Transboundary impacts of pesticide use in food production

Approximately 3.7 Tg of pesticides are used annually in global crop production to help protect yield, but pesticides pose risks to ecosystem and human health. In this Review, we summarize the pathways causing transboundary environmental and human health impacts of pesticide use in food production, and explore strategies to reduce reliance on pesticides. Once applied to crops, pesticides are transported through surface and groundwater flows, atmospheric dispersion and wildlife migration. Globally, 7.2% of pesticide input leaches below the root zone potentially reaching groundwater, with atmospheric droplets (10–50 µm in size) transported between 250 m and several kilometres from the point of application. International food trade drives pesticide use and, of all food products, fruit and vegetables have the highest embodiment of pesticide impacts, including risk to consumers through dietary intake of residues. Pesticide residues are found on 62% of rice from Pakistan and on 85% of harvested fruits, berries, pulses and leafy vegetables in Western countries. Moreover, residues on ~2–4% of domestic foods in China, New Zealand, the European Union and the USA exceed legal safety limits. Through stringent regulations on pesticide use and enforced compliance with pesticide residue limits, international trade can encourage adoption of low-pesticide cropping strategies and decision support systems that prioritize biodiversity and human health while maintaining yield. Future research should focus on quantifying transboundary pesticide impacts, constraining the environmental fate and transport of pesticides, and increasing environmental monitoring, especially in the Global South.