The American Public Health Association (APHA), the largest organization of public health professionals in the world, recently issued a policy statement seeking a moratorium on new Concentrated Animal Feeding Operations (CAFOs). And, the Washington, D.C., advocacy group wants federal and state governments to support more research to more precisely quantify exposures to pollutants in the air, water and soil by communities surrounding CAFOs.
CAFOs are, as defined by U.S. Environmental Protection Agency (EPA), facilities with more than 1,000 beef cattle, 2,500 hogs or 100,000 broiler hens.
Here are some of the risks outlined in the resolution approved by the Association's governing council during its 131st annual meeting in San Francisco.
- Increased numbers of CAFOs in an area often are associated with declines in local economic and social indicators.
- CAFO-generated manure has constituents and byproducts of health concern including heavy metals, antibiotics, pathogen bacteria, nitrogen and phosphorus, plus dust, mold, bacterial endotoxins and volatile gases.
- The manure is typically stored in open or covered pits or lagoons and later spread or sprayed untreated on nearby cropland, posing additional risks to public health.
- Manure pathogens capable of causing severe gastrointestinal disease and sometimes death in humans include Campylobacter and Salmonella species and Listeria monocytogenes, Helicobacter pylori, E. coli O157:H7, and the protozoa Cryptosporidium.
- An emerging scientific consensus is that antibiotics given to food animals contribute to antibiotic resistance transmitted to humans. Antibiotics, as well as arsenic and other metal compounds are routinely added to the feeds of concentrated animals absent any diagnosed illness - to promote growth and to compensate for the stress of raising animals under confinement - increasing the risks from antibiotic resistance.
- Routine, non-therapeutic animal uses account for an estimated 13 million pounds of antibiotics annually, most being identical or very similar to human medicines, as compared to 3 million pounds of antibiotics prescribed for humans.
- An estimated 25 to 75% of feed antibiotics pass unchanged into land-applied manure, posing additional risks to soil, water and air quality. Pig house dust, in a recent study, was found to contain total antibiotics at a concentration of up to 12.5 mg/kg dust with up to five separate compounds, including tylosin, tetracyclines, sulfamethazine, and chloramphenicol.
- CAFO manure generates gases of up to 400 volatile compounds, such as ammonia and hydrogen sulfide, many of which are known airway irritants, allergens or respiratory hazards. Numerous studies document serious respiratory problems among CAFO workers, including chronic bronchitis and non-allergic asthma in about 25% of confinement swine workers.
- Workers exposed to the potent neurotoxin hydrogen sulfide at levels only slightly higher than those at which its odor becomes detectable (5.0 ppm vs .025 ppm), have been found to have accelerated deterioration of neurobehavioral function. Scientists convened first by the Centers for Disease Control and Prevention (CDC), and more recently by the University of Iowa and Iowa State University, agree CAFO air emissions may constitute a hazard to public health, in addition to workersâ€™ health.
Moratoria on new CAFO construction already have been called for by the Michigan State Medical Society and the Canadian Medical Association. They cite existing scientific evidence of threats to worker health and public health, and insufficient data on whether those facing the risks are adequately protected.
The APHA statement also notes that "public health decisions must often be made in the absence of scientific certainty, or in the absence of perfect information" to prevent potential harm to reproductive health, infants and children. It also noted that CAFO emissions may contribute to children suffering disproportionately from asthma. Fetuses, infants and children also are more vulnerable to adverse impacts from bacterial and antimicrobial-resistant infections, and neurotoxin exposure.