Mould is neither plant nor animal, it is a single or many-celled organism that is defined as a type of fungi. Its job is to decompose dead organic material in the environment, such as dead plants and leaves. Given the right situation (water supply) and environment (food source), mould growth will thrive. These particular groups of fungi, known as mould, reproduce through the use of airborne spores. These spores are too small to be seen by the naked eye and are always present in the air of any environment. The colour of mould is influenced by the nutrient source and the age of the colony.
How Does Mould Grow?
As mentioned above, mould spores are ubiquitous (ever-present) and under the right circumstances, having a good food supply and damp environment, mould will have no problem spreading. Mould needs a few things to grow:
- Water source
Without some kind of moisture, mould has no chance of growing. Although it does prefer damp surfaces, mould can also grow on surfaces while drawing moisture from the air. A pipe leak in a wall is a good example of a good moisture source for mould to grow with. As the water is leaked from the pipe, a damp environment is produced in and on the timber frames and plasterboard of a house. Within this setting, mould will start to grow within 12-24 hours. - Food source
Mould requires organic food material to grow such as wood, plaster or even dust. While mould cannot grow specifically on inorganic materials such as glass and metal, it can grow on thin layers of dust found on top of them. - The amount of light
The amount of light in a room can heavily influence the type of mould growing within the environment as well as the number of spores released in the air. These effects vary between each type of mould. The amount of light in the room may also affect whether or not water is evaporated and vented out of a room. Typically, sealed low light areas do well in creating a good environment for mould growth.
Controlling and mediating any of these points will help you greatly in removing mould from the home or building.
How Does Mould Spread?
A mould is primarily spread through the use of airborne mould spores. These mould spores are produced by the mould itself as a means of reproduction. As mould is circulated in the air by air currents, when it has landed on a good food source, such as a damp piece of would, if left for too long, mould will start to grow. Since wood is a dead organic material, it works well as a food source for mould.
As mould begins to dry, it accelerates its release of mould spores into the air. As moisture decreases the released spore count grows exponentially.
Mycotoxins
Mycotoxins are a secondary metabolite produced by fungi mould. While they are not vital to sustaining the life of the mould, they are specially designed to give certain mould a competitive edge over others. It should be noted that not all mould produce Mycotoxins.
These mycotoxins either cling to the mould spores or are found in the spore themselves. As these mycotoxins are known to cause serious health effects, it can be very serious if these mycotoxins are inhaled or rubbed into any kind of skin tissue or body part. There have been more than 200 mycotoxins identified and are typically found within water damaged buildings.
Symptoms
A post of the symptoms of mould and their mycotoxins can be found here.