Assessment of Exposure to Perchloroethylene and its Clinical Repercussions for 50 Dry-Cleaning Employees.

The purpose of this article is the assessment of occupational exposure to perchloroethylene (PCE) and its clinical repercussions for dry-cleaning employees. The authors measured atmospheric levels of PCE and blood levels in a population of 50 exposed employees then conducted a study of clinical symptomatology in exposed and non-exposed subjects linked with this solvent. Fifty employees and 95 controls were studied. The median value of atmospheric PCE was 7 ppm (0.22-33), and the median blood level of PCE was 73.6 µg/l (11.8-144). These levels were correlated statistically to the action of sludge scraping and to the existence of automatic scrapers (p < 0.01). Eight percent of PCE blood levels were higher than the biological levels recently set in France. The exposed population did not show excessive signs of drowsiness nor of pre-narcotic syndrome or other symptoms studied. Dry-cleaning employees were exposed to PCE at atmospheric levels lower than the French and American chronic recommended exposure levels but some results were higher than recommended values. For PCE blood levels for the general working population, results were respectively lower than French and American national recommended levels in 92% and 94% cases. Risk should be considered, however, carefully in women of childbearing age, as 64% exceeded the recommended blood levels for pregnant women. This exposure did not generate any studied neurobehavioral symptomatology.

Study of the neurobehavioural toxicity of styrene at low levels of exposure.

Thirty workers in a dockyard exposed to concentrations of styrene lower than the TLV-TWA of 50 ppm and 30 control workers not subject to exposure but employed by the same company were subjected to three psychometric tests on one Monday morning and evening. The results were usually better in the evening than in the morning in both groups, which proves the lack of acute intoxication at the end of the day at this level of exposure. On the other hand, all of the tests conducted on the exposed subjects are significantly less good than those on the controls. The results suggest the existence of minor but significant organic mental disorders in the subjects exposed to a mean dose of 30 ppm in this study. These results are inconsistent with those of several recent studies. The advisability of lowering the TLV of 50 ppm in discussed.