Ontario has one of the toughest laws on pesticides in North America now that the Liberal government has announced a province-wide ban on the gardening chemicals.

John Gerretsen, Ontario's environment minister, said Tuesday morning the province is banning the sale and cosmetic use of pesticides -- a chemical used to control weeds. The ban is expected to take effect next spring.

The move replaces several similar initiatives put in place by local municipalities.

"Many municipalities have already shown leadership in banning or restricting cosmetic-use pesticides. We're extending that protection to all families wherever they live," Gerretsen said in a news release.

He said the government still needs to figure out what the penalties would be for violating the ban.

Ontario farmers are exempt from the new legislation. Pesticides can also be used to combat mosquitoes, which can carry diseases like the West Nile Virus. Golf courses are still able to use pesticides but certain conditions must be met to ensure a minimal impact on the environment.

" Our generation has taken to the cosmetic use of pesticide and I think that perhaps unwittingly, not realizing the dangers it represents to ourselves and most importantly to our children," Premier Dalton McGuinty said Tuesday morning at a news conference.

Studies on pesticides have found that people -- especially children and pregnant women -- who are exposed to the chemicals over a period of time are in danger of suffering from birth defects and learning disabilities.

"The bulk of the studies in terms of trends is very worrisome in terms of what potential exposure might be," Dr. Hirotoka Yamashiro, a prediatrician with the Hospital for Sick Children, told CTV Toronto.

There have also been studies that suggest there could be a link between pesticides and cancer as well.

The Canadian Cancer Society applauded the move and said it addresses a critical flaw in the patchwork of municipal bylaws by targeting pesticide retailers.

"A ban on sale is the critical piece that has been missing as municipalities do not have the jurisdiction to ban the sale of pesticides," said a news release issued by the organization.

The Liberals plan to spend over $10 million to implement the ban and educate the public on the dangers of pesticides.

With a report from CTV Toronto's Paul Bliss