Elevated blood lead levels in a riverside population in the Brazilian Amazon

Lead (Pb) is recognized as one of the most toxic metals. Sources of Pb exposure have been widely documented in North America, and the removal of Pb additives from gasoline was reflected in a dramatic lowering of blood Pb concentration. In Latin America, the removal of Pb from gasoline resulted in decreased exposure, but Pb levels in many areas remain high due to occupational and environmental sources of exposure. While many of the Pb sources have been identified (mining, industries, battery recycling, lead-based paint, ceramics), new ones occasionally crop up. Here we report on blood Pb (B-Pb) levels in remote riverside communities of the Brazilian Amazon. Blood Pb (B-Pb) levels were determined in 448 persons from 12 villages of the Lower Tapajós River Basin, Pará, Brazil. Socio-demographic and dietary information, as well as occupational, residential and medical history was collected using an interview-administered questionnaire. B-Pb, measured by ICP-MS, showed elevated concentrations. Mean B-Pb was 13.1 μg/dL±8.5, median B-Pb was 11.2 μg/dL and ranged from 0.59 to 48.3 μg/dL. Men had higher B-Pb compared to women (median: 15.3 μg/dL vs 7.9 μg/dL respectively). B-Pb increased with age for women, while it decreased for men. For both genders, B-Pb decreased with education. There were significant differences between villages. Exploratory analyses, using linear partition models, showed that for men B-Pb was lower among those who were involved in cattle-raising, and higher among those who hunted, farmed and fished. The distribution profile of B-Pb directed us towards artisanal transformation of manioc to flour (farinha), which requires heating in a large metal pan, with stirring primarily done by young men. In the village with the highest B-Pb, analysis of Pb concentrations (dry weight) of manioc (prior to transformation) and farinha (following transformation) from 6 houses showed a tenfold increase in Pb concentration (mean: 0.017±0.016 to 0.19±0.10 μg/g). This was confirmed in one of these villages where we sampled manioc paste (just before roasting) and the roasted farinha (0.05 μg/g vs 0.20 μg/g). While there may be other sources (ammunition, sinkers for fishing nets), the high concentrations in farinha, a dietary staple, assuredly makes an important contribution. Further action needs to reduce Pb sources in this region.     

Biologic markers of oxidative stress and nephrotoxicity as studied in biomonitoring of adverse effects of occupational exposure to lead and cadmium

OBJECTIVES: In this work, we studied impregnation levels of workers occupationally exposed to lead (Pb) and cadmium (Cd), usefulness of early urinary markers of nephrotoxicity, and occurrence of oxidative stress as the underlying mechanism involved in Pb- or Cd-induced adverse effects. Thirty-five men were recruited from a nonferrous metal smelter. Pb and Cd in blood (B-Pb, B-Cd) and urine (U-Pb, U-Cd) were measured. Relations between oxidative stress markers (malondialdehyde, superoxide dismutase, glutathione peroxidase, selenium, glutathione reductase, glutathione status, 8-hydroxy-2'-deoxyguanosine) and exposure levels, on the one hand, and early urinary markers (alpha-1-microprotein, beta-2-microglobulin, retinol binding protein, alpha and pi-glutathione S-transferases) and exposure levels, on the other hand, were evaluated. RESULTS: Mean exposure levels were moderate (B-Pb = 395.71 microg Pb/L; U-Pb = 95.19 microg Pb/g creatinine; B-Cd = 5.83 microg Cd/L; U-Cd = 4.67 microg Cd/g creatinine). Changes in malondialdehyde, glutathione status, 8-hydroxy-2'-deoxyguanosine, and alpha-glutathione S-transferases were closely correlated with exposure levels and did not depend on tobacco consumption. We showed that these workers showed moderate Pb and Cd exposure levels. CONCLUSIONS: Taken together, the data suggests the use of alpha-glutathione S-transferases excretion in urine as a hallmark of early changes in the proximal tubular integrity that could later lead to clinical disease if exposure is not reduced.     

