Potential uses of petrochemical products can result in significant benzene exposures: MSDSs must list benzene as an ingredient

According to 29 CFR1910.1200 (Hazard Communication Standard [HCS]), a material safety data sheet (MSDS) must list a carcinogen as an ingredient if its concentration in a product is 0.1% or more by weight. However, according to the HCS, when the concentration of a carcinogen in a product is less than 0.1% (by weight) it may not be necessary to list it as an ingredient on the MSDS. The standard stipulates that if potential uses of the product can result in exposures to the carcinogen that exceed the Occupational Safety and Health Administration (OSHA) permissible exposure limit or the ACGIH threshold limit value (TLV), then it must be listed. This article focuses on the failure of MSDSs to report benzene as a listed ingredient in products that incorporate petroleum-derived ingredients such as toluene and hexane. In the United States, approximately 238,000 people are occupationally exposed to benzene each year. Only rarely is benzene listed as an ingredient on MSDSs even though it often comprises more than 0.1% of petroleum solvents and, when its concentrations in petroleum-derived products are much less than 0.1%, inhalation exposures to benzene can be much higher that its OSHA PEL of one part per million (ppm) by volume (v/v) andACGIH TLV of/one-half ppm (v/v). As a consequence of benzene's omission from MSDSs as a listed ingredient, employers are frequently unaware of their requirement to implement 29 CFR 1910.1028 (Benzene Standard) and of the need to address employee exposures to benzene in the workplace. This article demonstrates that benzene should be listed as an ingredient on MSDSs, even at concentrations in benzene-containing products that are between one and two orders of magnitude below OSHA's 0.1% threshold. An exposure assessment methodology is presented that is applicable to employees whose conditions of exposure are similar to those in the published study. These workers make up a similar exposure group. The information and methodology presented here are germane to preparation of accurate MSDSs for benzene-containing products, employers who must comply with 29 CFR 1910.1028, and retrospectively estimating exposures to benzene.     

Consumer product exposures associated with urinary phthalate levels in pregnant women

Human phthalate exposure is ubiquitous, but little is known regarding predictors of urinary phthalate levels. To explore this, 50 pregnant women aged 18-38 years completed two questionnaires on potential phthalate exposures and provided a first morning void. Urine samples were analyzed for 12 phthalate metabolites. Associations with questionnaire items were evaluated via Wilcoxon tests and t-tests, and r-squared values were calculated in multiple linear regression models. Few measured factors were statistically significantly associated with phthalate levels. Individuals who used nail polish had higher levels of mono-butyl phthalate (P=0.048) than non-users. Mono-benzyl phthalate levels were higher among women who used eye makeup (P=0.034) or used makeup on a regular basis (P=0.004). Women who used cologne or perfume had higher levels of di-(2-ethylhexyl) phthalate metabolites. Household products, home flooring or paneling, and other personal care products were also associated with urinary phthalates. The proportion of variance in metabolite concentrations explained by questionnaire items ranged between 0.31 for mono-ethyl phthalate and 0.42 for mono-n-methyl phthalate. Although personal care product use may be an important predictor of urinary phthalate levels, most of the variability in phthalate exposure was not captured by our relatively comprehensive set of questionnaire items.     

喷漆工作场所苯系物水平与职业健康风险评价

目的 了解喷漆工作场所车间空气中苯系物的危害程度,以保护该类场所作业人员健康.方法 选择木制家具制造、汽车制造、室内外装潢和零件喷漆等喷漆工作场所进行现场调查和采样,并对样品进行定量分析;采用健康风险评价方法对苯系物进行风险评定.结果 车间空气中苯、二甲苯浓度存在超过国家职业卫生标准现象;苯系物浓度较高的木制家具制造和零件喷漆现场其苯、二甲苯非致癌风险度均＞1,甲苯的非致癌风险度均＜1,苯的致癌风险度均＞10-4,密闭环境喷漆二甲苯的非致癌风险度＞1.结论 油漆种类、作业方式、防护措施等因素的差异,造成工作场所苯系物浓度差异较大,部分工作场所的苯系物的致癌风险和非致癌风险处于不可接受范围.     

