Environmental contamination by arsenic and lead in some rural villages in India

This investigation focuses on the arsenic contamination problems in tube well groundwater systems and the different forms of arsenic and other toxic elements accumulated in human hair samples taken in a rural area of Allahabad, Uttar Pradesh, India. The local residents at the study site depend on groundwater as their major source of household water. The oxidation reduction potential (ORP) and pH of groundwater samples were measured directly after the sampling of groundwater. Arsenic concentrations were measured directly in water samples by a colorimetric arsenic analysis kit after the water was pumped from a tube well and/or at a nearby laboratory. Human hair samples from the residents of the villages in the study site were analyzed by PIXE to measure a wide range of elements. An atomic absorption spectrometer was also used to measure arsenic concentrations. The results indicated that the concentrations of arsenic in groundwater and human hair were significantly higher in the village of Bada Kanjasa than in the villages of Kanua and Chota Kanjasa (P< 0.05), clearly indicating that the higher arsenic concentration in groundwater reflected the accumulation of arsenic in human hair in the residents of Bada Kanjasa. The PIXE analysis also revealed an unusually high concentration of lead in human hair samples from Chota Kanjasa. Although the actual health effects and the detailed exposure mechanisms remain to be investigated, lead pollution is suspected to be the source of the exposure.