Risk Assessment Related to Contamination of Terrestrial Food Chains by Atmospherically Deposited Lead Particles

K. Mohammed, Muhannad

	Risk Assessment Related to Contamination of Terrestrial Food Chains by Atmospherically Deposited Lead Particles
Al-Mustansiriyah Journal of Science
Article 1, Volume 21, Issue 3, 2010, Pages 103-116
Author
Muhannad K. Mohammed
Abstract
An environmental impact and toxicity analysis of internal human exposure to settled lead particles released from electrical generators, vehicles and industries are undertaken in this study. The atmospherically deposited particles on the residential, commercial, and industrial areas of Baghdad City are collected on plastic containers for several weeks and analyzed in the laboratory for lead by using Flammable Atomic Absorption Spectrophotometer model 210, VGP (Buck, USA). Terrestrial food chain mathematical models are used in this study to estimate the contribution of contaminated food ingestion (agricultural crops and animal products) to the total lead dose received by population groups living in the area of the study. The likelihood or probability of adverse health effects to the exposed individuals of Baghdad population related to continuous ingestion of deposited particles on foodstuffs at the mean observed concentrations is estimated in this study by using a statistical linear no-threshold (LNT) dose-response model. The ground contamination following gravitational settling of lead particulates would results in contamination of foodstuffs such as milk (0.203 mg Pb/L milk), meat (0.356 mg Pb/kg meat), forage (42.383 mg Pb/ kg forage), fruits or vegetables (5.184 mg Pb/kg food crops). The results of toxicity analysis and quantitative risk assessment indicate that internal exposure to deposited lead particles can increase the risk of cancer to the public at a rate of 0.015% (one extra cancer cases per 6666 exposed individuals, adults), which is 1.5 times the maximum permissible risk level that are regulated by the EPA (10-4). Infants and children are found to be at greater risk than adults due to lower body weight (Riskchild (0.13%) > Riskinfant (0.034%) > Riskadult (0.015%)). Based on the allowable risks for carcinogens that are regulated by the EPA, the maximum contaminant levels (MCLs) have been derived for lead concentrations in vegetables (0.235 mg/kg), fruits (0.234 mg/kg), meat (0.026 mg/kg), milk (0.009 mg/L), milk products (0.011 mg/kg), and surface soil (31.8 mg/kg).

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