Evaluating Variability of Aerosol Concentration in Coal Mining Areas: A Case Study from Patratu Coal Mining Region, Jharkhand

Abstract

The monitoring of aerosol concentration becomes a high environmental priority in mining and adjoining areas and it is one of the key parameters to assess the atmospheric pollution. Human activities, coal mine fire, overburden dumping, transportation and other mining operations or coal based industries are responsible for increasing pollution in mining regions. In the present study aerosol optical thickness (AOT) was determined using handheld MICROTOPS II sunphotometer at five different wavelengths (340, 500, 870, 936 and 1020 nm), along with temperature and precipitable water vapour (PWV) which are estimated from the measurements of solar intensity at 936nm and 1020nm during peak winter period. The pattern of measured aerosol concentration along with water vapour and temperature were spatially analyzed in GIS environment with reference to land use/land cover map of the region. The study revealed that the study area (381 sq. km) was dominated by wasteland (98.64 sq. km, 25.89%) and forest cover 136.50 sq. km (35.82%) as mapped during the year 2009. The area under coal mining is 16.87 sq. km (4.42%), built-up land is 33.88 sq. km (8.89%) and cropped area is about 62.29 sq. km (16.35%). The spatial distribution of AOT in the wavelength region 340-1020nm exhibits that the AOT values are higher for smaller wavelengths and lower for larger wavelengths indicating the dominance of fine particles in the atmosphere compared to larger sized particles. In this study, the AOT wavelength 340nm is therefore taken for further analysis due to its higher variation in the area as well as its harmful effect on human health. It was observed that AOT concentration was higher in the industrial area in the vicinity of thermal power plant, Sponge iron factory, mining area and coal based small industries located within the urban area, whereas lower in the forest and low population density areas within the agricultural lands.