To understand the hazards and risks of toxic mould we recommend you read the two following papers:
NEW Review of PCA seminar and health hazards/liability of mould. Download PDF
NEW Risk and hazard assessments of mould exposure Download PDF
Toxic mould is recognised as toxigenic mould in the medical fraternity and while some have associated black mould with toxic mould the colour is immaterial as toxic moulds can be almost any colour.
All mould is allergenic but some can produce chemical toxins which can be amongst the most toxic chemicals known to man. It should be understood that mould growth reflects the environmental conditions are present for biological activity associated with a water damaged building (WDB). While mould may be visible or hidden the associated contaminates can include bacteria and chemicals produced from wet materials and indeed mould. All biological and chemical components of a WDB can be a health hazard and risk factors are involved.
Even moulds recognised as toxic do not necessarily produce toxins and their production may depend on their environmental challenges with regard to growth conditions and challenge by other moulds, bacteria and the use of biocides.
Who is affected by Mould?
Most people can live in harmony with mould and these are often referred to as the non-atopic population. Condition of the individual’s immune system and indeed genetics may have an influence on the resistance to or health risk of exposure. Those with a reduced or yet to be developed immune system such as the elderly or very young are examples but those on long term prescription drugs, HIV and chemotherapy and alcohol or drug abuse may see greater risk. Exposure or dose can be a major factor in detrimental health effects over time.
The most susceptible people are called “atopic” and these may form up to 40 % of the general population.
The health effects of mould can be divided into two basic areas:
Allergies can be
Intrinsic meaning you were born with a response or defence
Extrinsic meaning you have developed a response or defence
Toxic effects
Some moulds can create chemicals called mycotoxins which can be cytoxic affecting cells in liver , lungs, heart or neurotoxic affecting the brain, vision etc.
Toxins may be cleared from the body in a healthy individual but continuing exposure especially to persons with a weakened immune system may have serious health consequence.
Exposure issues
The level of exposure may be directly related to your symptoms and equally how easily your symptoms disappear and this can be equated as:
- Short term exposure to high levels of mould
- Long term exposure of low levels of mould
- Long term exposure to high levels of mould.
What are the long term effects of mould exposure?
The health hazards of mould have not generally been proven without doubt and all relevant agencies are continuously investigation these issues. It should be recognised that even smoking cannot be directly proven to cause cancer as some people smoke and don’t get cancer while others don’t smoke and do get cancer. Unfortunately the science at present does not match the need for evidence however thousands of published research papers have shown clear association with asthma and other illness.
The World Health Organisation and Institute of Medicine have undertaken literature searches and to which they based their respective major publications on the health hazards and risks.
How do you know if you have toxic mould in your property?
There are various pointers to assess;
- Historic or current water damage, including condensation and leaks
- New health complaints especially respiratory of fatigue based see medical section
- Visible mould or associated odour, (note. not all mould has odour or is visible)
Following these assessments you should seek medical advice.
Where mould is not visible or contractors have perhaps cleaned or painted over mould you may have to resort to air sampling and we can assist you if required. (see services)
How do you remove mould?
- You must fix the moisture issue first
- You must wear suitable protection
- In large areas 10 square feet you may need enclosures and negative pressure to prevent spore release. (See our resources pages) and in particular CIRIA and British Research Advice EPA and New York City Guidelines
Mould removal is not necessarily decontamination and millions if not billions of spores may be released into the air during mould removal which may require removal of substrates to reveal contamination. These spores may settle but re aerosolize easily and become an almost permanent source of exposure which may have detrimental effects to susceptible people.