Assessment of Pb, Cd, Cu, and Zn exposures of 6- to 10-year-old children in Mumbai

Population exposures to toxic trace metals are of great concern due to their nonbiodegradable nature and long biological half-lives for elimination from the body. Response to a toxic metal varies with age group; children are more sensitive and hence more at risk than others. The present study was therefore undertaken on 6- to 10-year-old children residing in various localities of Greater Mumbai and Thane. Blood samples from 566 children residing in 13 locations in Mumbai along with 410 air particulate samples and 64 "duplicate diet" samples were collected for this study. Levels of Pb, Cd, Cu, and Zn in these samples were estimated by differential pulse anodic stripping voltammetric technique. Intake of Pb, Cd, Cu, and Zn for 6- to 10-year-old children through ingestion and inhalation pathways have also been assessed. A correlation coefficient of 0.88 is observed between air lead and blood lead. It is also seen that every microgram increase in the Pb concentration in air (m-3) results in 3.56 microg increase in the blood Pb concentration (dl-1) in children. Similar correlation, however, was not observed in cases of Cd, Cu, and Zn.