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Exposure to combustion engine exhaust and its effect on crews of roll-on roll-off ships and car ferries and on bus garage staff were studied. The peak concentrations recorded for some of the substances studied were as follows: total particulates (diesel only) 1.0 mg/m3, benzene (diesel) 0.3 mg/m3, formaldehyde (gasoline and diesel) 0.8 mg/m3, and nitrogen dioxide (diesel) 1.2 mg/m3. The highest observed concentration of benzo(a)pyrene was 30 ng/m3 from gasoline and diesel exhaust. In an experimental study volunteers were exposed to diesel exhaust diluted with air to achieve a nitrogen dioxide concentration of 3.8 mg/m3. Pulmonary function was affected during a workday of occupational exposure to engine emissions, but it normalized after a few days with no exposure. The impairment of pulmonary function was judged to have no appreciable, adverse, short-term impact on individual work capacity. In the experimental exposure study, no effect on pulmonary function was observed. Analyses of urinary mutagenicity and thioether excretion showed no sign of exposure to genotoxic compounds among the occupationally exposed workers or among the subjects in the experimental study.

This cohort study comprised male workers who had been employed in a cadmiumnickel battery factory in Sweden. The subjects had been exposed to cadmium for more than 1 year between the years 1940 to 1980. Of a total of 528 exposed workers, 525 were traced. The observed number of deaths due to various diseases was compared to the expected number, calculated from national statistics. Between 1951 and 1980, 105 men died before the age of 80, compared to an expected number of 122. In a subgroup of workers, totalling 185 men, who were exposed for more than 15 years, 51 died compared to an expected number of 58. There was a significant increase in deaths from nephritis and nephrosis (three observed, 0.4 expected). Furthermore, nonsignificant increases were observed for cancer of the prostate (three observed, 1.6 expected), urinary bladder cancer (two observed, 0.4 expected), and pulmonary cancer (three observed, 2.5 expected). One case of cancer of the nasopharynx was recorded.

Parkinson's disease has been associated with heavy occupational exposure to carbon disulfide, and this solvent, as well as other organic solvents, may cause neurotoxic effects. Therefore, the hypothesis was raised that organic solvents in general may be associated with Parkinson's disease. A case-referent study design was applied, and some other suspected exposures were studied as well. The diagnosis registers of two Swedish hospitals were used as the source of subjects. Male in-patients with Parkinson's disease (the cases) or subarachnoid hemorrhage (referents), with symptom appearance between 35-69 a of age and residence in the vicinity of the hospitals, were included in the study. Occupational exposure to the chemicals under study were determined from questionnaire answers of 91 cases and 75 referents. No differences in exposure frequency to organic solvents in general were observed, but three cases had been exposed to carbon disulfide compared to none of the referents. Six cases, but only two referents, had been exposed to mercury, and further exploration of a possible association between exposure to mercury and Parkinson's disease is recommended. The outcome of the study does not support the hypothesis that occupational exposure to organic solvents in general increases the risk of Parkinson's disease, but the confidence intervals of the odds ratios do not rule out such possibilities.

In a cohort study of 5464 union organised Swedish chimney sweeps employed at any time between 1918 and 1980 mortality was studied from 1951 to 1982 with national statistics used as a reference. Follow up was possible for 98.6% of the individuals: 717 deaths were observed against 540 expected. There was an increased mortality from coronary heart disease, respiratory diseases, and several types of malignant tumours. Lung cancer mortality was significantly increased and positively correlated to the number of years employed. A fivefold risk increase for oesophageal cancer and liver cancer was found. The increased mortality could be attributed to exposure to combustion products in the work environment but not to smoking habits.

Published reports give justification for the belief that long-term exposure to solvents might induce chronic but nonspecific neuropsychiatric conditions. This case-referent study of data from a regional Swedish pension fund register indicated a risk ration of 1.8 in regard to nonspecific neuropsychiatric disorders among workers such as painters, varnishers and carpetlayers who are exposed to solvents as compared to workers not so exposed. Moreover a dose-response relationship seems to exist between exposure in terms of occupational years and neuropsychiatric conditions, the result being that persons affected are considered eligible for disability pensions.

The influence of occupational factors on the outcome of pregnancy was investigated in a prospective study of 3901 women who worked during their pregnancy and received prenatal care in Orebro County from October 1980 to June 1983. Data on occupational factors, social circumstances, and life-style factors were obtained from questionnaires. There were no significant differences in the incidence of adverse pregnancy outcome (spontaneous abortion, perinatal death, birth defects, or low birthweight) between the nine occupational categories used when nonoccupational factors were accounted for. No increased risk was found for exposure to organic solvents, but the adjusted risk ratio of adverse outcome was 1.28 (95% CI 0.91-1.80) for "other chemical exposures." The work conditions in this county have been generally favorable in recent years, and the results therefore cannot be generalized to conditions with higher exposures. Methodological problems such as misclassification of exposure and the possible bias resulting from different rates of legal abortions among occupational groups are discussed.

