Absorption and excretion of organophosphorous insecticide biomarkers of malathion in the rat: Implications for overestimation bias and exposure misclassification from environmental biomonitoring

► Rats, people and produce form the same suite of malathion degradation products. ► Degradation products of malathion in produce are readily absorbed and excreted in urine. ► If degradation products are used to infer exposure, preformed biomarkers must be considered.