Glossary of IAQ terms


Term Definition
Acetone Acetone is a manufactured chemical (volatile organic compound) that is also found naturally in the environment. It is a colorless liquid with a distinct smell and taste. It evaporates easily, is flammable, and dissolves in water. It is also called dimethyl ketone, 2-propanone, and beta-ketopropane. Acetone is used to make plastic, fibers, drugs, and other chemicals. It is also used to dissolve other substances. Acetone is often found in nail polish remover and fingernail glue remover. Exposure to acetone has been linked to headaches, nausea, dizziness, skin, throat and eye irritation, depression and vomiting.
Activated carbon Activated carbon is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for adsorption or chemical reactions.The most common forms of activated carbon are granular activated carbon (GAC), powdered activated carbon (PAC) and impregnated carbon.Activated carbon is used in gas and air purification, gold purification, metal extraction, water purification, medicine, sewage treatment, air filters in gas masks and respirators, filters in compressed air and many other applications.
Air purifier An air purifier is a device which removes contaminants from the air. These devices can be beneficial to allergy sufferers and asthmatics, and help reduce or eliminate second-hand tobacco smoke as well as other indoor air concerns.A complete air purification system should contain a large activated carbon filter, HEPA filter and pre-filters plus optional UV germicidal filtration. Some air purifiers produce ozone and are not recommended for use in residential settings.Commercial grade air purifiers are manufactured as either small stand-alone units or larger units that can be affixed to an air handler unit (AHU) or to an HVAC unit found in the medical, industrial, and commercial industries.
Allergen An allergen is a substance that can cause an allergic reaction. Allergens are substances that, in some people, the immune system recognizes as "foreign" or "dangerous" but cause no response for most people. Common allergens include animal proteins and animal dander, bacteria and viruses, chemicals, dust, drugs (such as antibiotics or medications you put on your skin), foods (such as milk, chocolate, strawberries, wheat), perfumes, plants, pollen, and smoke. Allergic reactions to allergens are common. The immune response that causes an allergic reaction is similar to the response that causes hay fever. Most reactions happen soon after contact with an allergen. Many allergic reactions are mild, while others can be severe and life-threatening. They can be confined to a small area of the body, or they may affect the entire body. The most severe form is called anaphylaxis or anaphylactic shock. Allergic reactions occur more often in people who have a family history of allergies. Although first-time exposure may only produce a mild reaction, repeated exposures may lead to more serious reactions. Once a person has had an exposure or an allergic reaction (is sensitized), even a very limited exposure to a very small amount of allergen can trigger a severe reaction.
Allergy A state of abnormal and individual hypersensitivity acquired through exposure to a particular substance called an allergen. An allergy is an exaggerated immune response or reaction to substances that are generally not harmful. In a person with allergies, the immune response to allergens is oversensitive. When it recognizes an allergen, it releases chemicals such as histamines, which fight off the allergen. This causes allergy symptoms. Allergy symptoms may include breathing problems (coughing, shortness of breath), burning, tearing, or itchy eyes, conjunctivitis (red, swollen eyes), coughing, diarrhea, headache, hives, itching of the nose, mouth, throat, skin, or any other area, runny nose, skin rashes, stomach cramps, vomiting and wheezing. There is evidence that infants who are exposed to certain allergens in the air (such as dust mites and cat dander) may be less likely to develop allergies. This is called the "hygiene hypothesis." It came from the observation that infants on farms tend to have fewer allergies than those who grow up in more sterile environments. However, older children do not seem to benefit. Once allergies have developed, treating the allergies and carefully avoiding allergy triggers can prevent reactions in the future.
Ammonia Ammonia (Anhydrous ammonia, Aqua ammonia, Aqueous ammonia ) is a colorless gas with a pungent, suffocating odor. Exposure can occur through inhalation, ingestion (solution), skin and/or eye contact. Ammonia is used in many industries, including agriculture, food and beverage industry, leather tanning industry, metal treating and manufacture. It is often used in permanent hair dyes, powdered bleach and other products. Weak ammonia can also be found in many commercial and household cleaners and detergents. Symptoms include irritation eyes, nose, throat; dyspnea (breathing difficulty), wheezing, chest pain; pulmonary edema; pink frothy sputum; skin burns, vesiculation.