The incidence of cancer was investigated among 5266 Swedish chimney sweeps employed for any period between 1918 and 1980. An analysis of the mortality has been reported earlier and showed an increased number of deaths from coronary heart disease, respiratory diseases, and lung, oesophageal, and liver cancer. Excess risks for cancer of the lung and oesophagus were confirmed in this analysis. Among the lung cancers, both squamous cell carcinoma and oatcell/undifferentiated carcinoma were in excess. In addition, a more than doubled risk for bladder cancer (23 observed v 9.8 expected cases) and an increase of malignancies of the haematopoietic system was found. There were, however, no cases of scrotal cancer, the classic occupational hazard among chimney sweeps. Chimney sweeps are exposed to polycyclic aromatic hydrocarbons generated by the combustion of organic material (coal, wood, coke, and oil). They are also exposed to cancerogenic metals (arsenic, nickel, and chromium). These results support the need for improved working conditions.

Nonspecific complaints such as fatigue, partial amnesia, loss of appetite, etc., have been reported by house painters and could be effects of occupational exposure to solvents. A random sample of union-affiliated house painters was compared for a number of parameters and psychological test results with a group of industrial workers having a corresponding age distribution. The groups proved to be on par in relevant background variables. A simple health cheok did not reveal ,any correlates to the subjective complaints, except for a somewhat lower hemoglobin concentration among the house painters. However, the painter group had significantly lower mean scores on psychological tests measuring intellectual capacity and psychomotor coordination than the reference group of industrial workers. The painter group also had significantly lower performances than expected on the memory test and the reaction time test. A discriminant analysis of indicators of change as derived from psychological tests, was carried out, and a point biserial correlation of 0.35 was obtained between the discriminant function and the dichotomous exposure variable defined by group affinity. Furthermore a study based on clinical patients, i.e., another body of data, indicated reasonable diagnostic validity for this discriminant function. Although no correlations were found within the painter group between exposure ("painter years") and the indicators of function change, rthe results indicate an effect of the work environment on health.

The effect on lung function of exposure in an asbestos cement plant was investigated in male workers, employed more than 10 years. The exposed group was selected to exclude subjects with pneumoconioses and ex-smokers and consisted of 77 smokers and 48 never-smokers. Referents were chosen from plants where asbestos had not been in use and restricted to those without X-ray signs of chest disease. The primary type of asbestos used was chrysotile and the general dust level in the two decades 1950-1970 seems to have been around 10 mg/m3 while the asbestos fiber concentration averaged 2 fibers/ml. The mean differences between exposed and referents were statistically significant for forced vital capacity and forced expiratory volume, -0.25 and -0.30 liters, respectively, after adjustment for age, height, tracheal area, and smoking category. No significant differences were detected between those with and without pleural plaques. Smokers and never-smokers were similarly affected. In conclusion, the group exposed to dust with comparatively low asbestos fiber concentration had a minor impairment of lung function, mainly due to obstructive changes.

Lead intoxication is a classical environmental hazard that can cause encephalopathy. During recent years several studies have suggested poor performances in psychological tests and increased numbers of subjective symptoms among workers with comparatively low blood lead concentrations. Forty-nine long-term lead-exposed male workers with time-weighted average blood lead concentrations between 1.3 and 3.3 mumol/l calculated from at least seven years' results have been compared with a referent group of 27 male industrial workers with normal blood lead concentrations and comparable intellectual backgrounds. Several indices of exposure were used. Both groups were examined with neuropsychological tests and a questionnaire covering neuropsychiatric symptoms. The exposed group performed less well in 11 of 14 non-verbal tests, and there were significant differences in tests of memory and reaction time. A non-linear dose-effect trend was indicated. The results are in accordance with those found in similar studies, and it is concluded that the blood lead concentration should be below 2.5 mumol/l to avoid the effects shown in this study.

The British MRC questionnaire was distributed to 377 male subjects participating in a health examination. Most of the subjects had been exposed to asbestos cement dust. Test scores from the questionnaire were compared with ventilatory function tests and with the diagnosis of chronic bronchitis. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV,) were recorded and the airways disorders were classified by lung specialists. The sensitivity of the questionnaire using two or more symptoms as indicative of chronic bronchitis was moderate, i.e., the questionnaire identified correctly 67 % of the individuals with decreased FVC as well as 72 % with decreased FEV1. In addition, it identified correctly 66 % of individuals with chronic bronchitis. Only every third subject reporting two or more symptoms had impaired lung function or chronic bronchitis. The validity of the MRC questionnaire appeared to be relatively low. However, it may reflect exposure to dust and can therefore be recommended for screening purposes.

