The study found that asthma treatments were four times more common in areas near drilling sites.
CLEVELAND - A U.S. Environmental Protection Agency official tells an Ohio fracking conference that a study of the threat to drinking water from the shale-drilling process won't be completed until 2016.
That's the word from Jeanne Briskin, coordinator of hydraulic fracturing research at the EPA's Office of Research and Development. She spoke Tuesday at a two-day conference on the subject in Cleveland.
The Akron Beacon Journal reports that Briskin said the EPA could release a preliminary report late next year. She described the work as "complex research."
Congress in 2010 directed the agency to investigate the threat to groundwater and air from the controversial hydraulic-fracturing process in Ohio and other states.
Critics say it is harmful to the environment.
The conference continues Wednesday.
A Warren man was charged for directing a former employee of a Youngstown-based company to dump fracking waste into a tributary of the Mahoning River, which is a source of public drinking water for several Ohio cities.
Crystalline silica is found in everyday materials, but it can cause health problems for workers exposed to it on a regular basis.