A STUDY of the health impacts of gas drilling has found water contaminated with fracking chemicals and toxic metals posed the most significant risk to humans and animals.
Most health problems were linked to unconventional wells that have become widespread in the US shale gas industry and often require hydraulic fracturing to release gas.
Extracting gas from shale is similar, though not identical, to coal seam gas production which has faced criticism from farmers and green groups over its potential impact on aquifers, farmland and human and animal health.
A state parliamentary inquiry into the impacts of coal seam gas is due to present its findings in April, and hydraulic fracturing and the use of certain extraction chemicals are banned in NSW.
The US study - by a Cornell University academic and a veterinarian - reviewed 24 cases in six US states where health problems had been linked to gas drilling.
The review ''strongly implicates exposure to gas drilling … in serious health effects on humans, companion animals, livestock, horses and wildlife,'' it said.
The Greens MP Jeremy Buckingham said the study had found a ''concerning correlation'' and should be heeded by policy makers in Australia.