BIOMARKERS OF HUMAN EXPOSURE TO PESTICIDES

For centuries, several hundred pesticides have been used to control in sects. These pesticides differ greatly in their mode of action, uptake by the body, metabolism, elimination from the body, and toxicity to h umans. Potential exposure from the environment can be estimated by env ironmental monitoring. Actual exposure (uptake) is measured by the bio logical monitoring of human tissues and body fluids. Biomarkers are us ed to detect the effects of pesticides before adverse clinical health effects occur. Pesticides and their metabolites are measured in biolog ical samples, serum, fat, urine, blood, or breast milk by the usual an alytical techniques. Biochemical responses to environmental chemicals provide a measure of toxic effect. A widely used biochemical biomarker , cholinesterase depression, measures exposure to organophosphorus ins ecticides. Techniques that measure DNA damage (e.g., detection of DNA adducts) provide a powerful tool in measuring environmental effects. A dducts to hemoglobin have been detected with several pesticides. Deter mination of chromosomal aberration rates in cultured lymphocytes is an established method of monitoring populations occupationally or enviro nmentally exposed to known or suspected mutagenic-carcinogenic agents. There are several studies on the cytogenetic effects of work with pes ticide formulations. The majority of these studies report increases in the frequency of chromosomal aberrations and/or sister chromatid exch anges among the exposed workers. Biomarkers will have a major impact o n the study of environmental risk factors. The basic aim of scientists exploring these issues is to determine the nature and consequences of genetic change or variation, with the ultimate purpose of predicting or preventing disease.