Mountain and stream

What is a CAFO and Why You Need to Know About It

Idyllic Farm

By Kirsten West ND, Lac, FABNO

Like many of you, my thoughts regarding farms (at least in the past) typically transitioned into images of red barns, green pastures, the solitary cow (or two), perhaps some chickens, rows of corn, birds chirping- basically, an overall picture of serenity. In fact, living next to a scene such as this appears quite nice.

Most recently, this “farm life” image has been turned on its head with the development of what is now called a CAFO. Quite frankly, not only would I not want one next door but I would prefer to be several miles (at least 60) away from one.

First, let us start with what CAFO means. A CAFO stands for a Concentrated Animal Farming Operation. You may ask what this has to do with health and most importantly why, I am writing about it… hold on to your seats.

CAFOs are multiplying across the country. They are considered a specific type of large-scale industrial agricultural facility that raises animals in high density for the consumption of animal products (meat, eggs, or milk). Notably, there is typically little to no horticulture. It has been argued that this is the future of farming as CAFOs allow for greater production of animal products with less cost, less land use, greater tax expenditures, and employment. However, the cost to the local communities, the land and the American population, at large, is huge.

The primary problem (as well as the most significant health issue) is MANURE.

A CAFO may hold anywhere from 200 to more than 1,000 cattle, 37,000 to more than 125,000 chickens, and anywhere from 16,000 to greater than 55,000 turkeys at any given time. As you can imagine, the manure production is not small. In fact, this production can range from 2,800 to 1.6 million tons a year. It is estimated that annually, livestock animals in the U.S. produce 3-20 times more manure than actual persons in the United States. That is equivalent to 1.2 to 1.37 billion tons of waste. This much manure has major impact on not only the communities surrounding the industrial farms, but also the environment as a whole.

CAFO manure is full of contaminants including but not limited to: E.Coli, growth hormones, and antibiotics. While manure is typically thought of as a value to the farming industry in this case, it is a detriment. In the past, farms (those akin to the nice picture I painted earlier) used the manure from their animals as fertilizer for their crops. Byproducts were utilized for production of plants and those plants were used to feed the animals. With CAFOs, this is no longer the case and, the majority of these operations, noted earlier, do participate in very little to any forms of horticulture. The question then becomes, what happens to the manure?

Ground disposal and application is the most common form of manure disposal. This in itself, is an issue, as the soil is only able to handle so many nutrients and it is these nutrients (nitrogen, phosphorus and micronutrients added to the animal such as heavy metals) which become of major concern. Often, these nutrients are either run off or leached into groundwater.  [Of note, CAFOs are required to hold permits that restrict the amount of manure discharge however, the accidental releases are large.]

When the soil is unable to absorb and utilize the allocated manure micro- and macro- nutrients are leached into the ground water. If a ground water system is contaminated, there is a serious threat to community drinking water in addition to those consuming water from private wells. Nitrates (one of the primary macronutrients in CAFO waste) can be a serious threat to all people, as these oxidize iron and turn hemoglobin into methemoglobin. This can create blood low in oxygen and has been linked to birth defects, miscarriages, poor general health, and of significance, can result in infant death (due to poor oxygenation and what has been termed “Blue Baby” syndrome). Nitrates are also linked to stomach and esophageal cancers. In addition, viruses have even been found in groundwater near CAFOs as the consistent leach of nutrients provides for sediment, a favorable attachment site for viruses.

From an ecological perspective, surface water has been shown to be affected. In areas with the highest CAFOs, lakes, rivers, and reservoirs tend to be polluted. Indigenous aquatic life dies, hormones that are leached into the water result in altered reproductive habits of aquatic species and overall lower fertility in female fish. In addition, protozoa, giardia being one of these, have been found in over 80% of surface water sites tested near CAFOs.

While the above issues associated with CAFO manure may go unseen to the naked eye (with the exception of blue baby syndrome), the odors dispersed by CAFOS cannot be argued by those in their wake. Depending on circumstances, these odors can be present 5-6 miles away. (While most studies indicate that 5-6 miles is the standard distance odors from CAFOs can travel, I beg to argue. There is a college town north of Denver housing a CAFO… We always knew when snow was coming as Denver would smell of manure (due to southern facing winds). This town was more than 60 miles north!) The important thing is this: these are not just odors. These smells have significant detrimental health effects and have been tied to tension, depression, anger, impaired balance and issues with memory. When odors are severe enough, those near factory farms can even develop CAFO-related Post Traumatic Stress Disorder.

The most common pollutants found in the air surrounding CAFOs are: ammonia, hydrogen sulfide, methane, and particulate matter.  Even without the noxious odors we all know to be associated with manure, these pollutants still exist within the air near CAFOs regardless of odor. Of those common pollutants listed, health effects are linked to each: Ammonia is a respiratory irritant and is linked to chronic lung disease, Hydrogen Sulfide causes inflammation of the moist membranes of the eyes and respiratory tract, as well as olfactory neuron loss, and the intake of Particulate matter can result in chronic bronchitis, chronic respiratory symptoms, and an overall decline in lung function over time. It is no surprise that children have higher rates of asthma and adults a greater incidence of respiratory illness/irritation in communities near a CAFO. As a health provider, I question the true causes of those who suffer from what appear to be “chronic allergies” and theorize that these odors place many at higher risk for the development of lung cancer. As we know, continued irritation and inflammation of any area of the body has the potential for future tumorigenesis – essentially, it is the wound that will not heal.

