On Pesticides, Science and Fear.

Have you heard the news? Almost two weeks ago, Health Canada announced that a sweeping scientific review had concluded 2,4-D -- one of the most common pesticides -- is safe when used as directed.

"There is reasonable certainty that no harm to human health, future generations or the environment will result from use or exposure to the product," reads the verdict of Health Canada's Pest Management Regulatory Agency.

What's that? This is the first you've heard about it? That's strange.

Ontario is in the process of banning lawn and garden pesticides, most of which contain 2,4-D. "Studies by public health experts are showing growing evidence of the potential health risks of pesticides," reads a press release from the McGuinty government, "particularly for children."

But Health Canada says that's not true, at least not with respect to 2,4-D. "Risks to homeowners and their children from contact with treated lawns and turf are not of concern," PMRA writes.

And that's not only the view of the government's scientists. An independent panel of scientists convened by Health Canada agreed.

And, as the PMRA noted, this is only the latest of many such findings: Regulatory reviews in the European Union, New Zealand and the United States all came to the same conclusion. So did a review by the World Health Organization.

So you would think that Health Canada's announcement would be major news. And yet, it wasn't major news. It wasn't even minor news. In fact, as far as I can make out, it wasn't reported in any newspaper.

Even the Globe and Mail --which seems to run an alarmist story about chemicals every third day -- published not a word about it.

Unfortunately, that's typical. As I demonstrate in my book Risk, the media routinely give prominent play to research that comes to scary conclusions while downplaying or ignoring studies that find there's nothing to worry about.

This tendency was neatly demonstrated by a 1991 examination of how the media covered two studies that appeared in the same edition of the Journal of the American Medical Association.

The first study had found evidence that a hazard existed; the second had found evidence that it did not. No prize for guessing which got more attention.
[Top]

In all, 19 news articles about the two studies appeared in the media. Of these, nine only mentioned the "bad news" study. None was exclusively about the "good news" study. Ten reported both -- but in each of these articles, significantly more space was given to the study that found the hazard existed than to the one that found it didn't.

That said, the media aren't solely responsible for the skewed information the public gets.

Back in 2004, the Ontario College of Family Physicians released a "pesticides literature review" which concluded there was a clear link between pesticide use and cancer. The docs called for a ban.

Naturally, this report got massive media coverage and it is now routinely cited by supporters of pesticide bans -- everyone from physicians' groups to David Suzuki -- as conclusive evidence. So for the docs, Health Canada's conclusions are, shall we say, a little awkward. And the PMRA knows it.

Health Canada's review included an examination of the doctors' report, the agency noted. However, "while that report focused on a subset of epidemiology studies from the public literature, Health Canada reviewed the extensive body of information available for 2,4-D to conduct a full human health risk assessment."

In the bland language of scientific bureaucracy, that's trash talk. Leonard Ritter was a little blunter when I spoke to him a few months ago.

"I don't offer patients advice on when they should have their gall bladder taken out," said the esteemed toxicologist and expert on pesticides at the University of Guelph. "And I sometimes think it would be better if physicians, largely family physicians, who really have no training in this area at all, it would be better to leave the interpretation of the data to people who are competent to do it."

So what did the docs say after Health Canada gave 2,4-D a clean bill of health? Nothing, it seems.

And they weren't the only ones staying silent as a mime. When Health Canada scientists drew cautiously negative conclusions about bisphenol A, Health Minister Tony Clement called a press conference and boasted about the government's ban-first-ask-questions-later attitude. But when Health Canada cleared 2,4-D, the minister didn't even bother to issue a press release.

And then there's Dalton McGuinty. Now that the premier is posing as a white knight defending children against evil chemicals, Health Canada's decision is most unhelpful. Naturally, McGuinty made like Marcel Marceau.
[Top]

So I called the Ontario Ministry of Health and asked if the Health Canada verdict would affect the pending ban. Apparently not. I say "apparently," because it was difficult to get a straight answer out of the spokesperson.

When I asked if this would change the government's view of the safety of 2,4-D, he responded "it's not a safety issue." Huh? Practically every statement the McGuinty government has made about the ban includes the claim that it will "protect human health, especially children's health." And that's not a safety issue?

No, says the spokesperson. "The issue is not public health. Our issue is you want to keep it out of the environment as much as you can." But why worry if its presence isn't dangerous? No answer. Instead, the spokesperson burbled on about how "it's in the food chain. It's in the aquatic environment. And it's man-made." All of which is irrelevant unless the stuff is actually dangerous.

I apologize to the reader. I'm sure that exchange comes across as confusing gibberish. But that's the point.

Now that a comprehensive scientific review has cleared one of the most common pesticides, the rationale for a sweeping ban is as flimsy as a dandelion after a shot of Roundup. So of course government spokespeople are spouting gibberish. That's what people do when they defend the indefensible.

I have to admit I didn't care much about this issue in the past. The benefits of a ban may be trivial but the costs won't be much more substantial. Lawns and gardens may get a little weedier, I suppose. And unforeseen consequences are always possible. But, really, why get worked up about it?

Well, now I'm worked up. This isn't about pesticides. It's about science and its place in our democratic life.

Science says 2,4-D is safe when used as directed. But that's not what we see in the media. It's not what we hear from physicians and activists. It's not what politicians tell us. And it's certainly not what's inspiring the bans that are popping up everywhere like weeds after a thunderstorm.

It's frightening to watch a major debate involving a scientific question move from stories in newspapers to politicians' speeches to legislative action -- all with little or no connection to the best science as interpreted by the best scientists.

This time, the cost may be an unnecessary proliferation of dandelions. But next time?

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