Occupational lead exposure aboard a tall ship

To evaluate occupational exposures to lead in shipfitters cutting and riveting lead-painted iron plates aboard an iron-hulled sailing vessel, we conducted an environmental and medical survey. Lead exposures in seven personal (breathing zone) air samples ranged from 108 to 500 micrograms/m3 (mean 257 micrograms/m3); all were above the Occupational Safety and Health Administration (OSHA) standard of 50 micrograms/m3. In two short-term air samples obtained while exhaust ventilation was temporarily disconnected, mean lead exposure rose to 547 micrograms/m3. Blood lead levels in ten shipfitters ranged from 25 to 53 micrograms/dl (mean, 37.8 micrograms/dl); levels in three of these workers exceeded the upper normal limit of 40 micrograms/dl. Blood lead levels in shipfitters were significantly higher than in other shipyard workers (mean 10.0 micrograms/dl; p less than 0.001). Smoking shipfitters (mean, 47 micrograms/dl) had significantly higher lead levels than nonsmokers (mean, 32 micrograms/dl; p = 0.03). Lead levels in shipfitters who wore respirators were not lower than in those who wore no protective gear (p = 0.68). Four shipfitters had erythrocyte protoporphyrin (EP) concentrations above the adult upper normal limit of 50 micrograms/dl. A close correlation was found between blood lead and EP levels (r = 0.70). Prevalence of lead-related symptoms was no higher in shipfitters than in other workers. No cases of symptomatic lead poisoning were noted. These data indicate that serious occupational exposure to lead can occur in a relatively small boatyard.     

Association between prenatal lead exposure and blood pressure in children

Background: Lead exposure in adults is associated with hypertension. Altered prenatal nutrition is associated with subsequent risks of adult hypertension, but little is known about whether prenatal exposure to toxicants, such as lead, may also confer such risks.Objectives: We investigated the relationship of prenatal lead exposure and blood pressure (BP) in 7- to 15-year-old boys and girls.Methods: We evaluated 457 mother–child pairs, originally recruited for an environmental birth cohort study between 1994 and 2003 in Mexico City, at a follow-up visit in 2008–2010. Prenatal lead exposure was assessed by measurement of maternal tibia and patella lead using in vivo K-shell X-ray fluorescence and cord blood lead using atomic absorption spectrometry. BP was measured by mercury sphygmomanometer with appropriate-size cuffs.Results: Adjusting for relevant covariates, maternal tibia lead was significantly associated with increases in systolic BP (SBP) and diastolic BP (DBP) in girls but not in boys (p-interaction with sex = 0.025 and 0.007 for SBP and DBP, respectively). Among girls, an interquartile range increase in tibia lead (13 μg/g) was associated with 2.11-mmHg [95% confidence interval (CI): 0.69, 3.52] and 1.60-mmHg (95% CI: 0.28, 2.91) increases in SBP and DBP, respectively. Neither patella nor cord lead was associated with child BP.Conclusions: Maternal tibia lead, which reflects cumulative environmental lead exposure and a source of exposure to the fetus, is a predisposing factor to higher BP in girls but not boys. Sex-specific adaptive responses to lead toxicity during early-life development may explain these differences.     

Indirect lead exposure among children of radiator repair workers

BACKGROUND: Secondary exposure to lead has been identified as a public health problem since the late 1940s; we investigate the risk of lead exposure among families of radiator repair workers. METHODS: A sample of the wives and children, aged 6 months to 6 years (exposed children) (n = 19), of radiator repair workers and a sample of children whose parents were not occupationally exposed to lead (non-exposed children) (n = 29) were matched for age and residence; their geometric mean blood lead levels are compared. Blood samples were obtained by the finger stick method and environmental dust samples by the wipe method; both were analyzed using a portable anodic stripping voltameter. RESULTS: Dust lead levels were significantly higher in the houses of exposed children (143.8 vs. 3.9 microg/g; P < 0.01). In crude analyses, the highest lead levels were observed among children whose fathers worked in home-based workshops (22.4 microg/dl)(n = 6). Children whose fathers worked in an external workshop (n = 13) also had high levels (14.2 microg/dl) (P < 0.01), while blood lead levels in non-exposed children were significantly lower (5.6 microg/dl)(P < 0.01). The observed differences remained significant after adjustment for age and gender. CONCLUSIONS: This study confirms that children of radiator repair workers are at increased risk of lead exposure and public health interventions are needed to protect them.     

