Organochlorine pesticides in the drinking water of Merida and its Metropolitan Zone, a Karst Region

This study was conducted to evaluate the quality of drinking water in 28 homes of Merida and 7 municipalities of its Metropolitan Zone, in Yucatan, Mexico. The organochlorine pesticides (OCP) were investigated since it represents important health risks. The karst groundwater in Yucatan is vulnerable due to the easy infiltration of contaminants. The use of prohibited OCP in agriculture and livestock production as well as the minimal infrastructure for drinking water sanitation also pose important public health risks. Samples were analyzed by GC-ECD. The concentrations of lindane (0.01896 ppm), heptachlor (0.09741 ppm), endosulfan (0.05796 ppm), DDT (0.00519 ppm), and endrin (0.00125 ppm) were above the international standards. Samples were analyzed for physicochemical parameters such as pH, electrical conductivity, CaCO3, MgCO3, hardness, Na+, K+, SO4=, and Cl-. Total hardness (405-646 mg/L) were above of international criterion. Adequate infrastructure to obtain safe drinking water for human consumption is strongly recommended.