Lead & Crystalline Silica Page

Quebecers have been aware of the harmful health effects of asbestos dust for years now, but there’s another deadly dust on the horizon: crystalline silica dust.

What is crystalline silica?

Quartz is a form of crystalline silica. The most common mineral in the world, it’s found in all forms of rock, including sand. Silica isn’t considered a health risk when it’s amorphous (inert), but when it’s released into the air in the form dust, after shattering, cutting or polishing marble, concrete, stone, granite, brick, mortar or any other material that contains it, it can easily be breathed deep into the lungs. The dust is so fine that it’s only visible under a microscope.

After asbestos, crystalline silica is the second most identified cause of death due to toxic dust inhalation and has been for the past ten years. A form of occupational lung disease, like occupational asthma and asbestosis, silicosis is irreversible and can lead to disability and/or death.    

Just because you don’t see anything in the air and there isn’t a cloud of dust around a worker doesn’t mean silica isn’t present. So, if you’re going to be doing work that requires demolition with a jackhammer — or the breaking, crushing, piercing, sawing, sanding and grinding of concrete or masonry structures — proper dust control and protection measures have to be taken.

Lead-based paint

Are you worried about the deterioration of paint in or on a building that was built before 1978? You should be, as it could contain lead.

What is lead-based paint?

A highly toxic metal that was used in paint before 1978, lead was originally incorporated into paints because of its water resistance, durability, washability, and capacity to make them opaque. Ingesting or breathing lead-based paint can cause a myriad of health effects, including neurological and behavioural problems in exposed children. Even though it was banned in paint in 1978, it’s found in buildings that were built before the ban.

Where is lead generally found?

High levels of lead are usually found in brightly coloured paints, like yellow and orange, because they require the use of lead-chromate pigments. High levels of lead are also found in white paints, as well as houses built before 1950. Homes that were built after 1990 shouldn’t contain any lead, because most paint manufactured for the general public in Canada and the United States barely contained any by then.

Windowsills and the nooks and crannies around windows are among the highest risk areas because of the amount of friction and contact that occurs when windows are opened and closed. Over time, this friction can cause the rapid deterioration and peeling of paint, faster than in other areas of the home. Another reason windowsills are particularly dangerous is how accessible to children they are.

Why is lead so dangerous for children?

Children under the age of six are most vulnerable to lead poisoning. The reason why is because lead is absorbed into the bones before it spreads to the rest of the body. Once spread, lead can cause irreversible neurological damage that reduces cognition in adulthood. Another reason kids are so vulnerable is their tendency to put things in their mouths, including lead dust, and even the smallest amounts of dust containing lead are dangerous for infants and children. Lead that’s absorbed by the mother while pregnant can also cause harm to the unborn child. We now know there’s no safe level of lead exposure.

Where is lead-based paint most commonly found?

Some residential, commercial and institutional buildings could have walls covered with lead-based paint. If the paint is peeling, coming off or deteriorating because of normal use (on doors, windows, stairs and ramps) or construction work, you and your children could be exposed to serious health hazards like anemia (a deficiency of red blood cells), which is one of the effects of lead poisoning along with brain and nervous system damage.

If you want to know if your house contains lead-based paint, you can send samples of the paint to a laboratory for analysis, or hire a contractor with analytical x-ray equipment to determine the elemental composition of painted surfaces, to detect lead.

What is asbestos?

Asbestos is a natural rock made of fibres that have insulating properties and its use in products like cement and plastic, increases their strength. There are several kinds of asbestos but the ones that are most used in Quebec are chrysotile, amosite and crocidolite. All kinds of asbestos fiber are known to have a carcinogenic effect in humans when inhaled. That’s why it’s essential that you investigate before demolishing, renovating or handling materials that may contain asbestos, especially when those materials are brittle.

Why is it important to check if materials contain asbestos?

Quebec regulations have prohibited the use of products containing asbestos fiber since February 15, 1990, so when buying or renovating a building built before then, it’s important to find out if it has asbestos-containing materials. Why? Mainly because the handling of asbestos-containing materials can lead to serious health problems and legislation obliges all employers to ensure that exposure be minimized. It also identifies acceptable exposure limits, safe protocols, and a legal framework for its safe disposal and burial.

When are you likely to be exposed to asbestos fibres?

Exposure to asbestos fibres depends on the brittleness of materials you’re handling as well as the type of work you’re doing. The more brittle the materials are, the more easily the fibers can come off and the more dust containing asbestos can be spread in the air. That’s why it’s essential to deal with professionals before undertaking any kind of work that might involve asbestos-containing materials. Using the wrong tools, wearing inadequate protection and using improper work methods could cause many problems for a building’s occupants.

What materials may contain asbestos?

There’s a wide range of materials that may contain asbestos, but we’re focusing on the ones that are most frequently found in residential, commercial, institutional and industrial buildings.

