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), are indeed saying that their regulatory process ensures that they are safe (cf. the 7 August 2001 interview on CBOT-TV Newsday with PMRA spokesperson Richard Martin). For a decade before that, we had to listen to one (Marie-Josée de Saint-Victor, of Agriculture Canada's Pesticides Directorate) 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 young girls? (Yes, in Canada it is - for head lice.) 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 few 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 are about 5000 other ingredients in those approved products that they choose to not call "active" (cf. The Globe and Mail, 9 June 2001). Pesticide people have co-opted the word "inerts" for these substances.
First, some ingredients are "active" in one formulation and "inert" in another. In the USA, where pesticide ingredients now have to be disclosed, 354 compounds have turned out to be "active" in one formulation and a secret "inert" in another. Second, no company is going to pay good money to put something into a pesticide product that doesn't do anything, which is what "inert" means. Let alone, spend millions on lawyers to protect the identity of those substances as trade secrets! The truth is that (again in the USA) 187 registered "inert" ingredients are formally listed as hazardous to health under US acts relating to clean air and water alone. Many are more hazardous to people than the "active" pesticides are - some are even more toxic to the target pest than the "active" ingredient in the same formulation.
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 of the most 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 - activators, dispersants, solvents, wetting agents and the like. A survey down the shelf of local gardening stores shows that on average two "active" ingredients are listed for each domestic class product there. On average, well over 90% of the contents of those products are undisclosed on their labels.
So, if science is to attempt to prove such mixtures are safe, we have about 500 known ingredients ("active") in combinations of two, times about 5000 unknown ingredients ("inerts") in combinations of two: 6x1012 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. For example, when asked for the results of studies of the effects of xylene, a common "inert", on people with asthma, Allen Rock, Minister of Health at the time (3 September 1998), answered, "Xylene is not registered as a pesticide in Canada." Translation: no tests. And, when the City of Ottawa asked the PMRA this question in 2002, they received the answer: the PMRA "cannot address the synergistic nature of products and ingredients because there is no effective way to judge potential element combinations. The potential combinations and dosages are endless."
Today, the PMRA states 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 6x1012: about a billionth of those required to scientifically prove that our pesticides are safe in the real world where things get mixed together.
Pesticide companies cry "unprofessional" (or worse) here. Those combinations don't exist in reality, they say. For example, the CBC program The Nature of Things (14 March 2001) presented observations made by Elizabeth Guillette that the intelligence of otherwise very similar children was demonstrably 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, Len Ritter, appeared on the program to poo-poo the notion that the situation in Mexico could possibly apply here in Canada. Farmers in Mexico mix all kinds of chemicals together without any supervision, he said.
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 PMRA 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. (This is in accordance with Canadian law, by the way. 'Public health' in Canada is deemed to exclude all people who have a 'predefined health condition'.)
But, we do know a few things. Depending on the area, 3-5% 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 severe over-reactions to substances in the environment: allergies (IgE response), allergies in all but name (MCS triggered by an overexposure), and MCS/EI/CFS/FM that may be caused by solvent-mediated brain infection by a virus. At least 5% of people have a hypersensitivy that can be clinically measured (some studies say 15%) - about 1/3 involve an IgE response. Then there are all the auto-immune health problems, again an over-reaction by a human body - Type I diabetes, lupus, 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 are 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. The position of Health Canada with regard to these people is simple: "they must take precautions to avoid exposure to these substances." (Allen Rock, op.cit.) But, Canadians, ill or not, can not take precautions to avoid exposure to toxins in pesticides spread by neighbours - federal legislation prevents it.
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. (And, don't forget insect repellants and sun-block lotions.) 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, each denied to me 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 at least 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 1016 formulant-drug-health combinations - a 1012 gap. Of course, the population of Canada is only 3x107. So, it can't be done! We need a study population greater than that of the whole world to directly judge whether or not pesticides are "safe".
To a real scientist, the conclusion is simple - 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. We should start by promoting the optimal health of real Canadians. All of us, not just of those of us in perfect health.
other notes on pesticides