139
parent chemicals can break down into similar metabolites, making identification of
the original chemical difficult to impossible. Finally, as if this wasn’t complicated
enough, individuals may metabolize some of these chemicals at widely different
rates, depending on genetics, medication, certain nutrients, and other factors leading
to different results in the analysis. There are very limited methods to account for this.
Linking a health risk or even a specific chemical exposure to fracking is often a
difficult business. Many of the targeted chemicals are present elsewhere in the environment and trying to tie a specific compound to fracking can be very challenging.
A classic case is the small town of Dish, Texas, located northwest of Dallas-Ft.
Worth in the Barnett Shale development area. The town’s mayor blamed fracking
for elevated levels of benzene that were found in blood tests run on some local citizens, and Dish became a 30-day wonder in the media and on the Internet.
In response to citizen concerns, the Texas Department of State Health Services
(2010) made an effort to collect urine and blood samples from 28 residents of Dish,
Texas. Tap water samples were also gathered, and investigators performed field
observations of odor and noise near the subjects’ homes. The location of nearby
well pads, storage equipment, and compressor stations was noted. In what can only
be described as a heroic effort to cross-check the data, staffers at the Texas
Department of State Health Services who lived in Austin, some 150 miles (240 km)
from the Barnett Shale play and 200 miles (322 km) from Dish, acted as human
guinea pigs by providing blood and urine samples both before and after spending
several days in Dish visiting residences near compressor stations and gas wells.
The results of the study found no difference in the benzene levels of the Health
Services employees before and after the site visit. A strong correlation was found
however, between elevated benzene levels in the residents of Dish and those who
smoked cigarettes. Most toxicologists will readily ascribe elevated levels of benzene in blood and urine to cigarette smoking. The Texas study concluded that smoking was the cause of elevated benzene in Dish residents, not fracking. Gasoline is
another major environmental source of benzene, where it is a major volatile component along with toluene, ethylbenzene, and xylenes, a combination known collectively as BTEX. The practice of self-pumping gasoline, which is common in nearly
all states other than Oregon and New Jersey, can result in elevated levels of benzene
in anyone who inhales the vapors or splashes gasoline onto their skin while fueling
a vehicle.
Despite these findings, a later study conducted on VOC exposures of well site
workers at six completion sites in Colorado and Wyoming still failed to account for
smoking or other non-occupational exposures to these chemicals (Esswein et al.
2014). Urine samples were collected from workers at each site during flowback
operations, which have been found to release the largest quantities of VOCs into the
air during shale well completion activities (Pekney et al. 2018). The goal of the
study was to try to determine how each participant’s job at the site might affect VOC
exposures, but by not correcting the biomonitoring results for other environmental
exposures, the results were inconclusive.
An illustration of how health concerns over fracking can get out of control is the
supposed contamination of the drinking water supply in the town of Pavillion,
8.1 Human Health
parent chemicals can break down into similar metabolites, making identification of
the original chemical difficult to impossible. Finally, as if this wasn’t complicated
enough, individuals may metabolize some of these chemicals at widely different
rates, depending on genetics, medication, certain nutrients, and other factors leading
to different results in the analysis. There are very limited methods to account for this.
Linking a health risk or even a specific chemical exposure to fracking is often a
difficult business. Many of the targeted chemicals are present elsewhere in the environment and trying to tie a specific compound to fracking can be very challenging.
A classic case is the small town of Dish, Texas, located northwest of Dallas-Ft.
Worth in the Barnett Shale development area. The town’s mayor blamed fracking
for elevated levels of benzene that were found in blood tests run on some local citizens, and Dish became a 30-day wonder in the media and on the Internet.
In response to citizen concerns, the Texas Department of State Health Services
(2010) made an effort to collect urine and blood samples from 28 residents of Dish,
Texas. Tap water samples were also gathered, and investigators performed field
observations of odor and noise near the subjects’ homes. The location of nearby
well pads, storage equipment, and compressor stations was noted. In what can only
be described as a heroic effort to cross-check the data, staffers at the Texas
Department of State Health Services who lived in Austin, some 150 miles (240 km)
from the Barnett Shale play and 200 miles (322 km) from Dish, acted as human
guinea pigs by providing blood and urine samples both before and after spending
several days in Dish visiting residences near compressor stations and gas wells.
The results of the study found no difference in the benzene levels of the Health
Services employees before and after the site visit. A strong correlation was found
however, between elevated benzene levels in the residents of Dish and those who
smoked cigarettes. Most toxicologists will readily ascribe elevated levels of benzene in blood and urine to cigarette smoking. The Texas study concluded that smoking was the cause of elevated benzene in Dish residents, not fracking. Gasoline is
another major environmental source of benzene, where it is a major volatile component along with toluene, ethylbenzene, and xylenes, a combination known collectively as BTEX. The practice of self-pumping gasoline, which is common in nearly
all states other than Oregon and New Jersey, can result in elevated levels of benzene
in anyone who inhales the vapors or splashes gasoline onto their skin while fueling
a vehicle.
Despite these findings, a later study conducted on VOC exposures of well site
workers at six completion sites in Colorado and Wyoming still failed to account for
smoking or other non-occupational exposures to these chemicals (Esswein et al.
2014). Urine samples were collected from workers at each site during flowback
operations, which have been found to release the largest quantities of VOCs into the
air during shale well completion activities (Pekney et al. 2018). The goal of the
study was to try to determine how each participant’s job at the site might affect VOC
exposures, but by not correcting the biomonitoring results for other environmental
exposures, the results were inconclusive.
An illustration of how health concerns over fracking can get out of control is the
supposed contamination of the drinking water supply in the town of Pavillion,
8.1 Human Health