南方某地16～60岁人群环境铅暴露现况调查

目的 了解南方某地16～60周岁人群环境铅暴露情况,分析影响血铅水平升高的危险因素以及铅暴露所致的健康损害.方法 随机选取居住于当地>5年,食用当地自产食物的人群,石墨炉原子吸收法检测血、尿、头发、趾/指甲样本中铅浓度.自制调查问卷面询.采用SPSS软件进行分析.结果 412名调查对象血铅水平为(64.1±1.8)μg/L,尿铅、发铅、指(趾)甲铅分别为(11.0±1.7),(11.7±3.4),(12.1±3.4)μg/g.对数变换的尿铅、发铅、甲铅与血铅呈正相关,对应Pearson相关系数分别为0.485,0.317,0.350;居住于D村、饮酒、男性是血铅升高的危险因素;发铅、指(趾)甲铅与失眠、记忆力减退、手脚麻木、视力模糊等自觉症状的发生有关.结论 A村铅暴露最严重,男性、饮酒是血铅增高的危险因素.     

职业铅接触者血铅、发铅、尿铅相关性的研究

本文通过对32名铅蓄电池制造工和36名排字工的血铅、发铅、尿铅的相关性研究,发现血铅/发铅(r=0.604),血铅/尿铅(r=0.548)均呈高度显著性相关(P<0.0005),故认为血铅是铅接触工人较好的健康监护指标。文章还进一步探讨了发铅作为铅接触者活体生物检测材料的应用前景。     

Effect of lead on blood pressure in occupationally nonexposed men

To determine if low-level exposure to lead has an effect on arterial blood pressure, demographic and clinical data of a group of 507 males without any occupational exposure to lead were analyzed in a retrospective study. The following variables were included in the analysis: age, height, weight, nicotine consumption, alcohol intake, blood lead, systolic blood pressure, diastolic blood pressure, and erythrocyte count. The effects of the variables age, weight, height, alcohol intake, nicotine consumption, and blood lead on blood pressure were investigated by stepwise linear regression analysis. The diastolic as well as the systolic blood pressure was significantly influenced by Body Mass Index, age, and alcohol. A significant effect of lead could be found only for diastolic blood pressure. None of the possible interactions were significant enough to merit inclusion in the statistical model. Regarding the strength of the effects on diastolic blood pressure we find that lead ranks after age, weight. In conclusion, this study shows that lead has an effect on diastolic arterial blood pressure in a survey of a group of middle-aged, occupationally nonexposed men.     

铅暴露对某铅蓄电池企业719名作业工人血清生化指标的影响

目的 探讨铅暴露对作业工人血清生化指标的影响。
方法 选取武汉市某铅蓄电池企业719名现场铅作业人员作为调查对象,按《职业健康监护技术规范》的要求对其进行在岗期间职业健康体检,采用石墨炉原子吸收光谱法和自动生化分析仪分别测定研究对象血铅及血清生化指标,包括丙氨酸氨基转移酶（alanine aminotransferase,ALT）和门冬氨酸氨基转移酶（aspartate aminotransferase,AST）。以400 μg/L为界,将人群分为血铅水平≥ 400 μg/L的高血铅组和血铅水平 < 400 μg/L的低血铅组。采用多元线性回归模型分析719名铅作业人员的血铅与血清生化指标的相关性。
结果 低血铅组与高血铅组的血铅均值分别为（221.71 ±105.15）μg/L和（583.24 ±153.54）μg/L。血清ALT异常56名,异常率为7.79%;血清AST异常20名,异常率为2.78%。低血铅组ALT为（23.68 ±18.47）U/L,高血铅组ALT为（23.07 ±14.48）U/L;低血铅组AST为（21.88 ±10.18）U/L,高血铅组AST为（23.71 ±17.71）U/L;两组以上指标差异均无统计学意义（P>0.05）。多元线性回归结果显示:血铅每增加1 μg/L,工人血清AST升高0.004 U/L。
结论 血铅水平与血清AST值存在正相关关系,铅的蓄积可造成对肝脏组织的损害。
     

