Pesticides not leading cause of cancer on P.E.I.: professor

Dave Stewart
Published on June 18, 2015

Dr. Len Ritter, professor of toxicology at the University of Guelph in Ontario, displays graphs contained in the Canadian Cancer Society’s latest report that show new cases and age-standardized incidence cancer rates in men are declining in Canada and staying about the same for women. Ritter was speaking to growers, field workers and industry partners in the P.E.I. potato industry on recently.


Dr. Len Ritter, professor of toxicology, says non-Hodgkin lymphoma rates, the cancer most often associated with pesticides, are lower in P.E.I. than anywhere else in the country

There is no evidence that the safe application of agricultural pesticides causes cancer, says a toxicology professor from Ontario.

Dr. Len Ritter, a professor emeritus at the University of Guelph, was in Charlottetown recently to speak to the P.E.I. Potato Board about his research into pesticides.

Fact Box: Cancer rates

Ritter points to statistics released recently by the Canadian Cancer Society that show cancer rates are expected to jump 40 per cent in P.E.I. by 2030. According to the report, that rise in cases will be led by upsurges in prostate and colorectal cancer cases in an aging population.

He points out that non-Hodgkin lymphoma rates, the cancer most often associated with pesticides, are lower in P.E.I. than anywhere else in the country when it comes to men and tied with Quebec for lowest rates in Canada among women.

Ritter says if pesticides were as bad as some say they are, rates of that type of cancer would be higher.

“You see the amount is the lowest in the country. If pesticides were driving it you would expect the reverse to be true,’’ Ritter said.

The toxicology professor says he doesn’t represent the Canadian Cancer Society, but does rely on its data, or Health Canada’s Pest Management Regulatory Agency (PMRA).

“My role is not to advocate the use of pesticides; not to promote a pesticide ban. It’s to introduce evidence-based information that I hope will allow people to enter debate on a more informed basis.’’

P.E.I. is on the high end of cancer rates when it comes to lung cancer and melanoma, which Ritter attributes to smoking and exposure to sun.

Ritter said that the international cancer society has identified concerns over Roundup, a commonly used herbicide. It can be used for killing grass before a potato field is plowed under.

“It’s a legitimate question . . . a complex issue. (But) it was always considered to be among the safest herbicides in the world and that continues to be the prevailing opinion.’’

Greg Donald, general manager of the P.E.I. Potato Board, said farmers in the province follow Health Canada and PMRA guidelines and don’t spray any more than they have to.

“There is a belief that farmers use pesticides because they want to. They are a tool amongst a number of other things that they use that they need to grow healthy and safe food,’’ Donald said, adding that growers are concerned about the public perception pesticides have.

“We wanted to get the facts,’’ Donald said. “Folks who use these chemicals are trained and use them according to the label.’’

Cancer rates in P.E.I.

Estimated new cases for selected cancers in P.E.I. this year:

140 - prostate

65 - colorectal

75 - lung

30 - bladder

15 - non-Hodgkin lymphoma

20 - kidney

25 - melanoma

15 - leukemia

15 - oral

10 - pancreas

10 - stomach

10 - esophagus

* Source: Canadian Cancer Society