Air Monitoring
Air monitoring will identify the presence of any contaminants.Information about pollutant pathways, contaminant concentration and potential for human exposure will help to identify the contaminant source and the health risk.
Airborne Particulates
The Canadian Environmental Protection Act has identified respirable particulate matter as being a toxic substance for humans.Airborne particulate matter is a mixture of organic and inorganic substances and can be solid or liquid. Particulates can be in the form of dust, smoke, fumes, and mists. Particulate sources include the outdoor environment, people, animals, clothing, paper, building materials, smoke, rust, dust, and micro-biological activities. Inefficient vacuum cleaners and ventilation ducts and filters can distribute them.
High particulate concentrations can irritate the lungs and are more of a health risk to those with pre-existing respiratory or cardiovascular disorders. Particulates may contain allergens, they may carry harmful chemical substances, or they may be insoluble when they reach the lung causing various lung diseases. The health effects from airborne particulates depends on the concentration of particulates, toxicity of the substances carried on the particle, and individual susceptibility.
The size range of concern to human health is 0.1 to 10 micrometers (µm) in diameter because these can reach the lungs. Particles larger than 15µm are too large to be inhaled. Particles between 10-15µm are deposited in the nasopharyngeal region of the respiratory tract. Particles smaller than 0.1µm, are generally exhaled.
Noxious Gases
NITROGEN DIXODIE AND NITROGEN MONOXIDE
Nitrogen dioxide (NO2) is a water-soluble red to brown gas with a pungent, acrid odour. Sources include cigarette smoke, vehicle exhaust, combustion processes, unvented gas appliances and heaters. Health effects depend on exposure and may include: eye, nose and throat irritation; changes in sensory perceptions; pneumonia; bronchitis; respiratory illness and pulmonary dysfunction.NOx (nitrogen dioxide and nitrogen monoxide) react with ammonia, moisture, and other compounds to form nitric acid and related particles. Human health concerns include effects on breathing and the respiratory system and damage to lung tissue. Small particles penetrate deeply into sensitive parts of the lungs and can cause or exacerbate respiratory disease such as emphysema and bronchitis, and aggravate existing heart disease. In the air, NOx reacts readily with common organic chemicals and even ozone, to form a wide variety of toxic products, some of which may cause biological mutations. Examples of these chemicals include the nitrate radicals, nitroarenes, and nitrosamines.
CARBON MONOXIDE
Carbon monoxide (CO) is an odourless, colourless, and tasteless gas produced by the incomplete combustion of hydrocarbons. Indoor sources of CO include combustion appliances (gas stoves, gas furnaces, hot water heaters, wood stoves), tobacco smoke, and motor vehicle exhaust brought in from the outdoors. Carbon monoxide inhibits oxygen transport in the blood through the formation of carboxyhemoglobin and inhibition of cytochrome oxidase at the cellular level. Depending on the dose, health effects can include a throbbing headache, nausea, vomiting, impaired vision, impaired coordination, coma, and death.In most buildings, levels of carbon monoxide will be between 0.5 to 2 ppm. CO levels above 5 ppm usually indicate the presence of combustion products, faulty equipment, or pressure problems leading to down drafting of combustion appliances.
Radon
Radon is a naturally occurring, chemically inert, colorless, odorless, tasteless radioactive soil gas. It is produced from the radioactive decay of radium, which is formed through several intermediate steps of the decay of uranium and thorium. Concentrations of radon vary from location to location.Radon can be transported by pressure into buildings through cracks, joints, and other holes in concrete foundations; directly through porous concrete blocks; through joints and openings in crawl space ceilings; and through leakage points in HVAC ductwork that is embedded in slab floors or located in crawl spaces. Additional sources of radon include ground-water, well water, and radium-containing building materials.
The only health effect of radon is lung cancer. No other sensory perception or acute health effects are known. Smoking accelerates the development of lung cancer in individuals who have been exposed to radon.
Control radon by:
- inhibiting radon entry into the building
- seal plumbing, electrical conduit and steel post penetrations through the concrete slab.
- using a polyethylene liner under the slab as a barrier.
- build a continuous air barrier at the interior finish.
- pressurization
- pressurize the basement.
- removing or diluting (fan-forced ventilation).
Volatile Organic Compounds
Volatile organic compounds are the most significant indoor air contaminant. They can cause short term and long-term health problems.Volatile organic compounds (VOCs) are chemical compounds that contain carbon and will off-gas into the air. VOCs will off-gas when they reach their boiling point, which varies for each compound, but generally, their boiling point lies between 0 and 260 ºC. The lower the boiling point, the more volatile the compound is considered to be. Thousands of VOCs exist. Some examples of VOCs include: acetone, benzene, chlorinated solvents, dichlorobenzene, limonene, 4-phenylcyclohexene, toluene and xylene. Almost all manmade materials release VOCs. Sources include: detergents, paints, pesticides, adhesives, cosmetic and personal care products, automotive products (oils, gasoline, automotive cleaners), building materials (pressed wood products, gypsum board, adhesive, plastic piping, vinyl or plastic wall coverings), vehicular exhaust, industrial emissions, tobacco smoke, and materials of biological origin (animal feces, spores, pollen, metabolic products). Indoor concentrations of VOCs often exceed outdoor concentrations even in highly industrialized areas (average of 2 to 5 times higher).
