The term Asbestos concerns a number of naturally occurring mineral fibers which have been used throughout history in a number of building materials. In more recent times (1950-present) Asbestos can be found in a number of household materials such as; flooring, ceiling tiles, roofing tar and sealants, window glazing putty, sink undercoating, drywall joint filler compound and spray-on materials including textured (popcorn) ceilings and exterior stucco and many others. While the adverse health effects of Asbestos have been proven fairly extensively (JPC-SE 2012) its economic importance has made a formal ban difficult. The use of Asbestos is regulated in Canada and the United States where the import, sale, and use of asbestos are prohibited except for some very specific applications.

There are a number of documented health effects arising from exposure to asbestos fibres, the diseases which occur as a result of asbestos exposure are; asbestosis, mesothelioma and lung cancer although there are a number of other health effects as well.

Asbestosis- Asbestosis is a chronic lung condition which results from the formation of scar-like tissue in the lungs. This scarring will cause a decrease in the elasticity of the lungs which will in turn limit the capacity of the lungs causing the most common symptom of asbestosis, shortness of breath. Asbestosis is typically the product of prolonged exposure to asbestos fibers over the course of several years with symptoms developing over the course of the exposure and worsening as time goes by. Methods of detection include regular chest x-rays and physical exams.

Mesothelioma- Mesothelioma is the formation of cancerous tumors on mesothelial tissues (mesothelium are the thin layers of tissue that cover many internal organs). While mesothelioma rates are quite low in the general population, they are significantly higher in groups where asbestos exposure is possible such as asbestos workers and workers in facilities with asbestos containing products. It can take as long as 30-40 years for mesothelioma resulting from asbestos exposure to manifest itself. The prognosis for mesothelioma patients is poor, with early detection being the best defense, as most treatment options do not significantly improve prognosis.

Lung Cancer- While there are a number of factors which can contribute to the formation of lung cancers asbestos exposure has been shown to increase the risk of lung cancer in the general population. Asbestos workers or people exposed to asbestos who smoke are significantly more likely to develop lung cancer during their lifetime. The relationship between asbestos exposure and lung cancer is complicated and dependent on a number of factors such as age when exposed, extent of exposure and duration, smoking history, type of asbestos exposed and many other factors. Laboratory tests including chest x-rays are the most effective means of diagnosis.

For more information on the health effects of asbestos exposure please refer to the Canadian Center for Occupational Health and Safety Fact Sheet: “CCOHS Asbestos Fact sheet”

When dealing with Asbestos in British Columbia the primary authority in regulating how asbestos is handled is WorkSafeBC, and they have a number of resources available to help homeowners and contractors deal with Asbestos safely. Before beginning any renovation or demolition project it is important to hire a certified professional consultant who will conduct a thorough survey of the building and complete an assessment of all hazardous materials. More Information on hiring a qualified professional to survey your home and have asbestos safely removed can be found in the following publications by WorkSafeBC:

“Asbestos Hazards When Renovating Older Homes”

“Asbestos: Frequently Asked Questions”

“Asbestos Awareness For Homeowners”


Lead is a naturally occurring metal which can cause adverse health effects with exposure. Lead has been used extensively throughout human history and can still be found in a number of products. Products such as tile glaze, paint, solder, piping, pigments, jewelry, toys and ammunition as well as many other products have contained lead in the past and may still contain lead depending on their country of origin. Lead exposure has been shown to be cumulative, where exposures build up over time as lead is not easily removed from the body once it has been absorbed by tissues and integrated into bones.

Lead is a highly poisonous metal which has been implicated in a number of detrimental health effects after exposure, these include both acute and chronic health effects. Acute exposure to lead has been shown to cause brain and kidney damage as well as death. Children and developing fetuses are particularly vulnerable to lead exposure. Chronic exposure to lead can cause a large number of different issues including anemia nephropathy, abdominal pains, weakness, memory loss and many other symptoms. Treatment for lead exposure involves limiting exposure and using chelating agents to pull lead out of the bloodstream and allow for elimination in urine.

For more information on the health effects of lead refer to the following:

“WHO Lead poisoning and health”

“NIOSH Lead information for workers”

When dealing with lead in British Columbia WorkSafeBC is the primary authority regarding the handling, testing and removal of lead containing materials. WorkSafeBC has put together an information packet for residents who are looking to get more information about lead risks to workers and the general public. Before beginning any project which may disturb potentially lead containing materials it is important to get the materials tested in order to prevent exposure. More information concerning the hazards associated with lead can be found on the WorkSafeBC website as well as the resources found on the following page:

“WorkSafeBC Lead Resources”


Mold is a term referring to a group of fungi which grow in the form of multi-cellular structures called hyphae which will then form conidia and spores. Molds differ from other fungi which are typically single celled such as yeasts. The spores produced by the conidia are how a mold spreads throughout its environment. Mold spores are an important part of the global ecosystem, they can be found both indoors and outdoors and have colonized essentially every continent on the planet. While the amount of mold spores in the air is typically low enough not to cause any issues the invention of indoor heating and plumbing has made molds a formidable presence in homes across the globe.

The growth cycle of a typical mold colony starts at the spore, which is a microscopic particle which contains all the information and resources required to start a new mold colony. Spores are spread through the air by wind or forced ventilation systems, mold spores can also attach themselves to clothing, pets, building materials or even your skin (which needs to have a fairly diverse eco-system to maintain your health). Once a mold spore lands somewhere moist it will begin to grow and divide, producing structures called “hyphae”-long filament like structures which will appear as a fuzzy patch once they have grown enough. When the conditions are just right and the mold colony is particularly happy it will begin to produce spores at the ends of the hyphae in specialized structures called “conidia”. These conidia will start shedding spores, which will be picked up by moving air, pets or other means and land on another surface, if that surface has the moisture and food the mold needs it will start a new colony and the cycle continues. Mold spores are extremely resilient, with some able to survive long dry periods and many others that are resistant to even the strongest cleaning chemicals.

While molds are an integral part of the microscopic world, they can be a nuisance or health hazard when they invade a living space. Large colonies of mold are unsightly, often producing large brown, black, green, blue or white stains on surfaces and large colonies have also been suspected of causing health problems. At present there is no conclusive evidence for or against the hazards of molds, however it is generally recommended that any mold growth is dealt with promptly as it can produce a number of unwanted smells and can damage the surface it is growing on.

As stated above there has not been a causal link established between mold or fungi and negative health effects except in immunocompromised individuals. With that in mind there have been a number of reports which seem to show a link between mold exposure and asthmatic response in individuals who already have asthma. Mold exposure may also cause symptoms which resemble allergic reactions such as a runny nose, cough or difficulty breathing and irritation of the eyes, although the fact that molds are abundant both indoors and outdoors makes any studies relating to the specific health effects of indoor mold growth difficult. Despite the lack of causal evidence mold growth is unsightly, produces a number of offensive odors and damages building materials, for these reasons alone it is highly recommended that any significant mold growth is dealt with promptly by professionals.

The lack of causal evidence between mold and heath problems has led to somewhat ambiguous regulations around mold detection and remediation. With that in mind it is the recommendation of WorkSafeBC, Health Canada and most municipalities that mold or any water damaged material is cleaned and sanitized properly or removed if the damage is great enough. There may be some re-occupation restrictions when a living or working space has been contaminated with mold and it is recommended that any water damage be inspected by a certified professional to provide guidance on clean-up or remediation. There is a wealth of information about mold available to interested parties, including the following:

“Mold Hazards (WorkSafeBC)”

“Indoor Air Quality (CCOHS)”

“Mould and Your Health”

Indoor Air Quality (Health Services BC)