Significance

Our study presents a global assessment of microplastic pollution’s impact on food security. By analyzing a comprehensive dataset of 3,286 records, we quantify the reduction in photosynthesis caused by microplastics across various ecosystems. This reduction is estimated to cause an annual loss of 109.73 to 360.87 million metric tons (MT) for crop production and 1.05 to 24.33 MT for seafood production. By reducing current environmental microplastic levels by 13%, these losses could be mitigated by 14.26 to 46.91 MT in crops and 0.14 to 3.16 MT in seafood. These findings underscore the urgency for effective plastic mitigation strategies and provide insights for international researchers and policymakers to safeguard global food supplies in the face of the growing plastic crisis.

Abstract

Understanding how ecosystems respond to ubiquitous microplastic (MP) pollution is crucial for ensuring global food security. Here, we conduct a multiecosystem meta-analysis of 3,286 data points and reveal that MP exposure leads to a global reduction in photosynthesis of 7.05 to 12.12% in terrestrial plants, marine algae, and freshwater algae. These reductions align with those estimated by a constructed machine learning model using current MP pollution levels, showing that MP exposure reduces the chlorophyll content of photoautotrophs by 10.96 to 12.84%. Model estimates based on the identified MP-photosynthesis nexus indicate annual global losses of 4.11 to 13.52% (109.73 to 360.87 MT·y−1) for main crops and 0.31 to 7.24% (147.52 to 3415.11 MT C·y−1) for global aquatic net primary productivity induced by MPs. Under scenarios of efficient plastic mitigation, e.g., a ~13% global reduction in environmental MP levels, the MP-induced photosynthesis losses are estimated to decrease by ~30%, avoiding a global loss of 22.15 to 115.73 MT·y−1 in main crop production and 0.32 to 7.39 MT·y−1 in seafood production. These findings underscore the urgency of integrating plastic mitigation into global hunger and sustainability initiatives.