This may be a "Chicken Little" warning, but it might be a good idea to be cautious of the black dust that's coming off corn during harvest this fall. In some fields the stalks literally are black, and combines are coated with black dust after only one pass through the field. Even in fields that look "normal," there are often pockets where black dust fogs from the header and straw chopper as those areas are harvested.
I've talked to representatives with several seed corn companies, and they say most of the dust is annoying but mostly harmless. BUT--any dust in high density can cause problems for folks with allergies or respiratory problems. Since most farmers over the age of 30 have dealt with cleaning musty grain from grain bins at some time, most farmers have some degree of sensitivity to grain dust and molds.
According to a press release by Alison Robertson, with Pioneer Seed's Department of Plant Pathology, most of the black cornstalks are due to saprophytic fungi--microorganisms that feed on dead plant material. A lot of cornstalks died early this year, and the recent round of widespread rain followed by a week of hot, humid weather encouraged widespread development of that mostly harmless fungi.
BUT--the same conditions that encouraged the growth of saprophytic fungi also favored the development of a lot of other molds and fungi. Some of them can make a person sick. I talked with several farmers who have already experienced the chills, fevers and muscle aches associated with "dust flu" after they were exposed to black dust while harvesting corn. At least two guys I know told me they also developed a rash on their arms after working in a situation where a lot of the black dust coated their exposed skin.
So. I sincerely hope that nobody gets sick this fall due to exposure to black dust, and that some of you email me this winter and harass me about this "Chicken Little" warning. But in the meantime, I'm carrying and wearing dust masks designed to stop mold spores whenever I have to work around combines that are spewing black dust. At least one large farmer in our area has switched all his cab filters from standard filters to special "allergy filters" that are designed to stop mold spores. Until we get a better grip on what's waiting for us in the fields this fall, it wouldn't hurt to use caution when working in dusty conditions.
A final note: another thing we've noticed is, even if nobody gets sick from the black dust, it's playing havoc with air filter longevity. Not only do cab and engine air filters plug quickly when exposed to that stuff, but it's so fine and organic that it's very, very difficult to blow out of the filters. If you're noticing poor ventilation in your cab, or your engine is short on power, make sure your air filters are as clean as you can make them.