Impact of CAFOs on Your Health


Research has proven what individuals have known for years: concentrated animal feeding operations, or CAFOs, are detrimental to the physical and mental health of rural Iowans and factory farm workers. A 2008 report by Pew Commission on Industrial Farm Animal Production sounded the alarm on the unacceptable risks to public health as livestock production moved away from the practice of having animals integrated into a traditional family farm and into the large confinement facilities.1 As more and more animals are confined in these facilities, the adverse health impacts grow as well.

Respiratory illnesses:
Respiratory illnesses top the concerns of anyone in or near a CAFO. Air emissions from the huge quantities of animal wastes generated within these confinement facilities put our most vulnerable citizens – children, the elderly, and anyone with pulmonary or heart disorders – at particular risk. The effects on children are especially concerning. A University of Iowa study found that Iowa children who attended school near a factory farm had a 25% asthma rate compared to only 12% for the control group.2 Furthermore, children living on CAFO sites had a 44% asthma rate, and children living on CAFO sites that use sub-therapeutic drugs had an astounding 56% asthma rate, as reported in another U of I study.3 Other studies have shown that at least one quarter of workers in hog confinements suffer from serious respiratory problems.4 People who live near CAFOs report more respiratory symptoms as well as diarrhea, headaches, and burning eyes than people who did not leave near such facilities.

MRSA and antibiotic resistance: 
By confining large numbers of animals in close quarters, the need for antimicrobial and antibiotic medications grows. Confinement owners for years have administered these drugs in sub-therapeutic levels to increase growth rates and to avoid disease.5 These are the same antibiotics that are used to treat humans, so the overuse that leads to drug resistance is especially dangerous to people.

The antibiotic-resistant MRSA bacteria is potentially deadly. Neighbors living within one mile of a CAFO holding 2,500 or more hogs had a 2.76% greater chance of carrying the MRSA bacteria.6 A study from John Hopkins found that workers in hog confinements carried livestock-associated bacteria in their noses. The study found that many of these bacteria were antibiotic resistant, and that the bacteria stayed in the workers’ noses for much longer than expected, posing risks to the community.7

The Obama administration has called for the reduced use of these drugs, but the use continues and so does the risk. These drugs are not simply absorbed by the animal – traces of antibiotics are in the manure that gets spread on fields, leaving antibiotic resistant genes in the soil.8 The manure spread on crop land spreads the dangers across the landscape. A Johns Hopkins Bloomberg School of Public Health study found 11% of MRSA and soft tissue infections in individuals were linked to living next to fields where swine manure was applied.9

Mental and emotional health and community health: 
Working in or living near confinement facilities can be extremely stressful and lead to physical and mental symptoms. Odors from CAFOs and from their manure, even at low concentrations, lead to gastrointestinal, stress-related, and respiratory symptoms. The toxins from air emissions, particularly hydrogen sulfide, also affect the neurological health of people, and have been shown to lead to confusion, tension, depression, and fatigue.

Quality of life decreases when a CAFO is nearby, with symptoms similar to Post-Traumatic Stress Disorder.10 When the fight against a new or expanding hog confinement pits neighbor against neighbor, the social fabric of a community is torn. Animosity and anger pervade a once-cohesive rural area. It is often those residents with the least political influence and those with the lowest-income who are most susceptible to the negative effects of a nearby CAFO. 12

Benefits of traditional farm practices:
The health impacts of CAFOs to workers, neighbors, and rural communities are in stark contrast to the benefits of traditional farms. Many epidemiological studies have shown that children who grow up on traditional farms – with animals raised traditionally on pasture – are protected from asthma, hay fever, and allergic sensitization.11 Finally, the connection that children and adults make with farm animals leads to increased empathy, compassion, and well-being – a benefit to us all.

Unacceptable risks: 1

Children and asthma attending school near a CAFO: 2

Study of children and asthma: 3

Statistics and references: 4

Sub-therapeutic antimicrobial use in hogs: 5


Research on hog workers and MRSA: 7

Antibiotic resistance: 8

MRSA on crop land: 9

Post-traumatic stress: 10

Community health, socioeconomic issues: 11

Benefits of traditional farms: 12

Additional resources:

Opinion of researchers at John Hopkins: linked from:

Impacts of CAFOs on Your Health used with permission from the Iowa Alliance for Responsible Agriculture