 2009), traditional medicines (Mathee et al., 2015), traditional drinking brews (Mosha et al., 1996), e-waste (Olafisoye et al., 2013), cosmetics (Orisakwe and Otaraku, 2013), cultural practices such as geophagia (Mathee et al., 2014; Nyaruhucha, 2009), food (Makokha et al., 2008) and the formal and informal occupational sectors (Haefliger et al., 2009). It is probable that in many African countries further, as yet unstudied, sources of lead exposure exist alongside those mentioned above. By the 1970 s, the use of firearms and shooting ranges had been
⁎ Correspondence to: South African Medical Research Council, Second Floor, Health Clinic Building, University of Johannesburg, Corner of Beit and Sherwell Streets, Doornfontein 2028, South Africa.
http://dx.doi.org/10.1016/j.envres.2016.11.021 Received 10 November 2016; Received in revised form 25 November 2016; Accepted 27 November 2016 0013-9351/ © 2016 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by/4.0/).
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Table 1 Profile of archers and gun shooters. Risk Factor
Archers
Shooters
Significance
N Age Sex
31 Mean: 34.7 (SD12.55); median: 32; range 19–64 years 25.8% female
87 Mean: 38.9 (SD13.77); median: 38; range=18–74 years 10.3% female
0.144 0.069
Educational Attainment % tertiary education
87.1%
54.9%
0.002
Employment status % unemployed
9.7%
7.1%
0.669
Monthly household income % with household income > R10 000.00
80%
74%
0.620
% users of tobacco
12.9%
27.6%
0.180
before being exported to Stata version 12, which was used to conduct the analyses. Sex, education and other categorical data are described in terms of frequencies, proportions and percentages. Continuous data are presented in terms of measures of spread and central tendency. Univariate analysis for individual characteristics and blood lead level were compared using χ2 or Fishers' Exact test for categorical data and a two-tailed student's t-test for normally distributed continuous data. The Mann-Whitney U test was utilized in univariate analysis of nonparametric continuous variables. The level of significance was taken at a two-tailed α=0.05.
recognized as a key source of lead exposure in the USA (Anderson et al., 1977), but to our knowledge, few if any studies on this group have been undertaken in African settings. In this paper we describe a study, the first to our knowledge, of blood lead distributions and associated risk factors, in a sample of users of shooting ranges in South Africa. 2. Methods A cross-sectional, analytical study of blood lead concentrations, and associated risk factors, was undertaken at archery and shooting ranges in the cities of Johannesburg, Ekurhuleni and Pretoria in South Africa's Gauteng Province. Written invitations to participate in the study were sent to 9 archery and 26 shooting ranges that had been randomly selected from databases provided by the South African National Archery Association (list of 17) and the South African Police Service (list of 64) respectively. Timeous, written, informed consent to participate in the study was received from four archery and 4 shooting ranges; however one of the archery ranges was eliminated when a mutually agreeable date for fieldwork could not be found in the time available. On fieldwork days, study participants, who were defined as adults aged 18 years or older, were regular shooters, not pregnant, and who had provided written, informed consent, were included in the study. The study protocol, consent form and participant information sheet had been approved by the Research Ethics Committee of the South African Medical Research Council. In three cases hand wipes were taken before and after shooting, as were surface wipes (tables and walls) in the shooting range. Dust samples were collected in accordance with the guidelines of the USA Department of Housing and Urban Development (http://portal.hud.gov/hudportal/documents/huddoc? id=lbph-40.pdf – accessed 25/05/2016). Analyses were undertaken by ICP/MS at a laboratory accredited through the South African National Accreditation System (SANAS). Blood lead levels were measured using a LeadCare®II blood lead testing instrument. An 50 μl aliquot of whole blood was obtained from a finger prick after participants had washed their hands with soap and water. The test was conducted immediately in the field or within 24 h of blood collection. All blood samples were collected and tested by a registered medical practitioner. Two participants for whom the LeadCare II instrument indicated highly elevated blood lead levels, had venous blood samples drawn for laboratory analyses, which confirmed highly elevated blood lead concentrations. All participants with a blood lead level > 25 μg/dl were counselled and referred to a medical practitioner for further investigation. A self-administered questionnaire was completed by each participant to collect information on socio-economic factors, shooting practices and health status. Data were captured in Excel, and cleaned and inspected for errors
3. Results The study sample, recruited from four gun shooting (three of which were indoor ranges) and three archery ranges (all outdoors) in and around Johannesburg and Pretoria, initially comprised 121 individuals: 67 gun shooters and 46 archers. Three of those recruited at the shooting ranges turned out to be shooting range workers, but not regular shooters, and were therefore excluded from further analyses. Fifteen of 46 (33%) archers reported that they were also regular gun shooters, and were thus re-classified as shooters, leaving a final study sample of 118 individuals, of whom 87 (74%) were gun shooters and 31 were exclusively archers. A profile of the study population, broken down by archers and shooters, is given in Table 1. 3.1. Blood lead distributions Blood lead levels in the total sample (archers as well as gun shooters; n =118) ranged from 2.0 to 60.0 µg/dl, with the mean and median levels respectively equalling 9.3 (SD 9.5) and 7.0 µg/dl. The blood lead levels of 62.7% of the sample equalled or exceeded 5 µg/dl, while 28.8% had blood lead levels > 10 µg/dl. In 5.9% of cases, blood lead levels were > 25 µg/dl. 3.2. Blood lead levels by place of recruitment (archery vs gun shooting ranges) Table 2 gives the blood lead distributions by shooting/archery range. As shown, blood lead levels amongst participants recruited at archery ranges ranged from 2.0 to 10.4 µg/dl, with the mean and median levels equalling 3.5 (SD 2.1) and 2.0 µg/dl respectively. Around 26.7% of this group had blood lead levels > 5 µg/dl, while the blood lead levels of 2.2% equalled or exceeded 10 µg/dl. Amongst those recruited at gun shooting ranges on the other hand, the respective values for the mean and median blood lead levels were 12.8 (SD 10.5) (a 3.7-fold increase) and 9.3 µg/dl, with individual blood lead levels ranging from 2.0 to 60.0 µg/dl. Amongst gun shooters 84.9% had blood 94
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Table 2 Blood lead levels by shooting/archery range.
