Pesticide risks need more research and regulation
Developing countries need stronger pesticide regulation and a better understanding of how pesticides behave in tropical climates, according to experts behind a series of articles published in Science today.
They also need an international body to carry out regular pesticide safety assessments — ensuring they are used properly by farmers who are given thorough training in their use — and to monitor the safety of chemical levels in food, the experts say.
In the face of projections that the global population will reach nine billion by 2050, scientists must develop new technologies to make pesticides safer, and continue research into crops that will not require pesticides at all, according to the special section in Science.
Millions of tonnes of pesticides are used each year in agriculture, sometimes with poor oversight and knowledge regarding their environmental impact, particularly in developing countries.
A review article by a team led by Kathrin Fenner, a senior scientist at the Eawag aquatic research institute in Switzerland, looks at pesticide degradation. It also identifies knowledge gaps in what happens to pesticides once they are applied in the field.
According to Fenner, the biggest challenge is relating what is measured in laboratory studies to what is observed long-term in the environment. One example is what happens to pesticides that have been in the soil for a long time and what products they leave behind as they degrade.
"There are situations that are not covered, or not fully covered, by laboratory studies, especially situations in low concentrations in groundwater," Fenner says.
Furthermore, laboratory studies carried out for pesticide regulation in the United States or Europe look at factors specific to those regions, such as climate and soil type, and not at the warmer climate zones where many developing countries lie.
"How relevant that really is to more tropical settings, where you have more organic, carbon-rich soils and higher temperatures, is also somewhat of a knowledge gap," says Fenner.
Efforts to lower dependency on pesticides altogether is one option addressed in the Science articles.
A review article by Jeffery Dangl, a biology professor at the University of North Carolina, United States, and his colleagues, reveals developments in the understanding of plant immune systems and DNA sequencing that allow scientists to engineer crops that are less susceptible to pests and disease, and thus require less pesticides.
The technology could help tackle environmental concerns, such as groundwater contamination. It could also help reduce plant diseases and recover crop losses.
Continue reading at ENN affiliate SciDev.Net.
Pesticide spraying image via Shutterstock.