FREDERICTON - The New Brunswick College of Family Physicians called on the provincial government Wednesday to implement a moratorium on shale gas fracking, saying it was worried about the possible harm it could cause to public health.

In a letter to all members of the provincial legislature, president Dr. Anick Pelletier said doctors are concerned about potential contamination of public water supplies and the possibility of air pollution or spills of toxic chemicals.

"We are urging you to protect our valuable resources and the public's health by putting a moratorium on hydraulic fracturing development in New Brunswick until further research can prove that the benefits clearly outweigh the risk of this practice," Pelletier said.

Pelletier said while fracking has been discussed by her counterparts in other provinces and at the national level, hers is the first group of family physicians to take an official stand on the issue.

"The family physicians of New Brunswick are really concerned," she said in an interview.

Environment Minister Bruce Fitch said he takes their concerns seriously, but did not commit to implementing a ban on fracking.

"The concerns that they're bringing forward are also concerns that we have too," Fitch said.

"I want to make sure that as the regulations are made stronger, they prevent some of the issues that are being brought forward today."

The Progressive Conservative government has promised to release new regulations for gas exploration and development within the next few weeks. Those regulations would be put out for public input before being legislated this fall.

Liberal Opposition Leader Victor Boudreau said the letter from the doctors reinforces his party's call for a moratorium until those regulations are in place.

Fracking involves pumping water and chemicals into a gas well to fracture rock layers and release trapped pockets of shale gas.

On Monday, researchers at the University of New Brunswick released an opinion paper that examines the potential impact on the province's water resources if gas exploration companies begin fracking for shale gas.

They said shale gas fracking should not proceed in the province unless there is an environmentally sound option for the disposal of waste water that is a by-product of the process.

According to the Natural Resources Department, three test wells for shale gas were drilled in New Brunswick between 2008 and 2010 and all three were fracked. A fourth such test well was drilled in late 2011 but has not been fracked.

There has been a public backlash to shale gas development in the province in recent months, including protests near exploration sites and at the provincial legislature.