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Exposure to water-damaged buildings causes many health effects. The complex mixture of contaminants present in the air and in the dust of water damaged buildings form levels of toxicity that can lead to a variety of symptoms commonly known as inflammatory response and includes mould illness.
There are many ways buildings become home to a toxic mix of microbes and harmful chemicals. Structures can promote the growth of fungi and bacteria, as a result of construction defects, damp subfloor areas, and buildings exposed to saturated groundwater conditions, excessive condensation, and exposure to constant high humidity, water ingress events which are not correctly remediated.
What are the types of causes of water damage?
There are many ways in which water and moisture can damage a building, these can include obvious water damage caused by weather events, including flooding, burst water pipes and sewage overflows. There are also many less obvious means of water damage that can result in mould contamination in buildings including water damage from failed waterproof membranes on balcony’s and in bathrooms and laundry areas, a slow dripping pipe within a wall cavity or in a roof space, excessive condensation in a subfloor area caused by underfloor HVAC systems, high humidity resulting from insufficient ventilation inside a home and the impact of rising damp on structural timbers and flooring.
What are the contaminants that are generated by water damaged buildings?
The indoor air quality of water damaged buildings is affected by the presence of various biological contaminants, including mould, bacteria, microbial metabolites, microbial fragments, and volatile organic contaminants. This collection of biological contaminants, referred to as ‘bioaerosols’, can lead to serious health problems.
Water damaged buildings provide ideal conditions for the growth of mould and other microbes that thrive in moist environments with cellulose-based food sources (such as wood, fibre boards and other building materials). The following are the main types of contaminants found in damp indoor environments:
What is a dangerous level of toxicity, how is it measured?
Mould and the other microbes in water damaged buildings cause toxic effects by producing allergens (substances that can cause allergic reactions) and inflammagens (substances that trigger inflammatory response). These include mould spores, mycotoxins, mould and bacterial fragments, endotoxins and exotoxins, among others.
At present, there are no specified Threshold Limit Values (TLVs) for airborne concentrations of these contaminants, as the limits have not been set by the EPA, OSHA, FDA or other similar organisations. Hence, there are currently no regulations or standards for airborne bio-contaminants or specific levels of toxicity. There is also uncertainty regarding the periods of exposure to biotoxins that can lead to health effects.
This lack of specific guidelines is mainly because the level of toxicity is difficult to ascertain since different persons can present different levels of reactions to these contaminants. The symptoms and the severity of health effects can vary depending on the extent of exposure, age and health status of the individual as well as the toxicity of the specific mould/mycotoxin and synergistic effects with other contaminants. Scientific and medical research is still ongoing regarding the relationship between biotoxin exposures and health effects to determine the exposure or concentration limits.
Recently, toxicologists have proposed a parameter called the Concentration of No Toxicological Concern (CoNTC) to represent the airborne concentration of mycotoxins and other airborne contaminants. A conservative CoNTC value of 30 ng/m3 has been suggested as the generic airborne concentration that is expected to pose no hazard to humans exposed continuously throughout a 70-yr lifetime. Several studies have demonstrated that airborne mycotoxins in indoor air are below the CoNTC. However, water damaged buildings could have higher levels of mycotoxins.
Testing the exposure or concentration of the microbial hazards is also not trivial. There are currently no valid methods for the quantitative analysis of microbial exposure or concentrations. The commonly used method of microbiological analysis reveals the species of microbes present and not their toxicity. Toxicological analyses based on different construction material samples are complex and not reproducible due to the large variety of available building materials. VOC and particulate matter measurements are limited to certain sizes and specific types of compounds. The established method for analysis of contaminants is the collection of indoor dust for toxicological analysis, which does not always give satisfactory results. Further research is required to develop suitable sampling and testing methods for indoor air quality in water-damaged buildings.
How does a water damaged building promote the growth of toxicity and these contaminants?
Mould, bacteria and other microbes require a combination of water/moisture, oxygen and an organic food source to survive, grow and multiply. A building already offers plenty of food sources for microbes in the form of wood, paper, carpet, insulation materials, and even the dust and dirt present in buildings. The addition of water to the mix ensures optimal growth conditions for various types of microbes, primarily mould and bacteria. Among the different building materials, wet cellulose-containing materials such as wallpaper, cardboard and wood are the most prone to mould infestation.
Also, inadequate ventilation in the buildings, HVAC systems, flat roofs that can collect and leak water, basements exposed to groundwater, poor plumbing, and other construction problems that allow water to remain in the building can also promote the growth of mould.
In particular, mould does not require sunlight to grow and can reproduce easily through spores. These spores float through the air and land on different damp materials to continue growing. According to the US EPA, porous and cellulose-containing building materials should be dried thoroughly within 24 to 48 hours of becoming wet. Otherwise, mould will start to grow due to the combination of moisture and organic food source.
It has been reported that fungal growth in buildings starts at a water activity (a(w)) near 0.8. Further, once the a(w) reaches 0.95, significant quantities of the secondary metabolites, mycotoxins, are also produced. Thus, a water damaged building becomes an ideal breeding ground for mould and eventually generates a harmful mixture of mould, bacteria, microbial fragments, secondary metabolites, microbial volatile organic contaminants, and other harmful toxic chemicals.
What are the effects on your health from these contaminants?
A water damaged building contains various contaminants, which can cause different effects on people upon exposure. Researchers are still studying the individual effects of the contaminants. Some well-studied contaminants are:
More than any single one of these individual contaminants, it is the exposure to the toxic mix of microbes, their metabolites, microbial fragments and VOCs/mVOCs that leads to various health effects, as described below. The onset of allergic reactions and other symptoms of exposure to mould and other biotoxins can be either immediate or delayed. Continuous exposure can also lead to several long-term effects.
Some health effects may appear immediately after exposure to a contaminant. These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable and may subside upon withdrawing from the contaminated building.
Moulds can also cause allergic responses and asthma attacks in some individuals and may cause localised skin or mucosal infections in persons with impaired immune systems. These effects can vary from person to person depending on various factors including previous medical problems, age and sensitivity to allergens.
Some health effects may appear years after the exposure has occurred or after repeated exposure. These long-term effects include respiratory diseases, heart disease and cancer. Prolonged exposure to mould and VOCs can result in damage to the liver, kidney and central nervous system.
In particular, Chronic Inflammatory Response Syndrome (CIRS) is an illness caused by exposure to the various biotoxins present within water-damaged buildings. A type of CIRS is ‘mould illness’ which is caused by exposure to mould and its metabolites. CIRS is presented as an acute and chronic, systemic inflammatory response, and the symptoms can vary from weakness, aches and cramps, respiratory issues, abdominal pain and diarrhoea, to problems with memory and concentration. More severe symptoms may be present in some persons.
How do I get checked by a medical professional?
If you have any health concerns, contact your Doctor immediately and they can run tests to determine any health impacts.
Five critical steps to successful mould remediation
There are five critical steps to successful mould remediation projects, following these five steps will reduce the risk of a recurrence of mould in a building.
Whom to contact in Australia?
PureProtect provides a highly trained team of professional remediation and restoration personnel, who have been trained to investigate and remediate mould and water damage in homes and buildings. Our team has a wealth of building and construction knowledge to accurately assess the source of water ingress and resulting mould contamination in homes and buildings and can develop remediation plans to fully restore your home or building.
Call PureProtect now on 1800 664 602.