Occupational exposures associated with work-related asthma and work-related wheezing among U.S. workers

BACKGROUND: National estimates of occupational asthma (OA) in the United States are sparse. METHODS: Using data from the Third National Health and Nutrition Examination Survey (NHANES III) 1988-1994, we analyzed associations between occupation and work-related asthma and work-related wheezing among U.S. workers. RESULTS: This study identified several occupations that were at risk of developing work-related asthma and/or wheezing, with cleaners and equipment cleaners showing the highest risks. Other major occupations identified were farm and agriculture; entertainment; protective services; construction; mechanics and repairers; textile; fabricators and assemblers; other transportation and material moving occupations; freight, stock, and material movers; and motor vehicle operators. The population attributable risks for work-related asthma and work-related wheezing were 26% and 27%, respectively. CONCLUSIONS: This study adds evidence to the literature that identifies work-related asthma as an important public health problem. Several occupations are targeted for additional evaluation and study. Of particular interest are cleaners, which are being increasingly reported as a risk group for asthma. Future intervention strategies need to be developed for effective control and prevention of asthma in the workplace.     

Occupational exposures among fathers of children with Wilms' tumor

An occupation-and-exposure linkage system was utilized to perform an epidemiologic case-control study of paternal occupation and Wilms' tumor in offspring. The first part of the study was designed to test the hypothesis that paternal lead (Pb) exposure is a risk factor for Wilms' tumor in offspring. The second part of the study was an exploratory analysis that sought to generate possible etiologic hypotheses about other paternal exposures in the workplace in relation to Wilms' tumor. Calculation of odds ratios indicated that there was no statistical difference in the frequency of occupational exposure to Pb, Pb alkyls, and Pb salts for fathers of children with Wilms' tumor and fathers of controls, a finding that contrasts sharply with the results of the one previously reported study in this area. In the exploratory phase of the study, case fathers were found more likely to have been exposed to boron, while control fathers were found more likely to have encountered insecticides, acetylene, o-chlorobenzylidene, oil orange ss, and diethylene glycol; the differences were statistically significant. Troublesome methodologic problems, including exposure misclassification, sample size, and multiple comparisons, are discussed.     

Occupational and other exposures associated with male end-stage renal disease: a case/control study

We conducted a case-control study of 325 men ages 30-69 who were diagnosed with end-stage renal disease (ESRD) between 1976 and 1984, and resided in four urban areas of Michigan in 1984. Cases were selected from the Michigan Kidney Registry and excluded men with diabetic, congenital, and obstructive nephropathies. Controls were selected by random-digit dialing and were pair-matched to cases for age, race, and area of residence. Telephone interviews were conducted with 69 percent of eligible cases and 79 percent of eligible controls. Risk of ESRD was significantly related to phenacetin or acetaminophen consumption (odds ratio(OR) = 2.66), moonshine consumption (OR = 2.43), a family history of renal disease (OR = 9.30); and regular occupational exposures to solvents (OR = 1.51) or silica (OR = 1.67). Particular occupational exposures with elevated risk were solvents used as cleaning agents and degreasers (OR = 2.50) silica exposure in foundries or brick factories (OR = 1.92), and silica exposure during sandblasting (OR = 3.83). Little or no trend of increased risk with duration of exposure was found for these occupational exposures, with the exception of silica in sandblasting. Limitations of these data include representativeness of cases, possible overreporting by cases, and misclassification of exposures inherent in self-reports.     

ARTICLE WITHDRAWN: Airborne asbestos exposures associated with the installation and removal of roofing products

This article has been withdrawn.     

Occupational exposure levels to benzene in Italy: findings from a national database

Purpose  

Benzene is classified as human carcinogen and the association with lymphohaematopoietic cancer has been observed in many occupational epidemiological studies. The aim of this study is to summarize data about occupational exposure levels to benzene in Italy.     

