Vast deposits of natural gas have driven a drilling boom across 32 states. Although the boom is helping the US generate more energy on its own soil, a study published Monday, May 4 points out a potential health problem linked with the practice, known as hydraulic fracturing or “fracking.” Business Insider, Australia. 6 May 2015.
http://www.businessinsider.com/chemicals-used-in-fracking-2015-5