Impacts of international food trade on methylmercury-related health risks

Methylmercury (MeHg), a neurotoxic compound, is primarily ingested through diet. Food trade is recognized as a significant pathway for the transmission of food-borne risks, but its impacts on global MeHg-related health risks remain unknown. Here, we develop an integrated framework incorporating food trade simulation, health risk assessment, and complex network analysis to reveal the impacts of international food trade on MeHg-related health risks (i.e., expressed in fetal IQ decrements). Results show that 7.3 × 10⁶ points (38%) of global fetal IQ decrements are embodied in the food trade, with 80% of them attributed to 4% of transactions. Global food trade mitigates 1.3 × 10⁶ points of fetal IQ decrements, primarily contributed by marine fish trade. Moreover, while certain imported foods embody substantial MeHg-related health risks, they mitigate the risks of importers compared with domestic foods. This study highlights the necessity of clarifying the role of food trade in managing MeHg-related health risks.