A University of Colorado School of Public Health study claims that air pollution resulting from hydraulic fracturing may contribute to acute and chronic health problems for those living near oil and gas drilling operations. Lisa McKenzie, et al., “Human Health Risk Assessment of Air Emissions from Development of Unconventional Natural Gas Resources,” Science of the Total Environment, March 2012. Based on three years of monitoring, the study examined effects on people living within a half-mile of wells.

According to the study, exposure to air pollutants, including benzene, ethylbenzene, toluene, xylene, heptane, octane, and diethylbenzene during well-completion activities presented the greatest potential for adverse health effects. During the completion phases, the study found that the pollutants with the greatest impacts were trimethylbenzenes, aliphatic hydrocarbons and xylenes, which can purportedly cause neurological and respiratory effects such as eye irritation, headaches, sore throat, and breathing difficulties. Researchers recommend further studies that include collection of data about potential area, residential and personal exposure where wells are operating.