Assessment of exposure to metals in lead processing industries

Inhalation of particulate matter in industrial environments has been associated with respiratory symptoms and lung diseases, which continues to lead to long- and short-term hazardous health effects on exposed subjects. The main objectives of this study were (a) to determine the dust exposure of workers from the lead industry in different operations and (b) to evaluate if the Exhaled Breath Condensate (EBC) can be used as a non-invasive tool to evaluate this exposure. Therefore, this cross-sectional study not only measured the exposure to Airborne Particulate Matter (APM) and to the associated elements but also analysed the EBC elemental composition. APM was collected in Ind1, Ind2, Offices and outdoor with Gent samplers, which delivers two size fractions: fine particulate matter (<2.5 μm), and coarse particulate matter (between 2.5 and 10 μm). EBC samples were collected from the workers and from a non-exposed group working in Offices. The techniques INAA and PIXE were used for the APM element characterization and ICP-MS for EBC elemental content. The PM_2.5 and PM_2.5–10 mass concentrations were significantly higher in the industries studied than in Offices and in the environment. At the industrial sites surveyed the coarse fraction dominated and both factories had different fingerprints: APM elements with higher expression were Pb, Sb, Na, Cl and Fe in Ind1 and Pb, Si, Br, Ca, Al, Cl and Na in Ind2. Most of these elements revealed a gradient of concentration where Ind.1 > Ind.2 > Offices and EBC revealed a clear translation of this exposure, suggesting the latter to be a potential good indicator of exposure to metals in occupational settings. Pb in EBC presented the most representative results. Even though EBC was found to reflect predominantly the inhaled coarser fraction it is more related to concentration levels of exposure than to the predominance of APM fraction.     

Contamination pathways of polychlorinated biphenyls (PCBs) – From the worker to the family

The improper recycling of old industrial sized capacitors and transformers in Dortmund, Germany, led to a contamination of workers and environment with polychlorinated biphenyls (PCBs). In 2010, a surveillance program was conducted for the former workers, their relatives, and residents next to the recycling company. In the human biomonitoring, elevated values for PCBs were detected in a proportion of the in-house relatives of the workers, including children. The aim of this study was to reconstruct the contamination pathways from the company to the family.Brought home working clothes of the former employees were identified as a first pathway for a contamination of the residential environment. Those clothes were cleaned at home, due to temporary employment contract. Washing machines and dryers were in consequence highly contaminated with PCBs. This led to a contamination of the relative's clothes and by this to a dermal uptake of PCBs. Another exposure pathway was the inhalation of PCB containing dust. In particular at locations, that were in contact with the working boots, high levels of PCBs were detected in the ambient monitoring. This established another exposure pathway by inhalation of PCB containing dust. The link between the residential influence factors and the PCB plasma concentration (n = 54) is shown by rank correlation.In conclusion, it should be avoided to take home potentially contaminated working clothes or boots, to prevent an exposure of children and other family members.     

Automatische Bestimmung der Delta-Amino-Laevulinsäure im Urin

Summary In a group of workers exposed to lead and a group of people representing the general urban and rural population of Finland the serum creatinine (S-Great) concentrations of 1342 men and 377 women, glutamic oxaloacetic acid transaminase (S-GOT) activities of 1464 men and 510 women, and glutamic pyruvic acid transaminase (S-GPT) activities of 377 men and 235 women were compared to the respective blood lead (B-Pb) concentrations. There was no correlation between S-Great, S-GOT, or S-GPT and B-Pb levels or exposure time. Only a random variation was found in the values of S-Great, S-GOT between different lead exposure categories. This finding does not exclude the possibility of either renal or liver damage at the B-Pb levels studied here, but it indicates that the measurement of S-Great, S-GOT and S-GPT cannot be recommended as a routine screening procedure for lead-exposed workers.Abbreviations B-Pb blood lead - S-GOT serum glutamic oxaloacetic transaminase - S-GPT serum glutamic pyruvic acid transaminase - S-Great serum creatinine     

Measurement by ICP-MS of lead in plasma and whole blood of lead workers and controls.