Archery range 1 Archery range 2 Archery range 3 Shooting range 1 Shooting range 2 Shooting range 3 Shooting range 4
(outdoor) (indoor) (indoor) (indoor)
% of gun shooters
N
Mean (SD)
Median
Range
% > 5 µg/dl
% > 10 µg/dl
5% 50% 55% 100% 100% 100% 100%
20 14 11 12 30 17 14
2.7 (1.4) 3.7 (2.5) 4.4 (2.2) 7.0 (4.26) 10.5 (7.0) 16.1 (9.8) 19.2 (16.3)
2.0 2.0 3.9 7.3 9.1 13.9 16.1
2.0–6.1 2.0–10.4 2.0–8.2 2.0–17.2 2.0–37.7 6.1–42.8 2.0–60.0
15.0% 35.7% 54.6% 58.3% 89.3% 100.0% 84.6%
0% 7.1% 0% 16.7% 36.7% 58.8% 71.4%
Table 3 Blood lead distributions in shooter/archer groups. GROUP
N
MEAN (SD)
MEDIAN
RANGE
% > 5 µg/dl
% > 10 µg/dl
Practised archery only Archers who also shot guns Gun shooters only (excluding archers and those who worked at a shooting range) Gun shooters who also work at the shooting range All gun shooters (including those who practised archery and who worked at a shooting range)
31 15 62 8 85
3.3 (2.25) 7.8 (10.26) 12.3 (10.18) 16.3 (7.83) 11.9 (10.15)
2.0 5.5 9.3 16.9 9.0
2–12 2–42.8 2–60 7.2–30.8 2–60
23% 53% 84% 63% 80%
3% 20% 45% 25% 42%
increased with an increase in the expected level of lead exposure. For example, the lowest blood lead levels were found in those who practised archery only (3.3 µg/dl), while archers who also shot guns had a higher mean blood lead concentration (7.8 µg/dl). The highest blood lead levels were found in gun shooters who also worked at a shooting range (16.3 µg/dl).
lead levels > 5 µg/dl, while 45.2% had blood lead levels > 10 µg/dl. In addition, while none of those recruited at archery ranges had blood lead levels > 25 µg/dl, 9.6% of gun shooting range recruits did. The difference in blood lead levels between those recruited at archery relative to gun shooting ranges was statistically significant (p < 0.0001), and remained so after taking account of differences in education, income and employment status. Mean blood lead levels at the three archery ranges were similar – however, blood lead levels increased with an increase in the proportion of archers who reported practising both archery and gun shooting. For example, the mean blood lead level at an archery range at which 5% of users also practised gun shooting was 2.7 µg/dl, while at an archery range where 55% of archers also shot guns the mean blood lead level was 4.4 µg/dl (see Table 2). At gun shooting ranges on the other hand, differences in mean blood lead levels were statistically significant. Specifically, the mean blood lead level at shooting range 4 was significantly elevated compared with mean levels determined at the outdoor shooting range 1 (p=0.014) and indoor shooting 2 (p=0.046) (see Table 2). The differences remained significant after taking account of income, education and employment status (p < 0.0001).
3.4. Risk factors for elevated blood lead levels in gun shooters The average age of commencement of gun shooting was 17 years. However, some participants reported being as young as three years of age when they started shooting guns, while others only started shooting after 50 years of age. Participants reported shooting for up to 69 years, with the mean number of years of shooting being 22. Most shooters (40.7%) were shooting more than once per month (but less than weekly), while 33% were shooting on a weekly basis or more frequently. Around 26.7% were shooting on a monthly basis or more seldom. For most shooters (51%), shooting sessions last for less than an hour, with a further 27% usually spending between 60 and 90 min at the range, while the remainder (22%) would visit the range for more than 90 min. The vast majority of shooters (92%) preferred the use of non-jacketed bullets. Forty percent of shooters reported potential exposure to lead during their work or recreational life (for example with paint, batteries, fishing sinkers, wheel balancing weights etc). In the South African context dedicated cleaners are usually employed to clean the range and collect casings, and shooters themselves are rarely, if ever, required to play any role in this regard. Five percent of guns shooters reported making use of traditional medicines from time to time. Amongst gun shooters, blood lead levels were not significantly associated with employment status or type, income or education (see Table 4). Blood lead concentrations were also not associated with frequency (p=0.283) or the usual duration of shooting sessions (p=0.2832). Nor were blood lead levels associated with the practice of keeping bullets in mouths, having accidentally swallowed a bullets, having been shot, being a hunter (54% of gun shooters were also hunters) or being a consumer of hunted meat. Blood lead levels were however, strongly associated with choice of shooting range (see Table 4).
3.3. Comparison of archers and gun shooters There were more females amongst the archers (25.8%) than among the gun shooters (10.3%), but this difference was not statistically significant (p=0.069). Archers and gun shooters were of similar age and employment status, and also had similar monthly household incomes. However significantly more archers than gun shooters had achieved a tertiary educational qualification (see Table 1). Amongst those who practised archery only, the median blood lead level was 2.0 µg/dl (mean=3.3 µg/dl), while that in gun shooters was more than four times higher at 9.3µg/dl) (mean=11.9 µg/dl) (see Table 3). Guns shooters also had a higher proportion of participants with a blood lead level > the reference levels of 10 µg/dl (39.1%) and 5 µg/dl (78.2%), relative to 0% and 19.4% in archers. The difference in mean blood lead levels between archers and gun shooters remained statistically significant after taking account of educational, occupational and employment differences (p= < 0.001, [CI: 4.8–10.6]). Fig. 1 gives a graphical presentation of the blood lead distribution of gun shooters relative to archers. Table 3 gives the blood lead distributions of various archer/shooter sub-groups in the study sample. As can be seen, blood lead levels
3.5. Dust analyses The average lead level in two surface dust wipe samples taken at 95
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Fig. 1. Blood lead distribution in archers relative to gun shooters.
