Pyrethroid and organophosphorus pesticides in composite diet samples from Atlanta, USA adults

Four pyrethroid (permethrin, cyfluthrin, cypermethrin, deltamethrin) and 3 organophosphorus (chlorpyrifos, diazinon, malathion) pesticides were measured in 4 days of 24 h duplicate diet samples collected from 12 Atlanta adults over two cycles (2005-2006). Samples were composited into 9 categories, by food type, to evaluate their contribution to daily intakes. The resulting 437 samples were analyzed using a multiresidue method using liquid-liquid and solid-phase extraction followed by quantification via gas chromatograph with electron-capture detection. Total daily intakes (mg/kg-d) were calculated by summing the mass of a pesticide in all composites collected that day and dividing by body weight. Chlorpyrifos, diazinon, and cypermethrin in were detected in a range of composite types at frequencies > or =30%, whereas other pesticides were detected at lower frequencies. Concentrations ranged from the detection limits (0.38-0.88 ng/g) to several hundred ng/g, exceeding U.S. tolerances in a few cases. We also detected pesticides in some foods labeled organic. Total daily intakes were below the U.S. Environmental Protection Agency's oral reference doses, except in 6% of cases when the organophosphorus concentrations were summed. Results show frequent dietary exposure of our participants to the target pesticides from a range of food types.