OBJECTIVES: To test a simple procedure for preparing samples for measurement of lead in blood plasma (P-Pb) and whole blood (B-Pb) by inductively coupled plasma mass spectrometry (ICP-MS), to measure P-Pb and B-Pb in lead workers and controls, and to evaluate any differences in the relation between B-Pb and P-Pb between people. METHODS: P-Pb and B-Pb were measured by ICP-MS in 43 male lead smelter workers and seven controls without occupational exposure to lead. For analysis, plasma and whole blood were diluted 1 in 4 and 1 in 9, respectively, with a diluted ammonia solution containing Triton-X 100 and EDTA. The samples were handled under routine laboratory conditions, without clean room facilities. RESULTS: P-Pb was measured with good precision (CV = 5%) even at concentrations present in the controls. Freeze storage of the samples had no effect on the results. The detection limit was 0.015 microgram/l. The P-Pb was 0.15 (range 0.1-0.3) microgram/l in controls and 1.2 (0.3-3.6) micrograms/l in lead workers, although the corresponding B-Pbs were 40 (24-59) micrograms/l and 281 (60-530) micrograms/l (1 microgram Pb/I = 4.8 nmol/l). B-Pb was closely associated with P-Pb (r = 0.90). The association was evidently non-linear; the ratio B-Pb/P-Pb decreased with increasing P-Pb. CONCLUSIONS: By means of ICP-MS and a simple dilution procedure, P-Pb may be measured accurately and with good precision down to concentrations present in controls. Contamination of blood at sampling and analysis is no major problem. With increasing P-Pb, the percentage of lead in plasma increases. In studies of lead toxicity, P-Pb should be considered as a complement to current indicators of lead exposure and risk.     

Occupational exposure of non-smoking restaurant personnel to environmental tobacco smoke in Finland

BACKGROUND: Environmental tobacco smoke (ETS) exposure levels in different restaurant types in Finland were assessed before the National Tobacco Act restricting smoking in restaurants was activated. METHODS: Exposure to ETS was determined by measuring nicotine in the breathing zone of non-smoking restaurant workers and by quantification of the nicotine metabolites cotinine and 3-hydroxycotinine in the urine of these workers during one whole work week. Altogether 23 workers from 15 restaurants were included in the study. RESULTS: The geometric mean (GM) breathing-zone nicotine level was 3.9 microg/m(3) (3.7 microg/m(3) in pubs, 1.4 microg/m(3) in dining restaurants, and 10.2 microg/m(3) in nightclubs). The GM cotinine and trans-3'-hydroxycotinine level in urine were 3.3 ng/mg((creatinine)) and 15.3 ng/mg((creatinine)), respectively. The exposure to ETS of restaurant workers in dining restaurants was clearly lower than that of workers in pubs and nightclubs as indicated by all ETS-markers used in the present study. During the work week, the cotinine and 3'-hydroxycotinine levels in urine of the study subjects increased. The correlation between breathing zone nicotine and urine cotinine and hydroxycotinine was 0.66 for both compounds. Post-shift cotinine and hydroxycotinine levels were not significantly higher than the pre-shift levels. CONCLUSIONS: If 9 ng cotinine/mg((creatinine)) is considered as the level above which heavy exposure has occurred, then this level was exceeded by 14 (approximately 60%) subjects at least once during the work week. Nicotine metabolite concentrations in the urine increased during the work week in 80% of the subjects, and the increase was especially noticeable for subjects working in both pubs and nightclubs. The study indicates that measures to restrict ETS exposure in restaurants are needed.     

Kidney effects in long term exposed lead smelter workers.

Occupational exposure to lead may cause kidney damage. This study was carried out on a cohort of 70 active and 30 retired long term exposed lead smelter workers. Their kidney function was compared with 31 active and 10 retired truck assembly workers who had no occupational exposure to lead. The lead workers had been regularly followed up with measurements of lead concentration in blood since 1950. Previous exposure to lead was calculated as a time integrated blood lead index for each worker. Blood and urine samples were obtained from all subjects. The concentration of lead in blood (B-Pb) and urine (U-Pb) was analysed. The urinary concentrations of several sensitive indicators of early tubular (U-beta 2-microglobulin (U-beta 2-m); U-N-acetyl-beta-glucosaminidase (U-NAG)) and glomerular kidney damage (U-albumin) were determined. The B-Pb and U-Pb values were significantly higher among active and retired lead workers compared with their corresponding control groups. The highest concentrations were found among the active lead workers. The concentrations of the parameters of kidney function investigated were of the same magnitude for exposed workers and controls. No clinical signs of renal impairment were found among the workers. No correlations of clinical importance existed between concentrations of U-albumin, U-beta 2-m, and U-NAG activity on the one hand and the concentrations of B-Pb, cumulative blood lead index, U-Pb, and lead concentrations in the calcaneus and tibia on the other, among lead workers and controls. Despite many years of moderate to heavy exposure to lead, particularly for the retired lead workers, no signs of adverse effects on the kidney such as early tubular or glomerular malfunction were found. Reversible changes in kidney function during the 1950s and 1960s could not be excluded, however, due to a greater exposure to lead during that time.     