Asbestos Asbestos is a natural mineral that can resist high temperatures, chemical attack and wear. It insulates well against heat and electricity. Asbestos crystals become long, flexible, silky fibers, so it can be made into a wide variety of forms. It can be spun into yarn, woven into cloth or braided into rope. Asbestos can also be added to materials as diverse as cotton and cement. Until the 1980s, asbestos was used in office buildings, public buildings and schools. It insulated hot water heating systems, and was put into walls and ceilings as insulation against fire and sound. Asbestos poses health risks only when fibers are in the air that people breathe. Asbestos fibers lodge in the lungs, causing scarring that can ultimately lead to severely impaired lung function (asbestosis) and cancers of the lungs or lung cavity.
ASHRAE American Society of Heating, Refrigeration and Air-Conditioning. ASHRAE is an international technical society organized to advance the arts and sciences of heating, ventilation, air-conditioning and refrigeration. The Society is organized into regions, chapters, and student branches and allows the exchange of HVAC&R knowledge and experiences for the benefit of the field's practitioners and the public. The Society has approximately 50,000 members and has headquarters at Atlanta, Georgia, USA.
Asthma An inflammatory disease of the lungs characterized by reversible (in most cases) airway obstruction. It causes the following symptoms: Shortness of breath, tightness in the chest, coughing and wheezing. Asthma has no set pattern. The symptoms can be mild, moderate or severe, they can vary from person to person, they can flare up from time to time and then not appear for long periods and they can vary from one episode to the next. Inflammatory (allergic) triggers can cause inflammation of the lungs' airways or tightening of the airways' muscles. Inflammatory triggers include dust mites, animals, cockroaches, molds, pollens, viral infections and certain air pollutants (like smog). Symptom (non-allergic) triggers generally do not cause inflammation, but they can provoke "twitchy" airways, especially if they're already inflamed. Symptom triggers include smoke, exercise, cold air, chemical fumes and other strong-smelling substances like perfumes, certain food additives like sulphites, certain air pollutants and intense emotions.
Bacteria Bacteria are tiny microorganisms that are present in most habitats on Earth, growing in soil, acidic hot springs, radioactive waste, water, and deep in the Earth's crust, as well as in organic matter and the live bodies of plants and animals, as well as in the digestive tracts of humans, termites and cockroaches. The study of bacteria is known as bacteriology, a branch of microbiology. Bacterial infections may be treated with antibiotics, which are classified as bacteriocidal if they kill bacteria, or bacteriostatic if they just prevent bacterial growth.
Benzene Benzene is a chemical that is a colorless or light yellow liquid at room temperature. It has a sweet odor and is highly flammable. Benzene evaporates into the air very quickly. Its vapor is heavier than air and may sink into low-lying areas. Natural sources of benzene include volcanoes and forest fires. Benzene is also a natural part of crude oil, gasoline, and cigarette smoke. Benzene is widely used in the United States. It ranks in the top 20 chemicals for production volume. Some industries use benzene to make other chemicals that are used to make plastics, resins, and nylon and synthetic fibers. Benzene is also used to make some types of lubricants, rubbers, dyes, detergents, drugs, and pesticides. Indoor air generally contains levels of benzene higher than those in outdoor air. The benzene in indoor air comes from products that contain benzene such as glues, paints, furniture wax, and detergents. Benzene works by causing cells not to work correctly. For example, it can cause bone marrow not to produce enough red blood cells, which can lead to anemia. Also, it can damage the immune system by changing blood levels of antibodies and causing the loss of white blood cells. The seriousness of poisoning caused by benzene depends on the amount, route, and length of time of exposure, as well as the age and pre-existing medical condition of the exposed person. Reported immediate symptoms include drowsiness, dizziness, rapid or irregular heartbeat, headaches, tremors, confusion, unconsciousness and death (at very high levels). Long-term health effects may include anemia, excessive bleeding and a weakened immune system, increasing the chance for infection, irregular menstrual periods and a decrease in the size of ovaries, low birth weights, delayed bone formation, and bone marrow damage (in animal studies) as well as cancer (leukemia).
