In 1996, Steve Wing, an epidemiologist at the University of North Carolina, was among the first to provide evidence of harm to poor people of color from airborne chemical and pathogen-laden emissions. Wing’s focus was on affected populations that lived near industrial-scale hog farm lagoons, considered among the most polluting industrial operations in the world. Recently, the first comprehensive assessment of deaths in the United States from airborne agricultural pollutants was published in the Proceedings of the National Academy of Sciences, providing strong vindication of the work of Wing and his colleagues.

According to the study, of a total of 17,900 deaths traced in one way or another to U.S. agriculture each year, about 80 percent are attributed to airborne contaminants from large-scale animal farms. Emissions from animal factory farms, known as confined animal feeding operations, or CAFOs, account for more annual deaths than pollution from coal power plants. One out of every four of these deaths is from pork feeding operations, which generate billions of gallons of wastes, largely dumped directly in open lagoons and then sprayed on farmland. Much as humans do, the hogs expel large amounts of bacteria-laden pathogens, hydrogen sulfide, and ammonia.

A typical CAFO holds thousands of hogs in close confinement, in cells just large enough for the animals to stand. They receive their feed by conveyor belt, along with antibiotics to stem infections and stimulate growth. In southeastern counties in North Carolina, about 10 billion gallons of fecal wastes are dumped directly from the animal cages into the lagoons each year. Fecal wastes discarded directly into the environment, from two of the North Carolina counties with the largest number of hogs, were found to be roughly equivalent in volume to the amount of waste sent annually to sewage treatment plants by the cities of Boston and Detroit.

However, unlike sewage treatment plants in the United States, hog CAFOs and their waste disposal practices are not subject to any form of federal regulation aimed at protecting public health and the environment.

After anaerobic digestion—in which bacteria breaks down the waste matter—the wastes are sprayed over agricultural fields. Based on geospatial data, the Environmental Working Group reports that more than 250,000 homes in North Carolina are within three miles of a CAFO.

Any time there is a heavy rain, runoff from the sprayed fields tends to occur. Several dozen North Carolina hog farms are located on a 100-year flood plain, in two counties with largely Black and low-income communities. In 2016, Hurricane Florence caused hundreds of fecal-laden waste lagoons to fail, contaminating the land and wells of nearby residential areas, in addition to several rivers and tributaries.

After attending several community meetings held by local citizen activists in the mid-1990s, Wing decided to document these problems in collaboration with the people who were affected most. Over the previous decade, the adoption of CAFOs had led to an exponential increase in the numbers of hogs in the state, along with a commensurate growth in largely uncontrolled waste disposal practices.

Soon people living near these concentrated industrial swine operations began to speak out and organize to stem the risks to their lives and homes. In the time-honored tradition of public health research, Steve began to undertake “doorstep epidemiology,” in which he attended citizen meetings and visited numerous homes near the hog CAFOs. Wing was not only seeking to document public health problems, he also wanted to help empower a movement to end environmental and racial injustice.

Eventually, in a study described as “ground-breaking in its design and scientific assessment,” Wing enlisted more than 100 people from 16 communities within 1.5 miles of a hog CAFO to help operate real-time air- and weather-monitoring equipment and to rate the noxious odor outside their homes. Respiratory symptoms, lung function, and blood pressure test results were also documented.

Over several years, Wing and his colleagues compiled a large body of data indicating that emissions from open lagoons and field spraying were harmful to nearby residents. Increases in blood pressure, asthmatic symptoms in children, headaches, diarrhea, and upper respiratory problems were documented. Odors described as being “like the smell of rotting corpses” were so strong and pervasive that residents could not venture outside of their homes for days on end. Wing and his colleagues reported communities of color were twice as likely to be impacted by health problems associated with the toxic fecal wastes in the air.

By 1999, the North Carolina Pork Council, dominated by corporations such as the Chinese-owned Smithfield Foods, which owns one of the world’s largest pork slaughterhouses in North Carolina, forced Wing to provide his research records, after threatening to sue. Steve successfully refused to comply with the demand for personal identifiers of nearby residents who cooperated in the study. Not only would this have violated personal privacy protections, but it could also expose the people in the study to harassment and intimidation.

This heavy-handed effort by the pork industry did not prevent Steve’s research from helping residents living near the CAFOs to obtain some measure of accountability in the courtroom. By 2019, several lawsuits filed against a Smithfield subsidiary responsible for managing the factory hog farms resulted in hundreds of millions of dollars awarded to dozens of residents. Pork corporations tried to muzzle Steve, but in the end they could only convince UNC to take away his parking space.

True to form, Smithfield and its allies in the North Carolina legislature have all but thwarted further multimillion-dollar lawsuits. According to court records, Smithfield’s Chinese parent company makes about $2 billion per year in profits.

Steve Wing passed away, at age 64, in 2016. That year, in his last published paper, Steve concluded: “By joining movements for human rights and social justice, health scientists can identify research questions that are relevant to public health, develop methods that are appropriate to answering those questions, and contribute to efforts to reduce health inequalities.”

His contributions to public health and environmental justice endure and grow in importance.

A senior scholar at the Institute for Policy Studies, Robert Alvarez served as senior policy adviser to the Energy Department’s secretary and deputy assistant secretary for national security and the environment from 1993 to 1999.