Occupational exposures and risk of pancreatic cancer

The objective was to analyze the relationship between occupation (and specific occupational exposures) and risk of exocrine pancreatic cancer (EPC). We conducted a multicenter hospital-based case–control study in Eastern Spain. We included 161 incident cases of EPC (59.6% men, 94 with histological confirmation, of whom 80% had ductal adenocarcinoma). Cases were frequency-matched with 455 controls by sex, age and province of residence. Information was elicited using structured questionnaires. Occupations were coded according to the Spanish version of the International Standard Classification of Occupations 1988. Occupational exposure to a selection of carcinogenic substances was assessed with the Finnish Job-Exposure Matrix (FINJEM). Odds ratios (OR) and 95% confidence intervals (CI) were estimated by multiple logistic regression, adjusting for sex, age, province, education, alcohol and smoking. A higher risk of EPC was associated with having worked as ‘Miners, shotfirers, stone cutters and carvers’, ‘Machinery mechanics and fitters’, ‘Building trades workers’ and ‘Motor vehicle drivers’ in men, ‘Office Clerks’ in women, and ‘Waiters’ in both sexes. Cases with ductal adenocarcinomas were more likely to have been exposed to chlorinated hydrocarbon solvents (OR = 4.1, 95% CI: 1.1–15.2, p-trend = 0.04). We also observed significant associations with exposure to ‘synthetic polymer dust exposure’ and ‘ionizing radiation’. Suggestive increases in risk were observed for ‘pesticides’, ‘diesel and gasoline engine exhaust’, and ‘hydrocarbon solvents’. Results support the hypothesis that occupational exposure to chlorinated hydrocarbon solvents is associated with exocrine pancreatic cancer.     

Hematological changes among Chinese workers with a broad range of benzene exposures

BACKGROUND: Depression of peripheral blood cells is a well-known indicator of benzene hematotoxicity. Previous studies of its effects on specific types of blood cells have yielded inconsistent results. We examine hematological findings and their possible relations with exposure markers validated in a recent biomarker project conducted in Tianjin, China. METHODS: Personal benzene exposures were sampled with 3-M organic vapor monitors, and analyzed by gas chromatography. The peripheral blood cells were counted by a cell counter. The WBC differential was manually counted on a total of 900 cells by a US commercial laboratory. RESULTS: A total of 130 exposed workers and 51 age- and gender-matched unexposed subjects were recruited in this study. Benzene exposure levels monitored on the day of biological sample collection for exposed workers ranged from 0.06 to 122 ppm. Their 4-week average and cumulative benzene exposure levels were 0.08-54.5 ppm and 6.1-623.2 ppm-years, respectively. Significant decreases of red blood cells (RBC), white blood cells (WBC), and neutrophils were observed and correlated with both personal benzene exposures and levels of urinary metabolites (S-phenylmercapuric acid and t,t-muconic acid) and albumin adducts of benzene oxide and 1,4-benzeoquinone. CONCLUSIONS: The depressions in RBC, WBC, and neutrophils observed in this study are not only exposure dependent, but also significantly different in the lowest exposed group (at or below 0.25 ppm) compared with unexposed subjects. The results of the present study appear to suggest that lymphocytes may not be more sensitive to chronic benzene exposure than neutrophils.     

Increased serum levels of advanced oxidation protein products and glycation end products in subjects exposed to low-dose benzene

Simple aromatic hydrocarbon benzene occurs naturally in crude oil and petroleum. Benzene has been internationally recognised as a haematotoxin and carcinogen. The involvement of oxidative stress is a major susceptibility factors for benzene hematotoxicity in humans. Advanced oxidation protein products (AOPPs) and advanced glycation end products (AGEs) are modified structures which can serve as markers of oxidative stress. The aim of this study is to assess modification of circulating AOPPs and AGEs, as early markers of oxidative stress, in subjects exposed to low dose of benzene. Furthermore the genetic polymorphism of glutathione-S-transferase (GST) may be related to health effects of benzene exposure, in fact both genotype T1 (GSTT1) and M1 (GSTM1) are involved in the detoxification of benzene oxide. The study was performed on 54 workers oil refinery employees. A group of 32 healthy age-matched subjects was included as controls. The AOPPs serum levels in oil refinery employees were higher in a statistically significant way than those measured in controls, but there were no significant changes in serum AGE levels between both groups. However, GST polymorphisms had not influence on serum levels of both biomarkers, so demonstrating that production of circulating AGEs and AOPPs in benzene parity-exposed workers levels is not dependent by GST genotypes. We can conclude that, in this condition, AOPPs are more sensitive marker of low benzene exposure than AGEs.     

