MBL Blog

Question:  I have found what appears to be a mould growing in my window. It is gooey in texture and clear in colour. The window is often wet with condensation to the point it drips down continually for hours on end.

I am not sure if the jelly like characteristic of the mould is because of the water or because that is its composition. Recently the mould was disturbed by somebody in our room (they opened the window). My wife had just left the room for a while with our infant daughter (10 months) for medical reasons as this person had to come in. When she came back into the room fifteen minutes or so passed when her nose started running, being allergic to mould she immediately told me it had been disturbed and she could smell it. She now has had for the last four days what appears to be cold like symptoms. What should we do? How long do these symptoms typically last?

Does my description of the mould sound at all like anything particularly dangerous?
Would this be a danger to our daughter? We don’t actually have anywhere else we could live so this is important to us how we handle it.  Could putting plastic window covering that seals with heat keep it from the room or would it disturb it too much?  It wasn’t here in the summer but seems to have happened from the washing that we’ve hung in the room drying without any ventilation. We’re concerned for our daughter so if you could let us know asap we’d so appreciate it. As I said, we live in this room and she is in the room nearly 24 hours every day. Thank you for your time.

Answer: It’s difficult to tell for sure what type of mould it is from the description you have just given. It’s even harder to say whether it’s dangerous. But all moulds are potentially a health hazard. There are a number of moulds that can grow on windowsills following condensation. The common ones are Cladosporium, Aureobasidium, Ulocladium and Alternaria. These moulds are generally dark colored or could appear black and therefore do not fit well the description you have given. It’s important to note that any mould can grow on windowsills as long as there is moisture and nutrients.

As for what to do, I would suggest you get a qualified professional to assess the problem and advise you on what to do. You have mentioned that there is poor ventilation which obviously explains why there is condensation on the windows. To control mould growth, the ventilation/condensation problem should be corrected. I would not recommend putting a plastic window covering to seal the mould. The best thing is to get professional help.

Symptoms associated with mould exposure would generally disappear once the mould is removed or the individual leaves the contaminated building.