People who live near natural gas wells are being exposed to elevated levels of several air pollutants, including the known carcinogen, benzene. That's the conclusion of a study from the Colorado School of Public Health. The study strongly suggests that a much closer look is needed at just how these pollutants are affecting people's health.

This study was a preliminary attempt to assess some of the potential health effects of living near these wells. It found that the greatest concerns occur within a half mile of the wells.

The report, based on three years of monitoring the air in Garfield County, Colorado, found a number of potentially toxic hydrocarbons in the air near the wells, such as xylene, ethylbenzene and toluene, chemicals known to cause respiratory and neurological problems. Garfield County has recently been the site of rapidly expanding gas development.

Needless to say, residents were not too pleased at the study results.

Extraction of natural gas is rarely a matter of drilling a simple hole in the ground any more. The quest for deeper, less accessible gas deposits increasingly relies on fracking to bring these deposits to the surface. Fracking (high pressure fracturing) is the injection of large volumes of pressurized liquid (water and chemicals) into rock deep underground to fracture the rock and allow the trapped gas to rise to the surface. Fracking has come under fire as environmentally hazardous for several reasons, most often for the water pollution it can cause.

Add air pollution to the list.

Natural gas is expected to play an increasing role in meeting future energy needs in the United States. As more wells are drilled, it's become more and more common for them to be located near areas where people live, work and play. And people living near these developments are raising public health concerns. Colorado rules allow gas wells to be placed as close as 150 feet from people's homes.

This study was a preliminary attempt to assess some of the potential health effects of living near these wells. It found that the greatest concerns occur within a half mile of the wells. But it can only estimate the health risks of people living near gas wells; it has no numbers that document the actual harm (number of cancers, illnesses) these wells have caused and do cause for nearby residents. It urges further studies to collect this information, as well as calling for reduction of emissions from these wells.

"Our data show that it is important to include air pollution in the national dialogue on natural gas development that has focused largely on water exposures to hydraulic fracturing," said Lisa McKenzie, Ph.D., MPH, the study's lead author and a research associate at the Colorado School of Public Health in a press release.

An article on the study was published online in the Journal of the Total Environment.