Cohort study among workers exposed to benzene in China: II. Exposure assessment

This report describes a retrospective exposure assessment method used in a follow-up mortality study of workers exposed to benzene. The approach quantified historical exposure to benzene in a multi-industry, multicenter cohort, involving 672 factories in 12 cities in China. Historical exposure data were collected to obtain exposure information related to 1,427 work units (departments) and 3,179 unique job titles from benzene-producing or -using factories in which written records and other data sources were evaluated. The basic unit for exposure assessment was a factory/work unit/job title combination which was considered separately during each of seven calendar-year time periods between 1949 and 1987 for a total of 18,435 exposure assignments. Historical information collected to estimate exposure included benzene monitoring data; lists of raw materials and factory products, and the percentage of benzene in each; the total amount and dates of use of benzene or benzene-containing materials; use of engineering controls and personal protective equipment; and other available exposure information. Overall, 38% (ranging from 3% for the earliest periods to 67% for the last period) of the estimates were based primarily on benzene monitoring data. In the absence of job-specific benzene monitoring data for a given calendar period, measurement results or exposure estimates for similar jobs and/or other calendar periods were used in conjunction with other exposure information to derive estimates. Estimated exposure levels are presented by industries and occupations. The highest average exposures during 1949–1987 were observed for the rubber and plastic industry (30.7 ppm), and for rubber glue applicators (52.6 ppm).     

Further reduction in lead exposure in women in general populations in Japan in the 1990s, and comparison with levels in east and south-east Asia

Objective: The objective of the study was to elucidate the current level of environmental lead (Pb) exposure of women in general population in Japan, where the use of organic Pb in automobile gasoline was phased out from 1973 to reach a zero level early in the 1980s. Methods: A survey was conducted in 27 sites throughout Japan from 1991 to 1997. Five hundred and eighty-eight non-smoking women from the sites offered 24-h food duplicate, peripheral blood, and spot urine samples. Pb in food duplicates (Pb-F), blood (Pb-B), and urine (Pb-U) were analyzed by inductively-coupled plasma mass spectrometry. The results of Pb-F and Pb-B were compared with observations from a study conducted from 1977 to 1981 on 339 women at the same sites. Log-normal distribution was assumed for the evaluation of the results. Results: Geometric means (GMs) of Pb-F, Pb-B, and Pb-U in the 1991–1997 study were 9.0 μg/day, 20.2 μg/l, and 2.18 μg/g creatinine, respectively. The values for Pb-F and Pb-B were substantially lower than the values (32.8 μg/day for Pb-F and 31.7 μg/l for Pb-B) obtained in the 1977–1981 study, which were already low when compared internationally. Cd-U values in the period from 1991 to 1997 also appeared to be among the lowest in the world. Analysis for time-dependent changes in Pb-U was, however, not possible at the time of this study because no values were available for the period from 1977 to 1981. Conclusions: Substantial reductions from 1977–1981 levels in environmental Pb exposure were observed among the study populations in Japan. Current exposure levels appear to be lower than those in other parts of Asia, the USA, and Europe. Received: 16 March 1999 / Accepted: 27 August 1999     

Occupational epidemiology in the rubber industry: Implications of exposure variability

The variability of exposure has important implications for the design of occupational epidemiologic studies. To assess the influence of this variability in the rubber industry, the efficiency of different schemes for classification of exposure to particulates, cyclohexane-soluble contaminants, and solvents was assessed. Groupings based on job title, plant, factors affecting exposure, published classifications, and the International Standard Classification of Occupations of the International Labor Organization (ISCO-ILO) were compared. Statistical parameters for contrast in average exposure between groups and precision of average exposure within groups were developed to enable comparison of the efficiency of different classification schemes. Grouping of exposure to particulates and dermal exposure appeared to be less efficient than grouping of exposure to solvents. Grouping of solvent exposure using occupational title groups, existing classification schemes, and schemes based on factors affecting exposure showed comparable high resolution in exposure levels. Even the most detailed grouping schemes based on the combination of plant and occupational title group showed relatively modest resolution in particulate and dermal exposure levels. Groupings based on factors affecting exposure showed similar resolution for these exposures, but had higher precision due to having fewer groups. Application of optimal exposure grouping strategies will benefit new research on cancer among rubber workers. Eventually, this might resolve the situation in which a complete industry was included on the list of proven human carcinogens.     

