Assessment of Environmental Impact of Iron Ore Mining on the Air Quality in Koira Mining Area, India

Abstract

Mining for iron ore produces large amounts of particulate matter (PM) and related gaseous emissions, making it a major stationary source of air pollution. In the mining zones of Barsua-Tensa and Koira in Odisha, India, this study evaluated the ambient levels of PM 10 and PM 2.5 as well as their chemical properties. Using respirable dust samplers (Envirotech APM 460 NL) and fine particle samplers (Envirotech APM 550) in accordance with IS:5182 standards, air quality monitoring was carried out at 10 sampling points throughout mining townships. Mass concentrations were calculated by gravimetric analysis, and microwave acid digestion (US EPA Method 3052) and ICP-MS analysis were used to characterize trace metals in a subset of PM 2.5 samples. The findings showed that PM 10 concentrations were higher than the National Ambient Air Quality Standards (NAAQS) at every test site, while PM 2.5 levels were higher than allowable limits at a number of sites, especially in Koira Township. PM 10 was rated as “Moderate” to “Extremely Hazardous” by the Air Quality Index (AQI), while PM 2.5 was rated as “Unhealthy for Sensitive Groups” to “Unhealthy”. Increased concentrations were closely linked to heavy haul-road traffic, which involved over 1500 dumpers moving iron ore concentrates at night. Significant concentrations of key elements (Na, K, Ca, Mg, Al, Fe) and trace metals (Ba, Zn, Mn, Cr, Ni, Pb, Hg, Cd, and As) were found in mineralogical examination, suggesting possible toxicological hazards. The results show that the ambient air quality in the mining corridors under study has significantly deteriorated, with Koira Township having the highest pollution burden. There are serious dangers to community and occupational health from prolonged exposure to increased respirable particles and metal-enriched dust, including systemic poisoning and respiratory morbidity. Coordinated emission control measures that target haul-road dust, improved traffic management, and cooperative regulatory oversight are necessary for effective mitigation in order to lower PM levels below tolerable bounds.