Occupational exposure to chlorophenates. Renal, hepatic and other health effects

A group of 71 chlorophenate-exposed sawmill workers were identified as part of a group undergoing an extensive health and environmental evaluation in a pulp mill. This group was compared with a group (N = 351) with no physical proximity to the area in which chlorophenates were used. Exposure was higher for those directly handling the wood and lower for those working in the area but not handling the wood. Those with chlorophenate exposure were not significantly more likely to report a history of jaundice or liver, kidney or heart disease. Moreover, the serum creatinine, bilirubin, glutamic oxaloacetic transaminase (GOT), and alkaline phosphatase values did not differ from those of the reference group. The hemoglobin level was similar in the three groups. But the peripheral blood leukocyte count was marginally lower in the exposed groups and their hematocrit was reduced, significantly so for the heavily exposed group. Urinalysis showed an increased prevalence of microscopic hematuria, especially with lower cell counts. No unequivocal explanation is available for the reduced hematocrit or the low level of hematuria.     

Occupational solvent exposure and neuropsychiatric disorders

Long-term exposure to solvents has been shown to induce neuropsychiatric disorders in workers. In this case-referent study the cases comprised 374 construction workers who had been awarded a disability pension due to a neuropsychiatric disorder in 1978-1980. Their matched referents were selected from construction workers who had been granted a pension due to o ther diseases in the same three-year period. The results of this study indicate that solvent exposure increases the risk of being prematurely pensioned due to neuroses, but early pensioning due to alcoholism or other neuropsychiatric disorders is not increased by solvent exposure. This same conclusion has been reached in earlier studies on this matter in other countries.     

Occupational exposure to wood dust. Health effects and exposure limit values

This article presents a review of the health effects of occupational exposure to wood dusts and of the data that could be used for setting occupational exposure limits for this nuisance. The causal role of wood dust in the onset of sinonasal cancers is solidly established by numerous epidemiological studies, and the magnitude of the risk is particularly high for adenocarcinoma induced by exposure to hardwood dust. However, no current data allows to rule out the carcinogenic role of softwood dusts and, in the view of protecting the health of the workers, it does not seem relevant to distinguish these two types of wood. Various impairments of the lung function have been frequently associated with exposure to both 'allergenic' and 'non-allergenic' wood dusts and may occur at very low concentrations. According to the SUMER 94 and CAREX studies, about 200 000 workers are currently exposed to wood dusts in France (about 1% of the working population between 1990 and 1994). When taking into account full professional careers, the percentage of workers having been occupationally exposed can be estimated to be about 15% for men and 5% for women. Measurements performed in France between 1987 and 2000 show that exposure levels are high, about 50% of the samplings being over 1mg/m(3) (actual TWA in France). Although the studies present limits, particularly for the quantitative assessment of individual exposure levels, it seems that nonmalignant effects are susceptible to arise at the level of 1mg/m(3); a limit value of 0.5mg/m(3) would credibly allow to protect exposed workers from most of the risks of nonmalignant pulmonary effects. However, it is impossible to assure that this value will avoid the induction of sinonasal cancer, even if this level is certainly lower than the levels to which the cases of sinonasal cancers published in the literature were exposed.     

Occupational exposure to ethylene oxide: effects and control

Ethylene oxide (EO) is widely used in the health care industry as a gas sterilant for medical products that cannot withstand the high temperature and humidity associated with conventional steam sterilization. As a consequence, approximately 100,000 health care workers are exposed to residual EO each year. The acute toxicity of exposure to EO has been well documented, and recent concern about the mutagenic potential of occupational exposure to EO has resulted in an effort to further reduce workplace exposure levels to EO. The Environmental Protection Agency has issued a rebuttal presumption against registration of EO as a pesticide and the American Conference of Governmental Industrial Hygienists (ACGIH) has proposed a sharp reduction in the threshold limit value permitted for EO. Recognizing the need for environmental health personnel to become more familiar with this workplace hazard, it is appropriate to briefly review the toxic effects of acute and chronic exposure to EO residuals. The authors describe a gas sterilization system successfully utilized at the U.S. Public Health Service Hospital in New Orleans, La., which has demonstrated exposure concentrations well below the EO threshold limit value recently proposed by the ACGIH, while preserving the principal goal of assuring the sterility of reusable medical products which cannot be subjected to steam sterilization.     

