Air pollution conjures up images of dirty factory smokestacks or crowded traffic-clogged cities. A recent study, however, revealed that one significant source of air pollution in America is actually associated with corn. The researchers found that the fertilizer used to increase crop yields can cause a kind of air pollution called PM2.5 (Particle Matter 2.5 micrometers thick), resulting in negative health impacts for people living nearby.
When farmers buy fertilizer, it often contains nitrogen in the form of the molecule ammonia. Ammonia can escape from the soil into the atmosphere. In the atmosphere, it can catch some particles and form PM2.5. PM2.5 is too big for the human body to break down and remove from the body. However, it is small enough that it finds its way into the small air sacks called alveoli in the bottom of the lungs. The human body can’t easily remove PM2.5 from the lungs, so it stays stuck, causing illness and death. Scientists had already estimated how many people become ill or die from different amounts of PM2.5 air pollution. Using this data, this study determined that air pollution caused by corn production kills 4300 people annually. The health problems caused by this air pollution cost about $39 billion annually.
Fortunately, air pollution caused by corn production can be mitigated. The authors suggest growing corn in regions where less fertilizer is needed, such as Minnesota, Iowa, and Nebraska. Farmers can also switch to fertilizers that provide plants the nitrogen they need without releasing ammonia into the atmosphere. In places where a switch to safer fertilizer is not an option, switching out corn for a crop that requires less fertilizer can also reduce air pollution.
Corresponding Author: Emily Kerr
Popular Press Article: Air pollution caused by corn production increases mortality rate in US
Original Scientific Article: Air-quality-related health damages of maize
Image Credit: Huw Williams, Wikicommons