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Ask A Toxicologist > I live in an area where hydraulic fracturing or "fracking" (natural gas drilling) occurs. Can you tell me what laboratory tests my doctor can perform to determine if I have been exposed to toxic substances as a result of this drilling?

I live in an area where hydraulic fracturing or "fracking" (natural gas drilling) occurs. Can you tell me what laboratory tests my doctor can perform to determine if I have been exposed to toxic substances as a result of this drilling?

posted on 9:47 AM, March 3, 2014

Due to potential water and air pollution caused by hydraulic fracturing, individuals living within close proximity to drilling areas are appropriately concerned about chemical exposures. The list of chemicals used in the hydraulic fracturing process is lengthy. For individuals living in shale areas, chemicals used in the process are similar, but may have proprietary mixtures that differ slightly. Drinking water contaminated with these chemicals is an undeniable concern for homeowners. Additionally, air contamination stemming from diesel engines, gas releases associated with drilling, and odors from retention ponds are also of concern. Whether the exposure is the result of water or air contamination, a patient may seek laboratory testing from a physician when poisoning is a concern.

Unfortunately, most of these chemicals are not easily measured in human blood or urine. Those that can be measured often have no ‘normal’ range, thus making it difficult to determine whether the presence of such chemicals is harmful. Individuals are constantly exposed to many of these chemicals, even in the absence of hydraulic fracturing, making interpretation of these results complicated. Indiscriminate testing for a long list of chemicals leads to needless concern when an isolated test returns positive without knowledge of a ‘normal’ range. Performing these tests on human samples and then interpreting the results are both extremely difficult.  When concerned about a chemical exposure, it is better to have your water or air tested by a reliable lab. Testing the water and air directly is more prudent than testing blood or urine. This testing can help determine if an exposure may be occurring, and can help direct a physician to provide additional patient-specific testing when necessary. Many times a physician may use laboratory testing that does not include measuring the chemical directly. Due to difficulties in measuring these chemicals in human samples, physicians often use other blood and urine tests to looks for overall indications of toxicity. Often, a local or state health department can help perform air and water testing. The hydraulic fracturing companies may be willing to perform tests, as well.

In many areas where hydraulic fracturing is performed, even in the absence of drilling, the soil and ground water often contain naturally occurring high levels of certain metals such as barium and arsenic. Similarly, if a concern exists for an exposure to heavy metals in ground water, testing the water, rather than the individual, is the better first option to rule out an exposure. Although some metals, like arsenic, have well-documented toxic levels in the human body, other metals such as barium, have no known range. Interpreting metal levels in human samples is extremely complicated, much like the testing performed for other chemicals. Therefore, we recommend first testing tap water to exclude the presence of heavy metals. If water samples have elevated metal levels, a physician can then provide additional, appropriate, and focused testing.

This above approach offers the best way to evaluate whether poisoning has occurred when exposed to toxic substances as a result of hydraulic fracturing. Both you and your physician can consult with a medical toxicologist in your area at any time if you have concerns regarding any chemical exposures.

Anthony F. Pizon, MD

Michael Abesamis, MD, MPH

Division of Medical Toxicology

Department of Emergency Medicine

University of Pittsburgh Medical Center