The precautionary principle in pesticides management

One of the most encouraging outcomes of the negotiations for a treaty aimed at eliminating Persistent Organic Pollutants was the inclusion of the ‘precautionary principle’. Carl Smith calls for application of this principle to pesticide regulation.

First introduced by German policy makers more than three decades ago(1), the ‘precautionary principle’ concept came to the global stage in 1992, when the United Nations Conference on Environment and Development (the ‘Earth Summit’) included it among 27 principles to guide environmental and developmental policies. Principle 15 states: ‘In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevalent environmental degradation(2).’ 
    The precautionary principle would seem to have particular relevance in the case of pesticides – a class of man-made chemicals designed to be harmful to life. But when it is evoked in policy proposals that could restrict the manufacture or use of pesticides, sparks begin to fly.
    While stating that it supports the use of precautionary measures, the pesticide industry believes that as a consequence of its own science-based evaluations, ‘there should be no need for further regulatory action and notably no need for action based upon a precautionary approach’(3).
    This optimism is at odds with a half-century of experience. But more importantly, it reflects a narrow view of the considerations that govern pesticides regulation. Until these basic assumptions are reconsidered, it will be difficult to move beyond the current operating basis, in which even the most dangerous products continue to be manufactured and traded for decades after their hazards are known.

Is precaution ‘scientific’?
In policy negotiations, it is common to hear warnings that application of the precautionary principle must be ‘science-based’. The inference is that a precautionary approach is likely to be at odds with basic operating principles of science. Is this really the case?
    Researchers Andrew Stirling and Sue Mayer offer a model that contrasts ‘scientific’ and ‘unscientific’ appraisals, and ‘narrow’ versus ‘broad’ (or precautionary) regimens (see below)(4). Working these characteristics back and forth against one another, and envisioning their application to real-world situations, it is difficult to sustain any concern that broad application of the precautionary principle would lead to ‘unscientific’ policies. 
    Modern science is characterized by inductive reasoning – arriving at conclusions or principles from multiple observations. However, it is extremely difficult to gather complete and accurate observations regarding the real-world impact of pesticides on health and the environment, especially from the broad perspective assumed in a national or international policy discussion. For example:

• Even in the case of the most dangerous and persistent pesticides, it is not possible to make an accurate determination of annual production and use. Production and trade figures are granted the status of ‘confidential business information’.
• Very few epidemiological studies are conducted in developing countries, where hazardous pesticide products are regularly used without adequate protection and stored unsafely. Even fewer studies address gender and social impacts and rarely is consideration given to specific effects on women, reproduction and children.
• Data provided to support the introduction of new pesticides are generated by the manufacturers. Government regulators, who represent the interests of public health and the environment, conduct no independent testing. 
• For obvious reasons, it is not acceptable to conduct experiments on human subjects prior to introducing pesticides to the market.
• Real-world variables, such as individual sensitivity and the synergies and interactions of multiple exposures, are limitless. It will never be possible to examine all cause-effect relationships.

In view of such realities, it must be admitted that any attempt to characterize the long-term impact of a specific pesticide on health or the environment is deductive rather than inductive – at best, a pretty good guess. 

A precautionary approach is a scientific approach

Unasked questions
In addition to the difficulties involved in gathering enough data to fully answer the questions about pesticides that scientists know we should ask, new research continues to raise new questions. Unfortunately, these questions tend to arise only after a pesticide has been in broad use, accumulating in the environment and the food chain. The following is a partial list of examples:

• Endocrine disruption: Certain pesticides (and industrial chemicals) can interfere with the normal functions of hormones and can affect women and men, girls and boys, in different ways. This can result in a wide variety of adverse effects – not only on specific body organs and systems, but also on the endocrine system itself. This finding has profound implications for the developing world, where women are commonly involved in pesticide mixing and application as well as tending and harvesting crops (and laundering pesticide-contaminated clothing). In addition to bringing these troubling revelations to international attention, the researchers involved pointed out that traditional risk assessment, with its focus on cancer, could be ignoring significant risk factors(5). 
• Heightened susceptibility among children: A review published in 1993 by the US National Research Council brought forward another set of unasked questions. The authors concluded, ‘Compared to late-in-life exposures, exposures to pesticides early in life can lead to a greater risk of ... cancer, neurodevelopment impairment, and immune dysfunction’(6). They also pointed out that virtually no research had been conducted to assess these risks. 
      Although this study was conducted to assess dietary risks for children in the US, it has far greater import for children in the developing world. In some developing countries, nearly a third of the agricultural work force is comprised of children. As many as 3 million children in Brazil alone are estimated to work in sisal, tea, sugar cane and tobacco plantations; 82% of the 6.1 million economically active children in Bangladesh work in agriculture(7). Rural children, girls in particular, begin their economic activity as young as five, six, or seven years of age. 
      According to the International Labour Organization, children can be found ‘mixing, loading and applying pesticides, fertilizers and herbicides’(8). UNICEF has echoed this unsettling picture in its State of the World’s Children report: ‘Children pick crops still dripping with pesticides or spray the chemicals themselves … eight-to-ten-hour days are not uncommon – and spent far from running water.’ 
• Forgotten pollinators. Animals and insects pollinate over three-quarters of the staple crop plants that feed humankind and 90% of all flowering plants in the world. The economic value of animal pollination to world agriculture has been estimated to be US$200 billion per year(9).
      Honeybees, the most economically important crop pollinators worldwide, are in decline. One-quarter of all managed 
  honeybee colonies were lost between 1990 and 1995, an event described as ‘one of the most severe declines in any agricultural input that US agriculture has ever experienced(10).’ An estimated 20% of all losses of honeybee colonies involve some degree of pesticide exposure(11). 
      More than 100,000 different animal species play roles in pollinating the 250,000 kinds of wild flowering plants on Earth. In addition to bees, wasps, moths, butterflies, flies and beetles, as many as 1,500 species of birds and mammals serve as pollinators(12). Now that declines have been noted, the adverse effects of pesticides on these animals, and the consequences for agriculture and the environment, are beginning to be examined – but the difficulty of answering these questions in retrospect is staggering. 

