Fracking and Your Health

frackingHydraulic fracturing, “fracking,” or “unconventional oil and gas development” has boomed in the last few years, but what exactly is it? No matter what you call it, in the U.S., fracking is now producing most of the natural gas and has opened up new sources of oil. Fracking is praised as helping the U.S. be more “energy independent.” But, the concern is whether it is harming our health, especially for people who live near drilling sites. These are most common in Colorado, Texas, North Dakota, and Pennsylvania.

Fracking uses more than 1000 chemicals, some of which are known to harm human health.[1,2,3,4] But scientists are still trying to understand how much of these chemicals get into the air and drinking water and what their health risks are.

Endocrine Disruptors

More than 100 of the chemicals used in fracking can affect our hormones. These are called endocrine-disrupting chemicals. These chemicals are in the water near fracking sites.[5] A study in Colorado found higher levels of endocrine disrupting chemicals in water samples from areas with more drilling sites compared to areas with fewer sites. In fact, 89% of the samples taken near fracking sites had chemicals which increased estrogen (a hormone that is high in females), and 41% had chemicals that blocked estrogen. In addition, 12% had chemicals that increased androgen (a hormone that is high in males) and 46% had chemicals that blocked androgens. In contrast, water from areas far from fracking rarely had chemicals that affect hormones.

What kind of impact could these chemicals have on human health? Exposure to higher levels of endocrine disruptors before birth or as a young child can cause obesity, behavioral issues and abnormal sexual development.[6] In adults, this exposure increases the risk of infertility, obesity, diabetes, or certain types of cancer, such as breast cancer, testicular cancer, and vaginal cancer.


The chemicals injected into the wells do not stay underground. They come back up as waste water. Waste water brings up naturally occurring radioactive materials. The most common is radium.[7] Like most radioactive materials, radium increases cancer risk. A study of waste water spills in North Dakota found that radium levels were 2-10 times higher up to 4 years after the spill.

Since water treatment plants cannot completely remove radium from the water, radium build-up is a serious problem with fracking.[8] A study of the water and soil downstream of a Pennsylvanian treatment plant found that the radium in the soil was 200 times higher than in nearby areas. The good news is that radium does not travel very far in water that is low in salt. But radiation contaminates the soil, plants, and animals around the treatment plant, and heavy rains can wash these contaminated soils downstream. The rest of the radium at the treatment plant collects into a sludge that is taken to a landfill.

Air Pollution

Fracking also releases harmful pollutants into the air.[9,10]  Some of these chemicals cause breathing-related problems or cancer. Formaldehyde, benzene, and ozone can make asthma, coughing and wheezing problems worse. Benzene also increases the risk for cancer and allergies. Fracking also releases small particles that get stuck in a person’s airways or lungs and cause similar breathing problems and increase the risk for cancer. Children and infants are particularly at risk to health problems caused by pollution.

Effects on Human Health

The amount of pollutants in the air or water decreases with distance from the fracking site. However, reports as of 2016 show that living anywhere near fracking operations may harm health. Two studies examined patients living in Pennsylvania. One found that living near more wells increased the number of people hospitalized for heart or nervous system problems.[11] The other found patients living near more fracking tended to have more problems with their asthma than patients that lived in areas with little activity. [12]

Living near fracking may also affect unborn children. A study in Pennsylvania found that mothers living near more fracking sites (at least 6 wells/ square mile) were 34% more likely to give birth to newborns who had a low birth weight compared to babies born of mothers who didn’t live near any.[13] A study in Colorado found that babies born to mothers living near a lot of fracking sites (more than 125 wells/ square mile) were about 30% more likely to have congenital heart defects.[14]

What is Being Done?

Fracking is mostly regulated by states. A few states have recently passed laws to reduce the environmental and health effects.  In 2012, Vermont became the first state to ban fracking followed by New York in 2015.[15,16] Maryland also passed a temporary ban in 2015.[17] California put in place new regulations on fracking in 2015.[18] About half of states require companies to tell either a state agency or the public what chemicals are used, however most of these states allow companies to keep some chemicals secret.[19] Some cities are also trying to regulate fracking.

If you want information about fracking operations where you live, you may be able to find information on FracFocus.[20] This is a registry for companies to list the chemicals used in the fracking process. However, it is voluntary for companies in most states, so some companies do not provide information. It also only concerns the chemicals used to break the rock during drilling, and not the chemicals used for operating the well. And while it doesn’t list chemicals that the company considers trade secrets, it can give you some idea of the chemicals used in your area.

All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.

  1. Kassotis CD, et al. Estrogen and Androgen Receptor Activities of Hydraulic Fracturing Chemicals and Surface and Ground Water in a Drilling-Dense Region. Endocrinology (2013).
  2. Environmental Protection Agency. Study of the Potential Impacts of Hydraulic Fracturing on Drinking Water Resources: Progress Report, (2012).
  3. US House of Representatives. Chemicals Used in Hydraulic Fracturing, (2011).
  4. U.S. EPA. Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources (External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-15/047, 2015.
  5. end Schug TT, et al. Endocrine disrupting chemicals and disease susceptibility. Journal of Steroid Biochemistry & Molecular Biology, 127 (2011) 204– 215.
  6. Diamanti-Kandarakis E et al (2009). Endocrine-disrupting chemicals: An Endocrine Society scientific statement. Endocr Rev 30(4):293-342.
  7. Lauer NE, Harkness JS, Vengosh A. (2016) Brine Spills Associated with Unconventional Oil Development in North Dakota, Environ Sci Technol. In press
  8. Warner NR, Christie CA, Jackson RB, Vengosh A. (2013) Impacts of shale gas wastewater disposal on water quality in western Pennsylvania. Environ Sci Technol. 47:11849-11857
  9. Field RA, Soltis J, Mruphy S. (2014) Air Quality Concerns of Unconventional Oil and Natural Gas Production. Environ Sci: Processes Impacts. 16:954-969.
  10. Webb E et al (2016) Potential hazards of air pollutant emissions from unconventional oil and natural gas operations on the respiratory health of children and infants. Rev Environ Health 31(2):225-243.
  11. Jemielita T, Gerton GL, Neidell M, Chillrud S, Yan B, et al. (2015) Unconventional Gas and Oil Drilling Is Associated with Increased Hospital Utilization Rates. PLoS ONE 10(7): e0131093.
  12. Rasmussen et al (2016). Association between unconventional natural gas development in the Marcellus shale and asthma exacerbations. JAMA Intern Med. In press.
  13. Stacy SL, et al (2015). Perinatal outcomes and unconventional natural gas operations in southwest Pennsylvania. PLOS ONE. 10(6): e0126425.
  14. McKenzie LM, Guo R, Witter RZ, Savitz DA, Newman LS, Adgate JL. (2014) Birth Outcomes and Maternal Residential Proximity to Natural Gas Development in Rural Colorado. Environ Health Perspect.122:412-417.
  16. New York State Department of Environmental Conservation (June 2015) Available at
  18. California Department of Conservation. Well stimulation program requirements.