Polybrominated diphenyl ethers (flame retardants) in mother-infant pairs in the Southeastern U.S.

Polybrominated diphenyl ethers (PBDEs) are commonly used flame retardants in foams, building material, electronics, and textiles. These chemicals leach into the environment, where they persist, and are found today in virtually every population worldwide. Several studies in recent years have detected the presence of PBDEs in maternal and infant samples. However, few of these studies were conducted in the U.S., and few examined paired or matched mother blood-cord blood samples. We analyzed serum from 10 mother-infant pairs for the presence of PBDEs in a patient population in the Southeastern U.S. Out of 35 measured PBDE congeners, five (BDE-28, -47, -99, -100, and -153) were present, with detection frequencies of 65–100 %. The total PBDE concentrations in maternal and infant sera were highly correlated (r² = 0.710, p = 0.0043). The levels of BDE-47, -99, and -100 and of total PBDEs were higher in the infant cord sera when compared with those in maternal sera (p < 0.017), suggesting that fetuses and neonates might have higher circulating concentrations of these potentially neurotoxic and endocrine disrupting chemicals compared with their mothers. The primary focus henceforward should be whether there are any deleterious effects from exposure to these chemicals on human health.     

Exposure of hairdressers to the main cosmetics used in hairdressing salons in France: A preliminary study

In recent years, more attention has been given to chemical exposure in hairdressers. This increasing interest is largely due to the various respiratory and skin symptoms observed in hairdressers. According to these symptoms, hairdressers are in contact with various sources of exposure. Particularly in France, little information is available to assess professional exposure of hairdressers. In order to gather information to assess exposure in hairdressers, 11 hairdressing salons were visited. All the salons were located in Brest City (France). Preferentially, small hairdressing salons were visited. Observations were performed to obtain salon characteristics and to record workers' practices. Calculations revealed that in the worst-case scenario, dermal professional exposure reaches 14.68 and 13.67 mg/kg/day for hair coloring and highlighting mixtures, respectively. Inhalation exposure represents 14.2 and 18.1 mg/kg/day for hair coloring and highlighting mixtures, respectively. These exposure values represent baseline values for exposure of French hairdressers working in small hairdressing salons.     

Fertility and exposure to solvents among families in the Agricultural Health Study

Background

Several studies have reported associations between solvent exposure and reduced female fertility, but the evidence is inconclusive for male fertility.

Objectives

To investigate the impact of solvent exposure on subfertility among families of male licensed pesticide applicators in the Agricultural Health Study cohort.

Methods

The couples enrolled between 1993 and 1997. Cross‐sectional questionnaire information on work tasks was used to assess exposure to solvents. The data were limited to couples (wife aged less than 40 years) with an attempt at pregnancy in the last four years (n = 2112).

Results

Twenty eight per cent of the couples were defined as subfertile (not conceiving a pregnancy after at least 12 months of unprotected intercourse, regardless of whether or not a pregnancy ultimately occurred). Adjusted subfertility odds ratios (OR) for exposure to solvents were calculated with logistic regression. Female (OR 1.42, 95% CI 1.15 to 1.75) and male exposure to solvents (OR 1.21 (95% CI 0.93 to 1.57) for monthly exposure and 1.40 (95% CI 0.97 to 2.03) for daily or weekly exposure) were associated with subfertility. In farming, spouses may share or exchange jobs. To account for potential dual exposure, variables for parental exposure (either parent exposed or both parents exposed) were also defined. Both were strongly associated with subfertility (OR 1.62 (95% CI 1.20 to 2.17) and OR 2.10 (95% CI 1.22 to 3.60), respectively).

Conclusions

Solvents may impair fertility of either gender, though the evidence for female effects is stronger than for male effects.     

Occupational and environmental human lead exposure in Brazil

The purpose of this paper is to present a review of data on assessment of exposure and adverse effects due to environmental and occupational lead exposure in Brazil. Epidemiological investigations on children lead exposure around industrial and mining areas have shown that lead contamination is an actual source of concern. Lead in gasoline has been phasing out since the 1980s, and it is now completely discontinued. The last lead mining and lead refining plant was closed in 1995, leaving residual environmental lead contamination which has recently been investigated using a multidisciplinary approach. Moreover, there are hundreds of small battery recycling plants and secondary smelting facilities all over the country, which produce focal urban areas of lead contamination. Current regulatory limits for workplace lead exposure have shown to be inadequate as safety limits according to a few studies carried out lately.     

