Lead, arsenic, fluoride, and iron contamination of drinking water in the tea garden belt of Darrang district, Assam, India.

Drinking water quality with respect to lead, iron, fluoride, and arsenic has been carried out in and around tea gardens of Darrang district of Assam, India. The district lies between 26 degrees 25(') and 26 degrees 55(') northern latitude and 91 degrees 45(') and 91 degrees 20(') east longitude and covers an area of 3,465.30 km(2). Twenty-five different sampling stations were selected for the study. Iron, lead, and arsenic were analyzed by using an atomic absorption spectrometer, Perkin Elmer AA 200, while fluoride was measured by the SPADNS method using a UV-VIS spectrometer, Shimadzu 1240 model. The study revealed that the water sources in the area are heavily polluted with lead. Statistical analysis of the data is presented to determine the distribution pattern, localization of data, and other related information. Statistical observations imply non-uniform distribution of the studied parameters with a long asymmetric tail either on the right or left side of the median.