Brazilian Blowout See Hair Straightening Treatment
Building Materials A building material is any material which is used for a construction purpose. Modern building is a multibillion dollar industry, and the production and harvesting of raw materials for building purposes is on a world wide scale. Often being a primary governmental and trade key point between nations. Environmental concerns are also becoming a major world topic concerning the availability and sustainability of certain materials, and the extraction of such large quantities needed for the human habitat. Some building materials can off-gas toxins into the ambient air.
Carbon Monoxide Carbon monoxide (CO) is a colorless and odorless gas. Because people can't see, taste or smell it, it can affect them before they even know it's there. Even at low levels of exposure, carbon monoxide can cause serious health problems. CO is harmful because it will rapidly accumulate in the blood, depleting the ability of blood to carry oxygen. Carbon monoxide is a common byproduct of the combustion (burning) of fossil fuels. A CO detector can be a good safety precaution and warning sign.
Carbon Dioxide Carbon dioxide is a colorless, odorless gas that has a faint acid taste. It can also be a liquefied compressed gas, or white flakes or cubes. In solid form, it is used as dry ice. Carbon dioxide can be found naturally in spring water, and is released when volcanoes erupt and trees are cut down. When people breathe, they exhale carbon dioxide. Carbon dioxide is also produced by burning fossil fuels, such as coal, oil, gasoline, and natural gas. The chemical formula for carbon dioxide is CO2. Carbon dioxide in its gas form is an asphyxiant, which cuts off the oxygen supply for breathing, especially in confined spaces. Exposure to concentrations of 10 percent or more of carbon dioxide can cause death, unconsciousness, or convulsions. Exposure may damage a developing fetus. Exposure to lower concentrations of carbon dioxide can cause hyperventilation, vision damage, lung congestion, central nervous system injury, abrupt muscle contractions, elevated blood pressure, and shortness of breath. Other symptoms are dizziness, headache, sweating, fatigue, numbness and tingling of extremities, memory loss, nausea, vomiting, depression, confusion, skin and eye burns, and ringing in the ears.
Carcinogen A carcinogen is any compound or element that will induce or promote cancer in humans or animals (a cancer-causing agent). Occupational carcinogens are agents that pose a risk of cancer in several specific work-locations.
Chemicals In chemistry, a chemical substance is a form of matter that has constant chemical composition and characteristic properties. It cannot be separated into components by physical separation methods, i.e. without breaking chemical bonds. They can be solids, liquids or gases. Synthetic chemicals can be found anywhere in our environment, and many of them are subject of research or concern in terms of their effects on human health.
Clean Air Delivery Rate Clean air delivery rate is the amount of clean air an air cleaner provides to a room or space. When determining CADR, the amount of airflow in a space is taken into account. For example, an air cleaner with a flow rate of 100 cfm (cubic feet per minute) and an efficiency of 50% has a CADR of 50 cfm.
Dust Dust consists of particles in the atmosphere, which come from various sources such as soil dust lifted up by wind (an Aeolian process), volcanic eruptions, and pollution. Dust in homes, offices, and other human environments contains small amounts of plant pollen, human and animal hairs, textile fibers, paper fibers, minerals from outdoor soil, human skin cells, and many other materials which may be found in the local environment. Dust may worsen hay fever and asthma. Dust in the airstream poses a serious health threat to children, older people, and those with respiratory illnesses.
EPA Environmental Protection Agency in the United States. The EPA is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by the US Congress. The EPA employs approximately 17,000 people, and engages many more on a contractual basis. More than half of EPA human resources are engineers, scientists, and environmental protection specialists; other groups include legal, public affairs, financial, and information technologists. The agency conducts environmental assessment, research, and education. It has the responsibility of maintaining and enforcing national standards under a variety of environmental laws, in consultation with state, tribal, and local governments. EPA enforcement powers include fines, sanctions, and other measures.
