A number of moulds are frequently found in carpet and mattress dust. Eurotium repens is the most frequently detected mould in mattress dust. Others include Aureobasidium pullulans, Alternaria alternata, Penicillium chrysogenum, Aspergillus penicilloides and Aspergillus restrictus.

More than 100 species of moulds have been recorded from carpet dust. As with mattress dust, the most frequently isolated mould in carpet dust is Eurotium repens. The others are Penicillium chrysogenum, Alternaria alternata, Aureobasidium pullulans and Phoma herbarum.

Concentrations of these moulds in carpet and mattress dust can be as high as 70 million colony forming units per gram of dust. Such high concentrations of moulds are likely to cause respiratory allergy or irritating symptoms. Therefore, it is import to regularly HEPA vacuum the carpets, mattresses and upholstered furniture to reduce the dust and spore concentration. If people are suffering from reoccurring respiratory allergy or irritating symptoms in a building where there is no visible mould, it is suggested that dust be tested for the types and concentrations of mould present.

While we are enjoying the summer, it can be a tough time for allergy sufferers. The concentrations of pollen and mold spores in outdoor environment is highest in summer months. Since mold spores and pollen tend to infiltrate into indoor environment their concentration indoors can also be very high in summer. Molds and pollen capable of causing allergic reactions in sensitive individuals are said to be allergenic. Allergy follows inhalation of large amounts of spores or pollen grains. The amounts capable of triggering allergy depends on the specific allergen and the sensitivity of the individual.


Types Of Mold Allergy
Molds as causative agents of respiratory allergy and asthma have been known since the 18th century. Allergic reactions to molds may be either immediate, developing within minutes of exposure (Type I), or delayed, occurring 4 - 8 h later (Type 111). Two of the most important allergenic molds are Alternaria alternata and Cladosporium herbarum. Concentration of these two molds are usually highest outdoors from June to October.


Fungi produce huge amounts of spores. In his book, "The Fifth Kingdom", Dr. Bryce Kendrick, gives the following examples:

• One specimen of the common bracket fungus discharges 30,000,000,000 spores per day every day from beginning of May to the end of September


• A 2.5 cm diameter colony of the green mold, Penicillium, can produce 400,000,000 spores.

Fortunately, these huge numbers are diluted by air and we inhale far much less spore concentrations.

Allergenic Pollen
Among the well known allergenic pollen is the ragweed pollen. Individuals sensitive to ragweed pollen are also sensitive to other pollen grains such as those of poverty weed and false ragweed. Concentrations of these pollens are highest within the months of June to September depending on the flowering time of the particular weed.