Workers' exposure to bioaerosols from three different types of composting facilities

Composting is a natural dynamic biological process used to valorise putrescible organic matter. The composting process can involve vigorous movements of waste material piles, which release high concentrations of bioaerosols into the surrounding environment. There is a lack of knowledge concerning the dispersal of airborne microorganisms emitted by composting plants (CP) as well as the potential occupational exposure of composting workers. The aim of this study was to investigate the workers exposure to bioaerosols during working activities in three different types of composting facilities (domestic, manure, carcass) using two different quantification methods (cultivation and qPCR) for bacteria and moulds concentrations. As expected, even if there are differences between all CP frameworks, independently of the type of the raw compost used, the production of bioaerosols increases significantly during handling activities. Important concentrations of mesophilic moulds and mesophilic bacteria were noted in the working areas with a respective maximal concentration of 2.3 × 10⁵ CFU/m³ and 1.6 × 10⁵ CFU/m³. A. fumigatus and thermophilic Actinomycetes were also detected in all working areas for the 3 CP. This study emphases the risks for workers to being in contact with aerosolized pathogens such as Mycobacterium and Legionella and more specifically, L. pneumophila. The presence of high concentration of these bacteria in CP suggests a potential occupational health risk. This study may lead to recommendations for the creation of limits for occupational exposure. There is a need for identifying the standards exposure limits to bioaerosols in CP and efficient recommendation for a better protection of workers' health.     

甲醛暴露工人外周血淋巴细胞遗传物质损伤水平的研究

目的评价甲醛暴露工人外周血淋巴细胞DNA和染色体损伤水平。方法选择2家密度板厂151名甲醛暴露工人(暴露组)和某推土机厂112名非甲醛暴露工人(对照组)为研究对象,用气相色谱法检测作业环境的甲醛浓度,采用彗星试验和胞质分裂阻滞微核试验,评价其外周血淋巴细胞DNA和染色体损伤水平。结果暴露组工人作业环境中的甲醛8h时间加权平均浓度(0.10～7.88mg/m3)高于对照组(<0.01mg/m3)。高暴露组Olive尾矩为3.95,95%CI为3.53～4.43;低暴露组Olive尾矩为3.03,95%CI为2.49～3.67;对照组Olive尾矩为0.93,95%CI为0.78～1.10,各组间差异均有统计学意义。暴露组彗星尾长为6.78,95%CI为6.05～7.60,均高于对照组,差异有统计学意义。高暴露组彗星尾长为12.59,95%CI为11.80～13.43;低暴露组彗星尾长为11.25,95%CI为10.12～12.50,差异无统计学意义。高暴露组的微核率为(0.65±0.36)%,低暴露组的微核率为(0.41±0.25)%,对照组的微核率为(0.27±0.13)%,各组间的差异均有统计学意义。各指标均有随暴露水平增加而增高的趋势,按吸烟情况分层后仍有增高的趋势。结论甲醛暴露可导致工人外周血淋巴细胞的DNA和染色体损伤水平增高,并且有随暴露水平增加而增高的趋势。     

Lead in finger bone, whole blood, plasma and urine in lead-smelter workers: extended exposure range

