Don't blame chemicals for this nonexistent epidemic.

Earlier this week, Premier Dalton McGuinty announced he would assemble a panel of experts to assess the evidence about the widely used chemical bisphenol A.

"Why is it that at the beginning of the 21st century one in four Ontarians are dying of cancer?" he said in an interview with the Toronto Star. "We need to do a better job of understanding the influence of these chemical toxins and carcinogens in our environment and our quality of life."

The people at Environmental Defence must have been over the moon. For years, they've been carrying on a misleading campaign to heighten public fears about synthetic chemicals and here was the premier of Ontario, fresh from a meeting with the group, not only announcing what Environmental Defence wanted but doing so in a way that makes it sound as if the Black Death is sweeping the land and every fourth person is keeling over in the ditch.

Of course, as a journalist who has written in the past that there is no epidemic of cancer and there's little reason to think synthetic chemicals would be the cause of it if there were, I am clearly an industry shill and not to be trusted. Or so I have been told on occasion.

So I called the Oxford University epidemiologist Sir Richard Peto -- arguably the world's leading expert on the subject -- and asked him about the premier's statement.

"It's misleading," he said.

For one thing, it's not true that one in four Ontarians are dying of cancer. Rather, one in four will die of cancer at some point in their lives. Big difference.
[Top]

But still, that sounds awfully scary. And that figure really is far bigger than it was in the past. So doesn't the premier have a point?

Not really, Peto said.

The critical thing to remember is that cancer is primarily a disease of aging. When we are young, the risk is extremely low. As we age, it grows rapidly.

The main reason why we are seeing more cancer is simply that "more people are not dying of other things. We don't die of childhood infections. We don't die of tuberculosis," Peto said. "Ninety-eight per cent of the kids born today will live to 35. That wasn't true in the first half of the 20th century. And once we reach middle age, a lot more live on into old age. So we've got a lot more middle age people and we've got a lot more old people." And, inevitably, a lot more cancer.

"If every other cause of death were eliminated, then everybody would die from cancer," Peto wryly noted. "Similarly, if everybody committed suicide at 35, then nearly all cancers would be avoided, but that wouldn't be a very efficient way of controlling cancer."

A better way of looking at the problem is to ask whether the risk is rising or falling for individuals of a given age. The answer to that varies from country to country, Peto said, because smoking rates vary and smoking is a massive component of the overall cancer picture. ("For the last 30 years, in countries like Canada, the United States and the United Kingdom, about half the male cancer deaths in middle age have been caused by smoking.")

But when tobacco is removed from the numbers, and people of the same age are compared, the results are encouraging. "The overall probability that, say, a 60-year-old man will die of cancer in the next year, or that a 60-year-old woman will die of cancer in the next year, is lower now than it was 10 years ago and it was lower 10 years ago than it was 50 years ago. So actually, cancer death rates, overall, are going down, not up."
[Top]

Notably missing from Peto's analysis are the chemicals environmentalists claim are driving cancer up and up. "I do think that the importance of environmental chemicals, in the sense that it's commonly understood, is exaggerated. It's exaggerated for political purposes." Some may do so cynically but more often, Peto feels, it's an honest mistake. "People can be very, very strong in their political beliefs. But the claim that these things dominate national trends just isn't true."

That happens to be the standard view among scientists, contrary to what some activists would have us believe. I went over the same ground with Leonard Ritter -- professor of environmental biology at the University of Guelph and executive director of the Canadian Network of Toxicology Centres -- and heard the same answers. I looked at the annual reports of the Canadian and American cancer societies and saw the same information. I read the World Health Organization's World Cancer Report and found Peto's views confirmed.

This leads to a rather disturbing conclusion about Dalton McGuinty. Either the premier didn't bother to get briefed on the subject before he made his outrageously alarmist statement. Or he knew how misleading that statement was but he said it anyway because it's good politics.

In either case, Leonard Ritter, for one, is not impressed. "I must confess that the quality of our leaders is a far greater concern to me than risks from pesticides or bisphenol A."

You can contact Dan Gardner at the Ottawa Citizen.
E-mail: dgardner@thecitizen.canwest.com

Back to Columns

Home

Copyright © 2005  Dan Gardner
Website Design & Management by:  GRA Web Site Design Ottawa