This isn't what you want to hear just as the price of oil is spiking. Natural gas, seen as a potential low-carbon alternative to coal and oil, might be more dangerous than previously thought, according to documents obtained by The New York Times. The problem is the technique used to get at the gas, which involves injecting water, sand, and toxic chemicals into the ground to break up the rock. Documents from the EPA, state regulators, and gas drillers show large amounts of radium and other chemicals being released by gas drilling, then tacken to treatment facilities poorly equipped to deal with them before being released into rivers that supply drinking water. Some of the wells in Pennsylvania produced wastewater with 1,000 times the level of radiation acceptable under federal drinking-water standards. Industry officials say they aren’t concerned, though, saying that the rivers will dilute the chemicals to safe amounts. But a never-reported study by the EPA and another confidential one by the drilling industry say that rivers aren’t able to fully dilute the chemicals.