A new study published on 1 April in Nature Sustainability estimates that air pollution from corn production results in 4,300 premature deaths annually in the United States (1). By performing a cost-benefit analysis, the researchers from the University of Minnesota discovered that the total health cost associated with corn production equates to nearly two-thirds the market value.
For the first time, the health damages associated with producing this staple crop were assessed. The team of researchers, led by Prof Jason Hill from the University of Minnesota’s College of Food, Agricultural and Natural Resource Sciences, collected data on pollution emissions, pollution transport by wind, and human exposure to increased air pollution levels to estimate the health damages associated with corn production.
Costs of corn production
Corn production is a major contributor to premature mortality from reduced air quality, mainly owing to fertiliser use. Nitrogen fertilisers increase concentrations of fine particulate matter in the atmosphere, specifically, ammonia, which damages human health.
Based on estimates, the total health costs associated with corn production total $39 billion (nearly €39 billion) per year. In addition, the total climate change damages ― based on greenhouse gas emissions of corn production ― are equal to $4.9 billion (around €4.4 billion) per annum.
Health damages varied regionally ― death tolls were lower in the Western corn belt, including Minnesota, Iowa, and Nebraska, compared to the Eastern states. In some regions, the cost of damages even exceeded the market price.
Higher-than-average impacts were due to the closer proximity of farms to highly populated urban centres; lower yields; use of animal manures, which result in higher ammonia emissions compared to synthetic fertilizers.
Agriculture is essential as it provides food to feed the growing population, but farming practices are associated with major environmental and health costs. Growing crops contributes to climate change, causes water pollution, and reduces air quality.
How to reduce the health impact of corn production
The human health impacts of maize production could be reduced by minimising fertiliser use, improving nitrogen use efficiency, and changing the locations where the corn is grown. The authors also suggest incentives for farmers focused on rewarding good practices like switching to less fertiliser-intensive crops.
Furthermore, precision agriculture ― instead of harmful nitrogen-based fertilizers ― could be used to achieve targeted emissions reductions in regions with low production efficiency.
Ensuring a sustainable future
Corn, or maize, is a dominant crop in the US but is also the most geographically widespread crop on the planet ― used for animal feed, biofuels, and human consumption.
Therefore, although the study was confined to the US corn belt, the findings suggest that perhaps further assessment of the global health and environmental costs of corn production is merited.
The authors write, “understanding the current environmental effects of agriculture, and linking them to dietary choices, is a critical challenge for the coming century.” Put simply, finding ways to reduce the health and environmental burden by changing our diets and optimising farming practices will be a challenging yet critical step towards a more sustainable future.
(1) Hill, J. et al. Air-quality-related health damages of maize. Nature Sustainability (2019) DOI: 10.1038/s41893-019-0261-y