Concentration, sources and health effects of silica in ambient respirable dust of Jharia Coalfields Region, India

Abstract

Background The concentration of silica in occupational conditions is well defined and estimated around the world. Many countries in the world have developed air standards for occupational conditions based on the percent silica in ambient air. This is due to the pulmonary effect caused by silica yielding diseases like silicosis and pneumoconiosis. In India, occupational exposure to silica dust is regulated by Directorate General of Mine Safety (Tech.) (S&T) Circular No. 1 of 2004 Under Reg. 123 of Coal Mines Regulations, 1957 for any metal/non-metal mining operations estimated gravimetrically. As no silica standards are prescribed in India for non-occupational conditions, venturing into such analysis was well envisaged and perceived. Methodology Air sampling was done at identified locations through high-volume samplers for 24 h, twice a week in pre-monsoon season (March to June) and the Whatman filter paper was sonicated at sufficient speed to isolate dust particles for energy dispersive X-ray. Results The percentage of silica in “PM10” was found lowest in mining sites (15%), and highest in transportation sites (35%) and mid-value for mixed sites (24%). Thus, risk level gets magnified due to addition of finer dust generated in transportation and mixed sites than mining due to diesel driven vehicles. Burning of any fossil fuel generates high percentage of finer dust (< 2.5 µm). Conclusions There should be proper prescribed standard for silica for non-occupational conditions.

Metal Element Traces Sampled from Peri-Urban Road Verge Particulate Matter

“…Consequently, numerous countries across the globe have established air quality standards tailored to occupational environments, which are focused on regulating the percentage of silica present in the ambient air. A multitude of operations, such as drilling, blasting, crushing, screening, transportation, pulverization, galvanizing, and various metalworking processes, generate significant dust emissions, including the presence of silica in the air [32]. In one of the samples obtained from the road verge, lead (Pb) was detected, possibly attributable to residual soil deposits.…”

Metal Element Traces Sampled from Peri-Urban Road Verge Particulate Matter

“…Consequently, numerous countries across the globe have established air quality standards tailored to occupational environments, which are centered on regulating the percentage of silica present in the ambient air. A multitude of operations, such as drilling, blasting, crushing, screening, transportation, pulverization, galvanizing, and various metalworking processes, generate significant dust emissions, including the presence of silica in the air [39].…”