DANVILLE —  Two months ago, Jonathan Cain, a grain farmer who lives near Middle Creek in Snyder County, started experiencing headaches and shortness of breath.

“At first, I thought I might have developed an allergy of some sort,” he said, recalling the symptoms that affected him for weeks before he went to his family doctor about it.

“I was coughing, too. I just felt terrible, all around, like I might even have some kind of pneumonia or flu,” Cain said.

What he had was ‘hypersensitivity pneumonitis,’ more commonly referred to as “farmer’s lung,” but he didn’t know it.

That’s common. It took a physician to figure it all out.

“Once he made the diagnosis,” Cain said, “I got better in a short few weeks. My doctor says I might have had this for a long time. And maybe I have some scarring in my lungs, but it could have been worse. The disease could have ended my life, and I’d have never known why.”

Farmer’s lung is serious business and poses a real health threat, said Dr. David E. Fisk, a physician at Geisinger Medical Center in Danville, who specializes in pulmonary ailments. It’s an allergic disease usually caused by breathing in dust from moldy hay. However, dust from any moldy crop — straw, corn, silage, grain, or even tobacco can also cause farmer’s lung.

“Farmers spend a lot of time in their barns, which are often open,” Fisk said. “But if some of the hay bales are wet, mold spores could grow. There is a reason for keeping bales dry. Or a bag of corn might be sitting around for a long time.”

The disease is one of the more insidious respiratory hazards to which farmers are exposed.

“It’s not an infection,” Fisk explained. “It’s an inflammation. It looks and feels like its pneumonia, but it isn’t.”

Fisk says he might see 10 to 12 diagnosed cases of it a year.

As the name suggests, farmer’s lung is caused by inhaling certain allergy-causing dust found in some agricultural operations. A recent study shows that exposure to pesticides may also be a risk factor for farmer’s lung.

Homeowners at risk

Homeowners with mold in basements are also at risk.

Once diagnosed, Fisk said, “Recovery time is rapid.”

When people with farmer’s lung can avoid breathing in dust from moldy crops or feed, they seldom have further problems, Fisk said. On the other hand, lengthy exposure can cause permanent lung damage, physical disability or even death.

Usually, people with farmer’s lung do not associate their health problem with exposure to moldy hay. Instead, they go to their doctors complaining of breathing problems.

“That’s exactly what happened with Cain.

How common is farmer’s lung?

Fisk said incidence varies from place to place.

The disease seems to occur in about 2 to 10 percent of farm workers, depending on the region. In some areas, blood tests have shown that 20 to 40 percent of farm workers have antibodies that react with antigens responsible for farmer’s lung. This test indicates that people have had at least an initial exposure to moldy dust.

The disease is most common in regions with wet weather at harvest time. Farmer’s lung is also more common on dairy farms, especially those not equipped with automated equipment for handling hay or feed. Attacks of farmer’s lung occur most often in late winter or early spring when stored hay or grain is used to feed livestock.

Degree of risk

The degree of risk depends on the amount of dust that has collected in the person’s lungs. There is little danger working with loose hay in an open field. But the risk increases when farmers or farm workers are breaking open bales of moldy hay or straw inside closed barns or cow sheds. A person can inhale an extremely large amount of dust in a very short time while working indoors.

Other people exposed to dust from moldy hay, straw or grain include grain handlers, stable employees, poultry workers, attendants of zoo and circus animals and pet shop workers.

Two extremes are associated with a sudden attack; at one extreme are the symptoms associated with a slow progressive illness. The allergic response of the afflicted person depends on the sensitivity of the individual and the amount of moldy dust entering the lungs. There are three different types of allergic responses: acute or intense attack, sub-acute or low-level response, and chronic or long-term response.

Acute farmer’s lung is easy to notice. It begins as an intense attack about four to eight hours after the person breathes in a large amount of dust from moldy crops. What follows are some signs and symptoms:

• Shortness of breath.
• A dry irritating cough.
•  A sudden general feeling of illness.
• Fever and chills.
• A rapid heart rate.
• Rapid breathing.

If the person avoids further exposure to moldy dust, the signs and symptoms usually decrease after l2 hours, but they can last up to two weeks. Serious attacks can last as long as 12 weeks. The symptoms are sometimes confused with pneumonia.

Chronic illness

Chronic farmer’s lung develops after several acute attacks over a period of years. It afflicts people who have been consistently exposed to large amounts of moldy dust. The illness can sometimes last several months and is marked by increasing shortness of breath, an occasional mild fever, and often, a significant loss in weight and a general lack of energy. The symptoms are accompanied by permanent lung damage and gradually worsen as exposure to moldy dust continues.

For those suffering from acute attacks of farmer’s lung, the first step is to avoid further contact with moldy dust. For serious cases, bed rest is recommended and oxygen therapy may be needed to relieve shortness of breath.

No cure exists for people who become hypersensitive to moldy dust.

Is farmer’s lung preventable? And if so, how?

There is no simple answer to that question, Fisk said.

Steps must be taken to avoid crop spoilage and production of bacterial or mold spores that cause the allergic reaction. Workers must also take precautions to avoid breathing in spores from moldy crops. The following measures are recommended:

• Keep bales dry.
• If possible, hay with a high risk of spoilage should be stored in silage instead of bales.
• Buildings with large amounts of dusty material should be properly ventilated.
• Farm chores that involve handling hay or feed should be mechanized as much as possible to reduce exposure to moldy dust.
• During cleaning of barns or stables, dust from moldy crops should be wet down before being swept to prevent it from becoming airborne.
• Use Approved, properly fitted dust respirators to help protect the lungs.