A cytogenetic study on the teaching staff of a polluted school with a questionable increased incidence of malignancies

Exposure to pollutants, in particular polychlorinated biphenyls (PCB), was established at a school built in 1966. Because of a statistically conspicuo us increased frequency of breast cancer observed in the teachers of the sch ool this study was performed to ascertain whether the teachers in the pollu ted school have an increased level of micronucleated cells (MN) or sister c hromatid exchanges (SCE) as an expression of a raised cytogenetic risk. Tea chers in a directly adjacent school served as one control group and those f rom a school about 30 km away as a second one. Each teacher had to answer a questionnaire and after venous blood samples had been taken, the number of MN and SCE in peripheral lymphocytes were determined. For the teachers in the polluted school, in addition, the length of stay in the building during the last month and year was recorded. Thereby no correlation with the numb er of MN and SCE was proven. In comparison with the two control groups, nei ther the number of MN nor SCE was increased in the teachers of the polluted school. Even if their predictive value for cancer risk assessment is dispu ted, MN and SCE have a high rating as standard procedures in the proof of a n exposure to genotoxic agents. This study thus does not provide any eviden ce that, for the teachers in the polluted school, a relevant exposure to ge notoxic agents exists.