Ethanol Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a solvent, and as a fuel. It is a good general purpose solvent that is found in paints, tinctures, markers, and personal care products such as perfumes and deodorants. It may also be used as a solvent in cooking, such as in vodka sauce. Ethanol is harmful on prolonged exposure or in high concentration. When in a concentration of more than 50%, ethanol causes local mucosal lesions through dehydration and albumin precipitation. Absorption, which occurs swiftly from the gastrointestinal tract, causes euphoria, with subsequent dizziness, inebriation, paralysis, diminished reflex, excitability, cyanosis, narcosis and respiratory paralysis.
Formaldehyde Formaldehyde is a colorless, flammable gas or liquid that has a pungent, suffocating odor. It is a volatile organic compound, which is an organic compound that easily becomes a vapor or gas. It is also naturally produced in small, harmless amounts in the human body. The chemical symbol for formaldehyde is CH2O. Formaldehyde is released into the air by burning wood, kerosene, or natural gas; from automobiles; and from cigarettes and other tobacco products. It is found in the air at home, at work, and outdoors, especially in smog. It is also found in some foods. Formaldehyde is used as a tissue preservative in medical laboratories, and as an embalming fluid in mortuaries. It is also used as a preservative in some foods, and as an antibacterial ingredient in cosmetics, household antiseptics, medicines, dishwashing liquids, fabric softeners, carpet cleaners, lacquers, and wood products. It is used as a preservative in some paints, paper coatings, and cosmetics; in the permanent press coating on fabrics; in carpets; and in some foam insulation materials. Formaldehyde is also found in most hair straightening treatments and can be used in the manufacturing of other chemicals. Formaldehyde is a known carcinogen because it causes cancer of the throat, nose, and blood. Other symptoms include build-up of fluid in the lungs, severe shortness of breath, bronchitis, rapid heart rate, allergic reactions of the skin and eyes, skin allergies and rashes, and asthma-like allergies with coughing, wheezing, chest tightness, as well as a drop in body temperature. People with asthma may be more sensitive to exposure to formaldehyde.
Hair straightening treatment Hair straightening is a hair styling technique which involves the flattening and straightening of hair in order to give it a smooth, streamlined, and 'sleek' appearance. It may be accomplished by using hair irons and hot combs, chemical relaxers, Japanese hair straightening, or Brazilian hair straightening. Brazilian hair smoothing treatments (also called Brazilian Keratin Treatment, BKT, Brazilian Blowout, Escova Progressiva, Keratin Cure or keratin straightening) are a method used by licensed hair stylists of temporarily smoothing the hair by sealing a liquid keratin and a preservative solution into the hair with a hair iron. These hair smoothing treatments have been an issue of controversy. In September 2010, Oregon's Occupational Safety & Health Administration (OSHA) received complaints of difficulty breathing, nose bleeds and eye irritation from stylists in one salon who claimed to have used one such hair treatment as directed. OSHA has issued a health hazard alert about the products.
HEPA High Efficiency Particulate Arrestor or Air filter is a type of air filter that is used in medical facilities, automotive vehicles, airplanes, home filters, or wherever very pure air is sought. To qualify as HEPA by government standards, an air filter must remove 99.97% of all particles greater than 0.3 micrometer from the air that passes through. HEPA filters are composed of a mat of randomly arranged fibers. The fibers are typically composed of fiberglass and possess diameters between 0.5 and 2.0 micrometers. Key factors affecting function are fiber diameter, filter thickness, and face velocity. The original HEPA filter was designed in the 1940s and was used in the Manhattan Project to prevent the spread of airborne radioactive contaminants.
Humidity Humidity is the amount of moisture or water vapor in the air. People produce moisture when they breathe or perspire and indoor plants as well as activities such as cooking, showering, bathing, doing laundry and dishwashing can add to the humidity in a building or home. Too much or too little humidity can create a host of difficulties, including allergic reactions and discomfort. To prevent window condensation during the heating season, the recommended indoor RH is 30 per cent to 50 per cent. When it is below -10°C (14°F) outdoors, recommended indoor RH is 30 per cent. Humidity can be controlled by increasing ventilation, using a dehumidifier (in the summer) or running the air conditioning.
