Some workers at oil and gas sites where fracking occurs are routinely exposed to high levels of benzene, a colorless gas that can cause cancer, according to a study by NIOSH.
The danger arrives with trucks bearing tons of sand. Off-loading that sand – which may contain up to 99 percent silica – can send clouds of thick dust into the air, exposing the lungs of fracking workers who are performing the task to serious inhalation hazards.