Table 4 Blood lead levels by selected risk factors (gun shooters only). Factor
N (%)
Mean Blood Lead Level
Geometric Mean (confidence intervals)
Median Blood Lead Level
Significance
Sex Female (n=9) Male (n=69)
9 (10.3%) 78 (89.7%)
7.8 (SD=7.1) 12.0 (SD=10.4)
5.3 (2.6–10.8) 8.9 (7.5–10.6)
3.8 8.5
0.065
Income < R10,000.00 monthly > R10,000.00 monthly
19 (25.7%) 55 (74.3%)
12.7 (SD=9.8) 12.0 (SD=11.0)
9.4 (6.2–14.3) 8.8 (7.1–10.9)
11.6 8.5
0.776
Education No tertiary education Tertiary education
37 (45.1%) 45 (54.9%)
11.5 (SD=8.5) 12.2 (SD=11.6)
8.9 (6.9–11.5) 8.8 (6.9–11.2)
9.0 8.5
0.946
Employment Status Employed Not employed
58 (66.7%) 29 (33.3%)
10.5 (SD=7.7) 13.9 (SD=13.9)
5.5 (3.0–9.9) 8.7 (7.2–10.4)
7.1 9.0
0.176
Frequency of Shooting Less than monthly > monthly, but less than weekly > weekly, but < 3/week > 3 times per week
23 (26.7%) 35 (40.7%) 21 (24.4%) 7 (8.0%)
8.4 (SD=5.5) 11.8 (SD=8.7) 14.3 (SD=15.2) 12.5 (SD=9.7)
6.6 (4.8–9.1) 8.6 (6.4–11.7) 10.1 (7.1–14.4) 9.8 (4.9–19.7)
7.7 8.5 9.3 9.8
Usual duration of shooting session <1h >1h
44 (51.2%) 42 (48.8%)
12.0 (SD=7.5) 11.1 (SD=12.5)
9.9 (8.1–12.1) 7.1 (5.3–9.5)
10.1 7.1
0.056
Casting of own bullets No Yes
65 (78.3%) 18 (21.7%)
11.5 (SD=8.1) 13.7 (SD=15.9)
9.1 (7.6–10.9) 8.6 (5.4–13.8)
9.3 7.0
0.810
Place/keep bullets in mouth No Yes
69 (83%) 14 (16.9%)
10.7 (SD=2.3) 18.5 (SD=17.5)
8.4 (7.0–10.0) 12.5 (7.6–20.5)
8.5 8.8
0.080
Hunts No Yes
39 (45.9%) 46 (54.1%)
9.8 (SD=7.8) 13.2 (SD=11.8)
7.5 (5.8–9.6) 9.5 (7.5–12.2)
7.2 8.8
0.162
Uses tobacco No Yes
63 (72.4) 24 (27.6)
11.6 (SD=10.6) 11.4 (SD=9.0)
8.3 (6.8–10.3) 8.7 (6.3–12.1)
8.2 10.2
0.924
Site of Recruitment of gun shooter Archery Range Shooting Range 1 Shooting Range 2 Shooting Range 3 Shooting Range 4
14 12 30 17 14
4.5 (SD=2.7) 7.0 (SD=4.3) 10.5 (SD=7.0) 16.1 (SD=9.8) 19.2 (SD=16.3)
3.4 (2.6–5.3) 5.8 (3.9–8.8) 8.7 (6.9–11.0) 13.7 (10.3–18.4) 13.6 (7.9–23.1)
3.9 7.3 9.1 13.9 16.1
< 0.0001
(16.1%) (13.8%) (34.5%) (19.5%) (16.1%)
96
0.001
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Fig. 2. Lead content in before-and-after hand dust wipe samples.
one of the shooting ranges was 1.4 µg/cm2 (the individual readings were 1.1 and 1.7 µg/cm2) which is well in excess of the reference level for floor dust of the US Department of Housing and Urban Development of 0.043 µg/cm2 (or 40 µg/ft2). Lead content analysis of hand dust wipe samples taken from three shooters before and after their shooting sessions, showed a marked increase in hand lead load (see Fig. 2), from an average of 3.6–35 ppm, representing a near tenfold increase.
original light yellowish colour had turned black. All the shooting ranges made use of inferior cleaning methods (ordinary domestic vacuum cleaners, brooms and dry dusters, as opposed to wet cleaning methods and high-efficiency particulate air (HEPA) vacuum cleaners). Handwashing facilities were also mostly second-rate; for example, all ranges provided only fabric towels (most of which appeared highly soiled on the days of fieldwork), and some provided no soap. None of the ranges provided disposable paper towels for hand drying. No lead hazard awareness materials were evident in any of the shooting ranges, and some clients were observed to be freely taking drinks and snacks into the range for consumption, and smoking, while shooting. The factors outlined above may explain why high dust lead loads were found on surfaces in the range, and why hand dust lead levels increased ten-fold during the course of shooting practice sessions in three of the shooters studied. The high risk of lead exposure in South African shooting ranges as demonstrated in this study, combined with low levels of awareness of lead hazards in the country in general (Haman et al., 2015), may increase the likelihood of shooters transporting lead particles on their hands, hair, skin, clothing, shoes and shooting equipment from the range into their vehicles and homes, with a concomitant elevation in the risk of lead exposure amongst their families/households. Though not included in the current study, children were frequently observed to join their fathers and grandfathers in shooting practice sessions, and may in this way also be directly exposed to lead at shooting ranges. Blood lead concentrations in the range determined in this group of gun shooters is associated with a range of detrimental health effects, including kidney damage, hypertension, cardiac disease and increased infertility (Kosnett et al., 2007; Martin et al., 2006; Schwartz and Hu, 2007), as well as a range of non-specific ill health effects such as headaches and gastrointestinal, joint and muscle pain. This study therefore strongly indicates a need for further, nation-wide research on the risk of lead exposure in users of private, as well as public shooting ranges, including those operated by sectors such as the police and military services in South Africa. It will be important in such research programmes to examine elements not ascertained in the current study, for example air lead levels in shooting ranges, health outcomes and social outcomes, and user range practices, such as switching from one range to another. There is a need for increased awareness within the South African health sector of the elevated risk of lead exposure and poisoning in groups making use of guns and shooting ranges, including hunters, conservationists, police and military personnel, and recreational shooters. The careful taking of occupational and recreational histories may be particularly useful in indicating the need for blood
4. Discussion This study has revealed the high risk of lead exposure in those making use of certain private indoor shooting ranges in South Africa. The blood lead levels of gun shooters (median=9.3 µg/dl) were found to be significantly elevated (more than four-fold) relative to their archer (control) counterparts (median=2.0 µg/dl). Users of indoor shooting ranges were shown to be at elevated risk relative to users of the only outdoor shooting range in this study. Blood lead levels also varied significantly among indoor shooting ranges. The findings confirm in an African setting (for the first time to our knowledge) the elevated risk of lead exposure observed in shooting ranges elsewhere in the world, including Sweden (Svensson et al., 1992), Germany (Ochsmann et al., 2009) and Jordan (Abudhaise et al., 1995). Since South Africa has no adult (or child) blood lead surveillance programme in place, it is not possible to compare the blood lead distribution in this group, with that in the adult general population in the country. However, relative to the blood lead reference level of 5 µg/dl in adults set by the National Institute for Occupational Safety and Health in the USA, the vast majority of shooters without occupational exposure in this study (84%), had elevated blood lead concentrations. Nearly a quarter of those who practised archery exclusively also had blood lead levels > 5 µg/dl, which may indicate a concern about ongoing lead exposure in the South African adult population in general. After taking account of socio-economic status and risk factors such as placing bullets in mouths, casting own bullets, having been shot, hunting and consuming hunted meat, the only factor significantly associated with elevated blood lead levels was choice of shooting range. The shooting ranges in this study were poorly ventilated, and not equipped with appropriate mechanical ventilation systems. At one of the shooting ranges, hessian sand bags were stacked as a bullet trap. In the shooting range where the highest blood lead levels were found, the walls had been overlaid with a rippled layer of spongy foam in an attempt at noise control. The hessian bags, and in particular the spongy material, served as effective traps for lead dust, and over time its 97
