'Mushroom Worker's Lung' ... Apparently It's Real

If you've been following my exploits so far this spring you are fully aware that I have Mushroom Fever. That's not a disease, per se, unless you consider an obsession a disease. It's just that I've just learned to love and enjoy hunting for wild edible mushrooms in the beautiful Pacific Northwest (PNW), previously in the fall (for Chanterelles and many more varieties) and more recently in the spring (for Morels).

The culprit: Pleurotus ostreatus
(Oyster mushrooms) pinning
from a straw log which used to
live in our "Upper Room."

Because there is a long winter season inserted between the two here in the PNW, with no wild mushrooms growing outdoors, I decided to feed my obsession by beginning the cultivation of edible mushrooms indoors. We have an attic room which we've used as a bachelor studio and home theater, and are currently also using as a work-out room, wine cellar, and now a mushroom-growing laboratory. I started this winter by growing Pearl Oyster mushrooms (Pleurotus ostreatus) and also crimini and portobello mushrooms (which are the same organism, crimini just the underdeveloped version and portobello the fully mature adult fruit).

I'd been doing this for some time in what we called "The Upper Room" and getting fairly good at it, I think, when my wife began to complain about allergy-like symptoms every time she worked out there ... congestion, low-grade fever, etc. She asked me if I would search the internet to see if there were any possible negative side effects from growing oyster mushrooms. "Yah, sure, honey," I said, convinced it was just her usual allergies combined with the fact that I was enjoying growing mushrooms indoors so much and therefore needed to be reigned in a bit. Seriously, I thought how could she possibly be allergic to being in the same room with an Oyster mushroom, if eating them didn't bother her in the slightest? I did intend to do a search but didn't jump on it very quickly.

So of course she grew tired of waiting for me to do it, and did a little "Let me Google that for you" research on her own. And lo and behold, she turned up quite a substantial number of case reports and other documentation online of the severely allergic effects that the spores of Pleurotus ostreatus apparently have on many people:

• Extrinsic allergic alveolitis caused by the spores of the oyster mushroom (PDF also in the U.S. National Library of Medicine here)
• Mushroom Worker's Lung resulting from indoor cultivation of Pleurotus ostreatus (PDF)
• Characterization of allergens from spores of the oyster mushroom, Pleurotus ostreatus
• Allergic asthsma to shiitake and oyster mushroom

And that's just a start.

Here's a fascinating article talking about how prolifically Pleurotus ostreatus produces spores ... a single large mushroom cap can eject, the article says, 100 million spores per hour! The estimate of the number of spores in a cubic meter of "clean, country air" where some Oysters might grow is therefore 10,000. The article concludes, "You can now buy the Oyster Mushroom in supermarkets.   It grows quite nicely in commercial mushroom houses.  As the mushrooms reach maturity, the level of  spores in the atmosphere of the mushroom house must be incredible."

By the way, mushrooms eject such a prolific amount of spores for precisely the same reason a human male creates such a large number of sperm. If it's any comfort to my wife, the article says only about 1 in a billion spores are estimated to survive the environment they are ejected into. (Roughly 10 hours' worth of work for a mature Pleurotus ostreatus cap, by my calculations. Not too bad. It took my wife and I several years to create two marvelous kids.)

Needless to say, I've now moved my straw log mushroom growing operation outdoors, next to my maple nursery logs. (Actually, it's doing better than I thought out there ... although I am a little concerned about what will happen if we get a heat wave this summer.)

I also have learned, once again, to apologetically recite the very humbling mantra: "Yes, dear, you were right. Once again." Note to self: The wife is always right.