Wednesday, April 22, 2009

Pesticides: Science vs. Emotion

It's not just municipalities and provinces discussing pesticide bans - the debate has found its way to Ottawa:
 
New Democrat MPs Peter Julian (Burnaby-New Westminster) and Pat Martin (Winnipeg Centre) called on the federal government this week to ban the non-essential use of pesticides.

They introduced a bill in Parliament to amend the Pest Control Products Act to place a moratorium on the cosmetic use of chemical pesticides in homes, gardens and on recreational facilities.

The moratorium would be in place until scientific evidence can prove pesticide use is safe. The bill requires approval by a parliamentary committee and if accepted, the moratorium would take effect on Earth Day, 2010.


By the way, Mr. Julian told me in our interview (which you can listen to via the player at right) that these pesticides "very clearly" cause cancer - I'm not sure where he gets that; even the Canadian Cancer Society doesn't go that far:
 
Studies show that pesticide exposure may be associated with cancer risk for adults and children. Although the evidence is not yet conclusive, it is growing and suggestive.

 
The broader question, though: is such a ban needed? I would argue no - in fact, I did, last year:
 
...the sweeping review of 2,4-D by Health Canada's Pest Management Regulatory Agency (PMRA) went largely unnoticed. Quite strange, really, considering that pesticide bans are in place or being debated right across the country.

Or maybe not so strange, when you consider the PMRA's conclusions, and their most inconvenient bearing on the pesticide ban crusade: "Products containing 2,4-D do not pose unacceptable risks to human health or the environment."

And: "an independent science advisory panel comprised of government and university experts-researchers in toxicology, epidemiology and biology . . . agreed with Health Canada's assessment that 2,4-D can be used safely when used according to label directions."

As for glyphosate, even the Pesticide Action Network concedes that glyphosate is "relatively less harmful than many of the products which compete with it in the market place."

That's from a declared anti-pesticide organization. From the science, it's even more conclusive. A review of the relevant literature  was published in 2000 in the peer-reviewed journal Regulatory Toxicology and Pharmacology. It found that "glyphosate is noncarcinogenic," that "there were no effects on fertility or reproductive parameters in two multigeneration reproduction studies with glyphosate," and concluded that "under present and expected conditions of use, Roundup herbicide does not pose a health risk to humans."

 
What about the cancer claims? Liberal MP Keith Martin raised some excellent points a few years ago during debate on this matter:
 
When we go through some of the studies, they show that a lot of the anti-pesticide comments are rooted in fear and fly in the face of common science.

Let us take a look at some of the premises. The first one is cancer rates. Have cancer rates gone up or have they gone down? We all know people who have had cancer and we know many more people have it. The reality is we are living longer. Males living in my province of British Columbia have the greatest longevity of any place in the entire world. Canadians ought to be proud of that. Indeed, Canadian women and men are some of the longest living people.

Cancer, perhaps above all others factors, is a function of age. As we get older, the incidence of cancer rises. Our ability to contract cancer increases with age. It is a function of our genetics, what we have done to our bodies such inaction, poor dietary habits and smoking.

Has the incidence of cancer increased? No. The number of people, per population, who get cancer has remained relatively static over the last 10 years. In some areas it has gone up. For example, the incidence of lung cancer in women has gone up because more and more women are smoking. The incidence of lung cancer in men has gone down. The incidence of cervical cancer has gone down because women have been more adept in having pap smears to monitor cervical cancer. This has saved thousands and thousands of women's lives. Thankfully we have those tools.

Do pesticides cause cancer? The anti-pesticide groups will not tell us this, but 99% of the pesticides we consume are natural.

I will be splitting my time, Mr. Speaker, with the member for Malpeque.

Over the decades ample studies have been done on pesticides. They have shown no increase in the incidence of cancer in populations that have been subjected to pesticides. Most of the pesticides we spray are natural. If we compare synthetic pesticides to natural pesticides, there will be no difference in the statistics of the mortality and morbidity. These chemicals, natural and synthetic, have been exhaustively studied for decades. Large populations have been looked at.
 
Also, Ottawa Citizen columnist Dan Gardner has been fiercely devoted to this issue - see here, here, here, and here.
 
The New Democrats say they want to start a debate on this issue - I'm all for that, so long as we're willing to put all the facts on the table.

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