Which Moulds Are Dangerous To Your Health
Mould is a type of fungus that often looks like fuzzy spots of different colors, including green, gray, or black. More than 100,000 mould species have been identified. Exposure to moulds can be linked to negative health effects, depending on the type of mould and the health status of the person.
You may have heard or read about “toxic mould.” Actually, moulds themselves are not toxic or poisonous.
You may have heard or read about “toxic mould.” Actually, moulds themselves are not toxic or poisonous. However, there are mould species that are “toxigenic,” meaning they produce mycotoxins. These mycotoxins are chemical byproducts of metabolic processes – any process performed to maintain life, such as converting food into energy or cellular respiration. Some mycotoxins can cause a toxic response in humans and animals, even in small amounts.
Moulds reproduce by creating spores that can be too small for the naked eye to see. The spores vary in shape and range from 2 to 100 microns in size (for comparison, a strand of a human hair ranges from 17 to 181 microns in diameter). Moulds release the reproductive spores, which can spread through the air, water, or on animals. Mould spores can cause health issues by triggering allergies or asthma attacks.
When mould spores land on a damp spot indoors, they may begin growing and digesting whatever they are growing on to survive. Moulds can reproduce in any moist place. They can grow on wood, paper, carpet, foods and other surfaces.
1. Allergenic Moulds
Everyone breathes in airborne mould spores, but some have an allergic reaction or experience asthma symptoms. Airborne mould spores can get into the nose, causing similar symptoms to other common airborne allergens, such as sneezing, itching, runny nose, congestion and dry skin. Mould spores can also enter the lungs, triggering an asthmatic episode.
The most common moulds whose spores can act as allergens include:
Alternaria – A common outdoor mould, often appearing as dark gray spots. The mould can grow indoors, especially damp surfaces with a food source, such as wood.
Penicillium – It is a blue-green mould that many people have seen growing on food. Some Penicillium species produce airborne spores that can act as allergens and asthma triggers for sensitive people.
Aspergillus – A mould that is so abundant that it is probably impossible to avoid breathing in at least some of its spores. There are a few species of the genus that can cause serious illness when inhaled by people who are immunocompromised, have a lung disease, or have asthma.
Cladosporium – One of the most widespread moulds. Indoors, it is common on wet building materials, such as gypsum board, acrylic painted walls, wood, wallpaper, carpet and mattress dust, HVAC fans, and wet insulation in mechanical cooling units.
2. Pathogenic Moulds
A pathogenic mould is one that can cause an infection in humans, even if they are in good health.
The most common pathogenic moulds include:
Aspergillus species: Can cause chronic pulmonary infections.
Cryptococcus neoformans – If an immunocompromised person inhales spores, they can stay in the body and cause a later infection if the immune system becomes even weaker.
Histoplasma capsulatum – Causes the infectious disease histoplasmosis. It’s acquired by inhaling airborne spores. Inhaled spores can also cause a lung infection (pneumonia). Those with a weakened immune system risk the infection spreading throughout the body which can be life-threatening. This mould is usually found in soil; however, it is also found where there are bat and bird droppings.
3. Toxigenic Moulds
The toxigenic moulds are the misnamed “toxic mould” species that may create the chemical metabolic byproducts called mycotoxins, which can cause a toxic response in humans and animals. Mycotoxins travel through the air on very small particles of dust or tiny pieces of wallpaper, which can easily be inhaled.
It should be noted that the presence of a toxigenic mould species does not necessarily mean the presence of mycotoxins. Also, it’s not possible to know if a mould is producing mycotoxins just by looking at it.
What You Can Do About Mould In Your Home?
The best way to control mould growth is to control moisture. Other actions you can take include:
- Fix any sources of water leakage. Homeowners may need a plumber or an HVAC contractor to eliminate water leaks (which is the most likely cause of the moisture on which mould is feeding).
- Reduce indoor humidity (optimal indoor humidity is around 40%).
- Use exhaust fans whenever cooking, dishwashing, and cleaning.
- Use soap and a sponge to remove visible mould.
- If any mouldy areas are dry, lightly spray a water mist on them. This will prevent you from sending mould spores into the air during cleaning.
- If you use bleach, make sure it won’t cause discolouration. Never mix bleach with ammonia. It will create toxic fumes.
- If there is excessive damage to a building or home after a flood and you are cleaning, be sure to put all materials used in cleaning in a heavy duty garbage bag and seal it. Take the bag outside through the closest exit. You don’t want any spores to become airborne.
How To Protect Yourself from Mould Spores and Mycotoxins
- Wear respiratory (nose and mouth) protection when handling moldy materials. An N95 particulate respirator is recommended.
- Wear clothing that covers your arms and legs to avoid contact with mould spores.
- Wash or discard the clothing after every cleaning.
- Wear gloves and protective eyewear.
- Using a high-performance HyperHEPA mould air purifier can help clean the air, even as work progresses. For example, the IQAir HealthPro can dramatically reduce airborne particulates including mould, and can also reduce or eliminate any musty odors.
Moulds can be found almost anywhere; they can grow on virtually any substance, providing moisture is present. However, if you are aware of the potential dangers and are taking the proper precautions, you can limit your risk of experiencing health effects from mould spore and mycotoxin exposure.