Toxic trace elements in maternal and cord blood and social determinants in a Bolivian mining city

This study assessed lead, arsenic, and antimony in maternal and cord blood, and associations between maternal concentrations and social determinants in the Bolivian mining city of Oruro using the baseline assessment of the ToxBol/Mine-Niño birth cohort. We recruited 467 pregnant women, collecting venous blood and sociodemographic information as well as placental cord blood at birth. Metallic/semimetallic trace elements were measured using inductively coupled plasma mass spectrometry. Lead medians in maternal and cord blood were significantly correlated (Spearman coefficient = 0.59; p < 0.001; 19.35 and 13.50 μg/L, respectively). Arsenic concentrations were above detection limit (3.30 μg/L) in 17.9 % of maternal and 34.6 % of cord blood samples. They were not associated (Fischer’s p = 0.72). Antimony medians in maternal and cord blood were weakly correlated (Spearman coefficient = 0.15; p < 0.03; 9.00 and 8.62 μg/L, respectively). Higher concentrations of toxic elements in maternal blood were associated with maternal smoking, low educational level, and partner involved in mining.     

Applicability of homogeneous exposure groups for exposure assessment in the chemical industry

The purpose of the study was to assess occupational exposure to chemicals, by taking the aspects presented in European standard EN 689 into account, especially with respect to homogeneous exposure groups and their suitability as the basis for exposure assessment. In addition, dermal exposure to chemicals was assessed when appropriate. The industries studied included a plywood factory, a paint factory and a sewage treatment plant of an oil refinery. The workers were classified into homogeneous exposure groups by the persons in charge of occupational health issues in the respective workplaces. The concentrations of the contaminants were measured in workplace air by breathing-zone and stationary sampling, and these approaches were compared. Dermal exposure was measured when applicable. The homogeneity of the grouping was tested with analysis of variance whenever possible. The tasks studied in plywood manufacturing fulfilled the criteria of homogeneous exposure groups for both respiratory and dermal exposure. The group of operators in the sewage treatment plant was highly homogeneous. The complicated organization of the tasks made the use of homogeneous exposure groups (HEG) unsuitable at the paint factory. These findings show that reliable exposure assessment cannot be achieved with a formal standard; instead, comprehensive occupational hygiene evaluation is needed. It should also have a great importance when exposure models are developed. Received: 27 December 1999 / Accepted: 6 May 2000     

Exposure assessment for study of olfactory function in workers exposed to styrene in the reinforced-plastics industry

BACKGROUND: This study was undertaken in conjunction with an evaluation of the olfactory function of 52 persons exposed to styrene vapors to provide quantitative styrene exposure histories of each subject for use in the interpretation of the results of olfactory function testing. METHODS: Current and historic exposures were investigated. Historic exposures were reconstructed from employment records and measurements of styrene exposure made in the subject facilities over the last 15 years. Current exposures were estimated for every exposed subject though personal air sampling and through pre- and post-shift measurements of urinary metabolites of styrene. RESULTS: The study population had been employed in the reinforced-plastics industry for an average of 12.2 +/- 7.4 years. Their mean 8-hr time weighted average (TWA) respirator-corrected annual average styrene exposure was 12.6 +/- 10.4 ppm; mean cumulative exposure was 156 +/- 80 ppm-years. The current respirator-corrected 8-hr TWA average exposure was 15.1 +/- 12.0 ppm. The mean post-shift urinary mandelic and phenylglyoxylic acid (PGA) concentrations were 580 +/- 1,300 and 170 +/- 360 mg/g creatinine, respectively and were highly correlated with air concentrations of styrene. CONCLUSIONS: This quantitative exposure evaluation has provided a well-characterized population, with documented exposure histories stable over time and in the range suitable for the purposes of the associated study of olfactory function.     

