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www.caps.20m.com Canadians Against Pesticides |
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Why Science Can't Prove a Pesticide is Safe JOHN SANKEY PESTICIDE EDUCATION NETWORK As soon as you begin the study of pesticides and their relationship to human health, you will meet up with statements that "the government says they are safe", from just about every lawn spray and extermination company in the country. Unfortunately, these statements are correct. Canadian government people
involved with approving pesticides for use (today, they are called the Pest
Management Regulatory Agency, PMRA), have indeed been saying that their
regulatory process ensures that they are safe. For years, we had to listen to
one who regularly stated that "most pesticides are safer than table salt".
(Right. Just sprinkle some 2,4-D on your breakfast eggs - delicious!)
How could chemicals as appalling as Lindane be "safe" to spray on people? The government's answer: "we rely on good science". Well, as one who trained as a scientist, and who spent 30 years earning my living at it, I have learned a few of the strengths and weaknesses of the modern scientific method. It is by far the most successful way we humans have ever found to understand the universe around us. But, it is also limited by what we can understand. A single electron around a single atom is simple - all it took was a dozen Nobel laureates to figure it out. A human body is not simple at all. To give you an idea of why science does not yet have the capability of understanding the effects of pesticides on human beings, here are some numbers. (What else do you expect from a scientist? As one of the best, William Thomson, put it 100 years ago, "When you can measure what you are speaking about and express it in numbers, you know something about it, but when you cannot express it in numbers your knowledge is of a meagre and unsatisfactory kind.") According to the PMRA, there are about 8000 pesticide formulations registered
for use in Canada. The PMRA will tell you that there are some 500 "active
ingredients" in those formulations. What the PMRA refuses to tell you is that
there at least 1000 other ingredients in those approved products that they
choose to not call "active". Pesticide people have co-opted the word "inerts"
for these substances.
First, some ingredients are "active" in one formulation and "inert" in another. Second, no company is going to pay good money to put something into a pesticide product that doesn't do anything! Let alone, spend millions on lawyers to protect the identity of those substances as trade secrets! It is unacceptable science to deliberately use a word to classify something in a way that is the direct opposite of what that word means. And, science relies on openness. If you do not publish something in a sufficiently complete way that an independent scientist can replicate your result, it is not acceptable science. No one can replicate an experiment involving secret substances. And so, when we have barely begun, the Canadian pesticide regulatory system fails to meet two basic criteria of the scientific method. Not only does the PMRA refuse to permit science to know the identity of most
pesticide formulants, they refuse to say how many there are, even how many there
are on average in typical pesticide products. However, basic physical chemistry
permits one to hazard the guess that there are at least two secret ingredients
in the average product - dispersants, solvents or wetting agents. A survey down
the shelf of local gardening stores shows that on average two "active"
ingredients are listed for each domestic class product there.
So, if science is to attempt to replicate the PMRA's work, we have about 500 known ingredients ("active") in combinations of two, times about 1500 unknown ingredients ("inerts") in combinations of two: 5x1011 combinations. The PMRA, of course, doesn't do things that way and never did - they tested the individual "active" ingredients, one at a time - 500 tests. Today, they state that they also test each new formulation as a whole. But, that was not done for the vast majority of pesticides being used in Canada, as they were approved decades ago. Even today, the PMRA's "science" is based on 8500 tests out of 5x1011: one sixtieth of a millionth of those required to scientifically prove that our pesticides are safe in the real world where things get mixed together. Pesticide people will cry "unprofessional" (or worse) here. Those combinations don't exist in reality, they will say. For example, recently, a CBC program The Nature of Things presented evidence that the intelligence of otherwise very similar children was demonstratibly lower in an area of Mexico where there is heavy agricultural pesticide use than in a nearby non-agricultural area. A former Canadian pesticide regulator was quoted on the program as poo-pooing the notion that the situation in Mexico could possibly apply here in Canada. After all, farmers there mix all kinds of chemicals together without any supervision. Well, unsupervised pesticide mixing is the norm right here in Canada, and always has been. |
I grew up in the fruit-growing area of Niagara. Growers there dumped lead arsenate (insecticide) and copper sulphate (fungicide) into their spray tanks (the two together were known as "Bordeaux mixture"), added nicotine sulphate (another insecticide) and microfine sulphur (another fungicide), then dumped in a bottle of detergent as a dispersant (a dishwashing liquid called "Pink Lux" was the favourite) and a gallon of kerosene (a wetting agent). If they were worried about soil grubs, they added a dose of a mercury compound. Then, they sprayed everything in sight, trees, earth, fences and all, with a nozzle big enough for a fire truck. Today, most of the lawn spray trucks cruising suburbia load up with a
fertiliser mix (at least three components, N P and K), a herbicide mix (the
standard one has three "active" ingredients plus presumably two others), a
fungicide (at least two more ingredients) and an insecticide (at least two
more). Twelve ingredients minimum, with virtually none of the potential
combinations tested by anyone. But, the bright green brochure left at the door
shows a happy child watching something like a butterfly or a bird on the lawn
they just sprayed.
