Thompson Mechanical Mould Remediation

MOULD REMEDIATION

What Are Moulds?

Moulds are those little cottony patches we often see on left-over food, bread, fruits, cheese, etc. Sometimes they can also be found spreading on old books and other things kept in the home which are exposed to dampness. These little patches of various colors are often taken for granted, but these can cause losses in millions of dollars in terms of damage to property and worse, damage to health.

Moulds are multinucleated, filamentous fungi composed of hyphae. A hypha, a branching tubular threadlike structure, is usually divided into cell-like units by crosswalls called septa. The whole mass of hyphae is termed a mycelium.

These hyphae and mycelium which we often see growing on things and in some areas of our homes and buildings, everywhere in our environment, can degrade appearance, induce health disorders and cause material decay.

Habitat

Wherever adequate moisture, temperature, and organic substrates are available, moulds are present. Although we normally think of moulds as growing in warm, moist areas, many species occur in habitats that are cold, periodically arid, or otherwise seemingly inhospitable.

Fungi are frequently found among the microbiota of soil and aquatic ecosystems. A major role of these fungi is decomposition of dead and decaying organic matter. Some species of fungi have adapted to a parasitic life style, causing disease in animals and plants.

Reproduction

Moulds reproduce by releasing millions of tiny spores. Mould spores are like seeds which germinate to produce a new mould colony when they land on a suitable place. Mould spores need moisture to grow and are usually found in damp, poorly ventilated areas of homes, such as bathrooms. You cannot see individual mould spores but you may be able to see mould colonies: grey, green or black, cottony, fuzzy or powdery growths on damp surfaces. Studies have shown that mould spores are a big source of indoor air pollution.

Moulds and fungi produce and release millions of spores small enough to be air-, water-, or insect-borne. They can also produce toxic compounds known as mycotoxins. Spores and mycotoxins can have negative effects on human health including allergic reactions, asthma and other respiratory problems.

Biologists who specialize in mould estimate that the total number of different mould species ranges from over 100,000 to as many as a million mould species.

Because moulds, mould spores, and mould toxins often have a very adverse effects on humans, it is interesting and important to note that only about 200 species of mould have been subject to medical studies to determine a particular mould's health effects on people.

But even if most species have not yet been medically studied, humans should minimize the amount of any kind of mould growing inside their living quarters or their work place.

Mould Health Problems (can be broken down into 3 groups):

1) Allergenic - Causing allergy and asthma symptoms. Up to 32% of all asthmatics are sensitive to moulds. A study performed by the Mayo Clinic found 93% of patients with chronic sinusitis were caused by mould.

2) Pathogenic - A disease caused by mould. Diseases associated with mould are usually caused by high exposure or found in immune compromised individuals.

3) Toxic - Mycotoxins are secondary metabolites (toxins not necessary for survival) produced to kill other fungi competing for the moulds food and water. Mycotoxins are highly carcinogenic and can cause serious health effects in almost anybody. They are neurotoxins (cause neurological damage) which can enter the body through digestion, skin or the respiratory system.

Three of the most dangerous types of mould that produce mycotoxins are:

Stachybotrys - Also known as "Stachy", "Black mould" and "Toxic mould", Stachybotrys is characterized by its slimy shiny appearance. It is probably the most dangerous of the moulds. Stachybotrys needs a lot of water to grow. It feeds on high cellulose materials with a low nitrogen requirement like paper, carpet, wood, etc. It takes 48 hours to begin growing and is often found where slow leaks have been discovered. Because the spores are heavy and wet they usually are not airborne, but when the mould becomes dehydrated or dies, the Stachybotrys poisons take to the air. Stachybotrys has been linked to lung disorders and brain damage.

Aspergillus - Can be yellow, green or black in colour. There are 150 species, 15 of which are common in dwellings. Aspergillus is easily airborne and produce aflatoxins which are the most extensively studied mycotoxins. They are more toxic than many known industrial cancer causing substances.

Penicillium - Can be white, blue/green, or green in color. They are extremely common in buildings. Penicillium produces over 100 classes of mycotoxins. Its spores are easily airborne and it thrives in indoor environments.

Did you know?

Don't use bleach on mould. Bleach does not kill most mould spores and even when dead the spores can be highly toxic causing severe health effects if inhaled, absorbed or ingested.

Did you know?

The most difficult contamination is when the problem is hidden inside a wall, roof or floor cavity. The contamination may be resulting in health effects in the building occupants but the exact location is unknown.

IGNORING MAINTENANCE PROBLEMS & MOULD CLUES

If you ignore roof leaks, water stains on ceilings, plumbing leaks, sewer line leaks, a wet or damp basement, a wet or damp crawl space, the indoor smell of mould, visible mould growth and high humidity you are exposing yourself to a potential mould problem that could be very costly to remediate. Keep indoor relative humidity between 30 to 40% and if necessary use a programmable dehumidifier to prevent possible mould growth from starting.

USING OTHER INEFFECTIVE PRODUCTS TO KILL MOULD

Applying products such as Kilz, regular paint, paint containing a so-called fungicide or mildicide, oil based paint, Lysol, ammonia, and other household cleaners and disinfectants are completely ineffective at killing mould in addition to the fact that dead or alive, the mould spores are equally as toxic. Painting over a mould problem does not solve it, it only hides the problem temporarily and provides the mould with additional nutrients to feed on in the paint itself!

ASSUMING THAT AFTER A WET AREA HAS DRIED, THAT IT IS THEN MOULD SAFE

Mould needs moisture to grow and to multiply as it decomposes the building materials and personal possessions. This moisture can come from elevated indoor relative humidity, direct leakage such as from a roof leak, flooding such as a burst pipe or accidental spillage such as knocking over a bucket of water. When the moisture source is removed the mould spores do NOT die. Instead, they become dormant, and can wait years for access to high humidity or a future water intrusion to begin their growth again. In addition, mould spores are aerosolized and disbursed in search of a new moisture source. Dormant mould and the aerosolized spores can cause heath problems in mould-sensitive people.

Penicillium mould

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Please click here to view an online document regarding Mould Guidelines within the Canadian Construction Industry.
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