When workplace safety expert Eric Esswein got a chance to see fracking in action not too long ago, what he noticed was all the dust.
It was coming off big machines used to haul around huge loads of sand. The sand is a critical part of the hydraulic fracturing method of oil and gas extraction. After workers drill down into rock, they create fractures in that rock by pumping in a mixture of water, chemicals and sand. The sand keeps the cracks propped open so that oil and gas are released.