Health Canada recommends that all mould, regardless of the species, be cleaned and that the underlying water or humidity problem be dealt with quickly to prevent potential health issues.
You should first look for obvious signs of mould growth like:
In most cases, there is no need to measure the actual concentration of mould in your indoor air, or to determine the specific species of mould that may be growing on indoor surfaces. Although possible to measure, the results of such tests are not really useful for a number of reasons:
Not all mould is obvious. It can also grow inside walls or above ceiling tiles, so it is important to check for the presence of mould anywhere damp or moist, and especially where water damage has occurred.
If you suspect a mould problem that you cannot solve on your own, Health Canada and the Canada Mortgage and Housing Corporation (CMHC) recommend that you contact a trained Indoor Air Quality Investigator for advice on building-related aspects of air quality. These investigators can do a visual inspection to identify areas of concern and make recommendations for improving the situation.
If you discover mould, follow these two steps:
You can generally clean small and moderate areas of mould by yourself, but you should consider getting professional help with extensive mould growth.
The CMHC classifies the amount of mould as
When removing mould, you should wear proper protective equipment, including rubber gloves, eye protection and a dust mask. You may also want to isolate the area by taping plastic sheeting to walls and ceiling to prevent the spread of dust and mould particles. Sensitive individuals should not be in the same or adjacent rooms during the work and may choose to leave the house until the mould is removed.
You might consider hiring a professional if there is a large amount of mould or if the mould keeps coming back after you clean it. A large amount of mould is often also the result of a larger problem, such as a leak in the foundation or a major flood, which may require professional help to fix.
If you rent your home or workspace, there's a limit to what you can do to correct mould problems. If your landlord is unaware of the structural building problems that cause mould, direct him or her to some of the resources available on this site.
Landlord and tenant's rights and obligations fall under provincial and territorial jurisdiction. Ideally, you and your landlord will be able to come to an arrangement to deal with any problems, but information on dispute resolution in landlord/tenant issues is available if required:
There are a lot of things to consider when looking for a new apartment, and if you are particularly concerned with the presence of mould, consider these factors: