They linger in the air we breathe and measure barely a fraction of the diameter of a human hair
. But despite their small size
, the particles have been linked to millions of premature deaths globally
, 及び serious cardiovascular and respiratory problems, especially in children and the elderly
PM2.5 particles kicked up into the air by tilling and fuel combustion in farm equipment are part of the problem, but the study found the majority of premature deaths are linked to ammonia emissions from livestock waste and fertilizer. Airborne ammonia reacts with other chemicals to form dangerous particulate matter.
“(It happens) mostly through ammonia, which is released when farmers use nitrogen fertilizer — which they use a lot of — or is released from animal manure,” said Jason Hill, a professor at the University of MInnesota and a co-author of the study.
The premature deaths connected to pollution from agriculture are heavily concentrated in California, ペンシルベニア, ノースカロライナ州, and along the Upper Midwest’s Corn Belt, the study found.
The researchers identified ways that both consumers and farmers can help reduce this type of pollution.
Eating less red meat and shifting toward plant-based diets could have huge health benefits, the study shows.
The study found that substituting poultry for red meat could prevent roughly 6,300 of the annual deaths tied to farming air pollution, and even larger reductions of 10,700 に 13,100 deaths could be achieved each year with large-scale shifts toward vegetarian, vegan, or flexitarian diets.
“It’s probably healthy for them (to switch) and healthy for other people, because other people are not breathing polluted air,” said Julian Marshall, another co-author of the study and a professor of environmental engineering at the University of Washington.
The study points to a few ways for farmers to cut down on the production of ammonia. Using fertilizer more precisely in order to maximize crop production can help. Farmers can also reduce the amount of ammonia produced from manure by covering animal waste and injecting manure into fields instead of spraying it.
Ian Faloona, an associate professor at the University of California-Davis, who published a study in 2018 on agriculture’s production of nitrogen oxides — another type of air pollution — said that making these changes can also be good for farmers’ bottom lines.
“最終的には, it’s going to be cost effective because you’re making the process more efficient,” Faloona said.
A spokesperson from the American Farm Bureau Federation questioned the study’s results.
“On first review, it seems filled with data gaps and giant leaps to stretch the definition of cause and effect,” 広報担当者は言った. “US agriculture is continually doing more using fewer natural resources and we’re proud of that progress.”
Hill said that he hopes that the report will show consumers and farmers alike that there are ways to reduce this problem.
“That’s the message of hope here — that we can actually do something about this,” ヒルは言った.