Colo. Study Points to Health Impacts from Gas Drilling
Charleston Gazette
19 March 2012
By Ken Ward Jr.
An important new study from the University of Colorado’s School of
Public Health raises questions about potential public health
impacts of the natural gas drilling boom in West Virginia and
across the country. Here’s what the news release from the school
says:
In a new study, researchers from the Colorado School of Public
Health have shown that air pollution caused by hydraulic
fracturing or fracking may contribute to acute and chronic health
problems for those living near natural gas drilling sites.
“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, lead author of the study and research
associate at the Colorado School of Public Health.
There are media reports out about the study in the Denver Post and
on the website of Colorado Energy News.
According to the news release:
The report, based on three years of monitoring, found a number of
potentially toxic petroleum hydrocarbons in the air near the wells
including benzene, ethylbenzene, toluene and xylene. Benzene has
been identified by the Environmental Protection Agency as a known
carcinogen. Other chemicals included heptane, octane and
diethylbenzene but information on their toxicity is limited.
The report, which looked at those living about a half-mile from
the wells, comes in response to the rapid expansion of natural gas
development in rural Garfield County, in western Colorado.
Typically, wells are developed in stages that include drilling
followed by hydraulic fracturing , the high powered injection of
water and chemicals into the drilled area to release the gas.
After that, there is flowback or the return of fracking and
geologic fluids, hydrocarbons and natural gas to the surface. The
gas is then collected and sold.
Garfield County asked the Colorado School of Public Health to
assess the potential health impacts of these wells on the
community of Battlement Mesa with a population of about 5,000.
The study is due out soon in the journal Science of the Total
Environment, and here’s the abstract:
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.
Keep in mind that the new natural gas drilling law championed by
Gov. Earl Ray Tomblin allows drilling in West Virginia within 625
feet of occupied residences, well within the 1/2-mile (2640 feet)
distance cited in the study as the area where residents would face
greater health risks.