"A new study out this month reveals unconventional oil and natural gas workers could be exposed to dangerous levels of benzene, putting them at a higher risk for blood cancers like leukemia. Benzene is a known carcinogen that is present in fracking flowback water. It’s also found in gasoline, cigarette smoke and in chemical manufacturing. As a known carcinogen, benzene exposures in the workplace are limited by federal regulations under OSHA. But some oil and gas production activities are exempt from those standards."