A new study conducted at Iowa State University has shown that many farmers may be more prone to such occupational hazards as hearing loss and a loss of hand strength than the general public.

Researchers at ISU looked at data collected by the National Pork Producers Association between 1991 and 1994 on non-farmers, farmers, pig farmers and confinement pig farmers to examine potential occupational health risks.

Dr. Terry Hurley, a research associate in economics, said the study was conducted because of concerns by the health profession and the agriculture industry that swine farmers and confinement hog farmers are at higher potential risk for adverse health consequences.

“One of the things they are interested in is, if confinement farmers have a higher risk of bad health outcomes, is there a way that we can protect them in a manner that would lower their insurance rates,” Hurley said.

The study found farmers seem to suffer from loss of hearing and hand strength more frequently than non-farmers, and hog farmers are especially prone to decreased hand strength, Hurley said.

The loss of hand strength among hog farmers may be linked to the greater use of heavy machinery and working with large animals, he said.

Farmers were less likely to report problems of hearing loss than most people even though clinical tests showed their hearing to be impaired, Hurley said.

“When we actually go to hearing tests, they test much worse than the population in general,” he said.

Dr. James Kliebenstein, an agricultural economist at ISU, said he thinks this apparent contradiction might be because the loss of hearing and hand strength are chronic problems which develop over a number of years and may not be as noticeable to farmers.

“It’s the type of occupation that your hearing is being impacted by small amounts each year, so that you don’t recognize that there is a hearing problem,” he said. “It just becomes a part of everyday life, and you don’t realize that you can’t hear as well now as you used to be able to.”

Machinery noises as well as the noise of squealing pigs can affect hearing, Kliebenstein said.

An interesting finding of this study is that in clinical tests, confinement hog farmers do not appear to be more prone to respiratory ailments than anyone else, Hurley said. This is something which appears to conflict with previous findings.

“Most of the medical community will swear that confinement hog farmers are at a much higher risk for respiratory ailments due to the fact that they are in these confinement buildings, and these buildings have a lot higher levels of dust and gas. But we didn’t find that to be the case,” Hurley said.

“There are some reasonable explanations why we didn’t find that to be the case, and it could still be the case,” he said.

One reason for the mixed findings may be that people who are prone to respiratory ailments don’t go into farming, Kliebenstein said.

“Individuals that have asthmatic problems and that sort of thing are not going to be in the occupation to begin with,” he said. “The occupation itself will be attracting individuals who do not have respiratory problems before they start.”

Hog farmers do report subjectively that they have more minor respiratory ailments, like sinus problems or coughs, than the general population, Kliebenstein said.

Many of the respiratory problems reported may be chronic problems that are not yet debilitating, Kliebenstein said. “It might be that you are coughing and wheezing and, over a period of 8 or 10 years, lung capacity starts being affected, but it is something that you don’t pick up over a short duration.”

Hurley said the results of the study may be suspicious.

“To be able to say unequivocally that there is no increased risk of respiratory ailments among confinement hog farmers, you need to look at individuals over a period of time to see if health has changed or stayed the same,” he said. “We want to be able to look at the same person at time 1 and time 2 and say ‘OK, has his health dropped, and has he been working in confinement during this time?'”