According to research published in the journal Environmental Health Perspectives
, residents living near animal farms, particularly those where pigs are reared, have higher levels of blood pressure compared with the wider population who do not live near such farms (when all other social and environmental factors have been taken into account).
The research, summarized by ScienceNOW
, indicated that the rise in blood pressure (hypertension) is triggered by the dust, allergens, ammonia, and hundreds of other volatile organic compounds that emanate into the atmosphere from animal farms.
According to Wired
, the research was based on studies carried out in North Carolina (where there are apparently more hogs than people) looking at large-scale concentrated animal feeding operations or industrial-sized pig farms.
For the study, participants sat outside their homes for 10 minutes, twice a day, noting the strength of the stench on a scale from 0 to 8. Researchers also measured the atmosphere chemically. The blood pressure of the study participants was also measured. The results revealed that both higher hydrogen sulfide concentrations and strong odors were linked to higher blood pressure.
Whether the increase in blood pressure is dangerous, however, was not explained in the study. Nonetheless, there may be health issues in relation to living in close proximity to hog farms. Previous research (American Journal of Public Health
) in North Carolina found that farm odor caused stress and negative mood states in neighboring residents.