Heath problems caused by mould

Mould and mildew can have an adverse effect on people. Those with allergies, asthma or other respiratory problems should stay away from infested areas, as many fungi will seriously irritate and inflame lungs. Some fungi can cause skin and eye irritation and infections. Prolonged exposure to germinating moulds in closed areas can damage the lungs, mucous membrane, cornea, respiratory tract, stomach, intestines, and skin. Some varieties of mould are highly toxic.

What is a Mould-Preventive Environment?

There are a number of factors which influence the growth of mould: environmental humidity and moisture content of materials, temperature, air circulation, light, and the chemical composition of potential substrates.

Humidity. The most important environmental factor to control is the amount of moisture in the air. Some moulds can begin growing at 70% relative humidity or higher and then continue growing at relative humidity of less than 70%.

Temperature. Most moulds thrive at warmer temperatures. When combined with high levels of humidity, temperatures of 70 to 75° Fahrenheit can cause mould to develop. Temperatures below freezing will not kill mould, but they do make it dormant. Few moulds will be active at temperatures of less than 50° Fahrenheit. Mould can also grow in conditions up to 140° Fahrenheit.

Air Circulation. In conjunction with humidity and temperature control, adequate air circulation will help prevent mould growth. Air circulation helps control moisture levels through evaporation.

Installing a heating/ventilation/air conditioning system with humidity control can solve all three problems of humidity, temperature, and air circulation at the same time. Air Circulation Systems are expensive, not easy to install or simple to maintain.

Not only do suitable systems assist in mould prevention, but they also stabilise the environment and hence eliminate the distortion of materials due to fluctuating temperature and humidity. Furthermore, maintenance of a stable environment slows down processes of deterioration caused by acid, light, and pollution.

Fans can be installed to improve air circulation. They are best placed near outside walls and close to floor level. Portable dehumidifiers can be used, particularly for localised problems. Although you can invest in several units, portable dehumidifiers tend not to be as effective in large spaces as a centralised systems with humidity control. Fans and vents in attics will increase air circulation by pulling air through the building. This is particularly useful when it is necessary to leave windows open. Desiccants (such as silica gel) can be used to absorb moisture in humid environments. They should not, however, be used where young children are able to reach them because ingestion may be dangerous. Desiccants are most useful for localised problems, especially those that can be contained in a small, enclosed space.

Light. Sunlight, and in particular ultraviolet radiation, generally inhibits mould growth. It was found that more light correlated with slower growth rates.