The Concentrated Animal Feeding Controversy
A Question of Sound Science
Concentrated animal feeding operations are controversial. This is one thing on which the proponents and opponents of CAFOs agree. The proponents blame the controversy on their opponents, labeling them as uniformed and irrational. They demand that “sound science” be used as the basis for all public decisions regarding regulation of CAFOs, not opinions and emotions. They point to the support of CAFOs by the USDA, state departments of agriculture, and agricultural universities as clear and compelling evidence that science has validated their legitimacy. Proponents dismiss persistent opposition of people in virtually every community where CAFOs are already commonplace, or want to locate, as the irrational fears of people who have been misinformed by environmental extremists.
CAFO opponents counter with studies from prestigious academic institutions and reports commissioned by various government agencies documenting serious health and environmental risks associated with CAFOs. They accuse agricultural scientists of being biased in favor of corporate agribusiness, as being more concerned about the industry of agriculture than the well-being of rural people. They claim their concerns, in fact, are based on sound science.
Obviously, scientists do not agree on the CAFO issue. So, whose science is “sound science?” To resolve the question, we need to start by understanding there isn't a single sound approach to doing scientific research or interpreting the significance of research results. The appropriate research methods and the interpretations depend on the question addressed. In fact, there is sound science on both sides of the CAFO controversy. The controversy arises from differences of opinion regarding the question to be answered and thus the appropriate research methods and interpretations.
CAFO proponents want to restrict the question to asking whether CAFOs can be designed, constructed, and operated in ways that will not threaten the health and well-being of rural people. They want to restrict the interpretation of significance to studies that produce statistically valid conclusions regarding identifiable causes of specific environment and human health effects. CAFO opponents want to expand the question to include whether CAFOs are actually designed, constructed, or operated in ways that pose significant risks to public health and the natural environment. They want to expand the interpretation of significance to include systematic scientific observations of the human health and environmental consequences of living next door to, downwind or downstream from, or in the same community with CAFOs.
The proponents' question of whether “socially responsible” CAFOs are technically feasible requires an engineering approach to science. A waste management system is designed, a prototype is built and tested under various simulated real-world conditions, and if the system seems to work, it is recommended for general use by CAFO operators. The simulations or test trials must be carried out under highly controlled conditions in order to evaluate the effectiveness of alternative components or aspects of the system. This approach is similar to the development of a new drug, where the drug is formulated, tested on animals, tested on humans, and if the drug is found to be safe and effective, it is approved for general use. The drug tests are carried out under highly controlled conditions in an attempt to isolate the specific effects and side effects of the drug.
CAFO opponents', on the other hand, question whether CAFOs are actually operated in a “socially responsible” manner, which requires a very different research approach. To answer this question, the natural environment – air, water, soil – potentially impacted by CAFOs must be tested to detect the presence and determine the concentration of various biological and chemical substances that represent risks to human health. Assessments of the health of people working in CAFOs and living in impacted areas provide scientific evidence as to whether actual illness or diseases have resulted from the health risks.
This latter approach is common to public health research and most of this type of research related to CAFOs has been carried out by medical schools and other public health organizations. It is similar to the follow up research that is now strongly recommended for all drugs with known potential side effects. Even though a drug has been approved for general use, its use can have dangerous and even fatal consequences for a significant segment of the general population. For example, the painkiller Viox was approved for general use but later had to be pulled from the market. The basic argument in support of public health research is that we shouldn't have to wait for people to die before we admit a mistake was made in approving a produce for general use.
Most opponents don't argue that it is impossible to design, construct, and operate a “socially responsible” CAFO; they argue that a large and growing body of scientific evidence shows that CAFOs in general have not operated in a “socially responsible” manner. They argue that sound science confirms that CAFOs represent a significant risk to public health and the environment, and thus, should be carefully regulated to minimize, if not eliminate, those risks. So the controversy boils down to conflicts over the validity and interpretation of public health research.
Those who deny the existence of
sound science indicating significant human health risks are either completely
misinformed or have a concept of science that is simply too narrow to address
the actual health risks of CAFOs. The
science of statistically verifiable causes and effects has its place, but it is
fundamentally incapable of addressing the complex real-world questions of
environmental health. For example, the health risks associated with tobacco
smoking were not proven in the laboratory, they were determined by assessing
the health of thousands of tobacco smokers. It took more than twenty years of
public health research to overcome the political propaganda of the tobacco
companies who denied any scientific proof of the linking between tobacco
smoking and health. A recent
Some CAFO proponents admit the legitimacy of public health research but argue that the scientific evidence linking CAFOs to health risks is “not conclusive.” They admit that various scientific studies have found compelling evidence of health risks but point to other studies that have found no significant evidence linking CAFOs to specific health risks. For example, a 2004 Government Accounting office (GAO) report concluded, “Antibiotic-resistant bacteria have been transferred from animals to humans, and many of the studies we reviewed found that this transference poses significant risks for human health.” The USDA responded to the draft report by suggesting that the conclusions of existing research on the issue was not conclusive, and suggested that the GAO include more studies that questioned the significance of the linkage of antibiotic resistance to CAFOs. The GAO responded, “We found that only a few studies have concluded that the risk is minimal, while many studies have concluded that there is a significant human health risk from the transference.”
There are reams of scientific research reports documenting the linkages
between CAFOs and various public health risks. The American Public
Health Association has called for a nationwide moratorium on CAFOs, citing more
than 40 scientific reports indicating health concerns related to CAFOs. The
citations include research from such prestigious institutions as the University
of North Carolina Medical School, the University of Iowa Medical School, and
the Johns Hopkins School of Public Health. The Director of the Johns Hopkins
School of Public Health, testifying before a
for presentation at the Annual Assembly
of the Missouri Catholic Conference,
 CAFOs and Public Health:
The Issue of Antibiotic Resistance http://www.ces.purdue.edu/extmedia/ID/cafo/ID-349%20HTML/ID-349.html
 U.S. Government Accounting Office Report 04-490, April 2004 Antibiotic Resistance; Federal Agencies Need to Better Focus Efforts to Address Risk to Humans from Antibiotic Use in Animals, http://www.gao.gov/new.items/d04490.pdf
 American Public Health Association, Association News, 2003 Policy Statements, http://www.apha.org/legislative.
 Robert Lawrence, MD,