Organochlorine pesticides in agricultural soils destined to native maize culture in the Alto Mezquital, Hidalgo, Mexico

The Mezquital Valley is considered the granary of Hidalgo state, which is located in Mexico, and is inhabited by the indigenous Hñähñu people. In the Alto Mezquital subregion, small-scale subsistence farmers practice both rainfed and irrigated agriculture. The presence and concentrations of organochlorine pesticides in soils from selected agricultural fields were assessed using solid-phase matrix microextraction and gas chromatography. Physicochemical soil characterization was carried out to correlate their effect with the presence of organochlorine compounds. According to the results, DDT and its metabolites (p,p′-DDE and p,p′-DDD) were detected in the analyzed soils, suggesting their historical and recent application, even though DDT is banned in Mexico. A positive correlation was found between organochlorine pesticide levels and clay content, indicating that this soil characteristic could influence the retention of these compounds in the soils of the Alto Mezquital. Overall, these findings highlight the importance of conducting studies to assess the adverse environmental and human health impact of DDT and its metabolites.