Exposure to organic solvents has been suggested to cause or exacerbate renal disease, but methodologic concerns regarding previous studies preclude firm conclusions. We examined the role of organic solvents in a population-based case-control study of early-stage chronic renal failure (CRF). All native Swedish residents aged 18 to 74 yr, living in Sweden between May 1996 and May 1998, formed the source population. Incident cases of CRF in a pre-uremic stage (n = 926) and control subjects (n = 998), randomly selected from the study base, underwent personal interviews that included a detailed occupational history. Expert rating by a certified occupational hygienist was used to assess organic solvent exposure intensity and duration. Relative risks were estimated by odds ratios (OR) in logistic regression models, with adjustment for potentially important covariates. The overall risk for CRF among subjects ever exposed to organic solvents was virtually identical to that among never-exposed (OR, 1.01; 95% confidence interval [CI], 0.81 to 1.25). No dose-response relationships were observed for lifetime cumulative solvent exposure, average dose, or exposure frequency or duration. The absence of association pertained to all subgroups of CRF: glomerulonephritis (OR, 0.96; 95% CI, 0.68 to 1.34), diabetic nephropathy (OR, 1.02; 95% CI, 0.74 to 1.41), renal vascular disease (OR, 1.16; 95% CI, 0.76 to 1.75), and other renal CRF (OR, 0.92; 95% CI, 0.66 to 1.27). The results from a nationwide, population-based study do not support the hypothesis of an adverse effect of organic solvents on CRF development, in general. Detrimental effects from subclasses of solvents or on specific renal diseases cannot be ruled out.
OBJECTIVE: The principal aim of the study was to estimate the level of exposure to organic solvents of graffiti removers, and to identify the chemicals used in different cleaning agents. A secondary objective was to inform about the toxicity of various products and to optimise working procedures. METHODS: Exposure to organic solvents was determined by active air sampling and biological monitoring among 38 graffiti removers during an 8-h work shift in the Stockholm underground system. The air samples and biological samples were analysed by gas chromatography. Exposure to organic solvents was also assessed by a questionnaire and interviews. RESULTS: Solvents identified were N-methylpyrrolidone (NMP), dipropylene glycol monomethyl ether (DPGME), propylene glycol monomethyl ether (PGME), diethylene glycol monoethyl ether (DEGEE), toluene, xylene, pseudocumene, hemimellitine, mesitylene, ethylbenzene, limonene, nonane, decane, undecane, hexandecane and gamma-butyrolactone. The 8-h average exposures [time-weighted average (TWA)] were below 20% of the Swedish permissible exposure limit value (PEL) for all solvents identified. In poorly ventilated spaces, e.g. in elevators etc., the short-term exposures exceeded occasionally the Swedish short-term exposure limit values (STEL). The blood and urine concentrations of NMP and its metabolites were low. Glycol ethers and their metabolites (2-methoxypropionic acid (MPA), ethoxy acetic acid (EAA), butoxy acetic acid (BAA), and 2-(2-methoxyethoxy) acetic acid (MEAA)) were found in low concentrations in urine. There were significant correlation between the concentrations of NMP in air and levels of NMP and its metabolites in blood and urine. The use of personal protective equipment, i.e. gloves and respirators, was generally high. CONCLUSIONS: Many different cleaning agents were used. The average exposure to solvents was low, but some working tasks included relatively high short-term exposure. To prevent adverse health effects, it is important to inform workers about the health risks and to restrict the use of the most toxic chemicals. Furthermore, it is important to develop good working procedures and to encourage the use of personal protection equipment.
BACKGROUND: Mechanisms for potential effects of extremely low frequency (ELF) magnetic fields on carcinogenesis have not been identified. A potential pathway could be an interaction with the endocrine system. AIMS: To analyse occupational exposure to ELF magnetic fields from welding, and tumours of the endocrine glands. METHODS: This case-control study was based on a cohort with an increased prevalence of high exposed individuals. A total of 174 incident cases of tumours of the endocrine glands, 1985-94, were identified and data were obtained from 140 (80%) of these cases; 1692 controls frequency matched on sex and age were selected, and information on 1306 (77%) individuals was obtained. A short questionnaire was sent to a work administrator at the workplaces of the cases and controls. The exposure assessment was based on questions about job tasks, exposure to different types of welding, and exposure to solvents. RESULTS: There was an overall increased risk for all tumours of the endocrine glands for individuals who had been welding sometime during the follow up. The increased risk was attributable to arc welding; for resistance welding there was no clear evidence of an association. We found an increased risk for the adrenal glands in relation to arc welding, and for the parathyroid glands in relation to both arc welding and resistance welding. An imprecise increase in risk was also noted for tumours of the pituitary gland for arc welding. No confounding effect was found for solvent exposure, and there was no sign of biological interaction. CONCLUSION: The increased risks of endocrine gland tumours related to welding might be explained by exposure to high levels of ELF magnetic fields.
The objective of this article was to find associations between cancer of the mouth and pharynx, occupation and chemical exposure. A cohort of Finns born between 1906 and 1945 was followed-up for 46.8 (21.5 in males and 25.3 in females) million person-years during 1971-95. Incident cases of cancer of the mouth and pharynx (n = 2,708) were identified in a record linkage with the Finnish Cancer Registry. The Census occupations in 1970 were converted to chemical exposures with a job-exposure matrix (FINJEM). Cumulative exposure (CE) was calculated as the product of prevalence, level and duration of the exposure. Standardized incidence ratio (SIR) was calculated for each of the 393 occupations, and for CE categories of the 43 chemical agents, using total Finnish population as reference. Relative risks (RR) comparing various CE-categories with unexposed ones were defined for selected agents by Poisson regression analysis. Elevated SIRs were observed among lawyers, authors, journalists, performing artists, musicians, electronics and telefitters, painters (building), building hands, dockers, unskilled labourers and hotel porters in males and private secretaries, dressmakers, shoemakers and cobblers, waiters, pursers and stewardesses in females. The multivariate analyses showed high RRs for high exposure to aliphatic and alicyclic hydrocarbons, pesticides and alcohol. In conclusion, occupations with high SIRs were mostly the ones with high consumption of alcohol. Exposure to solvents and possibly to pesticides, engine exhaust, textile dust and leather dust may increase the risk of cancer of mouth and pharynx.
Trichloroethylene is an animal carcinogen with limited evidence of carcinogenicity in humans. Cancer incidence between 1968 and 1997 was evaluated in a cohort of 40,049 blue-collar workers in 347 Danish companies with documented trichloroethylene use. Standardized incidence ratios for total cancer were 1.1 (95% confidence interval (CI): 1.04, 1.12) in men and 1.2 (95% CI: 1.14, 1.33) in women. For non-Hodgkin's lymphoma and renal cell carcinoma, the overall standardized incidence ratios were 1.2 (95% CI: 1.0, 1.5) and 1.2 (95% CI: 0.9, 1.5), respectively; standardized incidence ratios increased with duration of employment, and elevated standardized incidence ratios were limited to workers first employed before 1980 for non-Hodgkin's lymphoma and before 1970 for renal cell carcinoma. The standardized incidence ratio for esophageal adenocarcinoma was 1.8 (95% CI: 1.2, 2.7); the standardized incidence ratio was higher in companies with the highest probability of trichloroethylene exposure. In a subcohort of 14,360 presumably highly exposed workers, the standardized incidence ratios for non-Hodgkin's lymphoma, renal cell carcinoma, and esophageal adenocarcinoma were 1.5 (95% CI: 1.2, 2.0), 1.4 (95% CI: 1.0, 1.8), and 1.7 (95% CI: 0.9, 2.9), respectively. The present results and those of previous studies suggest that occupational exposure to trichloroethylene at past higher levels may be associated with elevated risk for non-Hodgkin's lymphoma. Associations between trichloroethylene exposure and other cancers are less consistent.
OBJECTIVE: To investigate major congenital and neural crest malformations (NCM; craniofacial and conotruncal defects) in the offspring of laboratory employees. METHODS: Data for 1951 females was linked to the Medical Birth Register (3003 pregnancies). Exposure information was based on questionnaires. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. RESULTS: The prevalence of "major malformations" were 2.3% (n = 41; exposed) and 1.9% (n = 23; unexposed). For the major malformations, solvent exposure before the third trimester gave an OR of 1.8 (CI = 1.0-2.9); "laboratory work in general," of 1.2 (CI = 0.7-2.0) unadjusted. OR for benzene use around conception/organogenesis was 5.3 (CI = 1.4-21.1) for NCM. CONCLUSION: No significant risk for laboratory work in general was seen, but there was an increased ratio for NCM relative to solvents, especially benzene. These results are based on small numbers and should be interpreted cautiously.
