Air pollution is an invisible killer. In the United States alone, nearly 100,000 people die prematurely every year from fine airborne particles that can damage lungs and contribute to cardiovascular disease, cancer, and stroke. Agricultural production is responsible for nearly one-fifth of those deaths. But how certain foods — and by extension, certain diets — impact air quality hasn’t been well-studied.

Research has made significant strides in connecting the dots between the emissions associated with 99% of all U.S. agricultural products and premature deaths in the lower 48 states. These insights create opportunities for producer-side and consumer-side alterations that could significantly reduce air pollution, potentially saving thousands of lives.

In this study, scientists used various sources of data from the U.S. Environmental Protection Agency and the U.S. Department of Agriculture to categorize the type and amount of agricultural air pollution and its location down to the county level. They placed emissions into two categories:

• farmed animal production, which includes dust kicked up by animals and waste created from confining, handling, and storing animals used for food
• crop production, which includes making and applying fertilizer, tilling the ground, running farm equipment, burning fields, and applying pesticides

The data was then used to evaluate a range of emissions scenarios via three different air quality computer models. These models were designed to estimate increases in specific agricultural emissions, where the emissions originated, and how many people died prematurely as a result.

The Damage Done

The results were staggering, revealing the significant impact of farming on air quality. The study found that agricultural production in the United States results in about 17,900 annual air quality-related deaths, 15,900 (89%) of which are from food production. This outcome costs U.S. taxpayers and the healthcare system $159 billion a year.

Of the 15,900 food production-related premature deaths, 80% are linked to the air pollution generated by raising animals used for food and growing the crops to feed them. Crops grown for human consumption result in 3,200 premature deaths, or approximately 20%.

When the researchers analyzed 11 different food groups based on serving size, protein mass, and caloric value, they found that red meat contributed the most to air quality-related health damage. Vegetables, beans, and peas did the least. Ammonia — which comes from farmed animal waste and crop fertilizers — was the leading cause of agriculture air quality-related deaths, responsible for 12,400 (or 78%) deaths annually. Dust from several sources, including tilling, burning, fuel combustion, and animal movement, caused 4,800 deaths.

It’s important to point out that of the 3,108 counties examined for this study, farming in just 308 of them resulted in 8,400 deaths — nearly half of all annual deaths calculated. Those counties are mainly located in California, Pennsylvania, North Carolina, and the region known as the “Upper Midwest Corn Belt.”

Life-Saving Interventions

Where there are challenges, there are often opportunities. The researchers conducted a review of previously published studies to uncover several effective methods for reducing emissions.

Food producers could:

• limit excess protein in farmed animal diets to reduce harmful waste
• adopt new fertilizer practices to better regulate nitrogen and ammonia levels naturally
• and plant trees around confinement facilities

Strategies for consumers include:

• substituting farmed birds for red meat
• shifting to a vegetarian, vegan, or flexitarian diet

When these interventions were modeled, the researchers found that reducing farm-based emissions across all producers could prevent 7,900 deaths per year, or 50% of total deaths from food production. If interventions focused solely on the 308 counties in California, Pennsylvania, North Carolina, and the Upper Midwest Corn Belt, 3,600 people could be saved annually. Additional strategies, such as reducing overeating, could save 700 to 1,200 people a year. The biggest impact came from shifting to a vegetarian, vegan, or flexitarian diet, which the authors claim could save between 10,700 and 13,100 people annually.

Advocacy Takeaways

For organizations that oppose factory farming, advocate for farmed animals, and support shifts to veganism and vegetarianism, this research provides substantial evidence for the link between food production and health-harming air quality. Although the health damages are similar to those caused by electricity production or gas-powered vehicles, food production remains less regulated. From environmental and agricultural policies that prioritize clean air to movements that encourage a shift away from animal-based foods, change will need to come from multiple directions to start saving lives.

Note: This research was funded by the U.S. Environmental Protection Agency, the Wellcome Trust, Our Planet, Our Health (Livestock, Environment, and People-LEAP), and the U.S. Department of Agriculture.