Reducing attenuation in exposure-response relationships by exposure modeling and grouping: the relationship between wood dust exposure and lung function

BACKGROUND: In a study of wood dust exposure and lung function, we tested the effect on the exposure-response relationship of six different exposure metrics using the mean measured exposure of each subject versus the mean exposure based on various methods of grouping subjects, including job-based groups and groups based on an empirical model of the determinants of exposure. METHODS: Multiple linear regression was used to examine the association between wood dust concentration and forced expiratory volume in 1s (FEV(1)), adjusting for age, sex, height, race, pediatric asthma, and smoking. RESULTS: Stronger point estimates of the exposure-response relationships were observed when exposures were based on increasing levels of aggregation, allowing the relationships to be found statistically significant in four of the six metrics. The strongest point estimates were found when exposures were based on the determinants of exposure model. CONCLUSIONS: Determinants of exposure modeling offers the potential for improvement in risk estimation equivalent to or beyond that from job-based exposure grouping.     

Occupational and environmental exposure to tribromophenol used for wood surface protection in sawmills

This study analyses the occupational and environmental conditions of sawmills where the lumber is protected from microorganism action by dipping it in 2,4,6 tribromophenol (TBP). Three processes were evaluated: hydraulic immersion, chain conveyor system and manual immersion. The biggest occupational exposure to TBP was registered in manual and chain conveyor systems. The average values in the workers' urine for TBP were 6.9 and 5.7 mg/g creatinine, respectively. For environmental exposure, the highest value in well waters was 25.1 microg/L and in soil was 4,602 mg/kg. It could be established that the hydraulic immersion system presents less occupational TBP exposure. Nevertheless, the hydraulic system, as well as the other two anti-stain alternatives, requires the introduction of pollution prevention efforts. To reduce the environmental exposure to TBP, the lumber-dipping tank area, the forklift traffic areas, and the storage areas need to be waterproofed. It is also necessary to implement a TBP solution recovery system to eliminate dripping from the lumber once it is removed from the fungicide dipping tanks.     

黄山市医疗照射频度水平调查研究

本文报道了黄山市 1998年医疗照射年频度水平。调查结果表明 :X线诊断、临床核医学及放射治疗的年频度分别为 14 3 .2 4、0 .0 3 6及 0 .2 0 2人次 /千人口。其中透视和拍片的年频度分别为 42 .18和 85 .94人次 /千人口。同时还分析了医疗照射随年龄、性别、季节及地区变化等情况。并与 1996年医疗照射频度水平进行了比较。     

云南省5年HIV职业暴露因素分析

[目的]分析艾滋病病毒（HIV）职业暴露现状,探讨职业暴露后应急预防处理方法。[方法]对云南省2005年～2010年报告的由于职业因素引起的HIV暴露案例进行分析。[结果]2005年～2010年共发生职业暴露1138人,包括医护人员和公安司法人员;暴露类型主要包括针刺伤647例（56．9％）、血液接触皮肤粘膜305例（26．8％）和抓伤96例（8．4％）。974（85．6％）人实施暴露后预防（PEP）,采用基本用药程序或强化用药程序进行干预治疗,所有病例随访未发现HIV抗体阳转者。[结论]HIV职业暴露后感染的危险度较低,但是应严格遵守安全防护措施,暴露后及时使用预防用药,可有效阻断发生艾滋病职业暴露后感染。     

Air,hand wipe,and surface wipe sampling for Bisphenol A (BPA) among workers in industries that manufacture and use BPA in the United States

For decades, bisphenol A (BPA) has been used in making polycarbonate, epoxy, and phenolic resins and certain investment casting waxes, yet published exposure data are lacking for U.S. manufacturing workers.

In 2013–2014, BPA air and hand exposures were quantified for 78 workers at six U.S. companies making BPA or BPA-based products. Exposure measures included an inhalable-fraction personal air sample on each of two consecutive work days (n = 146), pre- and end-shift hand wipe samples on the second day (n = 74 each), and surface wipe samples (n = 88). Potential determinants of BPA air and end-shift hand exposures (after natural log transformation) were assessed in univariate and multiple regression mixed models.

