Organochlorine Pesticides Residues in Blood of Peridomestic Populations of Virginia Opossum ( Didelphis virginiana ) from Ex-Henequen Rural Localities of Yucatan, Mexico

Organochlorine pesticides (OCPs) have been used for many decades, both for the control of pests in agriculture and for the control of vectors of human and animal diseases. Several recent studies have reported significant concentrations of these compounds in multiple environmental substrates due to their persistence, as well as the effect they have on ecosystem health, human health, and wildlife populations. In the present study, organochlorine pesticide residues were determined and quantified in 260 blood samples from different populations of the Virginia opossum ( Didelphis virginiana ) from 11 rural ex-henequen sites of the state of Yucatan, Mexico. The organochlorine groups detected, following an order of predominance and concentration, were: ΣDienes (0.0557 ppm) > ΣDDTs (0.0481 ppm) > ΣEndosulfans (0.0376 ppm) > and ΣHCHs (0.0319 ppm). The highest levels of OCPs were recorded in the opossums captured in the towns of Chicxulub and Cacalchen. In 6 of the 11 localities, the OCPs detected in the opossums showed significant differences in concentration, whereas the opossums in 4 of the 11 localities did not present this difference. The results confirm the presence and persistence of OCPs in the rural environmental of Yucatan due to both the misuse and abuse of the OCPs by rural populations. In addition, the synanthropic characteristics and abundant populations of D. virginiana in the Yucatecan region make it a good candidate to serve as a biomonitor of environmental pollution in the Yucatan Peninsula. This could aid in assessing the effects exposure to pesticides and other contaminants have on the health of the Yucatecan population, whether short, medium, or long term.