The United States has some of the richest natural gas deposits in the world, with most of that locked up in shale deposits east of the Mississippi River.
The National Wildlife Federation, in a 28-page report on shale gas extraction, finds that while most of the components in the hydraulic fracturing fluid used to get gas out of the rock formations are water and sand, the chemicals used may pose a threat to human health.
States such as Michigan, Pennsylvania and Texas have large reserves of shale gas. The NWF report finds that while natural gas has a dominant role in the energy future of the United States, its development shouldn't come at the cost of environmental health.
"Transparency, sensible oversight and reliable safeguards for air, water and wildlife are just commonsense when it comes to drilling for natural gas," Todd Keller, senior manager for public lands campaigns for the National Wildlife Federation, said in a statement. "What should be best practices for the industry are also what is best for local communities and wildlife habitat."
Energy companies engaged in fracking note the chemicals mentioned by groups like the NWF make up far less than 1 percent of the total volume of hydraulic fracturing fluid. They claim fracking is a common practice that, if done correctly, poses little risk to the environment.