Contamination of the Drinking Water in O Porriño, Pontevedra with Hexachlorocyclohexane (HCH) Isomers

Abstract

The burial of the waste generated during the lindane (gamma-hexachlorocyclohexane) production process in the industrial area of the Torneiros Industrial Park (O Porriño) between 1948 and 1964 caused the ground to become contaminated. Owing to its mechanical characteristics, the waste was used for years as filler in roads near the production area, the population not being aware of its hazardous nature. After remedial actions were taken to isolate the contaminant, the problem was believed to be confined to the Torneiros Industrial Park; however, water analyses conducted by the Miño-Sil Water Authority (CHMS) in the past few years have pointed to the potential presence of the contaminant in the ground of an area called Contrasto. In November 2017, an epidemic situation was declared due to lindane poisoning triggered by sanitation works in a street in the Contrasto area, after substantial amounts of lindane were detected during the earthworks. This study focuses on investigating the potential contamination of the drinking water for the population of Contrasto (O Porriño, Pontevedra) with HCH isomers, characterizing and assessing the risk of exposure of said population to these contaminants via sampling, and taking control measures aimed at ensuring the potability of the water in the area. To this end, the houses in the area and their water supply systems were identified. Samples were taken from these systems and analyzed for HCH isomers at the Galician Public Health Laboratory.