Nova Scotia should improve its environmental monitoring and assessment of human health before it allows hydraulic fracturing in the province, says the author of a discussion paper released by the review panel studying the controversial oil and gas extraction method.

Dr. Frank Atherton, Nova Scotia's deputy chief medical officer of health, says there is still some uncertainty surrounding the health implications of hydraulic fracturing.

"One of the key considerations is that we need to bear in mind those uncertainties and really think about what future research we need to do and how we should progress in Nova Scotia," he told CBC News.

Dr. Frank Atherton, Nova Scotia's deputy chief medical officer of health, is the author of a discussion paper on hydraulic fracturing and public health. (CBC)

One the positive side, he said, hydraulic fracturing could bring jobs to certain communities and the natural gas produced is cleaner-burning than coal.

The paper makes a series of recommendations to deal with possible health implications. One is to require companies to pay for site-specific health impact assessments before fracking.

"The sorts of technology we have at the moment are really quite blunt," Atherton said. "We have a good picture of the health of the population at the provincial level, but at the detailed level of communities, we don’t have good information."

Another recommendation is to require companies to disclose what chemicals are being pumped into the ground. Some oil and gas drillers in North America have refused to make this information public, citing competitive reasons.

Hydraulic fracturing, or fracking, involves blasting a mixture of water, sand and chemicals into a well bore to fracture the surrounding rock and release the trapped hydrocarbons, usually natural gas, coalbed methane or crude oil.

Atherton’s paper is one of a number that have been released by an expert panel studying the possibility of fracking in Nova Scotia. The panel is led by Cape Breton University president David Wheeler.

One recent report, which says fracking would not pose a serious threat to the province's groundwater supply, was criticized by environmentalists.

Atherton recommends building a proper health monitoring system before allowing companies to frack.

"You can’t invent an effective monitoring system overnight," he said.

"That actually requires quite a lot of work to bring together health data and environmental data, to set up the systems for measuring those things, and then to integrate those into one monitoring system takes time."