Yes mold can grow on any wood or plastic items placed inside the aquarium.
Mold/fungus is a common cause for allergy.
The spores from common molds function much like the pollen from ragweed. If you inhale the spores, you could get a case of allergic rhinitis, otherwise known as hay fever -- an unpleasant combination of runny nose, sneezing, watery eyes, itching, congestion and coughing. And if you have asthma, the spores may trigger attacks. More than 80 types of mold have been associated with lung, nose, and throat problems, according to the American College of Allergy, Asthma, and Immunology (ACAAI).
The best treatment for mold allergies is avoiding mold in the first place. But if you live in a place where mold is unavoidable, your doctor can offer additional help. You may need an antihistamine medication to control your symptoms. In severe cases, your doctor may prescribe a series of allergy shots to help reduce your sensitivity to mold.
YES. Very bad too. I had a fresh water aquarium and could not walk in the room. The top glass grew algae or mold. It was greenish. Sent spores out. My throat was so sore and the closer to the tank I got the worst it got. After I washed the top glass I was fine for a few days.
I ended up giving the fresh water fish back to the fish store and started a salt water tank. The salt splashing on the top glass seems to prevent the mold that I was allergic too. I now have a 150 gallon salt water tank. All live rock and live sand no wet dry filter just a power head with a small foam filter on the power head. Very simple low cost setup. Sorry I went off topic.
But the saltwater tank gives me no problems. Fresh water tank was hurting me pretty badly.
But don't count out humidity that can feed molds if you have a filter inside/under the stand. I was also allergic or something to my old stand that was sealed with urithane. The fumes were irritating triggered mucus. So slight no one else could smell the fumes. But when I put my nose near the wood I felt like puking and my mucus went wild. Built my own stand and sealed it with rustolium latex high gloss paint. No fumes that I can detect after dry. No feeling ill, no mucus. That was another irritation. Urithane fumes.