All about Toxic Black Mould and Mildew

Black mould shows itself as greenish black stains on walls and other surfaces. It is known to be highly toxic, and produces toxic by-products known as mycotoxins. If you come into contact with these, they can give rise to many unpleasant symptoms. It is beyond the scope of this article to go into medical detail -but if you have a weak or compromised immune system, you are more likely to suffer from mould.  That's why it is also known as Sick Building Syndrome, although there is some argument as to whether it really exists.

There is a problem in that the symptoms of toxic black mould are quite similar to other medical conditions - this makes it a bit hard to work out whether they are caused by conditions in your house, or are something unrelated.  The only sure way to work out if you are being affected by toxic black mould (mold) is to have a survey carried out.  This will be a very detailed building pathology survey - it will look for dampness under floors, in cupboards, in the walls.  It will monitor humidity levels in the house, and check air circulation.  

Some of the symptoms that commonly relate to toxic black mould (mold) include skin rashes, nausea, asthma or simply trouble breathing.  You may also feel dizzy.  Sinusitis can often happen - sinus headache, coughing, or running nose.  I often experience these sorts of symptoms when doing surveys in damp houses - I can almost smell the stuff when I walk in.  It gets worse when you turn the heating up, as all the spores start to go airborne.

The solutions are many, but the American Society of Heating, Refrigeration & Air Conditioning Engineers recommend a minimum of 8.4 air exchanges per 24 hour period.  This removes humid, toxic spore laden air, and maintains air circulation.  Its hard to achieve this in closed cupboards and wardrobes though, which is where most problems start.

Mould generally starts because air in your home is humid.  To understand what happens, you need to 

What is Toxic Black Mould

Toxic black mould is also commonly confused with, or associated with mildew, or powdery mildew.  They are both a type of fungi.  

The green furry stuff which develops on stale and degenerated food is mould.  Mildew also grows on the surfaces of clothes - especially leather, in places where moisture content is very high. It targets areas of little or no air circulation - like the back of wardrobes, kitchen cupboards, under stairs cupboards and so on.  It tends to target plants and living surfaces.

Toxic black mould tends to form on plasterwork, damp paintwork behind cupboards, under floors on timber.  It tends to form rounded patches. It smells... horrible, damp, earthy.  Black mould grows multicellular filaments called hyphae. The tubular branching hyphae has multiple, identical nuclei, and has a connected network. It is considered to be a single organism.  The same growth conditions as mildew - lack of air circulation, high humidity, and generally dark places.  It targets non living things, and loves things like bathroom tiles, grout, gloss paint behind kitchen cupboards, gypsum plaster surfaces, and even plastic. It is generally the cause of lethargy - which is not the case with mildew. 

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