And then there is the insect issue… When most people think of excrement, flies are often brought to mind. In fact, when manure is produced in high volumes, as it is in a CAFO, it acts as a breeding ground for flies, mosquitos and other insects. And while flies are often only considered a nuisance, they do have the ability to spread pathogens and other bacteria. In fact, houseflies near poultry operations have been linked to the spread of drug resistant bacteria (this makes sense as livestock are typically treated with a plethora of antibiotics resulting in strains no longer susceptible to their use- more on this below). In addition, mosquitos are tied to the spread of West Nile Virus, St. Louis Encephalitis, and Equine Encephalitis, among others.

The animal welfare piece seems without need of elucidation or description. Bottom line, the lives of animals used in CAFOs is nowhere close to how their lives would appear in in traditional faming. The rights of these animals, as living creatures are stripped. And while many argue if they even have “rights” there are an equal number, if not more, who feel very strongly about that they do. I am one of latter. In an effort to keep on track here in regards to the health risks associated with CAFOs, I will end dialogue regarding animal welfare now, as I will get carried away.

The last, final and very significant area of concern that I would like to address when it comes to CAFOs is this: the use of antibiotics. We, as a population, have already seen the toll overuse of antibiotics has taken in our hospitals, on our guts and on our overall health. The livestock industry is not clear of this practice either. In fact, the use of antibiotics in livestock continues to increase. The thinking is this: non-therapeutic doses of antibiotics in animal feed will help to produce an animal that will avoid illness (especially when confined so closely to other animals) and will thereby grow faster and produce more meat. Most animals are unable to metabolize antibiotics and these too, are leached into groundwater creating a double dose for them, and also, us. IN fact, 70% of all antibiotics and related drugs used in the U.S. each year, are given to cattle, hogs and chickens as additives to their feed. This practice has had the result of producing antibiotic resistant bacteria (of importance, it should be noted that recent measures have been taken to stop the use of non-therapeutic dosing of antibiotics and several food chains now refuse to use meat treated with antibiotics.)

So there you go- CAFOs and how they affect us, in a nutshell. Now the question is- what do we do about it?

One of the first steps we can start taking as consumers is electing to have all animal products, which are produced from CAFOs, labeled. (much like GMO labeling.) Even if this were the case, we (and especially those communities closest to a CAFO) will continue to suffer the very real and significant health detriments associated with CAFO establishment. As a doctor, it then behooves me to make some additional suggestions.

(Of note, I am making these suggestions to the population as a whole, not only to communities near a CAFO, as there are MANY other health concerns aside from those created by industrial farming practices.)

  1. Get a water filter. Please note that a refrigerator and Britta water filters are NOT the correct form of filters. A ROS, Berkey water filter ( ), or those from Pure Effect filters ( ) are typically the best as these will remove hormones and antibiotics from drinking water.
  2. Use an air filter in your house. Some examples that I am quite fond of are the following:
  3. Get a Venus fly trap (seriously!). Water it. If you note flies in and around your house, (and if you live in the proximity of a CAFO- you will) adding this household companion will offer you both, a mutually symbiotic relationship.
  4. Eat your garlic (as long as you do not have CBS/sulfur issues of course). No joke, this does work as a mosquito repellent. In additional oil of lemon and eucalyptus can work great as well. (If you are going to use essential oils make sure they are Organic, authentic and genuine essential oils: brand is Veriditas and you can order from (this is an affiliate site that offers these high quality oils))
  5. Please elect to be very mindful of the types of animal products you are eating. These should not only be GMO and from grass fed/finished sources (notably dairy and beef) but also from true pasture raised animals.
  6. If possible, buy local- and I do not mean CAFO local- I mean from local farms who still employ the concept of growing feed for their own livestock, avoid the use of antibiotics and pesticides. By doing this we can all support our own communities and cultivate true farm to table food.
  7. And of course, if you have the ability to take further action against the domination and growth of CAFOs please do so. This is imperative not only to our environment but also our health.

In conclusion: as a Naturopathic Doctor (and one specializing in the field of oncology), I see many ailments that have gone undiagnosed. These ailments have had a very large and significant impact on those they affect as well as their families. Because of this, it is always my mission (and that of my naturopathic colleagues) to determine the root cause of the “dis” ease. This is why I have written this article. Sometimes those things that take place around us go unnoticed, until it is too late and people are sick. By understanding those causes now, we are all better off.


Bowman, A., Mueller, K., & Smith, M. (2000). Increased animal waste production from concentrated animal feeding operations (CAFOs): Potential implications for public and environmental health. Nebraska Center for Rural Health Research.

Hribar, C. (2010). Understanding Concentrated Animal Feeding Operations and Their Impact on Communities.  National Association of Local Boards of Health. Retrieved at:

Congressional Research Service. (2008). Animal Waste and Water Quality: EPA regulation of concentrated animal feeding operations (CAFOs)

Environmental Protection Agency. (1998). Environmental impacts of animal feeding operations.