**3. Methodology**

The methodology in this study comprised of extensive review of investigation results in literature from 2010 to the present. Information gathered primarily contains but is not limited to published reports by the agencies in the Zamfara lead poisoning intervention. Secondary sources of information include published reports of discrete investigations on lead poisoning/contamination in Zamfara State as well as some other reviews on the subject matter. The first environmental health investigation report published by CDC in early 2010 confirmed that the primary source of lead exposure is soil ingestion but there was insufficient information on the quantities of lead in drinking water (groundwater and surface water). Likewise, the levels of lead in soil and mercury in air were not determined at the time. A report by JEU [2] revealed the lead concentrations in soil, surface and groundwater as well as mercury levels in the air.

A clinical investigation report that found the blood lead levels of affected children was conducted in late 2010 and covered wide areas of the state and targeted most if not all affected persons. Major events include data gathering and reporting on environmental and clinical investigations as reported from the sources of investigation. Events were carefully followed and reported with their originality through literature and oral communication with some stakeholders in the mission. Other information was originally sourced from the community leaders through visits, personal communications and other means of contact after seeking their permission. Information gathered includes the report by national and international agencies that participated in the mission. These include MSF, CDC, WHO, UNICEF, UNEP, OCHA, NCDC, TI, NWRI, etc.
