More on the risks of using pesticides

You may ask why I am posting issues on pesticides. You may ask what they have to do with GMO’s?


GMO crops use pesticides (herbicides, fungicides, insecticides) and because there is a resistance being created in weeds to these chemicals, all forms of pesticides are being manufactured in stronger batches. It’s a cycle that will be very difficult to break now. We are in it. This is the tipping point. It is up to every individual to come to some understanding of what the real issue is here. It’s not about the chemicals. It’s about control. Read on:

The Western Star

My letter last week about cosmetic use of pesticides has promoted some discussion both in The Western Star printed edition and its web edition.

I would like to reply to Tuesday’s letter from Lorne Hepworth of CropLife Canada.
He states “we can rest assured that before any pesticide is sold in Canada it undergoes comprehensive scientific review and risk assessment by Health Canada.”

Health Canada has created PMRA — the Pesticide Management and Regulatory Agency — which is the responsible body for reviewing all the studies submitted. But there are problems:

  • Underfunding — in 2002, $8 million of the funding was from the pesticide industry.
  • PMRA does not conduct its own in-house laboratory work. It reviews the research provided — most of it from industry sources and most of it not published in peer reviewed literature.
  • The industry requests PMRA to treat the material as “proprietary.” So this science remains hidden.
  • PMRA relies mainly on U.S.A. studies (80 per cent of the studies reviewed in the early part of the decade.)
  • Health Canada has a track record of approving pesticides, only to later phase them out due to health and environmental concerns. Examples: DDT, Eldrin, Diazinon, Dursan, Mecoprop.
  • PMRA  does not evaluate other chemicals in the formulation, so- called “inerts,” or the breakdown products.

Mr. Hepworth goes on to say “As for benefits … well maintained public and private spaces make for happier  healthier communities.” Happier I will not debate, but healthier? This I will argue is nonsense. In the comments on the web page, DB from NL worries at the use of the word “linked” when commenting on the link between pesticide exposure and different diseases. DB would like hard numbers and quantification.

I have great sympathy with this position, as epidemiology studies basically compare a cohort population that is exposed  — in this case say to a group of farmers exposed to a pesticide — with a cohort matched as far as possible. These studies are almost always repeated to try to correct for possible biases — age, gender, race, smoking rates, etc.

To do a controlled double blind trial, as is done with prescription pharmaceutical drugs, is not possible. It would be totally unethical to deliberately expose a population to an insecticide and give a matched population an inert substance without either group knowing what they were being given and follow them for a very long time.

Cancers have a long latent period before being manifest. Just look at tobacco and smoking.

There are good websites available that give access to valid scientific studies that document the relationship between pesticides and disease time and time again … and science has been showing this relationship for many, many years.

The following resources will, I think, convince DB from NL.

Look them up:

  • Environmental health perspectives. Asthma 10 times commoner in children exposed to pesticides before age one.
  • Medpage Today — Aberdeen University.  Parkinson’s disease increased with exposure to pesticides. Low exposure nine per cent. High exposure, i.e. farmers, 45 per cent increase.
  • Pubmed. These next studies show that exposure to pesticides in pregnancy increases the incidence of birth defects. This study shows that women in California living within 500 yards of fields being sprayed are 75 per cent more likely to have birth defects.
  • Acta Paediatrica. A study of birth defects showed an increase for women who started their pregnancies in April to July. During those months the levels of nitrates, atrazine and other pesticides in the ground water were much higher than in other months
  • American Journal of Epidemiology
  • Globe and Mail April 2009

These and many other research reports do not have the numbers in the way that DB from NL wants.

But the statistical correlation between the pesticide and the disease convinces me and most of the medical profession, especially those of us who see patients with these diseases. There is a relationship.

2 responses to “More on the risks of using pesticides

  1. Dr. Lorne Hepworth is President of CropLife Canada, an industry lobby group. He is notorious for his promotion of pesticides as highly beneficial to mankind and his uncritical assessment of the regulatory role played by Health Canada’s Pest Management Regulatory Agency (PMRA). In fact, the PMRA merely examines toxicological (rat) studies provided by the industry. The Agency employs about 350 toxicologists and has revealed in mid-2009 that it was employing only two epidemiologists. Yet it is epidemiology that links pesticides, such as the common herbicide 2,4-D, to various types of cancer, disruption of the endocrine system, neurological and immune systems damage, asthma, Parkinson’s, reproductive problems, diabetes as well as behavioral and learning disabilities in children. There is no mechanism at the PMRA to search and review pesticide literature submitted by independent scientists, and no bibliographies are compiled. Each report that happens to come across someone’s desk is examined in isolation from other data and if a single report by itself doesn’t overturn the agency’s decision it is to be discarded into the “disregard” files. When pesticides are used in combinations, such combinations are never tested, even though a synergistic (reinforcing) effect is likely. Moreover, so-called “inerts” may amount to as much as 90 percent of the ready to apply formulations. Used to increase the potency of the “active” ingredients, they are not identified by the pesticide industry and remain a trade secret. No wonder their very “inertness” is now being questioned! Industry spokesmen insist on 100% proof of given chemicals’ toxicity. They are unwilling to acknowledge the complexity of human bodies’ multiple contamination by various synthetic chemicals and in general what science is really about. Findings that are inconvenient to the industry are dismissed as “junk science”. Misleadingly, the 16th century dictum of Paracelsus “It is the dose that makes the poison” is elevated by the industry spokesmen to the level of Gospel truth. 21st century synthetic chemicals contaminated by dioxin during manufacturing may be highly toxic even in minute quantities. This dioxin is likely to be 2,7-DCDD, rather than the notorious 2,3,7,8-TCDD associated mainly with herbicide 2,4,5-T, the banned ingredient of Agent Orange. According to biochemist Dr. Meg Sears, “The PMRA knows that levels of 2,7-DCDD [the other dioxin], are much higher than levels of 2,3,7,8-TCDD in today’s herbicides–so much higher that they have to be analysed separately. The industry can run the equipment to produce less contaminated products, but the run won’t be as efficient because the temperature is lower. The PMRA is leaving it up to the industry to choose the samples, and the industry is well aware of this issue.” (E-mail to the author of this blog, dated 10 June 2008.)

  2. Nice post! I really like your posting.
    i will come back to read more of your posts.


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