Expert in the field

Kateřina Klánová, Ph.D.                                          

Expert in the field: Healthcare, branch hygiene with specialization on measurement   

and evaluation of bacteria and moulds in the life environment of humans.

Expert verdicts in English          



Moulds are a special group of fungi, called also microfungi or filamentous fungi. Moulds grow on organic materials (plants, soil) in the environment. Our environment is really full of these microscopic organisms. Moulds produce millions of tiny cells called spores, which can be carried long distances by wind before they germinate into new fungi. 

Moulds spores are present almost everywhere and elevated humidity in a given material lead to microbial growth and subsequent damage to products such as textiles, leather, wood, paper and many other things of organic origin. They can grow on different types of building material. They can grow and can destroy materials very efficiently.

Moulds need water for their life. Moulds will not grow on dry materials. If walls, leather or other materials are dried and kept dry, there will be no moulds. However, allowing them to get wet will encourage mould growth. Moulds are tolerant to temperature 40-100 ˚F. That is why a situation is worse in summer, or from spring to autumn. Organic matter (dirt) from the air can be also nutrition for their life.

When a spore lands on a suitable surface, such as wet walls, it germinates. The spore breaks open to send out a tiny thread – the first hypha. This hypha grows down into the wall and then starts dividing into many different hyphae. Eventually, the walls become filled with mould hyphae. After that comes time to reproduce.

The mould sends up a thread into the air, which divides many times, till it finally produces many, many spores. Mould spores will be introduced to the indoor environment from moulds on walls and other material.

Millions of spores are inhaled by humans and deposited on the mucosal surface of the upper airways and in the eyes. Microfungi can cause adverse health problems in several different ways. They can be the cause of airway allergy and may cause eyes, nose and throat irritation.

Inhalation of mould spores has toxic effects on many different organs. Some moulds may cause skin irritations after direct contact with the skin. Fungi can cause infections, i.e. be pathogenic. Some groups of pathogenic fungi can attact skin, hair and nails.

Growing moulds also produce microbial volatiles (unpleasant odours). Microbial volatiles are organic solvents such as alkohols, ketones, esters and hydrocarbons. There is growing evidence that microbial volatiles may have serious health implications, such as irritative effect. They also can be very troublesome. Curtains, carpets and clothing of people from houses with moulds will absorb the unpleasant odour. As you can see from photo documentation, there are visible areas of damage on the walls, household furniture etc. caused by the growth of the mould. Such massive growth of mould is always related to the production of a large amount of spores and creation of volatile organics.

From the hygienic point of view, it is strongly recommended using anti-fungicidal treatment. During the manipulation of the moulds it is a recommended practice that you work with them as you would with any other infectious materials, that is that you adhere to all safety hygienic regulations such as working in well ventilated area, wearing gloves and a face mask.

Penicillium cyclopiumMoulds on the wallMoulds on the furniture

Moulds on the facade

Moulds in the laboratory