A different debate
An increasing number of scientists are urging new terms for the debate on toxic chemicals, away from ‘How much risk is acceptable?’, and toward ‘How much contamination can be prevented?’(13)
    Such an approach embodies both common sense and practicality, particularly when the true complexity of assessing interactions between the variety of individual chemicals used in chemical-intensive agriculture is acknowledged. Researcher Joe Thornton cites estimates from the US National Toxicology Program that an abbreviated single-species toxicity evaluation of all the interactions in a mix of just 25 chemicals would require 33 million experiments at a cost of about three trillion dollars(14).
    In addition, an increasing number of scientists are noting that the value of services provided by ecosystems can be equal to or greater than the productivity gains promised by man-made chemicals. A report just published by the World Resources Institute raises serious questions about the likelihood that ecosystem-damaging practices such as pesticide-intensive agriculture offer a long-range means to feed the world(15).
    From a doggedly precautionary perspective, the first question regarding a pesticide would never be: ‘Exactly how toxic is it?’, but only: ‘Is it really needed at all?’
    Along the same line, a precautionary approach to regulation would not shunt aside the realities of storage and application that prevail in developing countries – it does not matter that the manufacturer’s label recommends the appropriate level of protective clothing if it is obvious that no such equipment will be available to the user. 
    Preventing harm is not a new idea to the community of non-governmental organizations, researchers and others working on pesticides issues. What is new is the notion that policy discussions might be guided by something more than arguments about the specific meaning of toxicity studies.
    In Mr. Thornton’s view, this shift is essential: ‘The impossibility of making reliable quantitative predictions of the impacts of individual substances on ecosystems and organisms falsifies the risk paradigm’s most basic assumption: that humans have the knowledge and technology to manage these impacts at the fine level of control implied by approving discharges and regulating individual substances’(16).
    Instead, he suggests an ‘ecological paradigm’ to guide precautionary action. It is based on four principles: zero discharge; clean production; a ‘reverse onus’, in which producers must prove synthetic chemicals pose no significant hazard (and that no alternatives exist); and shifting chemicals management from individual sources and substances to large classes of chemicals and the processes that produce them(17).

From concept to policy
The growing consensus to place precaution at the forefront of environmental policy efforts is a hopeful sign. In January 2001, the Swedish government backed a tough stance against toxic chemicals as part of the EU’s overhaul of regulations on hazardous substances. But any consensus for precautionary measures, must be reflected in strongly-worded and vigorously-enforced national and international policy. 
    If it is, those who are responsible for protecting public health and the environment will have the authority to be proactive, not reactive, and to carry out their work in a hands-on, engaged manner – a development that is long overdue.

References
1. W Gullet, Environmental protection and the precautionary principle: a response to scientific uncertainty in environmental management, Environment and Planning Law Journal, 1997, 14:52.
2. Earth Summit, UNEP, 1992.
3. Ibid.
4. A Stirling and S Mayer, Precautionary Approaches to the Appraisal of Risk: A Case Study of a Genetically Modified Crop, International Journal of Occupational & Environmental Health, 2000, VI:4, 296-311.
5. T Colborn and D Dumanoski, JP Myers, Our stolen future, Dutton, New York, 1996.
6. National Research Council, Pesticides in the diets of infants and children, National Academy Press, Washington DC, 1993.
7. C Bellamy, The state of the world’s children 1997, Oxford University Press, London, 1997.
8. Child labour: targeting the intolerable. International Labour Organization, Geneva, 1996.
9. D Pimentel, Economic and environmental benefits of biodiversity, BioScience, 1997, 47(11).
10.GP Nabhan and SL Buchmann, Pollination services: biodiversity’s direct link to world food stability, in G Daily, ed., Ecosystem Services, Island Press, Washington DC, 1996.
11. GP Nabhan and SL Buchmann, The forgotten pollinators, Island Press, Washington, DC, 1997.
12. M Ingram G Nabhan and S Buchmann, Our forgotten pollinators: protecting the birds and bees, Global Pesticide Campaigner 1996, 6(4).
13. J Tickner and P Hoppin, Children’s Environmental Health, A Case study in Implementing the Precautionary Principle, International Journal of Occupational & Environmental Health, 2000, VI:4, 281-288.
14. J Thornton, Beyond Risk. An Ecological Paradigm to Prevent Global Chemical Pollution, International Journal of Occupational & Environmental Health, 2000, VI:4, 318-330.
15. S Wood, K Sebastian and SJ Scherr, Pilot Analysis of Global Ecosystems: Agroecosystems, A joint study by International Food Policy Research Institute and World Resources Institute, International Food Policy Research Institute and World Resources Institute, Washington DC, 2000.
16. Op. cit. 14.
17. J Thornton, Pandora’s Poison: Chlorine, Health and a New Environmental Strategy, MIT Press, 2000.

Carl Smith is Vice President of the Foundation for Advancements in Science and Education (FASE). Since 1990, he has directed the FASE Pesticide Project, which reports on shipments of banned and hazardous pesticides from US ports. Most recently, he edited a special series of papers, ‘The Precautionary Principle and Environmental Policy: Science, Uncertainty and Sustainability,’ in International Journal of Occupational and Environmental Health, October/December 2000. A limited number of copies of the journal, are available at no cost to those with an active involvement in pesticides issues. Write to: carl.smith@fasenet.org

[This article first appeared in Pesticides News No.51, March 2001, p12-13]