Australia at high risk of pesticide pollution.

Credit: CC:0

Pollutants from agrochemicals and pesticides can disrupt the ecosystem and risk harming human health, despite greatly contributing to food security in the last half-decade.

Now, researchers from the University of Sydney had conducted a comprehensive risk assessment of global pesticide pollution.

The team, led by Fiona Tang, found that 64% of global agricultural land (around 24.5 million km2) is at risk of pollution from pesticides, and 31% is at high risk – some of which is in Australia.

About a third of the regions within the high-risk areas had high biodiversity – that is, many different species of animals lived there – and 19% were in low and lower-middle-income nations. The full results are shown in a paper published in Nature Geoscience.

The team defined ‘at risk’ areas as regions where pesticide residues in the environment were above concentrations considered to have no effect, and at high risk when residues were 1000 times higher than the safe level.

The Murray River watershed in Australia was listed as one of the top five areas of concern. Rivers, estuaries and lakes in China, South Africa, India, and Argentina made up the other four. Surprisingly, four of the five regions at high risk were within high to upper-middle income economies.

The authors suggest that policies need to be implemented in the high and medium risk regions in order to prevent contamination and environmental damage, whilst also preventing food loss.