Heavy metals and metalloids in organic and conventional vegetables from Chile and Mexico : Implications for human health

Abstract

The present study assessed the levels of heavy metals (HM; Hg, Cd, Pb, and Cu) and a metalloid (As) in commonly consumed vegetables (lettuce, tomato, green pepper, chard, and spinach) in Chile and Mexico. In Chile the HM and metalloid concentrations were generally lower than those in Mexico and higher in organic crops than in conventional crops. Moreover, the detection frequency of Cd and As in Chilean vegetables was 100%. In Mexico, the Pb levels in organic vegetables (lettuce, tomato, chili, and spinach) and conventional vegetables (spinach and tomato) exceeded the international regulation (IR). In Chile, only tomato showed Pb levels that exceeded the IR. The estimated dietary intake (EDI) values for Mexico were lower than the reference dose, although the EDI values were higher for As in all age ranges and mainly associated with tomato and lettuce in Chile. The target hazard quotient and hazard index values were < 1 (Chile and Mexico). Although the potential health risk is low, prolonged exposure to average concentrations of As (0.2 mg kg-1) in Chile may constitute a potential risk factor for the development of certain cancers. Additional research is necessary to properly regulate As levels in vegetables to ensure food safety.