There is another problem with "pesticide science". The PMRA does not, of course, test products on real human beings before their release. They use animals that are believed to have similar responses to toxins as we do - rats for oral toxicity, rabbits for dermal, and so on. But, toxicologists want to be sure that they can replicate their own experiments. So, they rely on genetically purified strains of rats for most of their tests. And, people aren't genetically purified! How many varieties of human beings are there in Canada, from the viewpoint of reaction to toxins? No one seems to have the slightest idea, and no one seems to even be attempting to find out. Our pesticide regulators, in concert with Health Canada, are all too obviously relying on "ignorance is bliss" with respect to Canadians who are not in perfect health. But, we do know a few things. Depending on the area, 2-5% of Canadians have
asthma sufficiently severe that they have been specifically treated by a doctor
for it. Asthma is a mostly an over-reaction to substances in the environment -
formaldehyde and chitin (insect skin) are well documented. Anyone with severe
asthma can be expected to react differently to things they breath in, such as
pesticide spray and vapour, than the average person.
There are at least three other varieties of human illness that involve over-reactions to substances in the environment: allergies (IgE response), allergies in all but name (triggered MCS), and non-triggered MCS/EI/CFS/FM. 2-4% of people have a hypersensitivy that can be clinically measured (about 1/3 involve an IgE response). Then there are all the auto-immune health problems, again an over-reaction by a human body - diabetes, rheumatism, arthritis. Of course, anyone who has received an organ transplant has to take drugs to keep their immune system suppressed for the rest of their life... The truth is that there must be at least a hundred different chronic health problems that Canadians have that, until demonstrated otherwise, must be assumed to make them more affected by a pesticide than the average rat-model Canadian. My best estimate is that 10% of the Canadian population has such a health condition. What about the drugs that people take? You sure won't find a rat on Prozac in the test suite of a pesticide regulator! You won't find one on birth control pills or common cold remedies either. How many drugs are there that might be expected to interact with components of pesticides in our body? Again, no one seems to have the slightest idea, and no one seems to be attempting to find out. In fact, the federal and provincial health ministries, and the matching regulatory bodies for doctors and for pharmacists, all deny that there is any list, anywhere, of even the drugs that may legally be prescribed by a physician, let alone of all the over-the-counter drugs. Well, from chats with a local pharmacist, and cruising the shelves of a few drug stores, I submit that there are more than a hundred different types of drugs, that must be expected to affect human reactions to pesticides, that are taken by a significant portion of the people here in Ottawa. My best estimate is that 10% of the Canadian populace is, at any one time, taking such drugs, and that half of these are taking them for a non-chronic health problem. So, it seems that approximately 15% of Canadians are not modelled acceptably by current pesticide regulatory practise. Canadians seem to agree - a number of health surveys have found that about 20% of us feel that we are in only fair to poor health. The bottom line is that PMRA "science" is based on 104 tests out of 1015 formulant-drug-health combinations - a 1011 gap. Of course, the population of Canada is only 3x107. So, it is actually easier to treat every single last person in Canada as unique, than to use current scientific knowledge to judge whether or not pesticides are "safe". The conclusion has to be - the scientific method is, with present knowledge, inadequate to deal with the toxicity of pesticides to real people. We will need new models of toxicity before that will change. And, as long as the secrecy that pervades the pesticide industry and regulators is maintained, the required knowledge is unlikely to be developed using the scientific method. We have, therefore, to rely on other judgement mechanisms than science to regulate pesticides for now. Perhaps, we could start with promoting the optimal health of real Canadians, not just of those in perfect health? Provided by the Pesticide Education Network. |
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