Chapter 20 - In vivo biomarkers and biomonitoring in reproductive and developmental toxicity

Abstract

This chapter discusses in vivo biomarkers and biomonitoring in reproductive and developmental toxicity. Biomonitoring is an important tool that can be used to evaluate human exposure to pesticides by measuring the levels of pesticides, pesticide metabolites or altered biological structures or functions in biological specimens or tissue. The most common insecticides that affect humans are organophosphate, carbamates and pyrethrins and pyrethroids. The most common herbicides that affect humans are triazines, phenoxyacid, chloroacetanilides and other herbicides. Fungicides, although widely used, are not the most common class of pesticides typically measured in humans. High-performance liquid chromatography, ultra-performance liquid chromatography and gas chromatography are typically interfaced with single-stage quadrupole mass spectrometers. Biomarkers of exposure should be, at a minimum, sensitive, specific, valid, biologically relevant and easy to collect in order to be useful as a surveillance tool and for improving quantitative estimates of exposure and dose. Low frequencies of detection of pesticide biomarkers can be an indication of infrequent and/or low level pesticide exposures, or an indication of insufficiently sensitive analytical methods. Sensitivity issues still can hinder the widespread detection of pesticides. A selected biomarker of pesticide exposure should be a valid indicator of an underlying exposure event. To be useful in large-scale studies, biomarkers should be easy to obtain, store and analyze. Biomonitoring data can be used for a variety of applications ranging from risk assessment to assessing the effectiveness of exposure mitigation strategies. Biomonitoring data can improve estimates of dose derived from exposure and kinetic models.