Risk of birth defects in a population exposed to environmental lead pollution

To investigate the relation between environmental lead and risk of birth defects in humans, we examined the prevalence at birth of congenital anomalies in an industrial area of northern Italy heavily polluted with lead. Through a population-based registry of birth defects, we identified anomalies diagnosed during three consecutive periods characterized by decreasing environmental lead exposure, 1982 1986, 1987 1990 and 1991 1995. In the lead-pol- luted area, we observed an excess risk of cardiovascular defects which decreased from 2.59 95% confidence interval ŽCI. 1.68 3.82 in the first period to 1.18 Ž95% CI 0.62 2.06. and 0.97 Ž95% CI 0.57 1.54. in the subsequent periods. We also found an excess risk of oral clefts and musculoskeletal anomalies, with decreasing trends over time. We could not identify homogeneous patterns of temporal variation for other congenital anomalies, neither did we detect cases of neural tube defects. These results appear to support an association between severe parental lead exposure and specific birth defects.