Indirect health effects of food consumption and trade via worsening of particulate matter air quality in China and worldwide

Modernized farming to meet the global food demands have led to a cascade of severe environmental threats. Excessive application of chemical fertilizer has led to large releases of reactive nitrogen compounds into the atmosphere, where they contribute to climate change and become major components of fine particulate matter (PM2.5) pollution with severe human health impacts. Here we first examined how the changing food consumption patterns from early 1980s to 2010s of the Chinese population could contribute to an indirect health risk via the worsening of PM2.5 air quality in China. We integrated historical food production and consumption data with the GEOS-Chem chemical transport model to perform model experiments, and found that ~30% of the total PM2.5 increases in China over the past 30 years could have been driven by increased agricultural production, among which ~20% is driven by heavier meat consumption and the other ~10% by both population rise and enhanced food crop consumption. Of the ~2 million Chinese premature deaths related to PM2.5 in 2010, ~10% are related to changes in dietary habits from early 1980s to 2010s, representing a significant dietary health risk that arises from collective meat consumption. We further examined how food demands from the Chinese population and eight other major food-producing countries affect their own and other countries air pollution via food trade. In 2014 alone, Chinese food production to feed the domestic food demand contributes significantly (1030%) to PM2.5 pollution in China, among which roughly half is driven by the meat and feed crop consumption. We also found that food import from other countries to China is generally not a major contributor to PM2.5 pollution in the exporting countries (e.g., <1%). Our study highlights the significance of food consumption and trade in shaping PM2.5 pollution in China and worldwide, and it is important to incorporate sustainable food consumption and trading strategies to safeguard the health of citizens and also global food security.