Moulds are fungi that grow in the form of multicellular filaments called hyphae. Moulds are considered to be microbes but microscopic fungi that grow as single cells are called yeasts. A connected network of these tubular branching hyphae has multiple, genetically identical nuclei and is considered a single organism, referred to as a colony.  

There are thousands of known species of moulds. Like all fungi, moulds derive energy not through photosynthesis but from the organic matter in which they live. Typically, moulds secrete hydrolytic enzymes, mainly from the hyphal tips. These enzymes degrade starchcellulose and lignin into simpler substances which can be absorbed by the hyphae. In this way, moulds play a major role in causing decomposition of organic material, enabling the recycling of nutrients throughout ecosystems

Many moulds also secrete mycotoxins which, together with hydrolytic enzymes, inhibit the growth of competing microorganisms.  Moulds are ubiquitous in nature, and mould spores are a common component of household and workplace dust. Every house has moulds present.!!  However, when mould spores are present in large quantities, they can present a health hazard to humans, potentially causing allergic reactions and respiratory problems.

Some moulds also produce mycotoxins that can pose serious health risks to humans and animals. Some studies claim that exposure to high levels of mycotoxins can lead to neurological problems and in some cases death. Prolonged exposure, e.g. daily workplace exposure, may be particularly harmful. Research on the health effects of mould has not been conclusive. The term "toxic mould" refers to moulds that produce mycotoxins, such as Stachybotrys chartarum

Mould in the home can usually be found in damp, dark or steam filled areas e.g. bathroom or kitchen, cluttered storage areas, recently flooded areas, basement areas, plumbing spaces, areas with poor ventilation and outdoors in humid environments. Symptoms caused by mould allergy are watery, itchy eyes, a chronic cough, headaches or migraines, difficulty breathing, rashes, tiredness, sinus problems, nasal blockage and frequent sneezing.

© The House Doc 2011