BIOLOGICAL MONITORING OF CHILD LEAD-EXPOSURE IN THE CZECH-REPUBLIC

The area around the Pribram lead smelter has been recognized to be hea vily contaminated by lead (Ph). In the early 1970s, several episodes o f livestock lead intoxication were reported in this area; thereafter, several epidemiological and ecological studies focused on exposure of children. In contrast to earlier studies, the recent investigation (19 92-1994) revealed significantly lower exposure to lead. From 1986-1990 , recorded average blood lead levels were about 37.2 mu g lead (Pb)/10 0 mi in an elementary school population living in a neighborhood close to the smelter (within 3 km of the plant). The present study, however , has found mean blood lead levels of 11.35 mu g/100 mi (95% CI = 9.32 ; 13.82) among a comparable group of children. In addition to blood le ad, tooth lead was used to assess exposure among children. Statistical ly significant differences (p < 0.05) were observed between the geomet ric mean tooth lead level of 6.44 mu g Pb/g (n = 13; 95% CI = 3.95; 10 .50) in the most contaminated zone and 1.43 mu g Pb/g (n = 35; 95% CI = 1.11; 1.84) in zones farther away from the point source. Both biomar kers, blood and tooth lead levels, reflect a similar pattern of lead e xposure in children. This study has attempted a quantitative assessmen t of risk factors associated with elevated lead exposure in the Czech Republic. Content of lead in soil, residential distance from the smelt er, consumption of locally grown vegetables or fruits, drinking water from local wells, the mother's educational level, cigarette consumptio n among family members, and the number of children in the family were factors positively related (p<0.05) to blood lead levels. The resultin g blood lead level was found to be inversely proportional to the child 's age.