INTERNAL AND EXTERNAL TETRACHLOROETHENE EXPOSURE OF PERSONS LIVING INDIFFERENTLY POLLUTED AREAS OF NORTHRHINE-WESTPHALIA (GERMANY)

An epidemiological study was performed to measure the internal and ext ernal tetrachloroethene exposure of persons living in two differently polluted areas of Northrhine-West-phalia (Germany). Tetrachloroethene concentrations: were determined in venous blood samples of 5- to 7-yea r-old children (n = 81) and 55-year-old women (n = 91) living in Essen , an industrial city located in the Ruhr area. 103 children und 131 wo men of the same age living in Borken, a small town north of the Ruhr a rea, served as reference group. Outdoor air samples were collected on passive samplers (sampling period: 4 weeks) from 70 measurement points per study area (about 2 km(2), mean distance 100 m). In the course of a year these measurements were repeated three times to sever seasonal variations. Parallel to the outdoor measurement periods, indoor air c oncentrations were determined in the homes of those women from Essen a nd Borken, who donored a blood sample. Tetrachloroethene levels in blu ed were generally low with a geometric mean of 0.05 mu g/L in women an d 0.021 mu g/L in children. Nevertheless, children and women living in the industrial area were found to have significantly higher tetrachlo roethene levels in blood than those of the reference group. In both st udy areas blood levels of women exceeded those of children by a factor of 2. Participants living in the neighbourhood of a dry-cleaning shop had distinctly elevated blood levels. The same applied to persons who stored dry-cleaned clothes at home. Like the internal exposure, exter nal exposure was also higher in Essen than in Borken. In both areas te trachloroethene concentrations indoors exceeded those outdoors. Outdoo r tetrachloroethene concentrations were significantly increased during the cold season, while the opposite was true for indoor levels. The c orrelation between indoor and outdoor exposure was found to be signifi cant, while those between blood levels and outdoor exposure became onl y significant when people living next to a dry-cleaning shop were excl uded. No significant relationship was observed between blood and indoo r tetrachlorethene levels. It is concluded that the higher tetrachloro ethene blood levels of the urban population result from the higher atm ospheric concentrations in industrial areas with tetrachloroethene emi tting sources like metal and textile industry. The fact that indoor ai r tetrachloroethene levels exceeded those outdoors can only be explain ed by the presence of additional indoor sources. Provided that women s pend on average more time indoors than children the higher indoor air concentrations may be the reason for the higher blood tetrachloroethen e levels found in women. Persons living near a dry-cleaning shop or st oring dry-cleaned clothes at home showed a higher internal and externa l exposure to tetrachloroethene than other persons. In individual case s it can by far exceed the average exposure of the general population, so that health impairments can not be generally excluded.