Causes of lead toxicity in a Nigerian city.

BACKGROUND Up to 70% of young Nigerian children have been reported to have blood lead concentrations > or =10 microg/dl. AIMS To better elucidate risk factors for lead toxicity among Nigerian families with children at risk for lead toxicity. METHODS Two geographic wards in Jos, Nigeria were selected for study, one previously reported to have a high mean blood lead level (37 (SD 13) microg/dl) and one with a lower mean blood lead level (17 (SD 10) microg/dl) in young children. Data pertaining to potential risk factors for lead exposure were collected from children and adults in 34 households. RESULTS The mean (SD) blood lead concentration of 275 subjects, aged 3 weeks to 90 years, was 8.7 (5.7) microg/dl (range 1-34 microg/dl); 92 (34%) had concentrations > or =10 microg/dl. In multivariate analysis, an age of 5 years and under, flaking house paint, residence near a gasoline seller, male gender, increasing maternal and paternal education, and use of a lead ore eye cosmetic were independently associated with greater blood lead concentration. Vehicle ownership was associated with reduced lead concentration. Compared with the low-lead ward, residence in the high-lead ward remained significantly associated with greater lead values, indicating that additional factors likely contribute to lead exposure. CONCLUSION Although the cause of increased lead levels in Jos appears to be multi-factorial, several remediable sources contribute to lead exposure in Nigeria.