Fraud Blocker

Common health effects of indoor mould exposure

Mould can significantly impact your health. Here are some important details to consider if you believe you have been exposed to mould.

Contact us

Scientific literature indicates that exposure to mould and indoor humidity causes symptoms of asthma. In addition, mould is known to cause type II allergy symptoms. Some of the most commonly reported symptoms from our customers, include:

  • Irritation, burning sensation
  • Redness, itchy eyes, throat secretion, nasal congestion
  • Sneezing, coughing
  • Bleeding or runny nose
  • Heavy breathing after a cold
  • Shortness of breath
  • Rash (redness, pimples, spots), other skin irritation
  • Muscle pain, decrease in physical abilities

Launching an attractive and scalable website quickly and affordably is important for modern startups — Stack offers massive value without looking 'bargain-bin'.

Source effect

Ask yourself the following questions

  • Did symptoms appear when I moved in?
  • When I am away a few days, do I feel better?
  • When I come back, do symptoms reappear?

If your answer to any of these questions is "yes," it is likely that your symptoms are the result of poor indoor air quality.

Note that children and the elderly are generally most at risk. Pregnant women and sick people must also be cautious regarding significant presence of indoor mould.

According to Health Canada, different parts and products of mould can cause different health issues.3

Mould affects your health in different ways:

Source Characteristics
Mould cell walls Cause inflammation
Spores and mycelia Cause allergies
Mycotoxin: Toxins produced by mould and mushrooms May be toxic and cause infectious diseases in humans (for example, Aspergillus fumigatus mycotoxins may cause Aspergillosis – bronchitis and lung disease)

3 Gazette du Canada, vol 141, no 13, 2007, p 710-713.

Symptoms may decrease significantly, or disappear altogether once you leave the contaminated area.

Over the years, our clients have asked us many questions about mould. Here is a list of frequently asked questions and our answers.

  • Will everyone in a house necessarily be affected if there is mold in the house?

    No, it depends on the sensitivity of each individual, the quantities of mould found, the species of mould, the time spent in an environment, etc. The people who are normally most at risk are the elderly, children, and people with respiratory disabilities or other disorders (atopic or immunocompromised people). Pregnant women should also exercise caution when dealing with mould.

  • Do symptoms associated with mould exposure go away if the problem is corrected?

    Normally, yes. If corrective work (decontamination) has been carried out to eliminate indoor mold, things should usually return to normal after a few days. If not, consult your doctor. It is possible that there is something else causing your symptoms, that there is another source of mold, or that the problem has not been completely fixed. In some cases, however, the symptoms may be irreversible.


  • Can we live in a contaminated space?

    Several factors can influence the determination of whether a space can be inhabited in the presence of mould contamination. It is important as a first step to make a complete investigation of the building in order to determine the extent of the contaminated surfaces, and what corrective measures must be put in place.

    On the other hand, always check the severity of your symptoms, if they are significant, you should preferably consult with your doctor and ask if you may need to leave the premises temporarily until the problem is resolved.

  • Are all kinds of moulds dangerous?

    Generally, all moulds are irritants to varying degrees (eyes, throat, nose) and cause allergic reactions.

    However, some moulds are more harmful than others. For example, mould families such as Penicillium or Aspergillus have several species that generate mycotoxins which can cause serious negative effects on health beyond irritation and allergies. This is the case with Aspergillus niger , Aspergillus flavus , Aspergillus fumigatus , Aspergillus versicolor, Penicillium citrinum , Penicillium cyclopium, Penicillium chrysogenum, etc. Other moulds like Alternaria alternata, Stachybotrys chartarum,  and Trichoderma harzianum can also have an impact on the health of the occupants. Cladosporium Cladosporoides is a common mould found in homes that can also cause symptoms. In fact, for some time now, we have noticed that it is found in the pollen forecasts (spore index) of weather media like other moulds.

    This is not an exhaustive list, and many other moulds are found in homes that can generate mycotoxins and cause symptoms in occupants.


  • Can mould contamination have any effect on our pets' health?

    Yes. Mould contamination can affect the health of humans and animals. Basically, moulds generate mycotoxins to defend their territory against other organisms in their environment. It is therefore possible that animals are also affected by these substances. Several customers have already asked us to do air tests in their homes because their animals were sick and the vets did not understand exactly what was wrong with them. Removing contamination in these cases proved to be a successful solution for the pets. In fact, animals can be even more affected by mould contamination because they are closer to the ground and therefore closer to household dust, where there is a large concentration of moulds.

What are the signs of the presence of mold in a building?


Call us

we are available at (514) 319-0231


Contact us to get a quote now

Molds are fungi that cannot be observed with the naked eye. They can appear as small colonies in several corners of a house. This is especially the case if you have moisture or water accumulation in your home.  Or if you have gypsum board or cardboard stored in a room of your home. These are favorable to the proliferation of mold.

Beware of mold!

If mold appears on small areas and you get rid of it quickly, it will not expose you to any particular risk. On the other hand, if their multiplication is important, these molds will spread particles in the air. The occupants of your home could breathe it. This is likely to generate health problems.

In reality, inhaling spores or fragments of mold, or even mold as such can cause various health problems. It can also degrade the state of health of vulnerable people or worsen a disease.

And that's not all, because many types of mold are the cause of mycotoxins. These are metabolites, as well as processed products derived from mold and considered toxic to humans. The presence of these toxins can trigger allergic reactions or respiratory disorders.


The symptoms you may experience can sometimes be caused by other factors, other kinds of air contaminants in a home, to name but a few:

  • Mites;
  • Cigarette smoke;
  • Allergens that come from pet hair;
  • Fragments floating in the air, which are for example from cooking food with wood...