Occupational solvent exposure and brain function: an fMRI study

Background: Deficits in cognitive function have been demonstrated among workers chronically exposed to solvents, but the neural basis for these deficits has not been shown.Objectives: We used functional magnetic resonance imaging (fMRI) to compare pathophysiological changes in brain function between solvent-exposed and control workers.Methods: Painters, drywall tapers, and carpenters were recruited from the International Union of Painters and Allied Trades, District Council 9 in New York City and District Council 21 in Philadelphia, Pennsylvania, and from the Carpenters Union in New Jersey. Twenty-seven solvent-exposed and 27 control subjects of similar age, education, and occupational status completed the N-Back working memory test during fMRI. After controlling for confounders (age; lifetime marijuana, cocaine, and alcohol use; blood lead; symptoms of depression; verbal intelligence), voxelwise group analysis and regional activation levels were compared and then correlated with an index of lifetime solvent exposure.Results: Solvent-exposed workers’ performance on the N-Back was significantly worse than that of controls. Activation of the anterior cingulate, prefrontal, and parietal cortices—areas serving working memory function and attention—was also significantly lower for solvent-exposed workers relative to controls. After controlling for confounders, we observed a negative correlation between lifetime solvent exposure and activation in these same regions among the solvent-exposed workers.Conclusions: This study is one of the few to document neural structures affected by exposure to solvents. Our findings provide a biological mechanism for the neurobehavioral deficits in working memory and attention that have previously been reported by other groups studying the effects of chronic exposure to solvents. These imaging markers, which are consistent with the neurobehavioral measures in our subject population, are consistent with altered brain pathology caused by prolonged exposure to solvent mixtures during construction work.     

Occupational exposure to ultraviolet radiation: a health risk assessment

This review applies health risk assessment methodology to the subject of occupational exposure to ultraviolet radiation (UVR). Ultraviolet radiation is produced by many sources, and for most people the sun is their main source of exposure. In the occupational environment, there are also many artificial sources, of which welding arcs are the predominant and most intense. Adverse health effects include photokeratitis, erythema, pterygium, some types of cataract, non-melanocytic skin cancer, and malignant melanoma. Outdoor workers and workers who are exposed to certain artificial sources (particularly welding arcs), frequently are exposed to UVR levels that are above the current exposure limits. Such workers may also be at an additional risk of developing nonmelanocytic skin cancer along with other chronic conditions, including malignant melanoma. A range of control measures is available but nevertheless, many workers (particularly those exposed to solar UVR) do not make full use of these measures. Therefore, the implementation of health education campaigns and other initiatives that encourage use are needed. Overall, although exposure to UVR presents a substantial risk for certain occupations, the current exposure standards and currently available control measures (if used) are considered to provide adequate protection for most workers.     

Occupational exposure limits in the context of solvent mixtures, consumption of ethanol, and target tissue dose

Individuals are exposed to mixtures, and never to single chemicals. Depending on the composition of the elements of mixtures, significant toxicological interactions between the components may occur. These interactions are complex and often difficult to predict, ranging from synergistic to additive and subadditive interactions. The nature of the interactions needs to be evaluated as the target tissue dose of the active form of each chemical. PBPK modeling is an effective tool for determining the target tissue dose and evaluating these interactions when data are available for model development. Some of the interactions are pharmacokinetic in nature, affecting the disposition of other chemicals in the body. Other interactions can be pharmacodynamic in nature, altering the effects that other chemicals have on the organism. For many organic solvents, these interactions occur principally at the level of the metabolizing enzyme, cytochrome P-450 2E1 (CYP2E1). Many solvents are known to induce or inhibit CYP2E1, or both. Mixtures may be comprised of concomitant exposures to chemicals or from components encountered separately on-the-job, off-the-job, through the diet, and otherwise. Examples of mixtures where the exposure to separate components occurs off the job will be discussed, with special emphasis on ethanol consumption as a modifier of solvent pharmacokinetics. The present practice of the linear extrapolation of the toxicity of individual mixture components in the interpretation of occupational exposure limits will also be critiqued.     

