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The toxic effects of hidden moulds

Posted by Geoff Beaty on 26 June 2021
The toxic effects of hidden moulds
Some people get sick from exposure to mould. Others have no symptoms and don't experience ill effects of any kind. Let's look at the potential dangers of mould exposure, symptoms of mould illness and how you can treat it, as well as how you can reduce your exposure to mould.

What is mould exactly?
Mould is a type of fungus. It is present almost everywhere, including the air. It can flourish both indoors and outside and there are millions of mould species.

Mould needs organic matter to feed upon and moisture in order to grow. When growing conditions are right, mould releases spores and volatile organic compounds (VOCs) into the air, which may make some people feel sick.

Mould is important for the planet's ecosystem, because it helps break down waste products and organic matter, such as leaves, dead trees, and garbage. 

Mould spores may be breathed in or absorbed through skin. Mould can also grow on food and may be hazardous if ingested.

Mould exposure outdoors
When you're outside, you may come into contact with mouldy surfaces in forests, beaches, backyards, playgrounds and pavements. Piles of wet leaves, damp wood, and rotted tree bark are all sources of mould. So are standing, stagnant water sources, such as wading pools and puddles.

Mould exposure indoors
Mould spores enter the home, school and workplace through a wide range of channels. They may attach themselves to clothing, shoes or your pet. Spores can float in through open doors and windows and through air conditioning or heating vents.

Some of the most common varieties of indoor mould are: Aspergillus, Cladosporium, Stachybotrys atra (also known as black mould) Mould needs moisture to grow. Damp, humid environments are particularly prone to mould growth. Poorly ventilated areas also pose a mould risk.

Indoor areas that commonly become mouldy include:

damp bathrooms or kitchens that have drippy faucets or leaking pipes
damp basements
damp carpet
wet paper
fireplace wood
damp ceiling tiles or drywall
potted plants
condensation on window sills
washing machines and dishwashers
Personal items, such as sponges, lunchboxes, thermoses and sippy cups, can also harbor mould.

Mould on food
The carcinogenic effects of food-borne mould contamination are well documented. Certain mould species thrive on foodstuffs such as cereal, bread, nuts and dried fruits. Some of these may contain toxic substances called mycotoxins.

Dangers of mould exposure
In general, normal amounts of mould in the environment do not pose a substantial health risk to healthy people with regular immune system function.

Some people may be more sensitive to mould spores than others, and they may develop respiratory symptoms after inhaling even a small number of spores. In large quantities, mould spores can cause ill health in almost anyone.

If you have a mould allergy, you may experience significant respiratory distress when you come in contact with mould.

Toxic mould
According to the World Health Organization (WHO), mycotoxins can cause severe, adverse health effects, such as:

acute poisoning
immune deficiencies
Some moulds produce toxins, mycotoxins, that are absorbed through the skin or GI tract or enter the body through breathing. Stachybotrys chartarum is a famous toxic mould, also referred to as "toxic black mould." But mould doesn't have to be black to be toxic; it can be any color, which is why testing is key for mould identification.

Mould toxicity can also be caused by other toxin-producing organisms besides just mould. These include fungi, actinomycetes, mycobacteria, and bacteria. The toxins they make can be classified into mycotoxins, endotoxins, inflammagens, beta-glucans and mVOCs (mould volatile organic compounds). 

Author:Geoff Beaty
Tags:NewsResourcesPrevention & RecoveryCancerEnvironmental toxins


  • The Institute for Functional Medicine
  • Society for Integrative Oncology
  • American Society of Clinical Oncology
  • Australian Traditional-Medicine Society
  • Naturopaths and Herbalists Association of Australia