Operating pesticide use reduction within the boundary of food security in peri-urban settings

Pesticide use in peri-urban areas afects the urban enviroment and public health,and reducing the use may present food security isues for urban dwellers.In this study,we explore how a muiallyadopted goal of a 20%reduetion in pesticide use could be achieved,along with local food security and environmental implica-tions,for Shanghai located in the densely populated East China.A regional Shanghai Agricultural Sector Model inorporating district-and technology-varying crop budgets,was developed to simulate the efects of pesticide reduction policy.Here we find that achieving the reduction goal had the largest implications in districts with high pesticide use totals and intensities,potentially reducing pesticide non point source pollution in the Yangtze River Estuary and Dianshan Lake;the production levels of rice and leafy vegetables would be most afected;and adopting machinery that allows more precise pesticide application modulates these results.Moreover,imposing the requlrements at the district-level caused more severe local food security concerns,and less environmental benefits.Furthermore,a closed Shanghai's agricultural economy would subtantally enlarge the regional het-erogeneity in the above-mentioaned outcomes.Exploring the ffects of a quantity control policy on current-use pesticides at diferent aggregation levels has important implications for regulating the use of agrochemicals.