Health Impacts of Shale Gas Development
Data suggest that shale gas development (SGD) poses a substantial risk to public health. Approximately 12.6 million people live within one-half mile of an oil and gas facility. Many, especially those in underserved and underrepresented communities, live near multiple sources of emissions. Nearly 2.9 million children attend school within a half-mile of these facilities.
SGD releases toxic chemicals, particulate matter, and other dangerous pollutants during all phases of the industrial process. The potential health consequences of SGD begin even before drilling starts and may last long after the operation has ended.
Research is mounting on pollution emitted at all stages of SGD and on health effects experienced by nearby residents. Many of the toxic chemicals that have been found in air and water samples around SGD operations have identifiable adverse health effects. For example, benzene is a known carcinogen (cancer-causing chemical), toluene is a neurotoxin, and hydrogen sulfide irritates the lungs and can cause asthma. Noise and light pollution are associated with hearing loss, sleeplessness, and other health issues. Prolonged stress can also lead to significant health problems, like heart disease, cancer, and depression.
Environmental Health Exposures
Toxic pollutants can enter our bodies through inhalation, ingestion, and absorption. Environmental pollutants can affect anyone, but some people like children, pregnant individuals, older adults with preexisting health conditions, and industry workers may be at greater risk. If you live near shale gas operations, you may be exposed in the following ways:
Breathing polluted air
Drinking contaminated water or cooking or bathing with it
Eating food grown in contaminated soil
Individuals may also experience harmful levels of stress and health problems from the noise, vibration, and light pollution associated with heavy industrial activities.
One frequently asked question is whether individuals living or working near SGD sites such as well pads, compressor stations, or production facilities should undergo biomonitoring (blood or urine tests) to determine if they have harmful chemicals in their body as a result of exposures from these operations. One common class of potentially harmful emissions from oil and gas development is “volatile organic compounds” (VOCs). While there are blood and urine tests available to assess exposures to VOCs, the results can be misleading, resulting in either false reassurance or unnecessary alarm. Before undergoing testing, it is important to understand the nature and limitations of these tests.
Some limitations in biomonitoring testing in the SGD setting include:
Most of the chemicals associated with SGD activity are cleared rapidly from the body, so a test may not show the presence of a chemical or metabolite even if someone is exposed to a pollutant. This may result in a “false negative” result, which can be inappropriately reassuring.
Some metabolites of potentially harmful chemicals are also metabolites of common foods or medications. Consequently, the presence of these substances in blood or urine may not result from a harmful chemical and thus may present a “false positive” result, which can be inappropriately alarming.
Many chemicals have multiple sources of exposure in the environment. Because of this, it can be difficult to determine if a positive result is from a SGD-related exposure or from some other exposure.
Some toxic chemicals do not have an associated, measurable metabolite in the blood or urine that is specific to the chemical of concern. In this scenario, even if an exposure to environmental pollutants did occur, there may be no way to detect that exposure.
Even if a chemical can be appropriately measured in blood or urine, for most chemicals or metabolites, there are no reference values to indicate whether the amount detected poses a health risk.
Although no specific testing protocol currently exists for monitoring low levels of environmental exposures, healthcare providers are encouraged to perform routine periodic blood and urine tests to monitor kidney, liver, and thyroid function as well as hematologic status. When patients are experiencing new symptoms, these should be evaluated in a thorough fashion, recognizing that environmental exposures may be contributing to the symptoms, but without automatically assuming that environmental exposures are responsible.
An additional note is that although the results of biomonitoring results in individuals are often difficult to interpret and therefore not routinely recommended, biomonitoring of populations, where results are average over a large group of individuals, may provide useful information regarding comparative levels of exposures to particular communities.
For more information, check out our factsheet on biomonitoring.