Objectives: To assess the historical exposure and to study the relationships between lead concentrations in whole blood (B-Pb), plasma (P-Pb), urine (U-Pb), finger bone (Bone-Pb) and duration of employment in workers at a secondary lead smelter and to compare the relationships between B-Pb and P-Pb with results from previous studies of populations with a wide range of lead exposure. Methods: In 39 lead workers (29 active, ten retired), recruited from those with the highest exposure at a German secondary lead smelter, levels of B-Pb, P-Pb and U-Pb were determined by inductively coupled plasma mass spectrometry (ICP-MS). Bone-Pb was determined by in vivo X-ray fluorescence (XRF). Results were compared with data from a previous study on 90 workers (71 active, 19 retired) with lower exposure, from a Swedish secondary lead smelter, as well as with previously collected data from 42 active Russian lead workers and 34 Ecuadorian lead-exposed subjects. Results: The median values in the active/retired German lead workers were: age 44/59 years, duration of employment 20/38 years, Bone-Pb 71/150 g/g, B-Pb 500/330 g/l, P-Pb 2.7/1.1 g/l, and U-Pb 25/13 mol/mol creatinine. Bone-Pb increased with duration of employment by 4.2 g/g per year and 1.6 g/g per year in German and Swedish workers, respectively. The median Bone-Pb was three times higher in both active and retired German workers than in Swedish smelter workers with essentially the same age distribution and duration of employment. The linear regression equation between B-Pb and log P-Pb in the combined group of Ecuadorian, German, Russian and Swedish lead-exposed subjects (n=176) was B-Pb=545×log[P-Pb] + 258 (r_s=0.94; P<0.001). Conclusions: The high Bone-Pb values recorded for the German smelters implied a historical lead exposure of considerable magnitude. The long-term high lead exposure also showed up in the B-Pb levels for both active and retired workers, leading to the implementation of necessary industrial safety measures in order to respond to biological threshold limits. The suggested equation describing the relationship between B-Pb and P-Pb in the combined group of subjects with a wide range of lead exposure can be useful in future cross-sectional and longitudinal studies of lead-exposed populations, relating, e.g., lead exposure to adverse health outcomes.     

Kidney effects in long term exposed lead smelter workers.

Occupational exposure to lead may cause kidney damage. This study was carried out on a cohort of 70 active and 30 retired long term exposed lead smelter workers. Their kidney function was compared with 31 active and 10 retired truck assembly workers who had no occupational exposure to lead. The lead workers had been regularly followed up with measurements of lead concentration in blood since 1950. Previous exposure to lead was calculated as a time integrated blood lead index for each worker. Blood and urine samples were obtained from all subjects. The concentration of lead in blood (B-Pb) and urine (U-Pb) was analysed. The urinary concentrations of several sensitive indicators of early tubular (U-beta 2-microglobulin (U-beta 2-m); U-N-acetyl-beta-glucosaminidase (U-NAG)) and glomerular kidney damage (U-albumin) were determined. The B-Pb and U-Pb values were significantly higher among active and retired lead workers compared with their corresponding control groups. The highest concentrations were found among the active lead workers. The concentrations of the parameters of kidney function investigated were of the same magnitude for exposed workers and controls. No clinical signs of renal impairment were found among the workers. No correlations of clinical importance existed between concentrations of U-albumin, U-beta 2-m, and U-NAG activity on the one hand and the concentrations of B-Pb, cumulative blood lead index, U-Pb, and lead concentrations in the calcaneus and tibia on the other, among lead workers and controls. Despite many years of moderate to heavy exposure to lead, particularly for the retired lead workers, no signs of adverse effects on the kidney such as early tubular or glomerular malfunction were found. Reversible changes in kidney function during the 1950s and 1960s could not be excluded, however, due to a greater exposure to lead during that time.     

Occupational exposure to solar radiation in Australia: who is exposed and what protection do they use?

Objective: Solar ultraviolet radiation (UVR) exposure is widely recognised as a leading cause of skin cancer, with outdoor workers being particularly at risk. Little is known on a national level about how many workers are exposed to solar radiation, the circumstances in which they are exposed, or their use of protective measures. Methods: The Australian Work Exposures Study (AWES) was a cross‐sectional telephone survey of 5,023 Australian workers aged 18 to 65. A subset of 1,113 respondents who indicated they worked outdoors was asked about their exposure to solar radiation in terms of the amount of time they spent working outdoors, their working location and their use of sun protective measures. Results: A total of 1,100 respondents (22% overall) were assessed as being exposed to solar radiation at work. Exposure was more likely among males and those residing in lower socioeconomic and regional areas. Sun protection was used by 95% of the respondents, although the level of protection varied among workers, with only 8.7% classified as fully protected. Conclusions: This study provides valuable information regarding solar exposure that has not previously been available. Implications: The results of this study will inform strategies for risk reduction.     

