The French Association of Environmental Health, known by its French initials ASEF, issued a statement saying most of the "hundreds of chemical products" used in the extraction of natural gas from underground shale formations present health risks.
ASEF President Pierre Souvet was quoted by the Platts news service as saying fractured shale emits heavy metals or naturally occurring radioactive substances.
"These pollutants can filter into groundwater supplies, contaminating the water that we consume and therefore affecting our health," he said.
The French government placed a moratorium on shale natural gas exploration. French supermajor Total, which had a permit to explore 1,670 square miles of land in southern France, said last year it would challenge the decision.
Ukraine and Poland, other countries rich in shale, have plans to go ahead with the process.
The French government plans to review shale natural gas during a September energy conference, Platts reports.