The term “fungi” is the biological classification of organisms that include mould, yeasts, and mushrooms. Fungi are decay organisms. They colonize 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. In the presence of water, fungi destroy building materials and cause health effects including allergy, pathogenic infection and toxic illness.
volatile organic compounds
Volatile organic compounds (VOCs) are the most significant indoor air contaminant. They can cause short term and long-term health problems. Thousands of VOCs exist. 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.
Airborne particulate matter is a mixture of organic and inorganic substances. Sources include the outdoor environment (soil, roads, agricultural dust, vehicles, industrial emissions, smoke from forest fires), people, animals, clothing, paper, building materials, tobacco smoke, fireplaces, rust, dust and dust mites, micro-organisms, inefficient vacuum cleaners and ventilation ducts. High particulate concentrations less than 10µm in size can be inhaled and irritate the lungs. Particulates may contain allergens or carry harmful chemical substances. The health effects will depend upon the concentration of particulates, toxicity of the substances carried on the particle, and individual susceptibility.
Asbestos is a natural mineral with unusual qualities. The main properties that make asbestos useful are its incombustibility, strength and flexibility when separated into fibres. Asbestos products that present the greatest concern in the indoor environment are those of a friable nature. An asbestos-containing product is deemed friable when it can be crushed by the application of hand pressure. Asbestos must be inhaled to cause disease. Asbestos can cause asbestosis, malignant mesothelioma, lung cancer, ovarian cancer, laryngeal cancer and other serious diseases.
Radon is a naturally occurring, chemically inert, colourless, odourless, tasteless radioactive soil gas. 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.
The only health effect of radon is lung cancer.
The only health effect of radon is lung cancer.
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), 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.
Carbon Dioxide (CO2) is a colourless, tasteless, odourless gas. The average concentration of CO2 in the atmosphere is 400 ppm and is rising due to global warming. Carbon dioxide is not a toxic gas. The main source of CO2 in the indoor environment is human exhalent. An additional source of CO2 is combustion. CO2 is used as an indicator of acceptable ventilation (how effective the HVAC system is in bringing in fresh air, distributing it into the space, and removing CO2). Health effects of CO2 levels over 800ppm include fatigue, headaches, perception of warmth, sleepiness, dizziness, shortness of breath, and general feeling of stuffiness.
Nitrogen monoxide (NO), also called nitric oxide, is a colourless gas. In the presence of oxygen it is converted to nitrogen dioxide (NO2). NOx (nitrogen dioxide and nitrogen monoxide) react with ammonia, moisture, and other compounds to form nitric acid and related particles that contribute to acid rain. Human health concerns include nausea, shortness of breath, and headaches. Long-term effects could include impaired immune and lung system function. 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.