Air quality impact of sponge iron industries in central India.

Emission load of particulate matter from 42 sponge iron industrial units located in clusters in the Indian State of Chhattisgarh was estimated to be 1,361 TPD. US EPA air pollution dispersion model ISCST-3 applied to predict the impact of the sponge iron industry emissions on ambient air quality showed contribution up to 546 microg/m(3) to the surrounding air basin causing the air quality exceeding the national ambient air quality standards. Electrostatic precipitator (ESP) has been suggested to all the above industrial units that would bring down the contribution to as low as 27 microg/m(3).

Seasonal variation of toxic benzene emissions in petroleum refinery.

Petroleum refineries are largest chemical industries that are responsible for the emission of several pollutants into the atmosphere. Benzene is among the most important air pollutants that are emitted by petroleum refineries, since they are involved in almost every refinery process. Volatile organic compounds (VOCs) are a major group of air pollutants, which play a critical role in atmospheric chemistry. These contribute to toxic oxidants, which are harmful to ecosystem, human health and atmosphere. The variability of pollutants is an important factor in determining human exposure to these chemicals. The ambient air concentrations of benzene were measured in several sites around the Digboi petroleum refinery, near the city of Gowahati in northeast India, during winter and summer 2004. The seasonal and spatial variations of the ambient air concentrations of this benzene were investigated and analyzed. An estimation of the contribution of the refinery to the measured atmospheric levels of benzene was also performed. The ambient air mixing ratios of benzene in a large area outside the refinery was generally low, in ppbv range, much lower than the ambient air quality standards. This article presents the temporal and spatial variation of air pollution in and around petroleum refinery and showed that no health risk due to benzene is present in the areas adjacent to the refinery.