The risk transfer pathways of toxic chemicals by food trade and logistics

Global food trade, driven by population growth and resource imbalances, has become a key vector for transferring persistent toxic chemicals (PTCs) across borders.1 While alleviating resource pressures, this system shifts environmental degradation, directly exposing populations to PTCs, including pesticides, dioxins, methylmercury, and polychlorinated biphenyls (PCBs).2,3,4,5 Current research prioritizes atmospheric/oceanic transport, yet food trade transfers PTCs 10-fold faster,5 as shown in the Europe-to-Africa PCB-contaminated fish trade.2 However, origin-tracing gaps and fragmented regulations hinder risk mitigation.3 We highlight recent advances in quantifying trade-driven contamination pathways, identify policy gaps (e.g., harmonized standards, blockchain traceability), and propose potential governance strategies to address transboundary health disparities amid expanding trade and climate disruptions.

An emerging transport pathway of toxic chemicals

A rapidly growing population and economic globalization have driven increasing global crop and meat trade in recent decades, particularly among areas and countries with agricultural resource surpluses or deficits. Demand for crops and meat is significantly driven by the services and resources embedded within traded foods. The increasing need for environmental carrying capacities is another driver promoting rapid global food trade and logistics. For example, China consumed 8 million tons of beef and over 100 million tons of soybeans in 2018, of which approximately 1 million tons of beef and 94 million tons of soybeans were imported. As a result, food imports remarkably relieve the stress on land and water shortages and reduce environmental and climate impacts in China. While the associations between food trade and agricultural resources have been explored extensively, human exposure and health risks related to food trade and logistics are still poorly understood. Pesticides, fertilizers, additives, and antibiotics have been widely used in food production.1 These chemicals often exhibit toxicity, persistence, and bioaccumulation, posing potential risks to both human health and ecosystems. Concern has been raised about whether toxic chemicals are delivered from their sources to receptors via the atmosphere, oceans, and transboundary rivers, where human food webs (the foods we consume) as “endpoints” of toxic chemicals are located. In this case, human exposure to contaminated foods is assessed at the endpoint of toxic substances. Figure 1 provides a schematic view of the atmospheric and food trade pathways.