Assessment of exposure to organochlorine pesticides and levels of DNA damage in mother–infant pairs of an agrarian community

Abstract

Exposure to organochlorine pesticides was studied in a group of mother-infant pairs living in a rural area where agriculture is the main economic activity. Fumigation in this zone is performed with airplanes, thus affecting the inhabited areas around them, including schools. Heparinized venous blood of mothers and umbilical cords was used to evaluate the olive tail moment in the comet assay, and micronuclei, chromatin buds, and nucleoplasmic bridges in peripheral blood lymphocytes. Cord blood samples were taken at the moment of birth only from natural and normal parturitions. Determinations of hexachlorobenzene, aldrin, heptachlor epoxide, oxichlordane, t and c-chlordane, cis-nonachlor, mirex, alpha and beta-endosulfan, alpha, beta and gamma hexachlorocyclohexane, and p'p'-DDT, p'p'-DDE were conducted to establish the differential distribution of the toxicants between compartments, i.e., mother and umbilical cord. Significantly higher pesticide levels were found in umbilical cord plasma than in mothers' plasma for almost all compounds tested, except DDE and oxychlordane. Significantly higher olive tail moments were found in umbilical cords than in mothers, whereas micronuclei frequencies were higher in mothers than in umbilical cords. However, neither the levels of micronuclei nor the olive tail moment were correlated with pesticide levels. Given that no other exposure to toxic compounds has been identified in this region, the lack of correlation between genotoxicity biomarkers and pesticide levels may be due to the variability of the exposure and to endogenous processes related to lipid mobility during pregnancy, the metabolism of the compounds, and individual susceptibilities.

Cumulative Chemical Exposures During Pregnancy and Early Development

“…Using wet weights, OC levels are higher in maternal than cord blood, though the difference is slight for some compounds [113, 114, 125]. Using lipid-adjusted measures, OC levels are typically slightly higher in cord than maternal serum, though the levels are not different enough to imply fetal accumulation [114, 125, 126]. Additionally, levels of DDE and dichlorodiphenyltrichloroethane (DDT) in maternal serum do not differ across trimesters of pregnancy [116, 127, 128].…”

A Systematic Review of Studies on Genotoxicity and Related Biomarkers in Populations Exposed to Pesticides in Mexico

“…Although the levels of organochlorine pesticides in newborns were significantly higher than in mothers, the differences in DNA damage did not show statistically significant differences. Most mothers take folic acid, which could prevent genetic damage, even though fetuses were exposed to pesticides during development [39,44,49], showing that the MN test in umbilical cord samples might be useful in the evaluation of transplacental genotoxic agents and can be compared with the DNA damage in their mothers after their study in Chihuahua, Mexico. Newborns and mothers from urban areas showed 1 ± 0.9 and 3.7 ± 1.4 MN in 1000 cells, respectively.…”

Alteraciones Del Ciclo Menstrual De Adolescentes Expuestas No Ocupacionalmente a Una Mezcla De Plaguicidas De Una Zona Agrícola De San Luis Potosí, México. Estudio Piloto

“…La diferencia entre las concentraciones detectadas en ambos estudios puede explicarse porque el estudio de Yáñez et al (2000) se realizó cuando aún se empleaba el DDT para el control del paludismo, mientras que el presente estudio se desarrolló 14 años después de la última aplicación de este insecticida. En un estudio realizado por Alvarado-Hernández et al (2013) en mujeres que eran atendidas de parto en un hospital ubicado en la misma región donde se desarrolló el presente trabajo, los autores evaluaron la exposición materna a una mezcla de plaguicidas OC, obteniendo como resultado de la Σ de OC una media de 10 600 ng/g de lípidos, la cual es tres veces más alta que la concentración promedio detectada en el presente reporte de investigación (3653.44 ng/g de lípidos). En ambos estudios se monitorearon los mismos plaguicidas OC (aldrin, a-BHC, b-BHC, g-BHC, hexaclorobenceno, heptacloro epóxido, trans-nonaclor, cis-nonaclor, 4,4'-DDE y 4,4'-DDT), lo que corrobora la persistencia de estos compuestos químicos y por ende el riesgo de exposición crónica a residuos de estos contaminantes para quienes habitan en la zona.…”