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Ochsmann, E., Göen, T., Schaller, K.-H., Drexler, H., 2009. Lead–Still a health threat for marksmen. Int. J. Hyg. Environ. Health 212, 557–561. Olafisoye, O.B., Adefioye, T., Osibote, O.A., 2013. Heavy metals contamination of water, soil, and plants around an electronic waste dumpsite. Pol. J. Environ. Stud. 22, 1431–1439. Orisakwe, O.E., Otaraku, J.O., 2013. Metal concentrations in cosmetics commonly used in Nigeria. Sci. World J. 2013, 959637. Pirkle, J.L., Brody, D.J., Gunter, E.W., Kramer, R.A., Paschal, D.C., Flegal, K.M., et al., 1994. The decline in blood lead levels in the United States. The National health and Nutrition examination surveys (NHANES). JAMA: J. Am. Med. Assoc. 272, 284–291. Schwartz, B.S., Hu, H., 2007. Adult lead exposure: time for change. Environ. Health Perspect. 115, 451–454. Schwartz, J., Otto, D., 1991. Lead and minor hearing impairment. Arch. Environ. Health 46, 300–305. Svensson, B.-G., Schütz, A., Nilsson, A., Skerfving, S., 1992. Lead exposure in indoor firing ranges. Int. Arch. Occup. Environ. Health 64, 219–221. Tong, S., von Schirnding, Y.E., Prapamontol, T., 2000. Environmental lead exposure: a public health problem of global dimensions. Bull. World Health Organ. 78, 1068–1077.
lead testing when members of these groups seek health care. Studies in Sweden for example, have shown police officers to be at elevated risk of lead exposure associated with their use of shooting ranges (Loefstedt et al., 1999). Shooting range measures to reduce lead exposure should include lead hazard awareness campaigns, the institution of effective ventilation mechanisms, installation of proper handwashing facilities, avoidance of material or surfaces in shooting ranges that may trap dust, improved cleaning methods and equipment (especially the use of HEPA vacuum cleaners and wet methods), medical surveillance for both clients and shooting range workers and the substitution of lead ammunition with copper-jacketed bullets or lead-free bullets. Training manuals or curricula for high risk groups such as police and military officers, recreational shooters, private gun owners and hunters should also include modules on lead hazards and protection measures. 5. Conclusion Shooting ranges in South Africa may constitute an important site of exposure to high levels of lead, as a consequence of inadequate ventilation mechanisms, low levels of awareness of lead hazards and poor housekeeping, and inadequate personal hygiene facilities and practices. Health and safety protection measures are needed to urgently directly address lead exposure concerns in users and workers – this will best be undertaken in the context of a holistic, national lead poisoning prevention programme for South Africa. Funding This study was funded by the South African Medical Research Council. Ethical review The protocol for this study was reviewed by the Human Research Ethics committee of the South African Medical Research Council. Author contributions The manuscript was written with contributions from all authors. All authors have given approval of the final version of the manuscript. Declaration of interest The authors declare no conflict of interests. Acknowledgements The authors appreciate the support from shooting range managers and owners, as well as the study participants. The assistance of Modiegi “Mirriam” Mogotsi, Louise Renton, Thandi Zwane, Patricia Albers, Reaford Beldon, Felicia Mpiti and Tahira Kootbodien is gratefully acknowledged. References Abudhaise, B., Alzoubi, M., Rabi, A., Alwash, R., 1995. Lead exposure in indoor firing ranges: environmental impact and health risk to the range users. Int. J. Occup. Med. Environ. Health 9, 323–329. Anderson, K.E., Fischbein, A., Kestenbaum, D., Sassa, S., Alvares, A.P., Kappas, A., 1977. Plumbism from airborne lead in a firing range: an unusual exposure to a toxic heavy
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Environmental Research journal homepage: www.elsevier.com/locate/envres
Exposure to lead in South African shooting ranges Angela Mathee
a,b,c,⁎
, Pieter de Jager
b,d
b
a,b,c
, Shan Naidoo , Nisha Naicker
crossmark
a
South African Medical Research Council (Environment & Health Research Unit), PO Box 87373, Houghton 2041, South Africa b University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050, South Africa c University of Johannesburg (Environmental Health Department, Faculty of Health Sciences), PO Box 524, Auckland Park, Johannesburg 2006, South Africa d National Health Laboratory Service (Epidemiology and Surveillance Unit, National Institute for Occupational Health), PO Box 4788, Johannesburg 2000, South Africa
A R T I C L E I N F O
A BS T RAC T
Keywords: Lead exposure Blood lead Shooting range Firearms South Africa
Introduction: Lead exposure in shooting ranges has been under scrutiny for decades, but no information in this regard is available in respect of African settings, and in South Africa specifically. The aim of this study was to determine the blood lead levels in the users of randomly selected private shooting ranges in South Africa's Gauteng province. Methods: An analytical cross sectional study was conducted, with participants recruited from four randomly selected shooting ranges and three archery ranges as a comparator group. Results: A total of 118 (87 shooters and 31 archers) were included in the analysis. Shooters had significantly higher blood lead levels (BLL) compared to archers with 36/85 (42.4%) of shooters versus 2/34 (5.9%) of archers found to have a BLL ≥10 μg/dl (p < 0.001). Conclusion: Shooting ranges may constitute an import site of elevated exposure to lead. Improved ventilation, low levels of awareness of lead hazards, poor housekeeping, and inadequate personal hygiene facilities and practices at South African shooting ranges need urgent attention.
