High levels of microbe contamination can cause symptoms like dizziness, headaches, asthma, respiratory infections and in extreme cases, pneumonia and blood poisoning. The air we breathe contains a mixture of microbes, including bacteria, viruses, mildew, mould and fungal spores. Mould breeds exponentially if moisture or warmth is present, constantly ejecting spores into the air which spreads mould to other areas. Bacteria and mould travel on floating particulate matter as well as resting on surfaces.

Worldwide studies in air quality reveal that:

• Normal outdoor air carries 50 to 600 bacteria and mould spores per 1000 litres of air
• A clean air conditioner delivers 1000 to 2500 bacteria and mould spores per 1000 litres of air
• When indoor air smells musty or people start to show ill effects, the indoor air is usually delivering well above 2500 bacteria and mould spores per 1000 litres of air
• A windy day can deliver 25,000 bacteria and mould spores per 1000 litres of air

Damp areas, older houses, humid or tropical areas are more prone to higher levels of bacteria, mould, mildew and fungal spores. Any musty smell in a room or cupboard is a sure indicator of mould presence even if it is not visible. Moulds are able to grow on virtually any substrate, including paint, glass, electrical equipment and textiles.

Active mould releases toxins, called Mycotoxins, which can have a detrimental effect on health when bacteria lodges into airways due to reduced immune defences. Mould and bacteria concentration increases closer to the ground level, which is why children are more prone to colds.