In this study an education, and a series of group sessions for patients with solvent-induced chronic toxic encephalopathy (TE) and their spouses are evaluated. Thirty-eight patients and 21 family members participated in a 1-day education scheduled with short lectures on the clinical examination of chronic toxic encephalopathy and the prognosis. A specialist in occupational medicine, a psychologist and a social worker gave the lectures. Small discussion groups were also arranged. Of the participants from the educational days, 16 TE patients and 14 wives attended a 10-week counselling and coping improvement program with separate group sessions once a week, for patients and spouses. Questionnaires were used to assess symptoms, social network, mastery and family climate, and the participants' satisfaction with the education and the group sessions. The majority of the participants experienced the 1-day information as useful and relevant. The 10-week group sessions were rated as meaningful and the design, number, duration and frequency of the sessions equally good. Self-reported symptoms, social network and mastery were measured before the group sessions, and 3 and 9 months after breaking up the group sessions. In most measurements, there were no statistically significant differences between the three points in time. However, the wives improved more than did the patients but the effect was not lasting the whole follow-up period. Considering the patients' dependence on their wives, it might be most important that the wives experienced some relief from their own symptoms.
Neurobehavioral hazards have been identified since long in occupational health, e.g. lead, mercury, certain solvents, and many others agents. There are reviews and books on "Occupational neurology" or "Prevention of neurotoxic illness in working populations". Many methods have been applied for studies of the central and peripheral nervous systems in humans: registered diagnoses, questionnaire ratings, clinical evaluation, psychometric tests, neurophysiological and neuroradiological methods, cerebrospinal fluid components etc. Some neurological disorders are well defined, while neuropsychiatric syndromes often are less precisely diagnosed. Decreased subclinical test results in exposed groups might predict an increased risk for later, more serious disorders but the longitudinal information on clinical importance is often lacking. Some historical lessons from the epidemiology of occupational neurology will be repeated and a few reflections on the suitability of different diagnostic entities for epidemiological research shall be made. Since the beginning of the 1970s' a number of studies from the Scandinavian countries have demonstrated long-term neurobehavioral effects from working conditions with relatively moderate exposure to organic solvents. Similar findings have been verified in studies from some countries outside Scandinavia while other studies have been inconclusive. Those results have caused considerable controversy and have been discussed at international conferences and in scientific journals. Very different outcomes have been investigated in those solvent studies, however, and most studies have had a cross-sectional design with inherent problems. The exposure has been assessed in different ways, e.g. by years of occupation, hygienic measurements of the present working conditions, biological monitoring, retrospective assessments on qualitative or semi-quantitative scales. Sometimes single solvent exposures have been studied but most of the studies concern mixtures of solvents from aromatic and aliphatic hydrocarbons. As the designs have varied the exposure assessment has been crude and many different outcomes have been studied, it is hardly surprising that the results and the interpretations have differed. The first results from a comprehensive investigation on 135 solvent exposed painters and 71 carpenters as referents, selected from active members of the respective trade union 1965-70 and investigated in the late 80s, will be presented. Clinical, including psychiatric, diagnostic work up and neuropsychological as well as neurophysiological tests have been performed. Psychological test results from military conscripts at age 19 were available for all. The individual exposure history has been carefully assessed.(ABSTRACT TRUNCATED AT 400 WORDS)
The new questionnaire Euroquest was designed to study effects from exposure to organic solvents, and it covers the most commonly reported symptoms associated with long-term solvent exposure. Its convergence and criterion validity were evaluated by means of comparison with the two well-established generic symptom questionnaires Symptom Checklist (SCL-90) and General Health Questionnaire (GHQ-30). Men with long-term exposure to organic solvents and symptoms common in toxic encephalopathy (TE) classified as TE type 2A (n=29) or 2B (n=28) according to their neuropsychological test performance, and a comparable group of non-exposed healthy referents (N=57), were included. The six Euroquest factors obtained by a factor analysis were labeled: 'emotional lability' 'cognitive disturbances' 'peripheral neurology' 'sleepiness' 'fatigue' and 'sleep disturbances'. These factors correlated well with most SCL-90 scales and with the GHQ-30 total score in the combined TE groups. The combined TE groups were correctly classified to a similar degree by the Euroquest factors 'cognitive disturbances' and 'peripheral neurology' (TE 82.5% and referents 93%) and the SCL-90 scales 'somatization, 'interpersonal sensitivity', 'obsessive-compulsive symptoms' and 'hostility' (TE 84.2% and referents 93.0%), but not as well by GHQ-30 (TE 61.4% and referents 79%). In comparison with the separate TE groups most referents, and a considerably higher percentage of 2B than 2A subjects, could be correctly classified with both Euroquest and SCL-90. With GHQ-30, only a few 2A cases and fewer than half of the 2B cases were correctly classified. In conclusion, the Euroquest factors converged with both SCL-90 scales and GHQ-30 score. With both the Euroquest and SCL-90 questionnaires a similar percentage of the TE subjects were discriminated from the referents, most conspicuously regarding TE 2B subjects, who had an objectified cognitive dysfunction. In a choice between Euroquest and SCL-90, the Euroquest may have the advantage of higher face validity, for TE subjects.