Health Risks from Hog Confinements

Here in Iowa, we’re used to a little bit of piggy stink. In recent years, though, as our state’s belly swells with industrialized hog farms, more and more residents are finding the overwhelming odors associated with Confined Animal Feeding Operations (CAFOs) unbearable. Moreover, a host of recent research is showing that toxic air emissions from these operations can adversely affect human health.

In 1970, the average Iowa hog farm housed fewer than 200 hogs, whereas in 2000, it spiked up to 1,500, tightly packed. Today, CAFOs operating at maximum capacity can hold up to 10,000 hogs or more. That’s a lot of swine—anda lot of manure to deal with.

Iowa’s livestock churn out an estimated 50 million tons of excrement each year. In industrial-sized hog farms, the manure accumulates as a liquid in pits beneath the confinement building, or in sewage lagoons outside. Naturally, these putrid pools give off an enormous stench.

Health-Hazardous Emissions

But it’s not just a matter of malodor. According to a 2002 jointstudy by Iowa State University and the University of Iowa, the manure pits become anaerobic and putrid, polluting the air with particulate matter and many gases—including ammonia and hydrogen sulfide—that can lead to a wide range of health complaints. Exposure to hydrogen sulfide is known to cause nausea, headaches, diarrhea, and even life-threatening pulmonary edema.

Researchers from the 2002 study concluded that “CAFO air emissionmay constitute a public health hazard and that precautions should be taken to minimize both specific chemical exposures (hydrogen sulfide and ammonia) and mixed exposures (including odor) arising from CAFOs.”

There appears to be ample evidence to support this notion. A 2000 North Carolina study (Wing and Wolf) found that people living in proximity toa 6,000-head hog CAFO reported increased rates of headaches, runny nose, sore throat, excessive coughing, diarrhea, and burning eyes compared to rural residents living far from livestock operations.

A 1995 North Carolina study (Schiffman and colleagues) found that residents who lived in the vicinity of intensive swine operations reported increased negative mood states, including tension, depression, anger, fatigue, confusion, and reduced vigor.

While a 1997 Iowa study (Thu and colleagues) found no increased incidences of depression and anxiety among residents living within two miles of a 4,000-sow CAFO, researchers found that both farm workers and community residents reported higher rates of chest tightness, wheezing, runny nose, scratchy throat, burning eyes, headaches, and plugged ears.

The 2002 UI/ISU study noted that CAFO workers run an extremely high risk of developing respiratory diseases including asthma, acute bronchitis, sinusitis, and rhinitis. Researchers concluded, “The scientific literature is quite clear that workers in swine or poultry CAFOs are at risk to acute and chronic respiratory diseases from concentrated emissions inside CAFOs.”

On the whole, CAFO workers are known to be a hearty bunch. But as the authors of the 2002 UI/ISU study pointed out, “Those in the general community, including the children, the elderly, those with chronic impairments such as pre-existing asthma or chronic obstructive pulmonary disease, are expected to be much more susceptible to CAFO exposures.”
So what’s being done about all this? Where does Iowa currently stand in terms of healthy air quality standards? Unfortunately, on somewhat stinky, and potentially unhealthy, ground.

The Need for Enforceable Air Quality Standards

In 2003, prompted by pressure from concerned citizens and organizations like Iowa Citizens for Community Improvement (Iowa CCI), the DNR acted to approve air quality standards for CAFO ammonia and hydrogen sulfide emissions, based on the 2002 ISU/UI study authors’ recommendations (no more than 15 parts per billion of hydrogen sulfide, 150 parts per billion of ammonia, and a 7:1 dilution rate for odor). The standards were set in place, but within days, the 2003 Iowa Legislature promptly put a halt to them.

“The legislators were responding to the powerful special interest lobbying of factory farms and not their constituents,” said Carissa Lenfort of Iowa CCI.

In response to the dust kicked up by agribusiness proponents, the 2004 Iowa Legislature passed HF 2523, a bill that would have essentially allowed CAFOs to pollute air with impunity. Fortunately, Governor Vilsack vetoed the bill. Later in the year, the Environmental Protection Commission (EPC), the Iowa DNR’s citizen oversight board, enacted a watered down setof air quality standards that called for no more than 30 parts per billion of hydrogen sulfide.

“It’s a step forward,” says Lenfort, “but the standards definitely need to be strengthened in order to actually protect public health.” As yet, there are no regulations for ammonia or odor. “We’re continuing to say that standards need to be set for those as well,” says Lenfort.

Establishing adequate air quality standards has thus far been an uphill battle, but if Iowa’s residents pull together, the climb is easier. It was only after Iowa CCI members submitted a 6,000-plus signature petition to the EPC calling for air quality standards (in 2001) that the board first began to consider establishing standards at all. Iowa CCI’s efforts eventually led to the joint report by ISU/UI in 2002, which, in turn, led to the establishment of today’s standards.

The home page of Iowa CCI’s webpage reads: “A wise man once wrote that the only solution to any problem is to ‘get to work on it.’ ” Residents who want to be part of the solution to the problem of CAFO air emissions should contact their state representative and senator and let them know they support the 2002 study’s recommendations. They can also visit the Iowa CCI website and click on the “What Can I Do?” link for other action steps.

Taking Control Locally

Another way to move the issue forward is to promote “local control,” which would ensure that each county has ultimate control over when, how, and if proposed CAFOs should be established and maintained in the area.

