Which is worse: brain cancer in children, or dandelions in the grass?

For the average Toronto city councillor, it's no contest. And that is why, after a stormy, knock-down, drag-out brawl between the environmentalists and the lawn-care companies, Canada's biggest city voted to take away its homeowners' rights to Weed & Feed.

The great pesticide fight has been the most bitter battle in recent city history. Even so, it's pretty certain that most citizens of the Greater Toronto Area have no idea they may soon be rendered eco-criminals for trying to kill their crabgrass (and subject to $250 fines). It's also pretty certain that many of them are hopelessly confused. How dangerous is this stuff, anyway? And even if we're not sure, isn't it better to be safe than sorry?

"More children have asthma and brain cancer," said Councillor Olivia Chow, expressing the enviro-view. "We don't know what impact these products have on children."

"You can't poison people," said a teary volunteer for the Toronto Environmental Alliance a few minutes after the pesticide-ban vote passed. "I have two kids, and I just want them to be safe."

"It's a victory for children," pronounced the head of the TEA.

These emotional arguments have carried the day in cities across Canada, including Halifax (where the ban took effect this spring) and about 50 towns in Quebec. Among these towns is Hudson, which won a landmark Supreme Court of Canada case declaring that cities could make up their own minds to ban the use of lawn-care products that the federal government says are legal. Other municipalities, including Kitchener, Cambridge and Waterloo, have already restricted pesticide use on public land such as parks and schoolyards.

Yesterday, CBC Radio's national current affairs show, The Current, had a touching interview with a woman who had become an anti-pesticide crusader after her son was stricken with lymphoma. She was sure that pesticides had caused his cancer. "So what do you say to Canadians who still don't want to ban pesticides?" asked the host. "Wake up, Canada!" she answered. "You'd rather see your child with a bouquet of dandelions than . . ." Cancer, she meant.

The anti-pesticide lobby leans heavily on the argument that we are killing our children. The TEA's radio ad campaign refers repeatedly to "harmful pesticides" that contain "chemicals associated with childhood cancers." It cites support from many impressive organizations, including the Canadian Cancer Society. The Canadian Institute of Child Health has suggested that pesticide use is a form of environmental child abuse.

Many in the media are persuaded, including the people who run The Current. After interviewing the cancer mother, the host had on environmental advocate Janet May, who told him that pesticides have also been linked to developmental problems and birth defects. The next guest was a spokeswoman for the lawn-care companies; after the host finished her off, he informed us that most of these products contain 2,4-D, an ingredient in Agent Orange, which was, as you will recall, used during the Vietnam War.

By now, you may be getting seriously alarmed. But here's a puzzle: If products such as Weed & Feed, Roundup and other garden-variety items are so toxic, why are they still legal? Why has the World Health Organization not warned against 2,4-D? Why have Health Canada, the European Union and countless other bodies repeatedly approved these products for use? Why is their use approved by virtually every country on Earth?

The other day, a radio talk-show host put that very question to Jane Pitfield, one of the Toronto city councillors who led the anti-pesticide crusade. She had an answer. "Politics," she said darkly.

In other words, thousands of scientists, governments and bureaucrats around the world have been hopelessly corrupted by the influence of Big Chem.

Is there another side to the story? Well, yes. But to get it, the media go to the lawn-care lobby. You can be excused if you don't entirely trust some guy who's paid to flak for Weed Man. Neither do I.

Unfortunately, one type of person the CBC show didn't bother to interview was an actual scientist. But that would have wrecked the story, because the overwhelming consensus in the science world is that this stuff is safe.

Len Ritter of the University of Guelph is one of the foremost pesticide scientists in Canada. He's spent more than 25 years in the field and has credentials as long as your arm. "If you look hard enough, you can find reports that raise concerns about anything," he told me. "But you have to look at the totality of the evidence. And the fact is that, by the most broadly based interpretation of the science, these lawn-care chemicals do not pose a threat."

Even scientists whose work is often cited by the anti-pesticide crusade caution that, when you add up all the evidence, it really doesn't demonstrate anything. They warn that "use" and "exposure" are two very different things, and the data on exposure just aren't there. Some children with cancer no doubt have romped on lawns with chemicals sprayed on them. No doubt they've also eaten ketchup.

Among the pre-eminent cancer investigators of our age is Sir Richard Doll, the scientist who established the link between tobacco and health back in the 1950s. He's spent his career assessing every cancer risk of our time. And he has said for years that we're wasting our time by focusing on pesticides.

Last week, at Dr. Ritter's invitation, Sir Richard gave a public lecture in Guelph. Afterward, a city councillor asked whether he'd support a ban on pesticides in the city. "No," he said, to her immense surprise. "There's no scientific basis for it."

Dr. Ritter says he doesn't give a darn one way or another about dandelion infestations, or the business interests of the lawn-care industry, or a citizen's inherent right to keep a tidy lawn. What he does care about is "the use of robust scientific data to make sound public policy decisions."

And in that we're failing miserably. Whenever a debate pits passion against science and faith against fact, the odds favour faith every time.

To him, the fear-mongering of the true believers is not just anti-scientific. It's a moral issue. "To suggest to parents who've lost a child to cancer that maybe lawn chemicals contributed to their loss . . . I have very, very strong feelings about that. To imply that a woman dying of breast cancer may have been poisoned by her lawn -- I don't think that is morally correct. These people have endured enough."

mwente@globeandmail.ca