Animal-based foods are connected to 15,900 annual deaths resulting from small-particle pollution from agriculture, a new study found.
Reducing excess protein in livestock feed and using nitrogen inhibitors and other fertilizer amendments and other techniques in just the 10% of U.S. counties with the highest mitigation potential would save 22% of deaths associated with food production, the scientists found.
Iowa ranked second to Illinois in annual deaths related to small particles (354), second to California in deaths related to ammonia (921), fourth in deaths related to nitrogen oxides (36) and fifth in deaths related to volatile organic compounds (9). Those deaths were associated with Iowa emissions but some could have occurred in another state, the study noted.
Researchers from the University of Minnesota, the University of Oxford in the United Kingdom, and colleagues published the findings in the Proceedings of the National Academy of Sciences of the United States of America.
“Poor air quality is the largest environmental health risk in the United States and worldwide, and agriculture is a major source of air pollution,” the authors wrote.
“We estimate the air quality–related health impacts of agriculture in the United States, finding that 80% of the 15,900 annual deaths that result from food-related fine particulate matter (PM2.5) pollution are attributable to animal-based foods,” the authors wrote.
Particles so small no one can cough them up
The study looked at particles so small people can’t cough them up. They are the same kinds of particles that come from vehicles and power plants. That kind of pollution is often associated with asthma and other lung disorders, cancer and strokes, resulting in thousands of early deaths a year.
The authors found the pollution comes from fertilizing crop ground, tilling the soil, operating machinery and from the animals themselves.
Changes in fertilizer practices and improved livestock waste management could combine with other changes to cut the number of deaths associated with the pollution by 50%, the study found. Of the 15,900 annual deaths related to air pollution from food production, 80% were attributed to animal-based foods, the scientists found.
The deaths were associated with ammonia from manure, dust and equipment emissions. Red meat was far more of a factor than other commodities. On a per-serving basis, red meat’s health toll was two times greater than eggs, three times more than dairy products, seven times greater than poultry, 10 times greater than nuts and seeds and 15 times more than other plant-based foods, the study found.
The researchers examined the production and use of 67 finished food products and 65 agricultural commodities that account for more than 99% of U.S. ag production.
The study calls on consumers to focus on plant-based foods to reduce the impact of animal agriculture.
“Dietary shifts toward more plant-based foods that maintain protein intake and other nutritional needs could reduce agricultural air quality–related mortality by 68% to 83%,” the authors wrote. “In sum, improved livestock and fertilization practices and dietary shifts could greatly decrease the health impacts of agriculture caused by its contribution to reduced air quality.”
Controversy over red meat
Many other studies have made similar comments about red meat consumption, including climate change studies from the United Nations. Some have warned that increased meat-eating in countries that are becoming more affluent will mean more emissions from the animals themselves, vehicles transporting them, and from processing plants and vehicles.
A May 2020 study by the Laboratory of Toxicology and Environmental Health in Catalonia, Spain, said: “Although meat means an important source of nutrients, it is also evident that a great consumption of this source of proteins has also a negative environmental impact. Livestock production does not only have a negative influence on (greenhouse gas) emissions, but also on the water footprint, water pollution, and water scarcity,” the authors wrote. They noted other research associating consumption of red meat with increased cancer risks.
Livestock organizations have questioned studies associating red meat with public health issues. New York University this year reported most large meat and dairy companies have not committed to becoming net-zero carbon operations by 2050. And a 2015 literature review study funded by the National Cattlemen’s Beef Association and the National Pork Board said: “The totality of the epidemiologic evidence on red meat and processed meat, including cooking methods and mutagenic byproducts, are not supportive of causal relationship with cancer.”