Commentary by Roger Gordon
I would appreciate being given the opportunity to respond to a couple of points made by Lorne Hepworth ("Pesticides can be used safely" - the Guardian Sep 6, 2013), who took issue with my previous submission to the Guardian on the issue of using cosmetic pesticides ("P.E.I. government should ban cosmetic pesticides - the Guardian Aug 29, 2013).
First, it is important to recognize that Mr. Hepworth, as president of Crop Life Canada, represents the interests of a global network of manufacturers and distributors of pesticides, including those commonly referred to as cosmetic or lawn ones.
Mr. Hepworth contends that I "cherry-pick Information to support his (i.e. my) view on the topic." Proving beyond any shadow of doubt that cosmetic pesticides cause cancer or other serious conditions in humans is difficult, because science must rely upon epidemiological or case history studies of human populations after exposure has been inflicted under uncontrolled conditions.
Thus, it is unsurprising that every single study would not show a positive correlation. Yet, many well executed investigations of this type in which robust statistical analyses have been performed do show a worrisome trend. In 2007, an international group of medical researchers extensively reviewed the literature connecting pesticides of various ilks with cancer in humans.
As an example, 10 of 12 studies showed a positive correlation for Non Hodgkin's Lymphoma, in four cases reaching statistical significance. Twelve of 14 case studies were positive, 8 reaching statistical significance. Dicamba, mecoprop and carbaryl (all being sprayed on lawns in P.E.I.) were among the culprits. When one pieces together the evidence from these "field" studies with laboratory evidence of damage at the molecular level, it is small wonder that the Supreme Court of Canada in 2001 ruled that a 100 per cent cast-iron cause and effect relationship was not required for a governing body to exercise the "precautionary principle" and ban these chemicals. It is also unsurprising that a growing list of respected bodies have advocated such a ban -the Medical Societies of P.E.I. and of Canada, Canadian Association of Physicians for the Environment, Ontario College of Family Physicians, to name but three.
A second point of Mr Hepworth's is that we should be reassured of the safety of these pesticides because they have been approved by Health Canada. I am afraid that this does not give me the same sense of comfort. In the first place, Health Canada only tests the active ingredients, whereas commercial formulations contain a variety of so-titled "inert" ingredients (solvents, dispersants, etc) that in many cases have undesired effects of their own.
Also, there are several examples of pesticides that were once approved by regulatory bodies in existence at the time that have, in light of subsequent knowledge, been banned. DDT, fenitrothion, and 2,4,5-T (the partner to 2,4-D in "Agent Orange") come to mind. Up until the 1970s, farmers were allowed to spray apple orchards with lead arsenate. So please, let's not look to Health Canada for peace of mind. The only responsible course is to ban these chemicals that are being sprayed unnecessarily on lawns.
- Roger Gordon of Stratford is a retired biologist and former Dean of Science at UPEI. During his career at several universities he conducted research and published extensively on controlling insect pests using biological, environmentally-sound strategies.