“Counties have the ability to site schools and other economic developments,” says Lenfort, “They should be allowed to site CAFOs. The local people know the land better than anyone. They know their county.”

Somewhat to this end, in 2004 the state of Iowa established the “Master Matrix,” a 44-question scoring system that purports to help counties maintain local control over CAFOs of 2,500 hogs or more.

Although the Matrix requires CAFO operators to meet standards in three categories (water, air, and community impacts), the system is often criticized for being somewhat lax. To date, the Matrix has yet to deny a single CAFO permit.

“It’s kind of a token thing in my mind,” says Iowa dairy farmer Francis Thicke, who is a member of the EPC and has written extensively on sustainable farming practices. “It’s a compromise. Several years ago when there was a push for local control, the farm lobbyists pushed back. It doesn’t equal local control, by any means,” he said.

So what can residents do to help establish local control?

“Contact your legislative reps, help get the message out there,” says Lenfort. “Join Iowa CCI and ask for local control. It’s going to take a lot of work, because we realize that factory farms have a lot of power and resources, and when you’re taking on powerful opponents, the fight’s always stronger.”

Interestingly, Iowa’s residents already seem largely in favor of local control. An informal 2001 survey by the Des Moines Register found that 71 percent of Iowans want local control, 9 percent are undecided, and a mere 20 percent are in favor of CAFOs. According to recent reports, there have been as many CAFO permit applications within the past six months of 2005 as there were in all of 2004. So if community members want to have moresay about CAFO siting, they’d be wise to speak up soon.

The New Old Solution

Then again, perhaps there’s an even simpler solution to the problem of noxious fumes emitted from CAFOs. In a recent Sierra Club article entitled “Naturally, Hogs Don’t Stink!” Thicke writes, “Industrial hog-lot manure accumulates in a liquid form, so it becomes anaerobic and putrid. When hogs are on pasture, their manure is dispersed on the soil and is aerobically decomposed, so putrid compounds do not form.”

When farmers raise hogs outdoors, rather than in cooped confinement lots, pigs don’t smell nearly so raunchy. Writes Thicke, “A friend of mine who raises hogs on pasture likes to boast that he can check his hogs on the way into town and nobody can smell that he has.”

It seems that with natural hog-farming, everybody wins. Pigs have healthier, antibiotic-free diets; farm pastures receive natural fertilization; manure lagoons don’t pollute the land, air, creeks, and lakes; and rural homeowners near hog farms don’t have to watch in dismay as their property value is devastated. But what about the farmers—won’t traditional, outdoor hog-farming cut back on profits?

Not across the board. Recent estimates by the Sierra Club state that for every new CAFO established, ten family farms are eliminated or forced to enter into corporate contracts. Today’s CAFO operators are, in Thicke’s words, essentially the “serfs of corporate agribusiness.” At present, four corporations control 59 percent of the hog market. The pigs and feed are provided by these large corporations, but the farmers are responsible for all the liabilities.

As factory farms grow in numbers, family farms diminish across the state. In the end, it seems CAFO proponents may end up being the ones “living high on the hog,” while those of us breathing the toxic fumes are finding new meaning in the expression.

Change—a Whiff Away

Many organizations are striving to ensure today’s hog farms are safe for humans, animals, and the environment, but we still have a ways to go. With education, awareness, and action, the CAFO trend could drastically change.


As Francis Thicke sees it, “Iowa is divided into three groups on the CAFO issue. The first group is extremely small. It’s those people with vested interests, who profit from CAFOs. The second group is a little larger. They’re the locals who’re against CAFOs because they’ve had personal experience with discomfort caused by them. The third groupis the huge majority. They know little about the pitfalls of CAFOs, but they’re just a whiff away from being against them. It’s just a matter of awareness—of enough people waking up and smelling the hydrogen sulfide.”

Sidebar: Feces Fiascos & Antibiotic Resistance

Certainly there are other health risks associated with CAFOs. In 1995, an eight-acre hog waste lagoon in North Carolina burst, releasing 25 million gallons of hog refuse into Onslow County. The spill killed as many as 10 million fish and closed 364,000 acres of coastal wetlands to shellfishing. Smaller spills are common, and often closer to home than Iowans imagine. In 1996, for example, 40 spills in Iowa, Minnesota, and Missouri killed close to 700,000 fish. In 1997, Indiana feedlots caused a total of 2,391 manure spills. A 100,000-gallon spill in 1998 killed close to 700,000 fish in Minnesota’s Beaver Creek.

And then there’s the issue of antibiotic resistance. Large-scale animal farms often feed animals antibiotics (U.S. farmers dole out atotal of 24.6 million pounds each year) to promote growth and treat diseases caused by overcrowded conditions. These antibiotics are making their way into the environment and the food chain, contributing to the rise of antibiotic-resistant bacteria and making it more difficult to treat human diseases.

There’s hope on both counts. North Carolina imposed an eagerly welcomed moratorium on new hog CAFOs in 1997, after the record-setting spill in Onslow County. The moratorium has been extended a number of times and is currently in place until 2007. As for the issue of antibiotic resistance, the American Medical Association recently went on record opposing the non-therapeutic uses of antibiotics in agriculture. Experience—the mother of wisdom. Let’s hope Iowa wisens up.


For excellent resources, see Jefferson County Farmers and Neighbors.