Occupational chronic exposure to organic solvents XI. Alkylbenzene exposure of varnish workers: effects on hematopoetic system

Summary Thirty-five spraymen, who were varnishing vehicles with alkyd-, phenol- and polyestervarnishes, which were dissolved in solvent mixtures mainly containing o-, m-, p-xylene and ethylbenzene, have been investigated. The concentrations of these solvents in air were 2.1, 7.9, 2.8 and 4.0 ppm on average. The levels of alkylbenzenes in blood and those of their metabolites in urine have been determined. At two of the six working places the spraymen were additionally exposed to n-butanol, respectively 1,1,1-trichloroethane, and several C₉-aromatic hydrocarbons. Some of the lacquers contained lead pigments. Alterations of blood cell counts have been observed under the described conditions of exposure. On average the number of lymphocytes was higher than that of segmented granulocytes. Erythrocytes and hemoglobin level of the spraymen were lower than those of the controls.     

Influence of occupational exposure to organic solvent mixtures on contrast sensitivity in printers

Contrast sensitivity measurement accurately evaluates the sensitivity of all human visual channels, even in a more detailed manner than simple acuity measures can. This is a study of visual contrast sensitivity in a series of subjects occupationally exposed to organic solvents. Contrast sensitivity was measured for 42 printers and 28 age-stratified controls using the Vistech VCTS 6500 chart. The exposed workers distinguished between following three groups of printers: "low exposed," "middle exposed," and "high exposed." Abnormal contrast sensitivity results were recorded for the right eye in 38% of the printers and 11% of the controls and for the left eye in 38% of the printers and 7% of the controls. Especially, we found a reduced contrast sensitivity in all three groups exposed to solvents for both eyes. We conclude that contrast sensitivity is abnormal in workers exposed to organic solvents. The reduced contrast sensitivity in printers seems to be an indicator of visual defects induced in response to organic solvents exposure.     

Occupational exposure to manganese.

The relationship between the degree of exposure and biological effects of manganese was studied in a group of 369 workers employed in the production of ferroalloys. Two other groups of workers, from an electrode plant and from an aluminium rolling mill, served as controls. Mean manganese concentrations at work places where ferroalloys were produced varied from 0-301 to 20-442 mg/m3. The exposure level of the two control groups was from 2 to 30 microgram/m3 and from 0-05 to 0-07 microgram/m3, in the electrode plant and rolling mill respectively. Sixty-two (16-8%) manganese alloy workers showed some signs of neurological impairment. These signs were noticeably less in the two control groups (5-8% and 0%) than in the occupationally exposed group. Subjective symptoms, which are nonspecific but may be symptoms of subclinical manganism, were not markedly different in the three groups. However, in the manganese alloy workers some of the subjective symptoms occurred more frequently in heavier smokers than in light smokers or nonsmokers. Heavier smokers engaged in manganese alloy production showed some of the subjective symptoms more often than heavier smokers from the control groups.     

Occupational exposure to trichloramine and trihalomethanes: adverse health effects among personnel in habilitation and rehabilitation swimming pools

Personnel in swimming pool facilities typically experience ocular, nasal, and respiratory symptoms due to water chlorination and consequent exposure to disinfection by-products in the air. The aim of the study was to investigate exposure to trichloramine and trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) from the perspective of adverse health effects on the personnel at Swedish habilitation and rehabilitation swimming pools. The study included 10 habilitation and rehabilitation swimming pool facilities in nine Swedish cities. The study population comprised 24 exposed swimming pool workers and 50 unexposed office workers. Personal and stationary measurements of trichloramine and trihalomethanes in air were performed at all the facilities. Questionnaires were distributed to exposed workers and referents. Spirometry, fraction of exhaled nitric oxide (FE_NO), and peak expiratory flow (PEF) were measured. Personal and stationary measurements yielded trichloramine levels of 1–76 µg/m³ (average: 19 µg/m³) and 1–140 µg/m³ (average: 23 µg/m³), respectively. A slightly higher, but not significant, prevalence of reported eye- and throat-related symptoms occurred among the exposed workers than among the referents. A significantly increased risk of at least one ocular symptom was attributed to trichloramine exposure above the median (20 µg/m³). Lung function (FVC and FEV1) was in the normal range according to the Swedish reference materials, and no significant change in lung function before and after shift could be established between the groups. Average FE_NO values were in the normal range in both groups, but the difference in the values between the exposed workers and referents showed a significant increase after shift. Hourly registered PEF values during the day of the investigation did not show any unusual individual variability. In conclusion, the increased risk of developing at least one ocular symptom at personal trichloramine concentrations over 20 µg/m³ combined with an increase in the difference in FE_NO during the work shift of the exposed workers should not be neglected as an increased risk of respiratory inflammation in the habilitation and rehabilitation swimming pool environment.     

