As you read this article there could be some mould growing silently somewhere in your house or in the office where you work. This thought may not have bothered you if you had not heard in the media phrases like “toxic mould” or “black mould”! These phrases create fear, panic and confusion. The objective of this article is to provide the reader with some basic facts about mould and the associated health effects.

Should One Be Concerned About Indoor Mould Growth?

Yes. Apart from mould being unsightly in a building there are 3 good reasons why people should be concerned about mould growth.

Health Risk

As mould grows indoors, it produces spores and/or chemical compounds that easily become airborne. The health effects associated with inhaling or getting into contact with these spores and chemicals may include runny nose, eye irritation, cough, congestion, aggravation of asthma and respiratory problems, headache, flu-like symptoms, fatigue, skin rash and other allergic reactions. Individuals with weak immune systems may also get infected by certain moulds as a result of exposure.

Legal Issues

Those responsible for building maintenance or health and safety of building occupants, contractors and other professionals involved in the building operations are at risk of being sued if occupants get sick from mould growth.

Material Damage and Impairment of Processes

Mould if allowed to grow, can impair the functioning of many processes from air conditioning units to electrical circuits. Surfaces of materials on which mould is growing get stained or discoloured and may disintegrate over time. Wood-rotting moulds are capable of weakening wooden structures.

Three Things You Should Know About Mould

• Mould growth is a fact of life for almost all industrial and indoor environments. However, mould growth can be controlled by providing adequate ventilation and maintaining indoor humidity at levels below 65%. When excessive moisture or water accumulates indoors, mould growth will often occur, particularly if the moisture problem remains unnoticed or unaddressed for more than 48 hours. The key to mould control is keeping the building dry and clean, timely maintenance and prompt repairs.
• Not all moulds are harmful but to be safe it is better to treat all moulds as potentially harmful. The colour of the mould does not determine whether it is harmful or not. Therefore, black mould is not necessarily bad mould. Mould related health effects depend on:
  • types of mould present,
  • amount of mould one is exposed to and for how long,
  • individual health status or sensitivity. Children, elderly and sick people are more vulnerable to mould.
• It is difficult to eliminate all mould spores in the indoor environment. However, the levels can be minimised by controlling growth. Monitor mould growth by looking for water stains or discoloration on the ceiling, walls, baseboards, floors, and window sills. Pay particular attention to the basement and the attic.

What Should You Do When You Find Mould?

If you are an indoor mould consultant

• Assess the extent of the mould problem.
• Discuss the problem with your client and reassure them.
• Have the dominant moulds identified preferably to species level. However, before sampling, prepare a sampling plan that details how and when samples
  would be collected, the type of samples to collect, collection requirements for each type of samples, the criteria to use to interpret results, and the benefits expected from sampling, i.e., what question(s) would be answered by the laboratory results and what actions would be taken. Share the sampling plan with the client.
• Discuss the lab results with the client. If the client is concerned about their health, advise them to seek medical opinion from their family doctors.
• Discuss the remediation plan (or options if any), the remediation costs and the expected results with your client.

If you Are a Property Manager or Homeowner

• Do not panic! The presence of mould does not necessarily mean that you or the building occupants could have adverse health effects or that they have even been exposed.
• Do not disturb the mould since this could help the mould in shedding more spores into the air.
• If what you suspect to be mould covers more than 10 square feet, seek the advice of a qualified consultant immediately. If unsure of how to handle mould covering less than 10 square feet, seek professional advice. Avoid exposing yourself or others to mould.
• Ask for the mould to be identified to reassure yourself or the building occupants that it is not among those that cause serious health effects.
• Discuss the problem with your family doctor or if you are the property manager reassure the occupants and let them know the actions you are taking.
• If you find a professional who seem to concentrate more on how the mould could or have affected you or the building occupants, seek a second opinion. A good professional should provide facts and avoid causing fear.

Should you have a question concerning indoor moulds, please send your question to My Question.