Hog farms might be nauseating, but a new study indicates that hog farm emissions, which include dust, irritants, allergens, hydrogen sulfides, ammonia, and other volatile compounds, could have an impact on the health of the people living nearby. Neighbors of such farms experience a rise in blood pressure when the odor of the farm is strong.
The scientists published their findings in the journal Environmental Health Perspectives. Concentrated animal feeding operations (CAFOs) have a number of measurable impacts on the environment, mostly from the massive quantities of manure that they produce. That waste contains microbes that can make humans sick, and it’s usually collected in open pits or sprayed on fields as fertilizer, risking the contamination of air, water, and soil.
The smell is also problematic, as the staggering stench has shown negative effects on stress and moods. Steve Wing, an epidemiologist at the University of North Carolina, Chapel Hill, sought to figure out if there was a link between the odors from CAFOs and some of these symptoms.
Using mobile monitoring equipment, the researchers measured the air quality of neighborhoods adjacent to hog CAFOs in North Carolina. Participating residents sat outside their houses for two 10-minute periods each day, reporting on the strength of the swine odor on a graded scale. Their blood pressure was also taken with an automated device.
Stronger odors and higher measured hydrogen sulfide concentrations correlated to higher blood pressure in residents. The most dramatic effects were nearly a 2 mmHg rise in diastolic blood pressure when the odor was rated 8/8 compared to no odor. This also gave a 3mmHg rise in systolic blood pressure when hydrogen sulfide concentrations reached 10 parts per billion compared to no detectable levels.
Wing suspects that the residents’ lack of control over the odor might account for the rise in blood pressure. There is no way of avoiding the smell wafting from a giant hog farm.
Reference: “Air Pollution from Industrial Swine Operations and Blood Pressure of Neighboring Residents” by Steve Wing, Rachel Avery Horton and Kathryn M. Rose, 1 January 2013, Environmental Health Perspectives.