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Biomarkers of Exposure and Effect in Migrant Farmworker Children of Mexican Origin from Urban and Agricultural Regions of Texas
Citation:
HERNANDEZ-VALERO, M. A., A. E. SWANK, S. Z. ABDEL-RAHMAN, L. A. JONES, AND D. M. DEMARINI. Biomarkers of Exposure and Effect in Migrant Farmworker Children of Mexican Origin from Urban and Agricultural Regions of Texas. Presented at Environmental Mutagen Society 39th Annual Meeting, San Juan, PUERTO RICO, October 18 - 22, 2008.
Impact/Purpose:
This study investigates the levels of pesticides in urine and the levels of chromosome aberrations in white blood cells of migrant farm worker chidlren.
Description:
Some organophosphate pesticides (OPs) induce chromosome aberrations (CA) in experimental systems and may be genotoxic in persons exposed to home-use levels of OPs. However, the genotoxic effects of OPs have not been studied extensively in environmentally exposed children, such as migrant farmworker (MF) children. Thus, we evaluated MF children for CA in the heterochromatic region of chromosome 1 (1q12) in peripheral blood lymphocytes by FISH and for 5 OP metabolites in urine (IMPY, DEAMPY, PNP, 3-MPNP, and TCPY) by LC-MS/MS with APCI using stable isotope-labeled internal standards. We studied a random sample of 22 MF children matched by age (± 2 years), sex, and ethnicity to 22 non-MF children from industrial (Houston metropolitan area) and agricultural (Lower Río Grande Valley, LRGV) regions of Texas. Most children were U.S.-born (81.8%), males (65.9%), and had a mean age of 12 ± 3.6 years. Results showed that 81.8% were exposed to at least 1 OP, with the MF children exhibiting the largest number of OPs in their urine (27.3% had 3-4 OPs). A dose response was observed between the number of OPs detected and levels of CA (3.9 ± 1.6 aberrations/1000 cells in children with no exposure to 6.5 ± .7 in children exposed to 4 OPs). Children residing in LRGV had the highest frequency of CA (5.6 ± 2.7 vs. 4.2 ± 1.8), followed by MF children (5.1 ± 2.3 vs. 4.4 ± 2.3). This preliminary study suggests an association between CA and pesticide levels in Mexican-American MF children.