"Under a new law, doctors in Pennsylvania can access information about chemicals used in natural gas extraction—but they won't be able to share it with their patients. A provision buried in a law passed last month is drawing scrutiny from the public health and environmental community, who argue that it will "gag" doctors who want to raise concerns related to oil and gas extraction with the people they treat and the general public."
"Pennsylvania is at the forefront in the debate over "fracking," the process by which a high-pressure mixture of chemicals, sand, and water are blasted into rock to tap into the gas. Recent discoveries of great reserves in the Marcellus Shale region of the state prompted a rush to development, as have advancements in fracking technologies. But with those changes have come a number of concerns from citizens about potential environmental and health impacts from natural gas drilling.
There is good reason to be curious about exactly what's in those fluids. A 2010 congressional investigation revealed that Halliburton and other fracking companies had used 32 million gallons of diesel products, which include toxic chemicals like benzene, toluene, ethylbenzene, and xylene, in the fluids they inject into the ground. Low levels of exposure to those chemicals can trigger acute effects like headaches, dizziness, and drowsiness, while higher levels of exposure can cause cancer."
Kate Sheppard reports for Mother Jones March 23, 2012.