Livestock Air Pollution From Farms Affects Lung Function

Livestock Air Pollution Associated With Lower Lung Function

Background: Inhaling air pollutants can contribute to breathing difficulty due to redness and swelling (inflammation) in the airways and can cause flare-ups (exacerbations) in those with COPD. (See posts on April 23, 2017, describing the State of Air Pollution in the United States AND on August 29, 2016, describing the association of air pollution and COPD-related hospital admissions). Farm workers are at increased risk of both asthma and COPD. Why? The air inside livestock farms contains high levels of organic dust. In addition, farm animals emit air pollutants. One of these is ammonia gas – an irritant gas formed by enzymes in animal waste. Other pollutants are hydrogen sulfide gas (smells like “rotten eggs”) and particulate matter (solid particles and liquid droplets found in the air) that contain bacteria and toxins.
Cows are one source of livestock air pollution

Dairy cows grazing

Study: Dr. Floor Borlee and colleagues from Utrecht University in the Netherlands studied whether people living close to farms were at risk for lung disease. They performed breathing tests on 2,308 adults and measured the number of farms within a certain distance from their homes (546 and 1,092 yards), the distance to the nearest farm, and estimated the average air pollution from these farms. This study was published in the November 1, 2017, issue of the American Journal of Respiratory and Critical Care Medicine (volume 196; pages 1152-1161).

The Netherlands has borders on the North Sea, Belgium, and Germany

The Netherlands is a small country with a large number of residents for size (high population density). It also has one of the highest number of livestock farms for size (high livestock farm density). Those living near the farms have been concerned about the potential health risks of inhaling farm emissions. Results: Average weekly levels of ammonia and particulate matter were
Pigs are a source of livestock air pollution


associated with lower levels of breathing test results – namely, the amount of air exhaled in one second (FEV1) and air flow exhaled from small airways (breathing test is called maximum mid-expiratory flow).  Ammonia levels had a stronger association than particulate matter. Conclusion: The authors concluded that livestock air pollution is associated with lower lung function in non-farming residents. They recommended further research into the impact of emissions from livestock farms on respiratory health of those with respiratory disease. My Comments: The results of this study demonstrate that farms and farm animals are a unique source of air pollution in addition to factories and automobiles.


As I have mentioned previously, if you have COPD, it is important that you not smoke and that you avoid inhaling “bad air” that contains pollutants. Obviously, you cannot live in a bubble. But, I encourage you to breathe the cleanest air possible and do what you can to reduce air pollution.

Donald A. Mahler, M.D. is Emeritus Professor of Medicine at Geisel School of Medicine at Dartmouth in Hanover, New Hampshire. He works as a pulmonary physician at Valley Regional Hospital in Claremont, NH, where he is Director of Respiratory Services.