1. Introduction Lead is associated with an array of contemporary products and activities (such as batteries, paint, the use of arms and ammunition, pottery and the crafting of fishing sinkers) and a broad range of detrimental health and social outcomes in children as well as adults (Bellinger and Needleman, 2003; Tong et al., 2000). Reductions in intelligence, shortened concentration spans, hearing loss, poor school performance, aggression and violence (Bellinger, 2008; Nevin, 2007; Schwartz and Otto, 1991) are amongst the detrimental health and social effects associated with lead exposure (Bellinger et al., 1991). In adults, lead exposure has been associated with kidney damage, hypertension, cardiac disease and lowered levels of fertility (Hu et al., 2007; Martin et al., 2006). Lead-related health effects have been demonstrated even at very low levels of exposure (around 3 µg/dl), and there is widespread consensus regarding the absence of a blood lead threshold of safety (Betts, 2012; Gilbert and Weiss, 2006). Growing recognition of the devastating personal and community consequences of lead exposure and poisoning prompted many countries to commence multi-faceted lead exposure reduction programmes in the 1970 s. Amongst the measures implemented were phasing out
the use of leaded gasoline, and controlling the use of lead in products such as paint, fishing sinkers, food cans and toys. In the United States of America (USA), where a concerted programme of action to reduce lead exposure has been underway since the 1970 s, children's blood lead levels have since declined considerably (Pirkle et al., 1994; Tong et al., 2000). In contrast to the experience in well-resourced countries, lead exposure reduction efforts have been relatively weak and piecemeal in many poorly resourced countries. In various African countries for example, studies conducted have indicated ongoing lead exposure from mining (Lo et al., 2012), paint (Mathee et al., 2007), fishing sinkers (Mathee et al., 2013), playground equipment (Mathee et al., 2009), traditional medicines (Mathee et al., 2015), traditional drinking brews (Mosha et al., 1996), e-waste (Olafisoye et al., 2013), cosmetics (Orisakwe and Otaraku, 2013), cultural practices such as geophagia (Mathee et al., 2014; Nyaruhucha, 2009), food (Makokha et al., 2008) and the formal and informal occupational sectors (Haefliger et al., 2009). It is probable that in many African countries further, as yet unstudied, sources of lead exposure exist alongside those mentioned above. By the 1970 s, the use of firearms and shooting ranges had been
⁎ Correspondence to: South African Medical Research Council, Second Floor, Health Clinic Building, University of Johannesburg, Corner of Beit and Sherwell Streets, Doornfontein 2028, South Africa.
http://dx.doi.org/10.1016/j.envres.2016.11.021 Received 10 November 2016; Received in revised form 25 November 2016; Accepted 27 November 2016 0013-9351/ © 2016 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by/4.0/).
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Table 1 Profile of archers and gun shooters. Risk Factor
Archers
Shooters
Significance
N Age Sex
31 Mean: 34.7 (SD12.55); median: 32; range 19–64 years 25.8% female
87 Mean: 38.9 (SD13.77); median: 38; range=18–74 years 10.3% female
0.144 0.069
Educational Attainment % tertiary education
87.1%
54.9%
0.002
Employment status % unemployed
9.7%
7.1%
0.669
Monthly household income % with household income > R10 000.00
80%
74%
0.620
% users of tobacco
12.9%
27.6%
0.180
before being exported to Stata version 12, which was used to conduct the analyses. Sex, education and other categorical data are described in terms of frequencies, proportions and percentages. Continuous data are presented in terms of measures of spread and central tendency. Univariate analysis for individual characteristics and blood lead level were compared using χ2 or Fishers' Exact test for categorical data and a two-tailed student's t-test for normally distributed continuous data. The Mann-Whitney U test was utilized in univariate analysis of nonparametric continuous variables. The level of significance was taken at a two-tailed α=0.05.