Asbestos is most often found in materials designed and used before 1990 like:

  • Flocking (applied by spraying);Insulation;
  • Plaster walls and ceilings;
  • Stucco;
  • Cement coating;
  • Attic insulation (vermiculite, zonolite, fibreglass wool)
  • Ceiling tiles;
  • Corrugated cardboard (ventilation systems);
  • Vinyl tiles;
  • Glues and adhesives;

If you have any doubts, and before starting work that involves any of the materials listed above, have a material characterization done to confirm or deny the presence of asbestos. Note that only a laboratory analysis can confirm or deny the presence of asbestos.

The 4 most asked questions about mold

Molds are part of the fungus family. They’re omnipresent in the environment and multiply via the dispersion of their spores in the air. The air and surfaces of our environment (indoors and outdoors) are naturally filled with spores that are waiting for certain conditions to be met (moisture, temperature, organic matter, oxygen) to sprout (producing hyphae) and produce mycelium (grouping of hyphae that form patches or colonies, making mould visible on materials) that can in turn sporulate and recontaminate if the same conditions are met.

Does mould deteriorate materials?

Contrary to popular belief, mould and mildew don’t deteriorate materials. They generally present themselves as surface discoloration and mainly affect indoor air quality. Wood-decay fungus is the only kind of fungus that has the enzymes to alter and rot materials like wood. Nevertheless, it’s important to understand that the development of wood-decay fungus also requires a moisture source.

The first sign of an unresolved water problem is the appearance of mould, but the inevitable result is the growth of wood-decay fungus, and rot. To find out more about the damages caused by wood-decay fungus, click here

Where does mildew smell come from?

Odours associated with moisture (damp ground) are often noticeable in buildings. These smells aren’t really of dampness though, because water doesn’t smell like anything. They’re actually caused by the microbial volatile organic compounds (VOCm) that are created when mould, mildew and other bacteria are allowed to fester indoors. The odours are a kind of defence that is more or less specific to each kind of mould and/or bacteria. Microbial volatile organic compounds are powerful gases that can easily go through material. If you think you smell dampness, what you actually smell is a hidden fungal growth problem.

Are mould and mildew toxic?

Mould and mildew aren’t considered toxic, but rather allergens. It’s the secondary metabolites produced by certain kinds of mould called mycotoxins that can be toxic. Many mould species identified in damp buildings are known to produce one or more classes of mycotoxins, which is why people refer to them as “toxic mould.” Unlike spores, mycotoxins aren’t volatile and most cases of reported exposure come from ingesting them (when they deposit on food). They can adhere to dust particles and spread through the air attached to these dust particles or spores, making them easy to breathe in.

It’s important to remember that the mere presence of so-called toxic mould, which can produce mycotoxins, isn’t a definite indicator of the presence of mycotoxins. The production of mycotoxins depends on very specific, very damp environmental conditions. To this day, they remain difficult, and expensive, to identify.

Do I need an air quality test?

In most cases, the answer is no! An air quality analysis or other form of laboratory analysis isn’t usually necessary during the initial assessment. Even if you see mould, the air quality test might not reflect what you see. The fungal load (kind and/or quantity per m3) shouldn’t affect the proposed decontamination protocol. If you have visible mould, you should remediate the situation no matter how much of it is present.

However, air quality analysis can be useful in cases where:

Occupants may be allergic, immunocompromised or diagnosed with an illness related to mould exposure;

You can smell microbial volatile organic compounds but no traces of mould are present;

You think your ventilation system is contaminated;

A forensic or technical-legal diagnosis is required;

The quality of decontamination work has to be validated. In this case, the results of the analysis should be accompanied by a detailed inspection noting the quality of the work performed and the conclusions drawn from the interpretation of the results by the investigator.

In all cases, the objective of a sampling strategy is to confirm or deny the assumptions made by the investigator during the initial inspection. The extent and scope of the contamination is then determined by comparing indoor air quality in different areas of the building, and outdoors. Sampling results should show similarities in quality and quantity, otherwise the areas are considered to be contaminated, and have an abnormal fungal profile.

If you see mould, think something might be contaminated or have a laboratory report identifying a fungal contamination, contact us

Better understanding the risks associated with smoke & soot

In the restoration and decontamination industry, a lot of importance is placed on sampling, laboratory analysis and the reduction of volatile particulate matter like asbestos, lead, mould, mildew, bacteria and all other sources of biological hazards. If these contaminants are disturbed or treated in an inappropriate manner, it can cause all kinds of material damage as well as seriously harm the health and wellness of those who live or work in or near the areas where they’re present. There are other toxins that are released into the air during restoration products that seem to go un-noticed, but are no less dangerous. They are the toxic fume particles and volatile organic compounds (VOCs) that are produced during structural fires.

What is smoke?