The geometric mean (GM) BPA air concentration was 4.0 µg/m³ (maximum 920 µg/m³). The end-shift GM BPA hand level (26 µg/sample) was 10-times higher than the pre-shift level (2.6 µg/sample). BPA air and hand exposures differed significantly by industry and job. BPA air concentrations and end-shift hand levels were highest in the BPA-filled wax manufacturing/reclaim industry (GM_Air = 48 µg/m³, GM_Hand-End = 130 µg/sample) and in the job of working with molten BPA-filled wax (GM_Air = 43 µg/m³, GM_Hand-End = 180 µg/sample), and lowest in the phenolic resins industry (GM_Air = 0.85 µg/m³, GM_Hand-End = 0.43 µg/sample) and in the job of flaking phenolic resins (GM_AIR = 0.62 µg/m³, GM_Hand-End = 0.38 µg/sample). Determinants of increased BPA air concentration were industry, handling BPA containers, spilling BPA, and spending ≥50% of the shift in production areas; increasing age was associated with lower air concentrations. BPA hand exposure determinants were influenced by high values for two workers; for all other workers, tasks involving contact with BPA-containing materials and spending ≥50% of the shift in production areas were associated with increased BPA hand levels. Surface wipe BPA levels were significantly lower in eating/office areas (GM = 9.3 µg/100 cm²) than in production areas (GM = 140 µg/100 cm²).

In conclusion, worker BPA exposure was associated with tasks and conditions affecting both inhalation and dermal exposure. The potential for BPA-related health effects among these workers is unknown.     

Proportionate mortality ratio analysis of automobile mechanics and gasoline service station workers in New Hampshire

A proportionate mortality ratio (PMR) analysis of all deaths recorded from 1975 to 1985 among New Hampshire white male residents (age 20 years or older) was performed using death certificate information. Among automobile mechanics, the analysis revealed increases in mortality from leukemia (PMR = 178, N = 6); cancers of the oral cavity (PMR = 163, N = 4), lung (PMR = 112, N = 36), bladder (PMR = 169, N = 5), rectum (PMR = 182, N = 4), and lymphatic tissues (PMR = 200, N = 6); and cirrhosis of the liver (PMR = 140, N = 13) and suicide (PMR = 177, N = 22; p < 0.05). Workers in the gasoline service station industry experienced a leukemia mortality excess (PMR = 328, N = 3; p < 0.05) as well as increases in deaths from suicide (PMR = 162, N = 4), emphysema (PMR = 245, N = 4), and mental and psychoneurotic conditions (PMR = 394, N = 3). These workers are potentially exposed to a variety of substances including gasoline vapor, benzene, solvents, lubricating oils and greases, and asbestos (from brake and clutch repair) as well as welding fumes and car and truck exhaust. Despite limitations regarding the small number of deaths and methodologic constraints, the results of this analysis suggest that one or more of the exposures experienced by these workers poses a significant carcinogenic risk. More definitive epidemiologic studies are required to determine if the leukemia excess is associated with exposure to benzene, gasoline, or other workplace substances.     

Neurobehavioral and health-related deficits in solvent-exposed painters

The health status of 133 solvent-exposed painters was evaluated using the Neurobehavioral Evaluation System (NES) and blood test results from a physical exam. The comparison group consisted of 51 sheetmetal workers, minimally exposed to solvents. Degree of solvent exposure was calculated using three different indices derived from questionnaire responses. Multivariate analyses, adjusted for age, alcohol consumption, and smoking, indicated that painters performed less well on the symbol digit learning and vocabulary tasks. Evidence was also found for a dose-effect relationship, particularly when several features of the work environment were considered in estimating exposure. Degree of solvent exposure predicted levels of serum lead, BUN, and SGOT. These findings indicate that questionnaire-based measures of solvent exposure can be useful predictors of neurobehavioral and health-related deficits. Verbal ability, often used by researchers as a measure of premorbid functioning, may be adversely affected by solvent exposure. © 1996 Wiley-Liss, Inc.     

湖南部分地区40岁及以上居民烹饪污染性燃料及生物燃料暴露情况分析

目的 了解湖南部分地区40岁及以上居民烹饪污染性燃料及生物燃料暴露情况,为污染性燃料和生物燃料暴露防控工作提供参考依据.方法 调查对象来自于2019年湖南省5个慢性阻塞性肺疾病监测点,采用多阶段分层整群随机抽样方法,面对面询问调查方式收集相关信息.对样本复杂加权后分析不同特征人群烹饪污染性燃料和生物燃料暴露情况.结果 ...