Concentrations of heavy metals such as Pb, Cd, Cu, and Zn have been determined by using differential pulse anodic stripping voltammetry (DPASV) in air particulates, diet, and children's blood residing at different locations of Tirupati. The reliability of the procedure for estimation of Pb, Cd, Cu, and Zn in environmental and biological samples by DPASV technique was checked by analyzing various standard reference materials. The observed daily intake of Pb, Cd, Cu, and Zn by children varies from 0.1014 to 0.3264, 0.0204 to 0.0372, 0.1953 to 0.3310, and 76.1902 to 78.3720 mg day 21 through inhalation, and 17.53 to 20.91, 1.92 to 2.32, 954.92 to 1264.70, and 5750.14 to 6774.56 mg day 21 through dietary intake, respectively. Retention times of Pb, Cd, Cu, and Zn in children's blood are estimated by using levels of these metals in air particulates and by duplicating diet and blood of children. The observed average retention times for Pb, Cd, Cu, and Zn are 17.32, 7.85, 2.12, and 1.92 days, respectively.