Non-cancer health risks associated with pesticide residues and heavy metal exposures in locally manufactured cereal-based baby foods in Kampala city

Abstract

Pesticides residues and heavy metals are major environmental pollutants and their toxicity is a problem of increasing significance for nutritional and environmental reasons. Data on the risk contribution of heavy metal contaminated cereal-based baby foods towards the disease burden in Uganda is inadequate. The study therefore assessed the awareness of exposure to pesticides, and heavy metals (HM) among manufacturers of baby foods, detected organochlorines and organophosphorus pesticides, determined the levels of selected HM (lead, cadmium, Arsenic, and mercury) and the non-cancer risks posed by these contaminants in cereal-based baby foods produced in Uganda. A set of pretested questionnaires was used to assess the level of pesticide and heavy metal responsiveness among manufacturers (n= 16) of baby foods. Samples of baby foods (n= 18) obtained from supermarkets, retail shops and groceries around Kampala City were analysed for organochlorines, organophosphate pesticides, and the heavy metals (As, Hg, Cd and Pb). Maximum levels of HM detected were 0.016 mg/kg, 0.016 mg/kg, 0.030 mg/kg, and 0.037 mg/kg for Pb, Cd, As, and Hg respectively. Pesticide residues were identified using Gas Chromatography coupled with Mass Spectrometry (GC/MS). Heavy metal concentration was determined using Atomic Absorption Spectrophotometry (AAS). Non-cancer risk posed to babies through heavy metal exposure in baby foods were determined for infants aged 6 to 24 months using the non-cancer hazard quotient (HQ) described by the United State Environmental Protection Agency (US EPA). The organochlorine 4, 4-Diphenyl DichloroTrichloro ethane (DDT) was the predominant pesticide detected in 88.8% of the baby foods tested. The concentration of As in baby foods ranged from 0.010 to 0.030 mg/kg, Hg content ranged from 0.003 to 0.037. The range concentration for Cd and Pb were 0.002 to 0.150 and 0.001 to 0.016 mg/kg, respectively The hazard quotient of heavy metals in cereal based baby foods for infants was below 1 for Pb, Cd and Hg but was greater than 1 for As, indicating potential risk to the infants for As. Hazard index values of the heavy metals were above 1 for all baby foods. The non-cancer risk due to heavy metal exposure in locally manufactured baby foods in Kampala was unacceptable. Therefore, regular monitoring of baby foods for chemical contaminants is recommended to ensure safety.