recognized as a key source of lead exposure in the USA (Anderson et al., 1977), but to our knowledge, few if any studies on this group have been undertaken in African settings. In this paper we describe a study, the first to our knowledge, of blood lead distributions and associated risk factors, in a sample of users of shooting ranges in South Africa. 2. Methods A cross-sectional, analytical study of blood lead concentrations, and associated risk factors, was undertaken at archery and shooting ranges in the cities of Johannesburg, Ekurhuleni and Pretoria in South Africa's Gauteng Province. Written invitations to participate in the study were sent to 9 archery and 26 shooting ranges that had been randomly selected from databases provided by the South African National Archery Association (list of 17) and the South African Police Service (list of 64) respectively. Timeous, written, informed consent to participate in the study was received from four archery and 4 shooting ranges; however one of the archery ranges was eliminated when a mutually agreeable date for fieldwork could not be found in the time available. On fieldwork days, study participants, who were defined as adults aged 18 years or older, were regular shooters, not pregnant, and who had provided written, informed consent, were included in the study. The study protocol, consent form and participant information sheet had been approved by the Research Ethics Committee of the South African Medical Research Council. In three cases hand wipes were taken before and after shooting, as were surface wipes (tables and walls) in the shooting range. Dust samples were collected in accordance with the guidelines of the USA Department of Housing and Urban Development (http://portal.hud.gov/hudportal/documents/huddoc? id=lbph-40.pdf – accessed 25/05/2016). Analyses were undertaken by ICP/MS at a laboratory accredited through the South African National Accreditation System (SANAS). Blood lead levels were measured using a LeadCare®II blood lead testing instrument. An 50 μl aliquot of whole blood was obtained from a finger prick after participants had washed their hands with soap and water. The test was conducted immediately in the field or within 24 h of blood collection. All blood samples were collected and tested by a registered medical practitioner. Two participants for whom the LeadCare II instrument indicated highly elevated blood lead levels, had venous blood samples drawn for laboratory analyses, which confirmed highly elevated blood lead concentrations. All participants with a blood lead level > 25 μg/dl were counselled and referred to a medical practitioner for further investigation. A self-administered questionnaire was completed by each participant to collect information on socio-economic factors, shooting practices and health status. Data were captured in Excel, and cleaned and inspected for errors
3. Results The study sample, recruited from four gun shooting (three of which were indoor ranges) and three archery ranges (all outdoors) in and around Johannesburg and Pretoria, initially comprised 121 individuals: 67 gun shooters and 46 archers. Three of those recruited at the shooting ranges turned out to be shooting range workers, but not regular shooters, and were therefore excluded from further analyses. Fifteen of 46 (33%) archers reported that they were also regular gun shooters, and were thus re-classified as shooters, leaving a final study sample of 118 individuals, of whom 87 (74%) were gun shooters and 31 were exclusively archers. A profile of the study population, broken down by archers and shooters, is given in Table 1. 3.1. Blood lead distributions Blood lead levels in the total sample (archers as well as gun shooters; n =118) ranged from 2.0 to 60.0 µg/dl, with the mean and median levels respectively equalling 9.3 (SD 9.5) and 7.0 µg/dl. The blood lead levels of 62.7% of the sample equalled or exceeded 5 µg/dl, while 28.8% had blood lead levels > 10 µg/dl. In 5.9% of cases, blood lead levels were > 25 µg/dl. 3.2. Blood lead levels by place of recruitment (archery vs gun shooting ranges) Table 2 gives the blood lead distributions by shooting/archery range. As shown, blood lead levels amongst participants recruited at archery ranges ranged from 2.0 to 10.4 µg/dl, with the mean and median levels equalling 3.5 (SD 2.1) and 2.0 µg/dl respectively. Around 26.7% of this group had blood lead levels > 5 µg/dl, while the blood lead levels of 2.2% equalled or exceeded 10 µg/dl. Amongst those recruited at gun shooting ranges on the other hand, the respective values for the mean and median blood lead levels were 12.8 (SD 10.5) (a 3.7-fold increase) and 9.3 µg/dl, with individual blood lead levels ranging from 2.0 to 60.0 µg/dl. Amongst gun shooters 84.9% had blood 94
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Table 2 Blood lead levels by shooting/archery range.
Archery range 1 Archery range 2 Archery range 3 Shooting range 1 Shooting range 2 Shooting range 3 Shooting range 4
(outdoor) (indoor) (indoor) (indoor)
% of gun shooters
N
Mean (SD)
Median
Range
% > 5 µg/dl
% > 10 µg/dl
5% 50% 55% 100% 100% 100% 100%
20 14 11 12 30 17 14
2.7 (1.4) 3.7 (2.5) 4.4 (2.2) 7.0 (4.26) 10.5 (7.0) 16.1 (9.8) 19.2 (16.3)
2.0 2.0 3.9 7.3 9.1 13.9 16.1
2.0–6.1 2.0–10.4 2.0–8.2 2.0–17.2 2.0–37.7 6.1–42.8 2.0–60.0
15.0% 35.7% 54.6% 58.3% 89.3% 100.0% 84.6%
0% 7.1% 0% 16.7% 36.7% 58.8% 71.4%
Table 3 Blood lead distributions in shooter/archer groups. GROUP
N
MEAN (SD)
MEDIAN
RANGE
% > 5 µg/dl
% > 10 µg/dl
Practised archery only Archers who also shot guns Gun shooters only (excluding archers and those who worked at a shooting range) Gun shooters who also work at the shooting range All gun shooters (including those who practised archery and who worked at a shooting range)
31 15 62 8 85
3.3 (2.25) 7.8 (10.26) 12.3 (10.18) 16.3 (7.83) 11.9 (10.15)
2.0 5.5 9.3 16.9 9.0
2–12 2–42.8 2–60 7.2–30.8 2–60
23% 53% 84% 63% 80%
3% 20% 45% 25% 42%
increased with an increase in the expected level of lead exposure. For example, the lowest blood lead levels were found in those who practised archery only (3.3 µg/dl), while archers who also shot guns had a higher mean blood lead concentration (7.8 µg/dl). The highest blood lead levels were found in gun shooters who also worked at a shooting range (16.3 µg/dl).
lead levels > 5 µg/dl, while 45.2% had blood lead levels > 10 µg/dl. In addition, while none of those recruited at archery ranges had blood lead levels > 25 µg/dl, 9.6% of gun shooting range recruits did. The difference in blood lead levels between those recruited at archery relative to gun shooting ranges was statistically significant (p < 0.0001), and remained so after taking account of differences in education, income and employment status. Mean blood lead levels at the three archery ranges were similar – however, blood lead levels increased with an increase in the proportion of archers who reported practising both archery and gun shooting. For example, the mean blood lead level at an archery range at which 5% of users also practised gun shooting was 2.7 µg/dl, while at an archery range where 55% of archers also shot guns the mean blood lead level was 4.4 µg/dl (see Table 2). At gun shooting ranges on the other hand, differences in mean blood lead levels were statistically significant. Specifically, the mean blood lead level at shooting range 4 was significantly elevated compared with mean levels determined at the outdoor shooting range 1 (p=0.014) and indoor shooting 2 (p=0.046) (see Table 2). The differences remained significant after taking account of income, education and employment status (p < 0.0001).
