Farming-related pollution leads to nearly 18,000 deaths a year in the U.S., according to a new study published Monday.

Reduced air quality from the agriculture industry results in 17,900 deaths annually, with ammonia accounting for 69 percent of those deaths, researchers wrote in the study published in the Proceedings of the National Academy of Sciences.

Many of the deaths occurred in California, North Carolina, Pennsylvania and the upper Midwest Corn Belt, researchers found, noting that about 80 percent of the deaths are related to pollution from animal agriculture. Such pollutants are much more loosely restricted under the Clean Air Act than comparable pollutants from sources such as vehicles and factories.

“We find that improvements in agricultural production, such as changing livestock feed practices to reduce the amount of excess protein ingested and therefore excreted as nitrogen, or using fertilizer amendments and inhibitors, can greatly reduce air quality–related health damages,” the study’s conclusion stated. “Implementing measures to reduce agricultural emissions across all producers could prevent 7,900 deaths per year (50% of total deaths from food production).”

Researchers wrote that the most substantial benefits could come from altering livestock waste management and fertilizer application procedures, projecting that 3,600 deaths a year could be prevented by producer-side interventions in only the top 10 percent of counties with high death rates from pollution.

The study also makes recommendations for demand-side interventions that could reduce risks, particularly reduced consumption of meat. Substitution of poultry in place of red meat could prevent more than 6,000 deaths a year, according to the study.

Environmentalists and sustainability advocates have frequently pointed to meat production as a major source of greenhouse gas emissions, with Microsoft founder Bill Gates saying in February that “all rich countries should move to 100% synthetic beef.”

Researchers in the report published Monday wrote, “Many of the food production solutions that could reduce air quality–related health damages, such as improving nitrogen use efficiency in crop and livestock production, or decreasing food loss and waste, are likely accompanied by other environmental benefits, such as decreasing greenhouse gas emissions, nutrient pollution, and undesirable land-use change.”

Farms’ air pollution contributes to almost 18K deaths in US annually: study | TheHill