Smoke is a complex mix of toxic gases and particles that are created by the mix of materials that burn during a fire. A typical structural fire can literally create tens of thousands of toxic chemicals and fumes. Research on cigarette smoke alone has identified over 7,000 chemicals, 70 of which are known to cause cancer, but studies have only scratched the surface of all the potentially harmful health effects that can result from being exposed to the chemicals that are released into the atmosphere during a structural fire.

What are the risks associated with exposure to smoke?

Smoke is the result of incomplete combustion, which produces tiny particles of carbon in the air. Once these particles fall, they become soot, so it’s the size of the smoke residue particles that makes them a respiratory risk. Soot particles measure around 2.5 microns or less, meaning they can be breathed deep into the lungs. To offer a better perspective on their size, red blood cells measure around 7 microns and the dust you see floating in the air through a sunlit window measures around 40 microns. Airborne soot is basically impossible to see, making it easy to inhale.

Anybody inhaling smoke needs to understand the potential health risks and take the necessary precautions to protect their health and safety. People who have their effects or property damaged by fire or smoke also need to be aware of the health risks to which they may be exposed long after the restoration process is finished, if adequate remedial measures aren’t taken. That’s why it’s so important to use professionals who use the right cleaning methods.

Wood decaying fungi and other lignivorous fungi

What are wood-decay fungi?

Just like mould and mildew, the appearance of wood-decay fungus is a sign of excessive moisture. It’s the only kind of fungus with enzymes that digest wood’s fibrous structure, which is composed of cellulose, hemi-cellulose and lignin, and it’s often classified according to the type of decay it causes (dry rot, brown or white rot and soft rot). In general, its presence doesn’t pose any threat to human health, but it can cause significant structural damage to buildings.

How does it grow?

Moisture, temperature and organic matter are always required! However, it’s the moisture that’s trapped in the materials, and not in the ambient air, that’s essential for the fungi’s growth. The kind of fungus that produces dry rot generally requires a moisture content higher than 25%. The kind of fungus that causes fibrous rot  require a moisture content higher than 40% and ascomycetes, which cause dry rot, requires a moisture content higher than 50%.

What’s dry rot?

Le plus connu des champignons lignivores est sans équivoque le Mérule (Serpula) qui compte 5 espèces recensées dont la plus connue, la Mérule Pleureuse (Serpula lacrymans). Cette espèce de champignons est la plus dévastatrice. Elle provoque la pourriture cubique des éléments de bois et est responsable d’importantes dégradations structurelles dans les bâtiments. En présence de conditions favorables (teneur en eau de 20 à 25% et température ambiante entre 20 °C et 26 °C), la Mérule Pleureuse (Serpula lacrymans) est généralement constituée d’un mycélium blanc, cotonneux souvent en forme de coussinet. Sa fructification très caractéristique est souvent en forme de plaque molle alvéolée et charnue de couleur orangé (rouille).
La Mérule Pleureuse se développe rapidement (approximativement 3 à 5 cm par semaine) et elle possède la caractéristique unique de pouvoir transporter l’humidité jusqu’à des endroits secs afin de les attaquer. Parmi les filaments très fins qui parcourt les matériaux attaqués, les cordons mycéliens (syrrotes) sont responsables du transport de l’eau qui assure à la croissance et peuvent parcourir de longues distances en s’introduisant même dans les joints de maçonnerie et dans les plâtres.
Malheureusement, l’ampleur de la colonisation (souvent cachée) des bois de structures du bâtiment nécessite parfois d’importantes destructions. La présence de la Mérule Pleureuse requiert toujours l’intervention d’un professionnel afin de déterminer l’étendue de la colonisation et d’élaborer un protocole de décontamination spécifique. Communiquer avec nous pour en savoir plus

The best-known wood-decay fungus is the Serpula fungus, which counts five different species, the most famous of which is the Serpula lacrymans: it’s also the most devastating. It causes dry rot in wood and is responsible for major structural damage in buildings. In favourable conditions (a moisture content that’s between 20 and 25% and temperatures that range between 20°C and 26°C) dry rot is generally made up of a white, cottony mycelium that’s pad or cushion shaped. Its characteristic fruiting bodies can be recognized by their soft, fleshy honeycombed appearance and orange (rusty) colour.

Dry rot spreads quickly (by approximately 3 to 5 cm per week) because it has the unique characteristic of being able to transmit moisture to dry places, in order to attack them. Among the very fine filaments that weave their way through the attacked materials, the mycelial cords (syrrotes) are responsible for transporting water that ensures growth and can travel long distances, getting into masonry joints and plaster.

Unfortunately, the extent of the (often hidden) colonization of structural timber caused be fungus in the building sometimes requires major demolition. The presence of dry rot always requires the intervention of a professional to determine the extent of colonization and develop a specific decontamination protocol. Contact us for more information