3.4. Risk factors for elevated blood lead levels in gun shooters The average age of commencement of gun shooting was 17 years. However, some participants reported being as young as three years of age when they started shooting guns, while others only started shooting after 50 years of age. Participants reported shooting for up to 69 years, with the mean number of years of shooting being 22. Most shooters (40.7%) were shooting more than once per month (but less than weekly), while 33% were shooting on a weekly basis or more frequently. Around 26.7% were shooting on a monthly basis or more seldom. For most shooters (51%), shooting sessions last for less than an hour, with a further 27% usually spending between 60 and 90 min at the range, while the remainder (22%) would visit the range for more than 90 min. The vast majority of shooters (92%) preferred the use of non-jacketed bullets. Forty percent of shooters reported potential exposure to lead during their work or recreational life (for example with paint, batteries, fishing sinkers, wheel balancing weights etc). In the South African context dedicated cleaners are usually employed to clean the range and collect casings, and shooters themselves are rarely, if ever, required to play any role in this regard. Five percent of guns shooters reported making use of traditional medicines from time to time. Amongst gun shooters, blood lead levels were not significantly associated with employment status or type, income or education (see Table 4). Blood lead concentrations were also not associated with frequency (p=0.283) or the usual duration of shooting sessions (p=0.2832). Nor were blood lead levels associated with the practice of keeping bullets in mouths, having accidentally swallowed a bullets, having been shot, being a hunter (54% of gun shooters were also hunters) or being a consumer of hunted meat. Blood lead levels were however, strongly associated with choice of shooting range (see Table 4).
3.3. Comparison of archers and gun shooters There were more females amongst the archers (25.8%) than among the gun shooters (10.3%), but this difference was not statistically significant (p=0.069). Archers and gun shooters were of similar age and employment status, and also had similar monthly household incomes. However significantly more archers than gun shooters had achieved a tertiary educational qualification (see Table 1). Amongst those who practised archery only, the median blood lead level was 2.0 µg/dl (mean=3.3 µg/dl), while that in gun shooters was more than four times higher at 9.3µg/dl) (mean=11.9 µg/dl) (see Table 3). Guns shooters also had a higher proportion of participants with a blood lead level > the reference levels of 10 µg/dl (39.1%) and 5 µg/dl (78.2%), relative to 0% and 19.4% in archers. The difference in mean blood lead levels between archers and gun shooters remained statistically significant after taking account of educational, occupational and employment differences (p= < 0.001, [CI: 4.8–10.6]). Fig. 1 gives a graphical presentation of the blood lead distribution of gun shooters relative to archers. Table 3 gives the blood lead distributions of various archer/shooter sub-groups in the study sample. As can be seen, blood lead levels
3.5. Dust analyses The average lead level in two surface dust wipe samples taken at 95
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Fig. 1. Blood lead distribution in archers relative to gun shooters.
Table 4 Blood lead levels by selected risk factors (gun shooters only). Factor
N (%)
Mean Blood Lead Level
Geometric Mean (confidence intervals)
Median Blood Lead Level
Significance
Sex Female (n=9) Male (n=69)
9 (10.3%) 78 (89.7%)
7.8 (SD=7.1) 12.0 (SD=10.4)
5.3 (2.6–10.8) 8.9 (7.5–10.6)
3.8 8.5
0.065
Income < R10,000.00 monthly > R10,000.00 monthly
19 (25.7%) 55 (74.3%)
12.7 (SD=9.8) 12.0 (SD=11.0)
9.4 (6.2–14.3) 8.8 (7.1–10.9)
11.6 8.5
0.776
Education No tertiary education Tertiary education
37 (45.1%) 45 (54.9%)
11.5 (SD=8.5) 12.2 (SD=11.6)
8.9 (6.9–11.5) 8.8 (6.9–11.2)
9.0 8.5
0.946
Employment Status Employed Not employed
58 (66.7%) 29 (33.3%)
10.5 (SD=7.7) 13.9 (SD=13.9)
5.5 (3.0–9.9) 8.7 (7.2–10.4)
7.1 9.0
0.176
Frequency of Shooting Less than monthly > monthly, but less than weekly > weekly, but < 3/week > 3 times per week
23 (26.7%) 35 (40.7%) 21 (24.4%) 7 (8.0%)
8.4 (SD=5.5) 11.8 (SD=8.7) 14.3 (SD=15.2) 12.5 (SD=9.7)
6.6 (4.8–9.1) 8.6 (6.4–11.7) 10.1 (7.1–14.4) 9.8 (4.9–19.7)
7.7 8.5 9.3 9.8
Usual duration of shooting session <1h >1h
44 (51.2%) 42 (48.8%)
12.0 (SD=7.5) 11.1 (SD=12.5)
9.9 (8.1–12.1) 7.1 (5.3–9.5)
10.1 7.1
0.056
Casting of own bullets No Yes
65 (78.3%) 18 (21.7%)
11.5 (SD=8.1) 13.7 (SD=15.9)
9.1 (7.6–10.9) 8.6 (5.4–13.8)
9.3 7.0
0.810
Place/keep bullets in mouth No Yes
69 (83%) 14 (16.9%)
10.7 (SD=2.3) 18.5 (SD=17.5)
8.4 (7.0–10.0) 12.5 (7.6–20.5)
8.5 8.8
0.080
Hunts No Yes
39 (45.9%) 46 (54.1%)
9.8 (SD=7.8) 13.2 (SD=11.8)
7.5 (5.8–9.6) 9.5 (7.5–12.2)
7.2 8.8
0.162
Uses tobacco No Yes
63 (72.4) 24 (27.6)
11.6 (SD=10.6) 11.4 (SD=9.0)
8.3 (6.8–10.3) 8.7 (6.3–12.1)
8.2 10.2
0.924
Site of Recruitment of gun shooter Archery Range Shooting Range 1 Shooting Range 2 Shooting Range 3 Shooting Range 4
14 12 30 17 14
4.5 (SD=2.7) 7.0 (SD=4.3) 10.5 (SD=7.0) 16.1 (SD=9.8) 19.2 (SD=16.3)
3.4 (2.6–5.3) 5.8 (3.9–8.8) 8.7 (6.9–11.0) 13.7 (10.3–18.4) 13.6 (7.9–23.1)
3.9 7.3 9.1 13.9 16.1
< 0.0001
(16.1%) (13.8%) (34.5%) (19.5%) (16.1%)
96
0.001
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Fig. 2. Lead content in before-and-after hand dust wipe samples.
one of the shooting ranges was 1.4 µg/cm2 (the individual readings were 1.1 and 1.7 µg/cm2) which is well in excess of the reference level for floor dust of the US Department of Housing and Urban Development of 0.043 µg/cm2 (or 40 µg/ft2). Lead content analysis of hand dust wipe samples taken from three shooters before and after their shooting sessions, showed a marked increase in hand lead load (see Fig. 2), from an average of 3.6–35 ppm, representing a near tenfold increase.
