What health considerations are there?


Shale energy development, as an industrial operation, comes with safety risks for both workers and the local community. Occupational fatalities in the United States are high in the oil and gas industry, at seven times the rate for all U.S. industries. 1  Unlike conventional oil and gas, however, shale development often takes place in close proximity to residences, in both rural and more heavily populated areas, which can also increase the risks to the public. As previously mentioned, The Wall Street Journal reported in 2013 that approximately 15.3 million people in the United States live within one mile of a well drilled since 2000. 2

The types of incidents that can threaten the safety of workers and community residents – causing injuries and even death – include vehicular accidents, spills of wastes and chemicals, blowouts (i.e., sudden, uncontrolled releases of gases or fluids), explosions, fires, and exposure to high levels of airborne chemicals.  

Vehicular Accidents

The leading cause of worker fatalities in the oil and gas industry is traffic accidents, which pose risks to both workers and the community. Traffic accidents have been on the rise in areas where shale development is occurring, with North Dakota, Pennsylvania, and Texas reporting increased road incidents involving industry trucks. 3 For example, Bradford County, Pennsylvania witnessed a 40% increase in truck traffic over a five-year period, with a corresponding increase in accidents involving large trucks. 4 The high rate of traffic accidents for the industry is attributed in part to the condition of the trucks, but may also be due to the oil and gas industry’s exemption from the highway safety regulations that limit the length of truck drivers’ shifts. 5

Uncontrolled Releases of Gas or Fluids at the Wellhead

Another safety issue occurs when gas or fluids are unintentionally released at the wellhead, causing a blowout. These rare instances can occur in both conventional oil and gas development and shale development when high pressure zones are encountered in the wellbore or there is a failure of the well casing and cement, valves, or other mechanical equipment. For this reason, blowout prevention devices are installed early in the process of drilling a well. A report from the Energy Institute at the University of Texas at Austin noted that data regarding blowout frequency are not available for onshore oil and gas wells, but offshore wells report 1 to 10 blowouts per 10,000 wells that have not yet had blowout preventers installed. 6

For workers, blowouts at the surface can create exposure risks, through inhalation of hydrocarbons and contact with chemicals. These unplanned releases can also on rare occasions lead to explosions and fires on the well pad, which endanger both workers and possibly nearby residents. 

Blowouts may also occur on the subsurface, which is harder to track, and may affect aquifers or water wells in the area. The University of Texas report cited two examples from conventional oil and gas development in Louisiana and Ohio in which underground pressure changes during drilling caused water wells in the vicinity to bubble or spout water. 7

Gas Migration into Residential Water Wells and Homes

Residents living in proximity to shale wells have also expressed concern about the possibility of toxic gases accumulating inside their water wells and homes, with inhalation risks and the potential for explosions. In most cases, such reported incidents have been attributed to naturally occurring methane migration that is unrelated to any shale energy development in the vicinity. 8

A few methane explosions in homes or well houses located near shale gas operations have been reported in Colorado, Pennsylvania, and Texas, with investigators concluding that gas may have migrated from hydraulically fractured wells nearby. In almost all such cases, gas migration occurred because well integrity was compromised due to faulty casings and/or inadequate cementing of the casings. 9

Hydrogen Sulfide

When drilling for oil and gas, workers run the risk of encountering hydrogen sulfide (or sour gas), a flammable, highly toxic gas with the odor of rotten eggs, although the odor becomes unnoticeable after a period of exposure. Although not common at conventional and shale development sites, hydrogen sulfide is toxic even at low concentrations; workers therefore wear meters to monitor for its presence. Low-level chronic exposure to hydrogen sulfide may also cause cumulative health risks for workers, as well as for nearby residents who can live many years in proximity to oil and gas facilities. 10


Most safety incidents are caused by the following:

  • an influx of trucks on local roads and unsafe driving behaviors, sometimes on the part of local drivers; inadequate driver training; drug use and fatigue while driving; and poorly maintained trucks 11
  • improper construction of wells or wastewater impoundments
  • faulty equipment, often due to inadequate maintenance
  • inadequately trained well pad personnel
  • failure to follow recommended  practices to prevent blowouts and spills
  • over-pressurized gas
  • weather, particularly extreme weather events

For options for addressing these safety concerns, see the “What Can Be Done?” section below


  1. OSHA, “Oil and Gas Extraction: Safety and Health Topics,” accessed December 1, 2014. The federal Occupational Safety and Health Administration (OSHA) is the regulatory agency for workforce safety.  The OSHA website houses a tool for the oil and gas industry that details potential health and safety hazards by stage of production, along with preventative measures and solutions for each (accessed November 22, 2014).
  2. Gold and McGinty, “Energy Boom.”
  3. Mike Lee, “In North Dakota’s Oil Patch, Wrecks Increase as Trucks Push onto Farm Roads,” E&E News, April 11, 2014; Resources for the Future, “Shale Gas Development Linked to Traffic Accidents in Pennsylvania,” March 2014; “In Texas, Traffic Deaths Climb amid Fracking Boom,” National Public Radio, October 2014.
  4. Adgate, Goldstein, and McKenzie, “Potential Public Health Hazards,” 8311.
  5. Ian Urbina, “Deadliest Danger Isn’t at the Rig but on the Road,” The New York Times (May 14, 2012)
  6.  Charles G. Groat and Thomas W. Grimshaw, Fact-Based Regulation for Environmental Protection in Shale Gas Development, Energy Institute (Austin: The University of Texas at Austin, February 2012), 22 
  7. Groat and Grimshaw, Fact-Based Regulation, 23
  8.  Groat and Grimshaw, Fact-Based Regulation, 23
  9. Groat and Grimshaw, Fact-Based Regulation. 23-24
  10. Earthworks Action, “Hydrogen Sulfide.” 
  11. Ian Urbina, “Deadliest Danger Isn’t at the Rig but on the Road,” The New York Times (May 14, 2012)