[Lead exposure level in umbilical cord blood and its related factors].

Six hundred and five specimens of umbilical cord blood were collected from Yangpu District, Shanghai, and blood lead levels were determined with graphite stove atom absorption spectrophotometry in 348 of them to study fetal exposure to lead and its related factors in the people of Shanghai. Survey on household social and environmental health status was conducted in families with the babies whose umbilical cord blood lead were above the 70th percentile and below the 30th percentile with a face-to-face questionnaire. Data were analyzed with multiple regression for the factors which affected the lead level in umbilical cord blood significantly. Results showed that blood lead levels in 348 cases were normally distributed, with a range of 0.08 to 0.84 mumol/L, a mean of 0.44 mumol/L and a standard deviation of 0.15 mumol/L. Specimens with cord blood lead level exceeding the safety criteria of 0.48 mumol/L accounted for 40.8 percent of the total. The study also found that passive smoking during pregnancy, exposure to lead in family members, one's living room adjacent to the major traffic roads, pollution by coal-burning smoke in the environment of one's residence, use of coal as domestic fuel, and eating preserved eggs during pregnancy all were risk factors for lead exposure. Multiple logistic regression analysis revealed that contribution of passive smoking to cord blood lead level was still statistically significant after adjusting other confounding factors. It concluded that environmental lead pollution could cause ad-verse effects on fetal development.