Contamination and Exposure Profiles of Persistent Organic Pollutants (PAHs and OCPs) in Groundwater at a Terai Belt of North India

A study of persistent organic pollutants in groundwater was conducted at selected locations in Gorakhpur (terai belt in the north part of India) for a span of 1 year in order to ascertain their contamination levels. Water samples were collected from nine stations which covers roadside, residential, and agricultural sites (three stations per area) of Gorakhpur in the year 2010-2011. Two different compounds were determined: polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). High-pressure liquid chromatography was used for PAH analysis whereas capillary gas chromatography with electron capture detector (ECD) was used for OCP analysis. The most often detected OCPs were pp-DDT (67%) whereas pp-DDD, pp-DDE, and beta-HCH occurred rarely. The concentration of pesticides ranged from 2.98 to 13.27 ng/L. Total concentration of the measured PAHs varied between 10.24 and 43.85 ng/L. Among all PAHs, ANT and FLT were predominant, while the most carcinogenic PAH, i.e., B(a) P represented only 2% of the total PAH content. Carcinogenic potency of PAH compounds was calculated and found to be insignificant at present level in the groundwater of Gorakhpur. Levels of POPs in the groundwater can help in environment risk assessment.