Publisher's Synopsis
Pesticides pose a significant risk to human health and the environment. They are persistent organic compounds that are ubiquitous in our surroundings (i.e., air, water, soil, food sources, and biological materials) and can be found in places including homes, schools, and work places. Extensive pesticide use and dispersal into the environment make biomarkers use relevant for easy assessment of exposure. Analyses of pesticides in biological samples (blood and urine) are limited; they are invasive and non-cumulative. Hair can accumulate pesticides and because of ease of sampling hair can be a good biomarker for pesticide analysis and exposure. This study consists of developing an effective method for extracting pesticides from hair (human and rat), and developing a sensitive method for detection using comprehensive two-dimensional gas chromatography (GC x GC) and gas chromatography with electron capture detector (GC-ECD) in controlled and uncontrolled environments. Several extraction methods were evaluated for determining organochlorinated pesticides in human hair. Hair samples collected from pesticide applicators and non-applicators in the Atlanta area were employed in the development of a novel non-invasive method for screening toxicological biomarkers by GC x GC. The hair was ground using a ball mill and underwent solid-liquid extraction of the chlorinated pesticides, which were quantified by GC x GC. In a controlled experiment, rats were administered different doses of chlorinated pesticides (Aldrin, Endosulfan, Lindane, 4, 4-DDT, and Endrin) either orally or dermally to (1) determine if chlorinated pesticides could be detected in rat hair by GC-ECD and (2) establish whether differences in dose lead to differential accumulation of pesticides in the hair, and (3) determine whether there are differences in concentrations between the two routes of exposure. Hair was collected from rats that were dosed for 2 weeks and 4 weeks. Hair was pulverized using a ball mill, underwent solid-liquid extraction of the chlorinated pesticides and analyzed by GC-ECD. Gas chromatography-mass spectrometry (GC-MS) was used for confirmation of random samples In addition, hair samples collected from individuals in the Houston area were analyzed for pesticides using GC-ECD.
