International conference in Costa Rica

Over 400 participants from all continents gathered in San José, Costa Rica, in February for a major pesticide conference, which combined both the human health aspects of pesticide usage and impact on the environment. Leslie London and Ingrid Eckerman report on the main findings.

The needs of developing countries, for whom the issues of food security and chemical safety are more critical, were the major focus at this significant conference. The objective was to have a policy impact, and to table key issues for the research agenda. 
    Costa Rica has developed a critical mass of scientists in the field at the National University (the Pesticide Programme, PPUNA) through the support of Sweden, the Netherlands and others. It was an appropriate host for this conference, which was also supported by the World Health Organisation Pan American Health Organisation (PAHO), the Swedish International Development Agency (SIDA) and the Royal Netherlands Embassy in Costa Rica.
    Topics ranged from the cost-benefit of pesticide use, the role of organic agriculture (see pp10-11), measurement of pesticides in aquatic environments, translation of research results into policy in developing countries, to the epidemiology of acute pesticide poisoning. The links between research and development and a round table on research needs in developing countries was debated. The keynote addresses presented environmental issues to scientists focusing on health, and vice versa, thereby maximising an interdisciplinary approach to a complex problem.

Costs of pesticide use
Careful attention to the costs of pesticide usage may illustrate a wide range of ways in which pesticides can generate both visible and hidden costs to society at large. These may occur through growing insect resistance, environmental damage, health damage, loss of aquatic resources and costs of monitoring. The argument was convincingly made that pesticide reduction programmes (as practised in Holland and Sweden) may increase the direct costs to consumers only marginally, and if health and environmental costs of pesticide use are included, will probably lead to a decrease in social costs.

Reduction or elimination?
There was debate at the conference on whether pesticides should be used at all. A minority argued that chemical-based production was essential for food security. The proponents of organic agriculture argued strongly that alternatives to chemical usage exist and are cost-effective. Somewhere in between, proponents of integrated pest management (IPM), argued that food security can be maintained or even increased by gradual reductions in pesticides, shifting away from more toxic pesticides, and by policies to encourage alternative methods of pest control.
    This point was elaborated in debates on whether 'safe use' of pesticides (an industry-sponsored campaign) could lead to improved health and environmental safety in developing countries. A strong argument was made that safe use is not possible under existing conditions in developing countries, and that this approach shifts the responsibility onto individual farmers and farm workers who do not have the capacity to manage chemicals safely.

The politics of health
Extensive research on the health problems of pesticide hazards has not led to significant policy changes. Rob McConnell of PAHO argued that pesticide poisoning needs to be raised on the political agenda and not left to health departments alone. Strategies for achieving this include focusing on the impacts on children and making pesticide poisoning one of the priority health issues for the country. This can lead to concrete programmes of action. He called for 'outbreak epidemiology' on pesticides: careful surveillance and investigation of sentinel cases or groups of cases to provide the basis for public health action.
    In a controversial presentation  on the epidemiology of pesticide poisoning, Prof. Jeyaratnam argued that morbidity and mortality from suicide far outweighed the occupational health hazards in developing countries. Other speakers pointed out that official statistics often misclassified occupational deaths as suicide because of disincentives to employers to report correctly, since they would have to pay higher insurance premiums, or compensation.
    A number of presentations explored the nature of chronic effects, which follow acute pesticide poisoning, that are poorly known and understood. Studies presented linked chronic neurotoxic effects to low-dose, long-term pesticide exposures. The South African study illustrated that improved passive surveillance for pesticide poisoning generates results that contradict many of the assumptions made from routine data-namely that rates are under-reported, occupational cases are neglected, and the proportion of cases involving women are greatly underestimated. Participants also noted that we know virtually nothing of the effects of exposure to different pesticides in combination.
    The conference, and the development of the PPUNA in Costa Rica, now an independent institution, provides a good example of how international aid can usefully lead to sustainable capacity in public health research, and to focused research relevant to policy development in developing countries.

Report by Leslie London of the University of Cape Town, South Africa, with additional material from Ingrid Eckerman, Population Health Unit, Nacka, Sweden. Abstracts can be obtained from PPUNA, Universidad Nacional, Apartado 86, 3000 Heredia, Costa Rica, Fax (506)2773583, e-mail ppuna@una.ac.cr.

[This article first appeared in Pesticides News No. 40, June 1998, page 9]