How easily can mold spread from place to place?

August 11, 2019 5:01 PM

I've heard people talk about mold spores spreading around or "reactivating" after a period of dormancy, but can't find much hard facts on this. A specific experience I wonder about regards mold spreading over my life after I left the windows in my car open during a rain storm.

Afterward, I smelt mold and noticed my eyes burned after being in the car. Weirder, some whey protein stored in a plastic container in the car tasted awfully of mold. Much weirder still, the "mother ship" large container of whey protein in my house then also started tasting like mold.
Can mold spread like the blob? (I.e., some spores get on my clothes and then when I opened the large container of whey in my house, they jump into that?)

posted by Jon44 to Health & Fitness (6 answers total)

Mold spores are everywhere. They are in higher concentrations in places that have had a mold outbreak but even so... anything that is in the right condition to get moldy (moisture present, exposed to air, want) will get moldy and anything that is not in a condition to get moldy (sealed, dry, cold) is not going to get moldy. If it's been humid and you've been opening the whey containers then it's conceivable that there's enough moisture that they've started to go off (which frankly seems more likely that the whey powder has gone off rather than gotten moldy per se).

Yo recap, mold spores can remain dormant for a long time and take hold when the conditions are right. But if the conditions aren't right then they will not establish a new colony.
posted by drlith at 5:39 PM on August 11, 2019 [4 favorites]

Yes! it is possible that the mold spread on your clothes and jumped to the whey. However, unless the whey was liquid, they probably didn't germinate and grow enough to make a noticeable taste. How long of a time period was it between when you were in the car and when you ate the whey? Is it possible that you just had mold stink stuck in your nose? If you deliberately cleared out your sinuses, or if you smelled something bright or cleansing, do you still notice the mold smell in your whey?

The other thing that can happen is that odors are made up of combinations of molecules. If the same molecule is in mold odor and whey odor, and you had a bad experience to mold smell, your brain might be primed to pick up on the same odor in the whey as a warning. It's cool, it keeps us from eating bad things more than once, but it can be annoying. Mold causes organic things to break down, which releases molecules with fun names like "putrescine" and "cadaverine." If the whey is even a little bit off, it'll also start to rot and put out similar odors. The presence of these compounds is why some people think milk that has been traditionally pasteurized has a slightly rotten taste compared to ultrahigh pasteurized milk or unpasteurized raw milk. (Which does not mean that drinking raw milk is healthier or better!)

I don't know what kind of hard data you want, but I once correctly identified that a student hung her car keys on a hook in her kitchen based on the mold colonies that grew when she swabbed her car keys in lab. It just meant that her fruit and bread would mold a little faster than average, but she spent her weekend disinfecting her entire kitchen anyway. So yes, mold spores can carry from point A to B, but as long as they're cold and dry they won't germinate to cause new problems.
posted by arabelladragon at 5:49 PM on August 11, 2019 [3 favorites]

Mold is not only everywhere, it will pretty much always be everywhere (unless you are working in a negative pressure clean room). See here for some scholarly work on sampling the air inside and outside several types of places in CA. It varies a bit, but nontrivial spore loads are pretty much part of our basic world background biota.

We prevent infestation not by avoiding spore, but by keeping our houses and cars an unwelcoming environment. This generally means allowing plenty of air circulation, keeping humidity low, etc.
posted by SaltySalticid at 6:51 PM on August 11, 2019 [3 favorites]

Just because in the 90's sensationalistic Local News turned "toxic black mold" into "a thing" doesn't mean that normal old day-to-day mold is anything to be concerned about. The house you live in, at some point during construction, was exposed to the weather and there started the current colony of mold that lives there.
posted by humboldt32 at 1:17 AM on August 12, 2019 [1 favorite]

I don't know where you live. I'm in Maine where it is quite warm and quite humid, and in July and August, especially, stuff gets moldy, sometimes alarmingly quickly, and even if sealed. I always forget to turn the fridge to a colder setting until I pull moldy food out. Park the car facing the sun, use the vent setting that lets in fresh air, make sure there's no pocket of wet carpet.
posted by theora55 at 11:05 AM on August 12, 2019

It's really easy to raise the temperature in your car to one that will kill most mold spores. Once you are confident that the car is bone dry, use the green house effect on a sunny day to raise the interior temperature to one that makes you refuse to get into the car until it has cooled down. That will do a lot to discourage the mould from surviving or spreading.
posted by Jane the Brown at 12:31 PM on August 12, 2019 [1 favorite]