DTN Agronomist Dan Davidson has never been shy about sharing his experiences on the farm he works with his brother in eastern Nebraska. Recently, he got sick while working with grain harvested during last fall's wet weather, and he wants other farmers to know that stored grain can pose health dangers.

Mold is a problem this spring because corn didn't mature and dry down properly last fall. Damaged grain left fines in bins that increase dust and affect drying. The fines are especially conducive to dangerous mold spores.

"We, along with many farmers, are handling corn grain that didn't store well over the winter, with lots of fines, mold and dust," Davidson said. "Because of the fines and poor drying, the grain has set up in bins and won't flow without some physical assistance."

Davidson was inside a grain bin for approximately two hours to load out 1,000 bushels of corn to dry. It was still at 19- to 20-percent moisture. Davidson used a long, steel rod to move the grain and help it flow to the auger.

The small face mask Davidson wore covered his nose and mouth but was inadequate for the clouds of dust he encountered. By the end of two hours, Davidson said he was exhausted, weak and had flu-like symptoms. He had difficulty breathing, was chilled and had a high fever that didn't break until the middle of the night.

"Over the past couple of days, I still feel weak, a little nauseous and have some lung congestion that won't go away," Davidson said.

Tom Dorn, University of Nebraska-Lincoln extension educator in Lancaster County, helped his dad check grain conditions -- a side business --when he was a kid. The government paid farmers to store grain on their farms, but many were too busy to watch the grain, and it spoiled. The Dorns crawled into bins to check the grain. If it was getting moldy, they'd break it up with shovels to get air moving through.

Dorn said he became ill with pneumonia-like symptoms after spending too much time in the bins.

It would not be surprising to find moldy corn bins this season, Dorn said, because grain was wetter than usual this harvest, and unless heated air was used for drying, it took a long time to remove moisture from that grain.

"The fungal organisms that attack corn in the field are brought in with the combined corn and go into the bin," he said. "They keep reproducing in the bin as long as the environment in the bin allows them to."

University of Nebraska-Lincoln Extension plant pathologist Tamara Jackson agreed there is definitely more grain mold this year.

"People had to harvest when they had the opportunity, but with the long, wet drying period, the fungi that started back in the fall have continued to grow, even in the best storage conditions," she said. "The fungi can grow extremely fast under warm conditions like we've been having. It's critical to keep monitoring grain, and if needed, go ahead and market it so it doesn't continue to deteriorate in the bin."

According to the University of Wisconsin Extension, breathing grain dust containing mold can affect the health of anyone exposed while harvesting, unloading, grinding or mixing grain.

Even lower-level exposure to dust and mold can cause symptoms such as wheezing, sore throat, nasal and eye irritation or congestion. Exposure to higher concentrations of grain dust can cause more serious symptoms, such as coughing, chest tightness, headache, muscle aches and fever.

Massive exposure to moldy grain dust can cause medical conditions such as Organic Dust Toxic Syndrome, and Farmer's Lung or hypersensitivity pneumonitis. Hypersensitivity pneumonitis and ODTC both cause inflammation of the lungs and tests are usually necessary to tell the two apart.

Taking precautions and controlling exposure risks are key to preventing grain dust and mold reactions.

The U-W Extension suggests farmers have a correct and clean air filter on the combine to minimize dust in the cab, adjust their combine to minimize grain damage and wear a dust mask (respirator) that fits and is certified by the National Institute for Occupational Safety and Health.

Davidson said he has mostly recovered from the symptoms, but will not forget the experience.

“In the future I will be more careful going into bins that have a lot of dust and mold. And if I have to I will wear a respirator and goggles to protect myself and won’t stay in a bin longer than 30 minutes at time.”

Cheryl Warren can be reached at Cheryl.warren@dtn.com