Lead effect on blood pressure in moderately lead-exposed male workers

BACKGROUND: The effect of lead (Pb) and potential confounding variables on blood pressure was examined in healthy male industrial workers 20-43 years of age. METHODS: In 100 Pb workers and 51 reference subjects, the following variables were measured: blood Pb (BPb), activity of delta-aminolevulinic acid dehydratase (ALAD), erythrocyte protoporphyrin (EP), blood cadmium (BCd), serum zinc (SZn), serum copper (SCu), hematocrit (Hct), body mass index (BMI), and blood pressure. The inter-relationship of biomarkers of Pb (BPb, ALAD, EP) and BCd, SZn, SCu, Hct, BMI, age, smoking, and alcohol to systolic and diastolic blood pressure was calculated by forward stepwise multiple regression. RESULTS: There was no significant difference in blood pressure between the two groups, possibly because the reference subjects had relatively high BPb levels and significantly higher BMI (P < 0.05) as compared to the Pb workers. According to the multiple regression results in Pb workers, an increase in systolic blood pressure was significantly associated with increasing EP (P = 0.001) and BMI (P < 0.002), or alternatively with increasing BMI (P < 0.004) and decreasing ALAD (P < 0.04) and BCd (P < 0.05). An increase in diastolic blood pressure was significantly associated with increasing BMI (P < 0.009) and EP (P = 0.05) and decreasing BCd (P < 0.04). With respect to the EP range of 0.73-13.94 micromol/l erythrocytes in 100 Pb workers, an increase of 17 mm Hg in systolic and 6 mm Hg in diastolic blood pressure was found. CONCLUSIONS: Long-term cumulative Pb exposure, which is better reflected by EP than by ALAD or current BPb level, can significantly increase blood pressure in moderately Pb-exposed male workers (long-term average BPb <400 microg/l; exposure duration 2-21 years).     

Occupational exposure to airborne lead in Brazilian police officers

Shooting with lead-containing ammunition in indoor firing ranges is a known source of lead exposure in adults. Police officers may be at risk of lead intoxication when regular training shooting exercises are yearly mandatory to law enforcement officers. Effects on health must be documented, even when low-level elemental (inorganic) lead exposure is detected. Forty police officers (nineteen cadets and twenty-one instructors) responded to a questionnaire about health, shooting habits, and potential lead exposure before a training curse. Blood samples were collected and analyzed for blood lead level (BLL) before and after a three days training curse. The mean BLL for the instructors’ group was 5.5 μg/dL ± 0.6. The mean BLL for the cadets’ group before the training was 3.3 μg/dL ± 0.15 and after the training the main BLL was 18.2 μg/dL ± 1.5. Samples were analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). All the participants in the training curse had significantly increased BLL (mean increment about 15 μg/dL) after the three days indoor shooting season.In conclusion, occupational lead exposure in indoor firing ranges is a source of lead exposure in Brazilian police officers, and appears to be a health risk, especially when heavy weapons with lead-containing ammunition are used in indoor environments during the firing training seasons.     

Cognitive effects of chronic exposure to lead and solvents

BACKGROUND: Occupational exposure to lead and solvents has declined steadily over the past 20 years, however, construction workers continue to be exposed to these neurotoxicants. The purpose of this study was to investigate the cognitive effects of chronic occupational exposure to lead and solvents. METHOD: Based on K-XRF of tibial bone lead and occupational history of solvent exposure, subjects were classified into four exposure groups: lead (N = 40), solvent (N = 39), lead/solvent (N = 45), and control (N = 33). All subjects completed tests to assess concentration, motor skills, memory, and mood. RESULTS: Relative to controls, the lead, solvent, and lead/solvent groups performed significantly more poorly on a test of verbal memory, while the lead and lead/solvent groups were slower than the solvent and control groups on a task of processing speed. Bone lead was a significant predictor of information processing speed and latency of response while solvent exposure was a significant predictor of verbal learning and memory. CONCLUSIONS: Bone lead was associated with slower speed of processing while exposure to lead and/or solvents reduced efficiency of verbal learning.     