Occupational exposure to insecticides and their effects on the auditory system

The objective of this investigation was to study the effects of occupational exposure to organophosphates and pyrethroid insecticides on the central auditory system. The study group consisted of 98 workers exposed to insecticides and 54 non-exposed workers. Data on work history, medical history, present diseases, occupational and non-occupational exposure to noise or chemicals and lifestyle factors were obtained through an interview. Central auditory system functions were assessed through frequency patterns and duration patterns testing. Fifty-six percent of the exposed workers had hearing dysfunction at the central level and its relative risk was 7.58 for the group with exposure to insecticides (95% CI 2.9- 19.8) when compared to the non-exposed group. The group exposed to insecticides and noise had a relative risk for central disorders of 6.5 (95% CI 2.2-20.0) when compared to the non-exposed group and 9.8 (95% CI 1.4-64.5) when compared to the group exposed only to noise. The finding suggests that exposure to organophosphates and pyrethroid products can induce damage to central auditory system. Further research is needed on the ototoxic mechanisms of these chemicals, and on hearing loss prevention measurements that are applicable and adequate to such risks and populations.     

医务人员血源性病原体职业暴露调查

目的了解医务人员发生血源性病原体职业暴露的特点和危险因素,探讨防治对策。方法采用回顾性调查方法,运用《医务人员血源性职业暴露登记表》对某院2013年1月1日—2015年12月31日发生的血源性病原体职业暴露事件进行调查分析。结果共发生血液/体液职业暴露246例。职业暴露人群以在职护士为主(95例,占38.62%);职业暴露发生地点主要为病房(148例,60.16%);职业暴露方式以锐器伤为主(219例,占89.02%);医务人员发生职业暴露时的操作环节主要为手术意外(69例,占28.05%);暴露源主要为乙型肝炎病毒(HBV),共123例(占50.00%);暴露医务人员经局部处理和预防用药后,无1例发生感染。结论医疗机构应加强医务人员血源性病原体职业暴露相关培训,提高防护意识,规范操作行为,改善工作环境,最大限度地减少职业暴露的发生。     

Occupational mercury exposure and male reproductive health

This retrospective cohort study was designed to investigate the relationship of male occupational exposure to elemental mercury and several reproductive outcomes. All subjects worked at least 4 months between 1953 and 1966 at a plant that used elemental mercury; 247 white male employees who had the highest exposures were compared to 255 matched nonexposed employees. Individual exposure to mercury was estimated from urinary mercury measurement records. Information on reproductive history and potential confounding variables was obtained through personal interview with each of the employees and with a subset of their wives. No associations were demonstrated between mercury exposure and decreased fertility or increased rates of major malformations or serious childhood illnesses. After controlling for previous miscarriage history, mercury exposure was not a significant risk factor for miscarriage. Because of this study's potential problems with long-term recall, further studies of the effect of mercury on pregnancy outcome are warranted in other populations.     

Occupational chronic solvent encephalopathy in Finland 1995–2007: incidence and exposure

Purpose  

The aim of the study was to define the incidence of chronic solvent encephalopathy (CSE) in Finland during 1995–2007, evaluate the duration and nature of exposure, and identify the work tasks where CSE is encountered.     