冷轧厂工人个体噪声暴露测量的初步分析

目的采用个体噪声暴露测量方法,了解冷轧厂工人噪声暴露的水平和特点,为防治轧钢工的噪声职业危害提供基础数据。方法以轧钢厂4个主要工艺中的11个工种为分组单位,每组抽取3～5人,用SH-126记录式个体声剂量计对白班（8：00至16：00）工人进行个体噪声暴露测量,同时填写工时记录,计算8h等效A声级。结果轧钢厂现场复杂,噪声源数量多、不稳定,工人同时受到多个噪声源的影响,个体噪声暴露声压级波动大。53名工人中个体噪声暴露最大值为100．0dB（A）。最小值为81．2dB（A）;噪声暴露水平最高的头部焊工为94．20dB（A）,最低的纵切剪切工为89．02dB（A）;质量枪验工组内极差最大,为16．3dB（A）;轧机主操作上极差最小,为2．3dB（A）。提示采取个体噪声暴露测量方法能比较准确、完整地反映冷轧厂作业工人的复杂噪声暴露情况。结论冷轧厂个体噪声暴露均超过85dB（A）,应加强噪声防护。个体噪声剂量计是以工人为主体,反映个体的噪声暴露情况和接触水平。     

地铁站勤务人员个体噪声暴露的监测与分析

目的 采用个体噪声暴露测量方法,了解地铁站勤务人员噪声暴露的水平和特点,为地铁站勤务人员的噪声职业危害控制提供依据。方法 以城市地铁某线路6个站点的4类岗位勤务人员为对象,用记录式噪声个体计量仪对地铁运行时间段内各岗位勤务人员进行个体噪声暴露测量。结果 城市地铁站的现场复杂,噪声源数量多、不稳定。在受检的48名勤务人员中,车站机房岗位的工作班内加权平均等效A声级（LAeq）水平最高为（81．8±2．5）dB（A）,车站控制岗位班内加权平均LAeq最低为（68．7±1．8）dB（A）;车站厅巡岗位班内加权平均LAeq水平极差最大为8．1dB（A）,车站控制岗位班内加权平均IAeq水平极差最小为4．0dB（A）。结论 地铁站勤务人员个体噪声暴露极不均一,用个体噪声暴露测量方法能较灵敏、完整地反映地铁站勤务人员的复杂噪声暴露状况。     

Variation in blood concentrations of cadmium and lead in the elderly

This study aims at characterizing blood concentrations of cadmium (B-Cd) and lead (B-Pb) in a group of 176 men and 248 women, 49-92 years of age (mean 68 years), selected from the Swedish Twin Registry. Metal concentrations were determined using graphite furnace atomic absorption spectrophotometry. B-Cd ranged from 0.05 to 6.8 microg Cd/L (median 0.36 microg Cd/L) and B-Pb from 5.6 to 150 microg Pb/L (median 27 microg Pb/L). As expected, smokers had higher B-Cd than nonsmokers (median 1.3 versus 0.32 microg Cd/L), while B-Pb was not significantly related to smoking habits. Among nonsmokers, women had higher B-Cd than men (median 0.35 versus 0.25 microg Cd/L). In men, but not women, B-Cd increased with age and consequently the gender-related difference in B-Cd was most obvious in the youngest age group. On the other hand, women had lower B-Pb than men (median 24 versus 30 microg Pb/L). In both men and women, B-Pb decreased between 50 and 70 years of age, perhaps reflecting decreased energy intake. In women, the highest B-Pb in the 50-55 years age group is probably related to an increased release of Pb from the skeleton during postmenopausal bone demineralization. After about 70 years, B-Pb tended to increase, which probably is a cohort effect due to much higher Pb exposure 10-30 years ago when leaded gasoline was used.     

Lead in finger-bone analysed in vivo in active and retired lead workers

In 75 active lead workers the median lead level in finger-bone (bone-Pb), as determined in vivo by an X-ray fluorescence method, was 43 micrograms/g (range less than 20-122). In 32 retired workers the median level was even higher, 59 micrograms/g (range less than 20-135), which indicates a slow turnover rate of lead in finger-bone. This was confirmed in 18 of the "active" workers, in whom bone-Pb was studied in connection with an exposure-free period. In spite of a significant decrease in blood-lead levels (B-Pb), no systematic change of bone-Pb occurred. There was an increase of bone-Pb with time of employment, but with a large interindividual variation. No association was found between bone-Pb and present B-Pb in the active lead workers. However, in the retired ones, B-Pb rose with increasing bone-Pb. The bone-lead pool thus causes an "internal" lead exposure.     

