WA8 Global Perspectives: Pesticide Risk Assessment in Developing Countries
A105 & A106
8:00 AM - 12:00 PM, Wednesday
() Assumptions and uncertainties? The need for improved understanding of the impacts of pesticides in tropical agro-ecosystems.
Taylor, G1, Critchlow-Watton, C1, Baird, D2, Little, D1, 1 Institute of Aquaculture, University of Stirling, Stirling, Stirlingshire, United Kingdom2 NWRI, Environment Canada, FrederictonFredericton, New Brunswick, Canada
ABSTRACT- The intensification of agricultural practices in tropical countries, over the past 50 years, has led to economic growth, higher productivity but a perceived continuing adverse impact on ecosystems. The Green Revolution saw many less developed countries adopt an agricultural strategy, which increased productivity through the introduction of high yielding crop varieties and external inputs of chemical fertilisers and pesticides. In these countries, pesticides continue to be viewed as a both a guarantee against crop failure and a means of maximising crop yield. There appears to be an urgent need for guidelines that reduce the impact of pesticides and support good land-use practices. However, little is currently known of the status of their use or abuse and the fate and impact of pollutants entering these systems. The majority of ecotoxicological studies on pesticide fate and behaviour have been conducted under temperate conditions. Tropical terrestrial and freshwater ecosystems cover 25% of the land area on the surface of the Earth, generate nearly 60% of the primary productivity of the planet and contain approximately two-thirds of the worlds flora and fauna. Given the diversity of tropical ecosystems, it is likely that far more complex environmental contamination issues will be encountered than those in temperate systems and that simple data transfer from one system to the other may not be appropriate for pesticide management. The extent to which a pesticide may impact on the environment is dependent on a number of factors, which have been successfully used to develop risk assessment models for temperate regions. By looking at specific examples of agro-ecosystems in Asia, this paper will attempt to highlight some of the assumptions and uncertainties that may prevent the transfer of existing methods for assessing pesticide risk to tropical agro-ecosystems. Research needs to improve current understanding and approaches will also be suggested.
Key words: pesticides, tropics, fate, effects