Cyclones and floods are usually associated with excess moisture, long periods of heat and humidity, and pooling of water. These factors all help to create an environment that is favourable to the growth of mould. In northern Queensland, mould is also a wet season issue, even without floods, and is not uncommon in buildings. People can be exposed to mould through inhalation, skin contact or ingestion.

People with a normal immune system are unlikely to be affected by mould. However, for some people, such as those with a true allergy to mould, asthma or lung disease, elderly people or people with chronic diseases like diabetes or people with low immunity, such as people on cancer chemotherapy, exposure to mould may cause them to develop health problems. If concerned, see your doctor. By reducing mould and by taking precautions when removing mould, you can help reduce the risk of mould-related health problems.

Identify mould

Sometimes you can see mould when it discolours walls, ceilings and other surfaces. If you can’t see it you might be able to detect a musty, unpleasant odour instead.

Air out the rooms

When returning to a flood-affected house or building, dry it out quickly by opening all the doors and windows. If possible, use fans, or air-conditioners on dry mode, to speed up the process. If the roof space was flooded, it also will need extra ventilation to speed up the drying process.

Porous items that can’t be easily cleaned and have been wet for more than two days should be thrown out. This includes items such as mattresses, carpet, leather goods and ceiling insulation.

Moisture control is an effective method for controlling mould growth. In high rainfall areas, such as north Queensland, this is difficult to achieve, but other factors – such as leaky plumbing, roofs and other fixtures should be repaired as soon as possible. If repainting walls or other hard surfaces prone to mould growth, anti-mould solutions can be added into paint to help minimise mould growth. Ask your painter or hardware supplier for details.

Plants and bushes growing on or close to outside walls help to hold in moisture and promote mould growth. Try to clear plants, bushes and soil away from walls.

Clean mould

Abrasively cleaning mould from a surface, such as with a dry brush, is not recommended. This could release spores into the air, which may cause adverse health affects and spread mould to other areas.

There are many effective products for killing and removing mould from walls, floors and other hard surfaces. Household cleaning agents or detergents can do an effective job if used correctly, as can white fermented vinegar cleaning solution.

Using bleach is not recommended because it’s not an effective mould killer. However, bleach will help to eliminate other disease-causing organisms that may be present because of contaminated floodwaters. Mixing cleaning agents is not recommended. For example, mixing bleach and ammonia can produce toxic fumes.

Items that can be washed, such as stuffed toys and linen, should be washed as usual. If in doubt, take them to a professional cleaner. Otherwise discard the items as advised by your local council.

Non-porous items such as glass-ware and some plastics can be washed in hot water with a bleach solution or with a good quality disinfectant and air dried. If using a dishwasher, clean and disinfect it first. Do the wash using a full cycle and hot water.

Air conditioning and other ventilation units are a good environment for moulds and other bacteria to grow. Using the unit without cleaning it properly first can cause mould spores to become airborne and be inhaled or spread to other areas. It’s recommended that you have air conditioners and ventilation units serviced by a qualified technician.

Protect yourself

Wear good quality rubber gloves while touching and cleaning mouldy items to protect your hands and nails. Protect your eyes by wearing safety goggles with closed in sides.

If you have a lot of mould to clean or have allergies, wear an N95/P2 disposable respirator. Standard dust masks do not protect you from microscopic spores and bacteria. Be sure to follow the manufacturer’s instructions and fit the mask properly.

Wear protective clothing that can be thrown away or washed easily.

Prevent mould growth

Reducing the amount of moisture is the best way to control mould growth. While you can’t control factors like rain, you can repair other sources, like leaky plumbing, roofs and other fixtures, as soon as possible.

If you’re repainting walls or other hard surfaces you can add an anti-mould solution to the paint to help slow down mould growth. Ask your painter or hardware supplier for details.

Plants growing on or close to external walls can hold in moisture and promote mould growth. Make sure your walls and weep holes are clear of plants and soil.

Salvaging damaged collections

State Library of Queensland’s conservation experts have gathered together the most effective methods to ensure the long term preservation of your previous family objects, such as books, diaries, pictures and photographs.