Health risks associated with environmental radiation exposures

Much is known about health effects associated with exposure to ionising radiation. Numerous epidemiologic studies of populations exposed to radiation under a variety of circumstances have been conducted. These studies have clearly shown that radiation exposure can result in an increased risk of many types of cancer, and the findings are supported by a substantial body of literature from experimental studies. Despite the fact that radiation exposures from environmental sources comprise a relatively minor component of total population exposure, this type of exposure is often the most feared by the public. An accident like Chernobyl or a natural disaster like that at Fukushima provides a unique opportunity to learn more about the health risks from environmental radiation exposures. However, establishing the infrastructure and expertise required to design and conduct all aspects of a complex field study presents formidable challenges. This paper summarises the principal findings from the main studies of environmental radiation exposure that have been successfully undertaken. Although such studies are often exceedingly difficult to conduct, and may be limited by an ecologic design, they can be informative in assessing risk. Any new environmental study that is initiated should focus on special circumstances; additional ecological studies are not recommended.     

Airborne benzene exposures from cleaning metal surfaces with small volumes of petroleum solvents

Airborne benzene concentrations were measured in a room with controlled air exchange during surface cleaning with two petroleum-based solvents (a paint thinner and an engine degreaser). The solvents were spiked with benzene to obtain target concentrations of 0.001, 0.01, and 0.1% by volume in the liquid. Personal samples on the worker and area samples up to 1.8 m away were collected over 12 events (n = 84 samples) designed to examine variation in exposure with solvent type, cleaning method (rag wipe or spatula scrape), surface area cleaned, air exchange rate, solvent volume applied, and distance from the cleaned surface. Average task breathing zone concentrations of benzene represented by 18–32 min time-weighted averages were 0.01 ppm, 0.05 ppm, and 0.27 ppm, when the solvents contained approximately 0.003, 0.008, and 0.07% benzene. Solvent benzene concentration, volume applied, and distance from the handling activities had the greatest effect on airborne concentrations. The studied solvent products containing 0.07% benzene (spiked) did not exceed the current OSHA permissible exposure limit of 1 ppm (averaged over 8 h) or the ACGIH Threshold Limit Value of 0.5 ppm, in any of the tested short-term exposure scenarios. These data suggest that, under these solvent use scenarios, petroleum-based solvent products produced in the United States after 1978 likely did not produce airborne benzene concentrations above those measured if the concentration was less than 0.1% benzene.     

Occupational medicine monitoring of workers exposed to benzene

Based on the present level of perception of the benzene biotransformation, the influence of reactive metabolites on the haematopoetic system - maintaining low MAK rates of 5 mg/m3 and below them - is presented. Consequences for the rate of the biological exposition test utilized at present result from this statement. The importance of a regular SCE determination in circulating lymphocytes, of the longtermed examination of possible damages of sperm and the differentiated analysis of individual kinds of lymphocytes, incl. of the cell-mediating immunity is emphasized besides the performance of a regular supervision of the external exposition, i.e. by means of personal dosimeters. To clarify the benzene influence, the research should be orientated on the damages of the cytoskeleton and the stroma cells within the haematopoetic system.     

Leukemia risk associated with low-level benzene exposure

BACKGROUND: Men who were part of an Australian petroleum industry cohort had previously been found to have an excess of lympho-hematopoietic cancer. Occupational benzene exposure is a possible cause of this excess. METHODS: We conducted a case-control study of lympho-hematopoietic cancer nested within the existing cohort study to examine the role of benzene exposure. Cases identified between 1981 and 1999 (N = 79) were age-matched to 5 control subjects from the cohort. We estimated each subject's benzene exposure using occupational histories, local site-specific information, and an algorithm using Australian petroleum industry monitoring data. RESULTS: Matched analyses showed that the risk of leukemia was increased at cumulative exposures above 2 ppm-years and with intensity of exposure of highest exposed job over 0.8 ppm. Risk increased with higher exposures; for the 13 case-sets with greater than 8 ppm-years cumulative exposure, the odds ratio was 11.3 (95% confidence interval = 2.85-45.1). The risk of leukemia was not associated with start date or duration of employment. The association with type of workplace was explained by cumulative exposure. There is limited evidence that short-term high exposures carry more risk than the same amount of exposure spread over a longer period. The risks for acute nonlymphocytic leukemia and chronic lymphocytic leukemia were raised for the highest exposed workers. No association was found between non-Hodgkin lymphoma or multiple myeloma and benzene exposure, nor between tobacco or alcohol consumption and any of the cancers. CONCLUSIONS: We found an excess risk of leukemia associated with cumulative benzene exposures and benzene exposure intensities that were considerably lower than reported in previous studies. No evidence was found of a threshold cumulative exposure below which there was no risk.     