Hair-Pb longitudinal profiles and blood-Pb in the population of young Slovenian males

Hair-Pb longitudinal profiles of 25 mm hair length were measured in a population of Slovenian men (aged 18-25 years) using "tape sandwich" solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS). From these data two parameters related to Pb exposure were deduced. Hair-Pb proximal (H-Pbprox.) denotes the Pb content of the proximal 3mm hair segment, while Hair-Pb average (H-Pbaver.) denotes the average Pb content of a 25 mm hair length. The former were found to be on average at least a factor of 2 lower than the H-Pbaver. values that are normally reported in the literature for hairs of 20-50 mm length. Hair-Pb gradient (H-Pbgrad.) defined as the difference in Pb content between the distal (25 mm) and the proximal (3 mm) hair segments divided by the hair length was found to be highly correlated to the level of air Pb pollution (R=0.9931; P<0.001; n=5), while association between H-Pbprox. and air-Pb was not significant (R=0.5765; P>0.05; n=5). Simultaneously, lead in whole blood (B-Pb) was determined by ETAAS as another parameter of Pb exposure. The frequency distribution of log B-Pb values followed a symmetrical Gaussian shape with a median value of 35 microg Pb/L. Log H-Pbprox. frequency distribution, on the contrary, showed a Poissonian shape. Transformation of the data revealed the existence of four homogeneous groups of males with different median H-Pbprox. values (40, 86, 326 and 2500 ng/g). The major proportion of the Slovenian male population ( approximately 70%) has H-Pbprox. contents between 60 and 600 ng/g. A weak but statistically significant association was found between logs H-Pbprox. and B-Pb (R=0.3957; P<0.05; n=247) but when only those subjects were retained whose both parameters were determined with reasonable accuracy and were either above or below the predetermined value (B-Pb=50 microg/L; H-Pbprox.=450 ng/g), substantial improvement in the strength of correlation was observed (R=0.7049; P<0.01; n=84). The poor strength of association between these parameters was attributed to the large variation in Pb intake and different kinetics of Pb appearance in hair and blood. This statement is consistent with reports dealing with the relationship between H-Pb and B-Pb found in the literature.     

Application of classic epidemiological studies and proteomics in research of occupational and environmental exposure to lead,cadmium and arsenic

The metals/metaloids lead (Pb), cadmium (Cd), and arsenic (As) are among the leading toxic agents in the environment. They represent an important source of dangerous exposure in humans, particularly in industry workers. The most serious consequences of exposure to those heavy metals are cancers and cardiovascular diseases. In studies of human exposure to Pb, Cd, and As alone and in a mixture markers signaling the subtle, early lesions that occur in the human body are still lacking. It is appropriate to develop high throughput techniques and use non-invasive materials. The techniques currently used in classic epidemiological studies allow selection of single markers of changes of exposure to chronic low dose levels of metal/metaloids mixtures. However, application of proteomic techniques in such studies may allow the selection of new biomarkers of environmental and occupational exposure to heavy metals characterized by high sensitivity and specificity. As presented in our review paper, proteomic techniques in combination with appropriate statistical methods allow the selection of potential markers to estimate the changes in the human body when exposed to those heavy metals.     

职业暴露甲萘威对女性生殖内分泌的影响

分别选择某农药厂甲萘威生产女工67名为暴露组、厂行政办公区女性工作人员47名为对照组。对环境空气中甲萘威及其相关气体如异氰酸甲酯(MIC)、氨气及总酚进行持续3d的监测,同时选择暴露区及对照区各3人进行个体采样和皮肤污染量测定;运用回顾性队列研究的方法对其月经和妊娠结局进行评价。测定其血清中的卵泡刺激素(FSH)、黄体生成素(LH)、孕酮(P)、催乳素(PRL)和雌二醇(E2)水平。结果显示暴露组空气中甲萘威、总酚浓度明显高于对照组(P<0.01),个体采样及皮肤污染量结果均显示暴露组甲萘威浓度显著高于对照组(P<0.01);暴露组自然流产发生率显著高于对照组(P<0.05)。提示甲萘威农药生产职业暴露可能对女工的妊娠结局有一定的影响。