Human Health Impacts of Factory Farming

The management and welfare of animals raised for food directly impacts human health. Intensive farming operations or “factory farms,” which may house tens of thousands of animals in close quarters, serve as ideal incubators for disease. Several major human health concerns are associated with intensive farming, including: increased transfer of infectious agents from animals to humans, antibiotic resistance, food-borne illness, and the generation of novel viruses.

Human Health Impacts of Factory FarmingThe sheer number of animals raised within confinement operations increases the transmission of infectious agents within flocks and herds and, by extension, between animals and human workers. Confinement-induced stress may also increase the frequency of illness and the shedding of viruses and bacteria, and intensive farming facilitates the generation of novel viruses like H1N1 (swine flu) in pigs.

Antibiotic resistance, stemming from the use of antibiotics to promote growth and suppress disease within confinement operations, presents a serious health concern. The low-level dosing of livestock and poultry with antibiotics that are identical or related to drugs used in human medicine has contributed to the spread of multidrug-resistant infections in humans. The Centers for Disease Control (CDC) estimates that each year two million people in the United States contract antibiotic-resistant infections. CDC has also confirmed a link between the routine use of antibiotics in farm animals and the growing problem of antibiotic-resistant bacteria, which is responsible for the deaths of at least 23,000 Americans each year.

Animal and manure management on confinement operations, animal transport, and meat processing can also contribute to food contamination and food-borne illness like E. coli and Salmonella. A 2013 study by Johns Hopkins Bloomberg School of Public Health found an association between living near high-density pig operations, or crop fields fertilized with manure from high-density pig operations, and methicillin-resistant Staphylococcus aureus, commonly referred to as “MRSA.”