Plasma-lead concentration: investigations into its usefulness for biological monitoring of occupational lead exposure

BACKGROUND: The lead concentration in plasma is correlated to that in whole blood with a two to fourfold variation. It has never been investigated if this variation is inter-individual. METHODS: Lead and hemoglobin were determined in blood and plasma from 13 lead workers with a history of relatively high blood-lead concentrations, sampled three times during 1 day. The variation in the distribution of lead between cells and plasma was studied, but not the variation in the lead concentrations as such. RESULTS: Blood hemoglobin decreased with rising plasma lead (0.9-3.0 microg/L). Regarding the distribution of lead, no effect of current exposure during the day or of recent meals appeared. As much as 84% of the overall variance of the distribution of lead between cells and plasma could be attributed to individual factors. After adjustment for erythrocyte volume fraction this decreased to 67%. Plasma samples with elevated hemoglobin concentrations (due to in vitro hemolysis) had somewhat elevated lead concentrations. CONCLUSIONS: Plasma lead is not significantly altered by variation in a single day's exposure and, therefore, the choice of time of the day is not critical for sampling. However, plasma lead is negatively correlated to blood hemoglobin and mild hemolysis (not visible by the eye) in a sample may increase plasma lead with up to 30%. Finally, plasma provides lead exposure information that differs from whole blood, but it is not clear which one of these is the biomarker with the closest relation to exposure and/or effects.     

Relationship between external and internal parameters of exposure to manganese in workers from a manganese oxide and salt producing plant

In a plant producing manganese (Mn) oxides and salts, 11 different workplaces were identified. The current exposure to airborne Mn (total dust, personal sampling, n = 80) varied from 0.07 to 8.61 mg/m3. The geometric mean and median values amounted approximately to 1 mg/m3 and the 95th percentile was 3.30 mg/m3. The concentration of Mn in blood (Mn-B) in a group of 141 Mn-exposed male workers ranged from 0.10-3.59 micrograms/100 ml compared to 0.04-1.31 micrograms/100 ml in a group of 104 control subjects. The ranges of the concentrations of Mn in urine (Mn-U) were 0.06-140.6 and 0.01-5.04 micrograms/g creatinine for the exposed and control groups, respectively. The average level of Mn-B in the Mn group was more than twice as high as in the control group (arithmetic mean, 1.36 vs 0.57 microgram/100 ml) and that of Mn-U was ten times higher in the Mn group (geometric mean, 1.56 vs 0.15 microgram/g creatinine). The Mn-B level did not change significantly after 8 h of Mn exposure, whereas the Mn-U level dropped rapidly when exposure ceased (half-life less than 30 h). On an individual basis, neither Mn-B nor Mn-U correlated with the current levels of Mn-air or duration of Mn exposure. There was also no relationship between Mn-B and Mn-U. On a group basis, there was no correlation between the mean Mn-B levels and the current levels of Mn-air at each workplace.(ABSTRACT TRUNCATED AT 250 WORDS)     

