Study of spatiotemporal variation of atmospheric mercury and its human exposure around an integrated steel plant, India
- ISSN: 16807316
- DOI: 10.5194/acp-10-5535-2010
Mercury release by coal combustion has been significantly increased in\nIndia. Mercury content in coal has been analyzed to 0.272 ppm by Central\nPollution Control Board. Toxicological effects of elemental Hg (Hg(0))\nexposure include respiratory and renal failures, cardiac arrest, and\ncerebral oedema, while subclinical exposure may induce kidney,\nbehavioral, and cognitive dysfunctions. The present work is focused on\ndispersion pattern and interphase exchange phenomena of ambient mercury\nbetween air-particulate matter evaluations of alongwith dominance of\nvarious major routes of human exposure-dose response using regression\nanalysis around an integrated steel plant in central India.\nSource-downwind type stratified random sampling plan using longitudinal\nstudy design has been adopted for ambient monitoring of total mercury,\nwhile representative sampling plant has been adopted for persona\nexposure-dose response study In space- time framework. Control sites and\nsubjects have been chosen from uncontaminated area (100 km away from any\nindustrial activities). 06 ambient air monitoring stations and 17\nsubjects from workers, non-workers but local residents' categories and\nfrom controlled sites have been chosen for the study. Samples of mercury\nbiomarkers (blood, breast milk and urine) have also been collected from\nsame subjects in each month during sampling period. The sampling period\nwas March 2005 to February 2006. Samples of 30% acidified KMnO(4) for\nair-Hg absorption, PM(10), RPM and biological samples were analyzed for\ntotal mercury by ICP-AES using standard methods. Local soils and ground\nwater were also monitored for total mercury content during the sampling\nperiod. Results have shown that mercury concentration is very high\ncompared to prescribed limits in all receptors. Results of exchange\nphenomenon have shown the higher transfer of mercury from air to\nparticulate during combustion in steel plant environment due to presence\nof huge amount of iron particles, in contrast to results obtained in\nother industrial locations earlier. Plant workers have shown 1.5 to 2.5\ntimes higher personal RPM-Hg levels compared to Category 2 and 20-30\ntimes higher than Category 3. All biomarkers have shown higher Hg\npresence compared to prescribed standards. Regression analysis between\nexposure routes and bio-receptors has been investigated. Dominance\nstatus of selected routes of bio-accumulation has been varied from\ncategory to category.