Two-thirds of agricultural land globally are at risk of pesticide pollution

A team of Australian researchers mapped the risks of pollution from 92 chemicals commonly used in agricultural pesticides across 168 countries and their results should give us pause.

The scientists have found that nearly two-thirds, or 64%, of arable land used for growing crops is at risk of pesticide pollution with nearly a third of at-risk areas facing considerable threats from chemical pollutants.

The overall land area identified to be at risk amounts to a staggering 24.5 million square kilometers, or two and a half times the size of Canada, the second largest country in the world.

At the highest risk of large-scale pesticide pollution are several mass producers of rice and other essential grains that feed billions in Asia, including China, Japan, Malaysia, and the Philippines, the researchers say.

Worse: among the high-risk areas, a third are in regions with high biodiversity where dangerous chemicals are posing a constant threat to wildlife.

Another 5% arable land at risk are in water-scarce areas. Harmful chemicals from pesticides can filter Into surface and groundwater sources through runoff and infiltration, which could lead to a loss of precious freshwater in areas already suffering from shortages.

“We identify watersheds in South Africa, China, India, Australia and Argentina as high-concern regions because they have high pesticide pollution risk, bear high biodiversity and suffer from water scarcity,” the scientists write in a study published in the journal Nature.

Troublingly, the use of pesticides has been growing globally and numerous experts have sounded the alarm about the harmful effects of these chemicals. Insect populations worldwide are under stress, for instance, which means key pollinators like bees and bumblebees going absent from more and more areas.

At current rates, the use of pesticides globally is expected to increase further still in coming years.

“In a warmer climate, as the global population grows, the use of pesticides is expected to increase to combat the possible rise in pest invasions and to feed more people,” Federico Maggi, an associate professor at the School of Civil Engineering and the Sydney Institute of Agriculture who was an author of the study.

Reducing the rate of pesticide use will be essential if we are to protect biodiversity at and near agricultural areas, stresses Fiona Tand, a research associate at the University of Sydney who was the study’s lead author.

“Although protecting food production is essential for human development, reducing pesticide pollution is equivalently crucial to protect the biodiversity that maintains soil health and functions, contributing towards food security,” Tang says.