Parental occupational lead exposure and lead concentration of newborn cord blood

The purpose of this study was to determine the influence of parental occupational lead exposure on the lead levels of newborn cord blood in the Taipei area. From September 1984 to June 1985, 5,000 pregnant women voluntarily participated in the study at the Taipei Municipal Maternal and Child Hospital. Each woman was interviewed regarding her and her husband's occupational exposures; 2,948 successfully delivered healthy newborns, and cord blood samples were obtained using Terumo Venoject, and 242 samples were analyzed by graphite furnace atomic absorption spectrometry using an Instrumentation Laboratory 251 instrument. Nine cord blood samples were from newborns with both parents exposed, 26 samples had maternal exposure only, 105 samples had paternal exposure only, and 102 were nonexposed. The results showed that the average lead level of cord blood with both parents exposed was 8.9 +/- 2.9 micrograms%, maternal exposure 9.0 +/- 3.8 micrograms%, paternal exposure 8.3 +/- 3.4 micrograms%, and 6.9 +/- 3.2 micrograms% in the nonexposed group. There were significant differences between the nonexposed and the maternal exposure groups, and also between the nonexposed and paternal exposure groups. All 26 maternal exposures were from lead soldering operations. Multivariate analysis revealed that, after control of father's exposure status, newborn cord blood lead level increased 0.27 micrograms% for each hour the mother spent on lead soldering during a normal working day, thus suggesting that soldering during pregnancy may be hazardous to newborns. Paternal contribution to the cord blood lead levels seemed to be through either working at home with the pregnant mother also at home or bringing work clothes home for laundering.     

Take-home lead poisoning in a child from his father's occupational exposure

With the publication of revised CDC guidelines in 1991, concern about childhood lead poisoning has increased. Exposure to lead-based paint and paint dust is currently considered the major source of lead poisoning in the United States. We describe a child who had elevated BLL related to lead-contaminated clothing that the father brought home from his workplace. © 1996 Wiley-Liss, Inc.     

Field evaluation of a portable blood lead analyzer in workers living at a high altitude: a follow-up investigation

BACKGROUND: Field-portable instruments can offer expeditious analytical results to health professionals in field settings and in areas lacking laboratory infrastructure. This study further evaluated an electroanalytical field-portable instrument, which rapidly analyzes blood lead concentrations. METHODS: A portable anodic stripping voltammetry (ASV) instrument was evaluated utilizing paired samples from 243 employees working at an elevation of approximately 3,800 meters in Peru. Each worker donated two venous blood samples, one of which was analyzed by the ASV device and the other by a reference analytical method, graphite furnace atomic absorption spectrometry (GFAAS). RESULTS: According to the GFAAS results, the mean blood lead concentration measured was 46(+/-16) mug/dl; this was significantly greater than the mean ASV measurement of 32(+/-11) mug/dl (paired t-test; P < 0.0001). The accuracy of the ASV estimation decreased as the measured blood lead concentration increased. CONCLUSIONS: The results from this investigation were significantly different from the previous study, which was conducted near sea level. The exact causes for the discrepancies between the portable ASV results from the two studies are unclear, but are thought to be related to differences in blood chemistry between the Midwestern United States and Peruvian Andes worker cohorts. Portable ASV blood lead measurements from populations living at high altitudes should be viewed with caution. Am. J. Ind. Med. 46:656-662, 2004. Published 2004 Wiley-Liss, Inc.     

苯作业职业暴露评估与致癌风险模拟

目的通过对苯等化学致癌物慢性暴露致癌风险的定量评价,为我国职业危害因素的控制以及职业肿瘤等严重职业病的预防和管理提供科学依据,进行职业危害防控。方法选取某大型石油化工企业新建50万t/年苯乙烯装置作为研究对象,以目前国际上普遍采用的健康风险评价四段法的步骤,即风险辨识、剂量-反应评价、暴露评价和风险表征等,以苯致癌风险概率作为评价目标进行定量化分析;应用ERDEM软件对内暴露剂量进行数值模拟,采用多阶模型分析暴露剂量与致癌反应之间定量关系;针对暴露与风险的不确定性,采用Crystal ball蒙特卡洛模拟方法分析概率分布规律。结果该装置工人苯暴露的致癌风险明显超过了美国EPA制定的人体致癌风险值1×10-6,需要采取相关措施降低风险。结论利用ERDEM暴露分析软件及crystal ball蒙特卡洛模拟软件对内暴露剂量及风险概率进行数值模拟,可以得到致癌风险值的概率分布及其统计分布特征,从而为风险管理者提供更准确的信息。