Human Health and the Environment: GMOs, PESTICIDES… In 2005

Monday 28 May 2007


Let’s go back over the facts:

“The worldwide production of chemical substances rose from one million tonnes in 1930 to 400 millions de tonnes nowadays, with about 100.000 different substances that do not, for the most, exist spontaneously in nature. The European chemical industry was, in 1998, the first in the world” (preliminary report on health and the environment in France on 13 January 2004). Among all those chemicals, one finds pesticides (insecticides, herbicides, pest control and antifungal agents and stem shortening defoliants). In parallel, from the point of view of health, we have to admit that there has been a major increase in serious pathologies such as cancers, allergies, male infertility, low female fertility, neonatal malformations, endocrine and neurological disorders. 

Let’s take a look at the figures below: mortality induced by the various types of cancers in France, according to INVS (French Institute of Health Vigilance): 
  • In 1980 : 125.144 deaths
  • In 2000 : 150.045 deaths

Incidence of the various types of cancers in France according to INVS: 
  • In 1980: 172.177 
  • In 2000: 278.253

These figures alone are frightening, even if we are not saying that pesticides are the sole responsible for this state of things. But here we must naturally envisage a reflection on the complexity of interrelations and avoid a binary mode of thought: “one product = one effect”.
Pr Charles Sultan, Chief Consultant of Pediatric Endocrinology at the CHU University Hospital of Montpellier noticed that neonatal malformations in boys are increasing almost four folds in farmer children or in people living in areas exposed to pesticides. 

More than 99% of GMOs cultivated in the environment on the world market are herbicide-tolerant GMOs or insecticide-producing GMOs. As far as GMOs producing insecticides are concerned, no one is pointing out the actual pesticide tonnage per hectare contained in the plants, nor the quantities buried in the soil after the harvest. All this leads us to think about the cumulative effects of pesticide-GMOs on the other agricultural pesticides. 

So far, no serious research proving that GMOs reduce the use of pesticides has ever been conducted. Furthermore, the presence of toxic products in the environment has led authorities to decide on standard values and thresholds that should be complied with or that should not be exceeded. When you start thinking about the interactions between health and the environment, the impact on health of any toxic or potentially toxic product is (or ought to be) studied and assessed. Such studies (if they are conducted) use statistical methods and they are assessed with a probabilistic approach.

Looking at things from the point of view of fundamental ecology highlights the complexity of the circulation of matter within ecosystems and within large biogeochemical cycles, as well as phenomena of bioaccumulation and bioamplification in trophic chains. 

How could the evolution of toxic substances be followed up with certainty and in a relevant manner, while taking into account:

  • The effects on the starting-point molecule, its metabolites, cross effects, with other toxic or not toxic products.
  • The bioaccumulation and bioamplification effects in the food chain.
  • And finally, the effects on humans, taking into account different variables, such as  age, gender, potential pregnancy, or pre-existing pathological states?

Four major points do make the situation more complex:

  • Molecules with toxic effects are generally not released in the environment just by themselves, adjuvants are generally necessary to improve their efficiency, besides, more often than not, they are completely unknown, due to “manufacturing secrets”; which is the case for a large number of pesticides.
  • The study of the effect/dose relationship highlights the fact that the doses are not in the order of a gram or a milligram, but infinitesimal, which makes their analytical tracing even more difficult and costly.
  • In the case of GMO pesticides, the residues left in the soil are not taken in account.
  • Setting standards depends mostly on the economic context. 

No scientist or expert can seriously pretend being able to apprehend all this. Setting standards, maximum values and thresholds is certainly necessary, but it is a mere safeguard approach to avoid catastrophes, and some kind of false security from a health point of view.

Curiously the GMOs / pesticides / health problematics seems to be shirked. The study of real and potential risks makes us realize ipso facto the difficulty in measuring the impact on health. As a matter of fact, such measuring should be understood as multi-dimensional in space: simple effects, crossed effects, predispositions… And as a function of time too: in the short, medium and long term... Seeing the analysis of the risks and seeing how difficult it is to measure their impact on health, and appreciating the complexity of the GMOs / pesticides / health relationships, we have to realize how little research is conducted on the matter. 

Due to the high levels of pesticide release and possibly of GMOs in the environment, without any subsequent controls and without any possible return to the former state of things, it is crucial, urgent and necessary to have a global vision of the impact of pesticides and GMOs on the environment and human health. This makes such a study on the health consequences vital and it should be conducted by transdisciplinary study groups with the help of experts acting as consultants, as should always be done for all ecological questions. 

The GMOs / pesticides / health question, like any other question on the environment-health interactions, will force us to redefine sooner or later not so much the methods of research itself, which must remain free, but rather the methods for using scientific findings. To be able to face, for example, the increasing number of cases of cancer, infertility, sterility and congenital malformations, the withdrawal of all toxic products should be an aim to reach for. This may be perceived as a hindrance to economic development, but does economic reasoning take into account the cost of enduring pain and of the suffering induced for sick people and their families? Wouldn’t this “ideal” goal be in the end more of a generator than an inhibitor of the knowledge of reality, and couldn’t it turn out to be a driving force towards the extension of scientific and technological diversity?