Lead toxicity continues to remain a major environmental health risk throughout the world. Previous research has shown that about 50% of Pakistani children have blood lead levels (BLL) >10 ¿g/dL. There is growing evidence of an association between children exposed to lead levels and lowered cognitive function, and delinquent behavior in young adulthood. This study will contribute to understanding the role of various sources of lead exposure in Pakistan. These data will provide a basis for intervention in Pakistan at the national level that will result in reduction of BLLs in children. The findings of this study also are directly relevant to lead prevention/control programs in other countries in South Asia.