Environmental lead exposure in a population of children in northern France: factors affecting lead burden.

Background: This study is part of the assessment of a site in northern France polluted by lead from industrial emissions. Our objectives were to look for the factors that influence lead burden in children aged 8-11 years.

Methods: A cross-sectional population-based study took place in 1996-97 and included 400 children (200 of whom lived on the metal-polluted site).

Results: The geometric mean of the blood-lead levels of children living on the polluted site was 39.5 microg/l (95% CI = 36.3-43.1); that of the non-exposed children was 30.6 microg/l (95% CI = 27.8-33.6) (P < 0.0001). Analysis of the variations in the mean blood-lead levels showed associations with: distance from the smelting plants (mean blood-lead level fell by a factor of 1/1.3 (95% CI = 1/1.2-1/1.4) for each km from the smelter over the range of 1-3 km and was constant thereafter) and consumption of tap water (when the water pipes were made of lead, the mean blood-lead level of children who drank tap water was twice as high (95% CI = 1.2-3.4) as that of children who did not).

Conclusions: The children's blood-lead levels were essentially linked to two factors: proximity to the smelters and drinking tap rather than bottled water.