Occupational exposure associated with reproductive dysfunction

Evidence suggestive of harmful effects of occupational exposure on the reproductive system and related outcomes has gradually accumulated in recent decades, and is further compounded by persistent environmental endocrine disruptive chemicals. These chemicals have been found to interfere with the function of the endocrine system, which is responsible for growth, sexual development and many other essential physiological functions. A number of occupations are being reported to be associated with reproductive dysfunction in males as well as in females. Generally, occupations involving the manufacture/or application of some of the persistent chemicals that are not easily degradable as well as bio-accumulative chemicals, occupations involving intensive exposure to heat and radiation, occupations involving the use of toxic solvents as well as toxic fumes are reported to be associated with reproductive dysfunction. Occupational exposure of males to various persistent chemicals have been reported to have male mediated adverse reproductive outcomes in the form of abortion, reduction in fertility etc. with inconclusive or limited evidence. Nevertheless, there is a need for more well designed studies in order to implicate any individual chemical having such effects as in most occupations workers are exposed to raw, intermediate and finished products and there are also several confounding factors associated with lifestyles responsible for reproductive dysfunction. There is an urgent need to look at indiscriminate use of persistent chemicals especially pesticides and persistent organic pollutants (POP's) as these chemicals enter the food chain also and could be potential for exposure during the critical period of development. It is also necessary to impart information, and to educate about the safe use of these chemicals, as a very sensitive reproduction issue is involved with exposure to these chemicals. Occupational exposures often are higher than environmental exposures, so that epidemiological studies should be conducted on these chemicals, on a priority basis, which are reported to have adverse effects on reproduction in the experimental system.     

Personal exposures of benzene treated workers and a simple biological monitoring

A simple method of biological monitoring has been developed for occupational benzene exposure. Personal benzene exposure monitoring using a passive sampler and GC/FID was carried out on 74 workers from a benzene-treated company. Their urines were collected before and after work-shift. After treatment of urine samples using solid phase extraction (SPE), trans, trans-muconic acid(t, t-MA) concentration in the elute was analysed by HPLC. Correlation between benzene exposure (X: ppm) and urinary t, t-MA concentration (Y: mg/g x creatinine) for non-smokers was Y = 0.948X + 0.586 (r = 0.798, P < 0.01) and Y = 0.885X + 0.894 (r = 0.871, P < 0.01) for smokers, respectively. The t, t-MA concentration on 1 ppm TLV exposure to benzene was estimated as 1.5 and 1.8 (mg/g creatinine) for non-smokers and smokers, respectively. These values are in agreement with some investigators. This indicates that our simple method for biological monitoring of benzene exposure can be of great service.     

A survey of personal exposures to benzene in Mexico City.

Benzene is a widely distributed environmental contaminant that causes leukemia. It is an important component in gasoline, it is used frequently as a solvent or chemical feedstock in industry, and it is emitted as a product of incomplete combustion. In Mexico City, investigators suspect that benzene exposure might be elevated and may pose a risk to the population; however, no published data are available to confirm or disconfirm this suspicion. We, therefore, conducted a survey in 3 occupational groups in Mexico City. Forty-five volunteers who used portable passive monitors measured their personal exposure to benzene during a workshift. None of the participants smoked during the monitoring period. Benzene exposure was significantly higher among service-station attendants (mean = 359.5 microg/m3 [standard deviation = 170.4 microg/m3]) than among the street vendors (83.7 microg/m3 and 45.0 microg/m3, respectively) and office workers (45.2 microg/m3 and 13.3 microg/m3, respectively). However, the benzene exposure levels observed among office workers were substantially higher than levels reported elsewhere for general populations. Our results highlight the need for more complete studies by investigators who should assess the potential benefits of setting environmental standards for benzene in Mexico.