Health effects from VOCs depend on the type of chemical, the amount of exposure, and sensitivity of the individual. Symptoms include: 1) eye, skin and respiratory tract irritation; 2) headaches; 3) central nervous system depression (fatigue, headache, drowsiness, dizziness, weakness, blurred vision, irritability, difficulty concentrating, fine motor deficits, cardiac arrhythmias); 4) carcinogenic effects; and, in high concentrations, 5) liver and kidney damage. People with environmental hypersensitivity often react to VOCs at very low concentrations.
Fungi
The term “fungi” is the biological classification of organisms that include mould, yeasts, and mushrooms. Fungi are decay organisms. They colonize (grow on and consume) dead organic material, which includes building materials such as wood, gypsum board and fabrics. By doing this, they are merely fulfilling their mission within the natural ecosystem.Fungi produce spores that under appropriate conditions can reproduce the entire organism. It is the combination of a source of spores, moisture or ambient humidity, surface temperature, and the availability of appropriate nutrients that lead to the success of fungal growth. As part of their metabolism, fungi can produce carbon dioxide, volatile compounds, alcohols, ketones, antibiotics, and mycotoxins. The volatile compounds are responsible for the ‘musty’ odours commonly associated with fungal growth.
Like all other organisms, each particular type of fungi is named by identifying their genus and species. Take for example Cladosporium herbarum. ‘Cladosporium’ represents the genus and ‘herbarum’ represents the species. There are many species of fungi within each genus. Some species within the same genus cause health effects and some do not. This is why it is important to identify fungi to the species level in order to know the potential health risk.
Fungal-related human health effects include:
- allergy
- pathogenic infection
- illness from toxins
| Allergy | Pathogenic Infection | Illness from Toxins |
|---|---|---|
| Asthma Hay Fever Hives |
Grows in/on a person's body Lungs, sinus, skin |
Headaches Nervous system depression Dizziness Immune system depression Nausea Respiratory distress Nose bleeds Bleeding of the lungs Fatigue Inability to concentrate |
Allergy:
Fungi can cause Type I and Type III allergic reaction. Type I allergy symptoms include asthma, hay fever, and hives. Type III symptoms include fever, chills, rash, arthritis, and kidney damage. A person must be sensitized to fungi (have an existing fungi allergy) to be affected.Pathogenic infection:
Some fungi can cause pathogenic infection (grow on or inside a person’s body: usually lungs, sinus, or skin). Aspergillus fumigatus can cause lung disease by growing in a person’s lungs through inhalation of its spores. Pathogenic infection is rare and usually affects only immune compromised individuals (persons recovering from recent surgery, or people with immune suppression, asthma, hypersensitivity pneumonitis, severe allergies, sinusitis, or other chronic inflammatory lung diseases). However, amount of exposure is also a factor. People not considered immune compromised, but with long term exposure to certain fungi spores can develop pathogenic infection. Some sinus infections are not bacteria-related (and therefore can not be treated successfully by antibiotics), but fungi-related.Illness from Toxins:
Illness can result from exposure to the toxic chemicals (mycotoxins and volatile organic compounds) produced by fungi. Some of these illnesses produce symptoms including dizziness, fatigue, inability to concentrate, headaches, nausea, shortness of breath, impaired vision, impaired co-ordination, learning impairment, liver and kidney damage, heart tissue damage, nervous system depression, respiratory distress, nose bleeds, bleeding of the lungs, and immune system depression. Only some fungi excrete chemicals that are harmful to human health and only under certain conditions. Little is known about long-term exposure to low levels of mycotoxins and the volatile chemicals produced by fungi.| One of the insidious characteristics of fungi is that some can produce toxins that weaken a person’s immune system thereby increasing the opportunity for pathogenic infection. Fungi that produce toxins are called toxigenic fungi. Stachybotrys (or ‘black mould’) is the most common example, but many other fungi are capable of producing toxins. An identification analysis to the species level (not just to the genus level) is necessary to determine if a particular fungus is toxigenic. However, even if a toxigenic fungus is identified, it can never be certain that it is producing toxins. Reasons for that may depend on the substrate it is growing on or many other factors. Much about the nature of fungi is still not fully understood. It is generally agreed by mycologists and indoor air quality experts that once a toxigenic fungus is identified, to assume it is producing toxins and to respond accordingly. |
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