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Carbon Dioxide (CO2)
About 5% of the air we breathe out is Carbon Dioxide the level increase in inadequately ventilated occupied rooms. It is often used to assess the efficiency of ventilation. It is a good indicator of Indoor Air Quality. When the concentration rises, people start to feel tired and listless and they have trouble concentration. A high CO2 level is usually a sign of poor ventilation and the presence of odours and other pollutants such as volatile organics compounds. Poor ventilation increases the risk of high humidity and in the worst case, a radon build-up in the building. Demand Controlled Ventilation (DVC) is often based on Carbon Dioxide measurement. Using DVC in a room, it can be ventilated only when there is an actual need for it (example: conference room, classroom etc). In summary, over ventilation can waste substantial air con energy while under ventilation will course heavy loss of productivity and health. Carbon Monoxide ( CO ) A colorless, odorless and tasteless gas. A major source of CO is vehicle exhaust any also any process of combustion can produce Carbon Monoxide. Auto trucks or bus exhaust from attached garages, nearby roads, or parking areas can also be a source. Worn or poorly adjusted and maintained combustion devices (e.g., boilers, furnaces) can be significant sources, or if the flue is improperly sized, blocked, disconnected, or is leaking. At low concentrations, fatigue in healthy people and chest pain in people with heart disease. At higher concentrations, impaired vision and coordination, headache, dizziness, confusion, nausea. Can cause flu-like symptoms, and fatal at very high concentrations. Volatile Organic Compounds (VOC) Usually released into air from synthetic and composites materials. It is usually occurs during construction, finishing and furnishing of home because of the nature of its host materials. It also can be released by chemicals in aerosol sprays, paint, high-concentration cleaning chemicals, cooking stoves, air fresheners, office equipment, or cigarette smoke. VOCs are emitted by a wide array of products numbering in the thousands. (Example: paint and lacquers, paint strippers, cleaning supplies, pesticides, building materials and furnishing, office equipment such as copiers and printers, correction fluids and carbonless copy paper, graphics and craft materials including glues and adhesives, permanent markers, and photographic solutions). They are no specified symptom of VOCs. The symptoms are conjunctival irritation, nose and throat discomfort, headache, allergic skin reaction, dyspnea, declines in serum cholinesterase levels, nausea, emesis, epistaxis, fatigue, dizziness. At high concentration, VOCs can act as central nervous system depressants, irritants, narcotics, and carcinogens with the potential to significantly increase a person's risk of acquiring cancer. VOCs problems are widespread, common symptoms from these report include headaches, drowsiness, eye irritation, rashes, and respiratory and sinus problems. Ozone A toxic gas with vastly different chemical and toxicological properties from oxygen. Ozone neutralize odour however when there is no smell, it is fishy smell by itself. It also effectively kills airborne bacteria but is not recommended to occupied enclosures where there is exposure to people. When inhaled, ozone can damage the lungs. Low amounts can cause chest pain, coughing, shortness of breath, and throat irritation. Ozone may also worsen chronic respiratory disease such as asthma and compromise the ability of the body to fight respiratory infections. Formaldehyde A colourless gas with a pungent odour. Found in hundreds of different products, including insulation material, ceiling tiles, particle board, plywood, office furniture, carpet glues, various plastics, synthetic fiber in rugs, upholstery and other textiles, pesticides, paint and paper. Levels of emission increase with temperature. It irritates the eyes, nose and throat of most people at levels of 1ppm or higher. "Hypersensitive" individuals, up to 1 person in 10, may be irritated at levels below 1ppm. Other symptoms such as coughing, diarrhea, vomiting, dizziness, loss of memory and lethargy. Concern that formaldehyde may cause cancer is based on a study by the Chemical Industry Institute of Toxicology that exposed to 14.3ppm of formaldehyde during "workdays" over a two year period developed nasal cancer. OSHA concludes in its regulation that formaldehyde should regarded as a potential occupational carcinogen. |
Suspended Dust Particles Floating particles include tobacco smoke, micro-scopic dust, pollens, mold, dust mites pet dander (skin flakes) dropping and body part cockroaches, rodents and other pests of insects, viruses, and bacteria that is small enough to be inhaled. Tuberculosis, measles, staphylococcus infections, Lagionella and influenza are known to transmit by air. Symptoms are eye, nose and throat irritation, respiratory infections and bronchitis, lung cancer. Minimizing the distribution of dust is crucial in reducing the risk for airborne contaminants. Particle counts can help determine if barriers and efforts to control dust dispersion are effective. These types of monitoring are helpful when performed at various times and various perimeter locations. Gaps or breaks in barriers' joints or seals can then be identified. Airborne Bacteria Microorganisms proliferate in environments wherever air, dust, and water are present. So that, air-handling systems drain pan and coils is can be ideal environments for microbial growth. The spread of airborne infectious disease via droplet nuclei is a form of indirect transmission. Droplet nuclei are the residuals of droplets that, when suspended in air, subsequently dry and produce particles ranging in size from 1-5 micro meter. These particles can: 1. contain potentially viable microorganism, 2. be protected by a coat of dry secretions, 3. remain suspended indefinitely in air, 4. be transported over long distance, The microorganisms in droplet nuclei persist in favorable conditions (e.g. a dry, cool atmosphere with little or no direct exposure to sunlight or other sources of radiation). Pathogenic microorganisms can be spread via droplet nuclei include Mycobacterium tuberculosis, VZV, measles virus (i.e. rubeola), and smallpox virus (i.e., variola major). 6 several environmental pathogens have lifecycle forms that are similar in size to droplet nuclei and may exhibit similar behavior in the air. The spores of Aspergillus fumigatus have a diameter of 2-3.5 micro meter, with a settling velocity estimated at 0.003cm/second (or about 1meter/hour) in still air. With this enhanced buoyancy, the spores, which resist desiccation, can remain airborne indefinitely in air currents and travel far from their sources. Surface Bacteria and Fungi Accumulation of dust and moisture favor slime growth in drain pans and cooling coils increase the risk for spread of health-care-associated environmental fungi and bacteria. Clusters of infections caused by Aspergillus spp., P. aeruginosa, S. aureus, and Acinetobacter spp. have been link to poorly maintained air conditioning systems. Bursts of organisms can be released upon system start-up, increasing the risk of airborne infection. Proper engineering of the HVAC system is critical to preventing dispersal of airborne organisms. Fungi are present almost everywhere in indoor and outdoor environments. The most common symptoms of fungal exposure are runny nose, eye irritation, cough, congestion, and aggravation of asthma. There have been reports linking health effects in offices contaminated with moldy surface contaminated with fungal growth. Mold contamination of building components that are chronically moist or water damaged. Biological contaminants are often found in damp or wet areas such as cooling coils, humidifiers, condensate pans, or invented bathrooms can be moldy. Lead Most of the lead in our air used to come from soldering activity, vehicles using leaded gasoline, leads based pain. Today, metal processing, refining and recycling facilities are the major source of lead in the air. A highly toxic metal can cause serious damage to the brain, kidneys, nervous system, and red blood cells. Lead exposure can result in delays in physical development, lower IQ levels, shorten attention spans, and increase behavioral problems as it affects the central nervous system. Blood lead levels as low as 10 micrograms per deciliter can impair mental and physical development. At high levels at or above 80 micrograms per deciliter of blood can cause convulsions, coma, and even death. |