Occupational exposure to toluene: neurotoxic effects with special emphasis on drinking habits

Summary Neurotoxic effects of toluene were examined in 43 male rotogravure printers exposed to toluene (age 27–63, mean 41 years; duration of exposure 11–40, mean 22 years) and 31 male offset printers of the same age with slight exposure to aliphatic hydrocarbons. A neurological examination, tests for autonomic nervous function, electroencephalography, psychological tests and computerized tomography of the brain were carried out in addition to a standardized interview. Exposure levels were evaluated for each person separately on the basis of his work history and the results of an earlier study on exposure levels at the same printing shops. Besides a thorough history of alcohol consumption, information about the printers' drinking habits was obtained from the occupational health care centers of the printing shops. The examinations found only slight abnormalities, and there were no statistically significant group differences in the prevalences of abnormalities. No correlations between the abnormalities and the exposure indices were found either. One of the retired workers, however, who had been exposed to high toluene concentrations for over 40 years, had been diagnosed as having chronic organic solvent intoxication. Heavy drinkers of alcohol were clearly more common in the toluene-exposed group. This study detected no clinically significant abnormalities attributable to toluene alone among workers exposed to 68–185 ppm (mean 117) of toluene for over 10 years. The connection between alcohol consumption and toluene exposure is interesting and deserves further study.     

Occupational exposure to polychlorinated biphenyls in electrical workers. II. Health effects

Health conditions were evaluated in 80 electrical workers exposed for many years to polychlorinated biphenyl (PCB) mixtures with a 42% mean chlorine content, who had blood PCB concentrations from 41 to 1319 micrograms/kg. The clinical study was based on personal history data, physical examination, and laboratory tests (red cell and leukocyte count; determination of haemoglobin, packed cell volume, bilirubin, serum protein electrophoretic fractions, pseudocholinesterase, AST, ALT, GGT, and OCT). Fifteen workers were found to have skin diseases--chloracne (4), folliculitis (4), oil dermatitis (1), juvenile acne (1), and dermatitis due to irritative or allergic agents (5). Sixteen workers showed more or less pronounced hepatic involvement, consisting most often of hepatomegaly with an increase in serum GGT, AST, ALT, and OCT values. In two workers bleeding cavernous haemangiomas were discovered, in one case associated with chronic myelocytic leukaemia. All the workers with chloracne were employed on electric capacitor impregnation with PCBs, and no definite association was found between chloracne and blood PCB concentrations. Conversely, a significant positive association was found between the abnormal liver findings and blood PCB concentrations, particularly trichlorobiphenyl blood concentrations. The abnormal hepatic findings observed are similar to those reported in experimental animals given PCBs, and in some workers such findings should probably be considered as clinical signs of hepatic microsomal enzyme induction.     

Occupational exposure to polychlorinated biphenyls in electrical workers. II. Health effects.

Health conditions were evaluated in 80 electrical workers exposed for many years to polychlorinated biphenyl (PCB) mixtures with a 42% mean chlorine content, who had blood PCB concentrations from 41 to 1319 micrograms/kg. The clinical study was based on personal history data, physical examination, and laboratory tests (red cell and leukocyte count; determination of haemoglobin, packed cell volume, bilirubin, serum protein electrophoretic fractions, pseudocholinesterase, AST, ALT, GGT, and OCT). Fifteen workers were found to have skin diseases--chloracne (4), folliculitis (4), oil dermatitis (1), juvenile acne (1), and dermatitis due to irritative or allergic agents (5). Sixteen workers showed more or less pronounced hepatic involvement, consisting most often of hepatomegaly with an increase in serum GGT, AST, ALT, and OCT values. In two workers bleeding cavernous haemangiomas were discovered, in one case associated with chronic myelocytic leukaemia. All the workers with chloracne were employed on electric capacitor impregnation with PCBs, and no definite association was found between chloracne and blood PCB concentrations. Conversely, a significant positive association was found between the abnormal liver findings and blood PCB concentrations, particularly trichlorobiphenyl blood concentrations. The abnormal hepatic findings observed are similar to those reported in experimental animals given PCBs, and in some workers such findings should probably be considered as clinical signs of hepatic microsomal enzyme induction.