original light yellowish colour had turned black. All the shooting ranges made use of inferior cleaning methods (ordinary domestic vacuum cleaners, brooms and dry dusters, as opposed to wet cleaning methods and high-efficiency particulate air (HEPA) vacuum cleaners). Handwashing facilities were also mostly second-rate; for example, all ranges provided only fabric towels (most of which appeared highly soiled on the days of fieldwork), and some provided no soap. None of the ranges provided disposable paper towels for hand drying. No lead hazard awareness materials were evident in any of the shooting ranges, and some clients were observed to be freely taking drinks and snacks into the range for consumption, and smoking, while shooting. The factors outlined above may explain why high dust lead loads were found on surfaces in the range, and why hand dust lead levels increased ten-fold during the course of shooting practice sessions in three of the shooters studied. The high risk of lead exposure in South African shooting ranges as demonstrated in this study, combined with low levels of awareness of lead hazards in the country in general (Haman et al., 2015), may increase the likelihood of shooters transporting lead particles on their hands, hair, skin, clothing, shoes and shooting equipment from the range into their vehicles and homes, with a concomitant elevation in the risk of lead exposure amongst their families/households. Though not included in the current study, children were frequently observed to join their fathers and grandfathers in shooting practice sessions, and may in this way also be directly exposed to lead at shooting ranges. Blood lead concentrations in the range determined in this group of gun shooters is associated with a range of detrimental health effects, including kidney damage, hypertension, cardiac disease and increased infertility (Kosnett et al., 2007; Martin et al., 2006; Schwartz and Hu, 2007), as well as a range of non-specific ill health effects such as headaches and gastrointestinal, joint and muscle pain. This study therefore strongly indicates a need for further, nation-wide research on the risk of lead exposure in users of private, as well as public shooting ranges, including those operated by sectors such as the police and military services in South Africa. It will be important in such research programmes to examine elements not ascertained in the current study, for example air lead levels in shooting ranges, health outcomes and social outcomes, and user range practices, such as switching from one range to another. There is a need for increased awareness within the South African health sector of the elevated risk of lead exposure and poisoning in groups making use of guns and shooting ranges, including hunters, conservationists, police and military personnel, and recreational shooters. The careful taking of occupational and recreational histories may be particularly useful in indicating the need for blood
4. Discussion This study has revealed the high risk of lead exposure in those making use of certain private indoor shooting ranges in South Africa. The blood lead levels of gun shooters (median=9.3 µg/dl) were found to be significantly elevated (more than four-fold) relative to their archer (control) counterparts (median=2.0 µg/dl). Users of indoor shooting ranges were shown to be at elevated risk relative to users of the only outdoor shooting range in this study. Blood lead levels also varied significantly among indoor shooting ranges. The findings confirm in an African setting (for the first time to our knowledge) the elevated risk of lead exposure observed in shooting ranges elsewhere in the world, including Sweden (Svensson et al., 1992), Germany (Ochsmann et al., 2009) and Jordan (Abudhaise et al., 1995). Since South Africa has no adult (or child) blood lead surveillance programme in place, it is not possible to compare the blood lead distribution in this group, with that in the adult general population in the country. However, relative to the blood lead reference level of 5 µg/dl in adults set by the National Institute for Occupational Safety and Health in the USA, the vast majority of shooters without occupational exposure in this study (84%), had elevated blood lead concentrations. Nearly a quarter of those who practised archery exclusively also had blood lead levels > 5 µg/dl, which may indicate a concern about ongoing lead exposure in the South African adult population in general. After taking account of socio-economic status and risk factors such as placing bullets in mouths, casting own bullets, having been shot, hunting and consuming hunted meat, the only factor significantly associated with elevated blood lead levels was choice of shooting range. The shooting ranges in this study were poorly ventilated, and not equipped with appropriate mechanical ventilation systems. At one of the shooting ranges, hessian sand bags were stacked as a bullet trap. In the shooting range where the highest blood lead levels were found, the walls had been overlaid with a rippled layer of spongy foam in an attempt at noise control. The hessian bags, and in particular the spongy material, served as effective traps for lead dust, and over time its 97
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lead testing when members of these groups seek health care. Studies in Sweden for example, have shown police officers to be at elevated risk of lead exposure associated with their use of shooting ranges (Loefstedt et al., 1999). Shooting range measures to reduce lead exposure should include lead hazard awareness campaigns, the institution of effective ventilation mechanisms, installation of proper handwashing facilities, avoidance of material or surfaces in shooting ranges that may trap dust, improved cleaning methods and equipment (especially the use of HEPA vacuum cleaners and wet methods), medical surveillance for both clients and shooting range workers and the substitution of lead ammunition with copper-jacketed bullets or lead-free bullets. Training manuals or curricula for high risk groups such as police and military officers, recreational shooters, private gun owners and hunters should also include modules on lead hazards and protection measures. 5. Conclusion Shooting ranges in South Africa may constitute an important site of exposure to high levels of lead, as a consequence of inadequate ventilation mechanisms, low levels of awareness of lead hazards and poor housekeeping, and inadequate personal hygiene facilities and practices. Health and safety protection measures are needed to urgently directly address lead exposure concerns in users and workers – this will best be undertaken in the context of a holistic, national lead poisoning prevention programme for South Africa. Funding This study was funded by the South African Medical Research Council. Ethical review The protocol for this study was reviewed by the Human Research Ethics committee of the South African Medical Research Council. Author contributions The manuscript was written with contributions from all authors. All authors have given approval of the final version of the manuscript. Declaration of interest The authors declare no conflict of interests. Acknowledgements The authors appreciate the support from shooting range managers and owners, as well as the study participants. The assistance of Modiegi “Mirriam” Mogotsi, Louise Renton, Thandi Zwane, Patricia Albers, Reaford Beldon, Felicia Mpiti and Tahira Kootbodien is gratefully acknowledged. References Abudhaise, B., Alzoubi, M., Rabi, A., Alwash, R., 1995. Lead exposure in indoor firing ranges: environmental impact and health risk to the range users. Int. J. Occup. Med. Environ. Health 9, 323–329. Anderson, K.E., Fischbein, A., Kestenbaum, D., Sassa, S., Alvares, A.P., Kappas, A., 1977. Plumbism from airborne lead in a firing range: an unusual exposure to a toxic heavy
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