North-to-south transfer of grain and meat products significantly reduces PM2.5 pollution and associated health risk in China

Population and agricultural resource distribution disparities drive the multidimensional challenge of ensuring food security, especially in large and diverse nations like China. Agricultural practices and trade patterns have profound implications not only for national food security but also for global environmental and health outcomes. Although regional agricultural trade has great potential to alleviate food supply pressures, little is known about the environmental and health consequences of agricultural trade on a national scale in China. This study firstly estimated ammonia (NH₃) emissions, a precursor of PM${}_{\mathrm{2.5}}$, driven by interprovincial grain and meat trade (GMT) for 2017 in mainland China. Then, PM${}_{\mathrm{2.5}}$ pollution and associated health risks induced by GTM were simulated using a coupled meteorology atmospheric chemistry model and integrated exposure–response model. We found that approximately 30% of NH₃ emissions from grain and meat production were trade-related, demonstrating a dramatic virtual transfer from Northern China to Southern China. Interprovincial GMT dramatically reduced PM${}_{\mathrm{2.5}}$ levels and the associated health burden in Southern China, but enhanced in Northern China. Given higher population intensity and reduced PM${}_{\mathrm{2.5}}$ levels in Southern China, interprovincial GMT was estimated to avoid 4,851 (95% confidence interval: 3,444–5,870) premature deaths in China in 2017. Our results illustrate the need for rethinking trade patterns for optimality to minimize the mixed impacts of the GWT on the environment, human health, and food security, and to provide supports to the development of more effective policies to achieve these goals.