An excess mortality from chronic cardio-cerebrovascular diseases among dynamite workers has recently been reported from two Swedish explosives industries. This study summarizes the exposure situation with regard to nitroglycol and nitroglycerine during the last two decades in one of these factories. The manufacturing process is described as well as the sampling and analytic procedures. The mean 8-hour TWA concentrations of nitrate esters for different job types during three seven-year periods 1958-1978 have been calculated from a large number of simi-annually measured short-time samples. The concentrations are estimated to have been in the range of 0.2 - 1.1 mg/m3, with the highest levels for cartridge fillers and mix house workers. The representativeness of short-time samples was found to be comparatively good in relation to 8-1/2 hour personal air sampling. The presented exposure calculations could be used for international comparison and dose-response discussions in future epidemiological studies on chronic effects of nitrate esters.

The mortality and incidence of cancer in three groups of workers with occupational exposure to ethylene oxide have been assessed. Eight cases of leukemia have occurred among 733 ethylene oxide-exposed workers compared with an expected 0.8 cases. Six cases of stomach cancer have been reported compared with 0.65 cases expected. These epidemiologic results provide support for an increased risk of malignancy in individuals with extended and intermittent exposure to low concentrations of ethylene oxide.

A cohort study of 142 male Swedish capacitor manufacturing workers was performed. PCB had been used as a dielectricum in power capacitors between 1960 and 1978. Mortality was investigated for the period 1965 to 1982 and cancer incidence from 1965 to 1980. Twenty-one deaths and seven cancers were observed, which was in agreement with the anticipated numbers calculated from national statistics. One person had developed two rare tumors, a slow growing mesenchymal tumor (desmoid) and a malignant lymphoma. The results cannot rule out the possibility of a carcinogenic risk from PCB exposure because of the small size of the cohort and relatively brief follow-up period, but they do not indicate any excess mortality or cancer incidence in this factory so far.

BACKGROUND: Professional drivers are at an increased risk of myocardial infarction but the underlying causes for this increased risk are uncertain. METHODS: We identified all first events of myocardial infarction among men age 45-70 years in Stockholm County for 1992 and 1993. We selected controls randomly from the population. Response rates of 72% and 71% resulted in 1067 cases and 1482 controls, respectively. We obtained exposure information from questionnaires. We calculated odds ratios (ORs), with and without adjustment for socioeconomic status, tobacco smoking, alcohol drinking, physical inactivity at leisure time, overweight status, diabetes and hypertension. RESULTS: The crude OR among bus drivers was 2.14 (95% confidence interval = 1.34-3.41), among taxi drivers 1.88 (1.19-2.98) and among truck drivers 1.66 (1.22-2.26). Adjustment for potential confounders gave lower ORs: 1.49 (0.90-2.45), 1.34 (0.82-2.19) and 1.10 (0.79-1.53), respectively. Additional adjustment for job strain lowered the ORs only slightly. An exposure-response pattern (by duration of work) was found for bus and taxi drivers. CONCLUSIONS: The high risk among bus and taxi drivers was partly explained by unfavorable life-style factors and social factors. The work environment may contribute to their increased risk. Among truck drivers, individual risk factors seemed to explain most of the elevated risk. Language: en

Ethylene oxide, a gaseous sterilant extensively used within health care facilities, is known to be a mutagen in bacteria and in human lymphocytes. The Environmental Protection Agency as well as the National Institute of Occupational Safety and Health have recently stipulated certain conditions for the use of ethylene oxide despite the lack of case reports or epidemiologic studies concerning carcinogenicity. We report three cases of leukemia that occurred between 1972 and 1977 in a relatively small group of Swedish workers exposed to ethylene oxide. According to national statistics, 0.2 cases of leukemia would have been expected. The time-weighted average ethylene oxide concentration was 20±10 ppm. ( JAMA 241:1132-1133, 1979)

In Reply.— Dr Divine and Mr Amanollahi, representing the Texaco Company, have objections to our conclusions on ethylene oxide and very definite opinions on alternative conclusions. They say that we "overlooked the lack of leukemia cases and overall mortality for workers in groups A and B at plant 3." The results from groups A and B are available in our original report to the Swedish Work Environment Fund, 1 and the expected number for leukemia ( International Classification of Diseases , codes 204 through 207) in group A was 0.04 and in group B, 0.02; ie, cases could only have been expected if ethylene oxide had outstanding carcinogen properties at very low levels. The statistical power of the study by Morgan et al 2 to detect an increased risk of leukemia was not strong, according to the authors themselves. We think there were strong reasons for aggregating the three different Swedish plants