There are over 150 recognized species of aspergillus, all of which are considered allergenic. The different types of aspergillus have been found in various environments, but are most common on decaying food, vegetation, soil and feed products in tropical and subtropical regions. Many aspergillus species cause extrinsic asthma, with acute symptoms including edema and bronchospasms and chronic cases potentially resulting in pulmonary emphysema. Other species reportedly can cause opportunistic ear and eye infections, as well as pulmonary infections. Furthermore, there are a number of species that produce mycotoxins, which potentially cause disease in humans and animals. While toxin production depends on the strain of species of this fungus, as well as where and on what it grows, some of these toxins are carcinogens in various animals and others are potentially carcinogenic to humans.
While cladosporium is commonly found outdoors, this fungus can also grow indoors. It can be found on fibreglass duct liner in supply ducts in indoor spaces, as well as on dead plants, food, straw, soil, paint and other textiles. It can lead to mycosis (fungal infection), with acute symptoms including edema and bronchospasms, while chronic cases can result in pulmonary emphysema.
Colourless mould is a white (i.e. colourless) form of fungus. Some moulds grow completely white because that is the colour of their spores, while others will start colourless before turning black or blue after they have produced their coloured spores. Colourless mould can be a range of different fungi and has no specific types, similar to black mould. It is best to contact a professional right away to determine what type of mould it is.
There are a large amount of organisms that fall into the penicillium category making it difficult to identify. It’s commonly found in things like soil, food and grains, but it can also grow in paint and compost piles, and most alarming for homeowners: carpet, wallpaper and interior fibreglass duct insulation. Certain species of penicillium produce mycotoxins. It also causes extrinsic asthma, with acute symptoms being edema and bronchospasms and chronic cases potentially resulting in pulmonary emphysema. It may also result in hypersensitivity pneumonitis (also known as allergic alveolitis), an allergic inflammation of the lungs.
The slow growing stachybotrys is often seen as a dark coloured fungus on building materials high in cellulose and low in nitrogen. Some species of this mould can produce trichothecene mycotoxin, which is poisonous if inhaled, through its fungal spores. This toxin thrives in spaces with temperature fluctuations and a relative humidity above 55%. Because the toxins produced by this fungus suppresses the immune system, chronic exposure can result in cold and flu symptoms, headaches, sore throats, fatigue, diarrhea, sporadic hair loss and overall illness. If inhaled, it can also lead to the lung disease pneumomycosis. It can be hard to detect in indoor air samples unless it’s disturbed. While the spores die quickly after being released, they are still toxic and allergenic.