Human Health Risk Assessment of Air Emissions from Development of Unconventional Natural Gas Resources by Lisa M. McKenzie, Roxana Z. Wittera, Lee S. Newmana, John L. Adgatea, Colorado School of Public Health, University of Colorado, March 19, 2012, erierising
Results: Residents living ≤ ½ mile from wells are at greater risk for health effects from NGD than are residents living > ½ mile from wells. Subchronic exposures to air pollutants during well completion activities present the greatest potential for health effects. The subchronic non-cancer hazard index (HI) of 5 for residents ≤ ½ mile from wells was driven primarily by exposure to trimethylbenzenes, xylenes, and aliphatic hydrocarbons. Chronic HIs were 1 and 0.4. for residents ≤ ½ mile from wells and > ½ mile from wells, respectively. Cumulative cancer risks were 10 in a million and 6 in a million for residents living ≤ ½ mile and > ½ mile from wells, respectively, with benzene as the major contributor to the risk.
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