HVAC Heating, Ventilation and Air Conditioning systems/units or technology to control indoor and automotive environmental comfort. The three central functions of heating, ventilating, and air-conditioning are interrelated, especially with the need to provide thermal comfort and acceptable indoor air quality within reasonable installation, operation, and maintenance costs. HVAC systems can provide ventilation, reduce air infiltration, and maintain pressure relationships between spaces. The most recognized standards for HVAC design are based on ASHRAE data.
IAQ Indoor Air Quality. People in North America spend close to 90% of their time inside; at home, at work and in recreational environments. Most people, however, are unaware of the effects that poor indoor air quality can have on their health. Key sources of air pollutants include biological pollutants ( living organisms like mould, bacteria and dust mites) as well as chemical pollutants (gases and particles that come from combustion appliances, tobacco smoke, household and personal care products, various building materials and outdoor air). A lack of ventilation, especially in air-tight buildings, is a key factor that impacts the quality of indoor air. The concentrations of many pollutants indoors exceed those outdoors. Health effects from indoor air pollutants may be experienced soon after exposure or, possibly, years later.
Irritant A stimulus or agent which causes irritation (a state of inflammation or painful reaction to allergy or cell-lining damage). Irritants are typically thought of as chemical agents (for example phenol and capsaicin) but mechanical, thermal (heat), and radiative stimuli (for example ultraviolet light or ionizing radiations) can also be irritants. Irritation also has non-clinical usages referring to bothersome physical or psychological pain or discomfort.
LEED Stands for Leadership in Energy & Environmental Design. It consists of a suite of rating systems for the design, construction and operation of high performance green buildings, homes and neighborhoods. LEED certification is obtained after submitting an application documenting compliance with the requirements of the rating system as well as paying registration and certification fees. In order to establish a building's point awards in each credit category, buildings applying for certification are compared with a theoretical baseline building defined by a LEED methodology or the more stringent of either ASHRAE/ANSI/EISNA codes or local codes. Certification is granted solely by the Green Building Certification Institute (GBCI), which is responsible for the third party verification of project compliance with LEED requirements.
Mold Molds are part of the natural environment. Outdoors, molds play a part in nature by breaking down dead organic matter such as fallen leaves and dead trees, but indoors, mold growth should be avoided. Molds reproduce by means of tiny spores; the spores are invisible to the naked eye and float through outdoor and indoor air. Mold may begin growing indoors when mold spores land on surfaces that are wet. There are many types of mold, and none of them will grow without water or moisture. Molds have the potential to cause health problems. Molds produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins). Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals. Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis). Allergic reactions to mold are common. They can be immediate or delayed. Molds can also cause asthma attacks in people with asthma who are allergic to mold. In addition, mold exposure can irritate the eyes, skin, nose, throat, and lungs of both mold-allergic and non-allergic people. The key to mold control is moisture control. If mold is a problem in your home, you should clean up the mold promptly and fix the water problem. It is important to dry water-damaged areas and items within 24-48 hours to prevent mold growth.
Occupational Health and Safety Occupational safety and health is a cross-disciplinary area concerned with protecting the safety, health and welfare of people engaged in work or employment. The goal of all occupational safety and health programs is to foster a safe work environment. As a secondary effect, it may also protect co-workers, family members, employers, customers, suppliers, nearby communities, and other members of the public who are impacted by the workplace environment. It may involve interactions among many subject areas, including occupational medicine, occupational (or industrial) hygiene, public health, safety engineering / industrial engineering, chemistry, health physics. There are occupational safety and health organizations or administrations in almost any country, region or province.
Odors An odor (commonly referred to as a smell) is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors. The terms fragrance and aroma are used primarily by the food and cosmetic industry to describe a pleasant odor, and are sometimes used to refer to perfumes. In contrast, malodor, stench, reek, and stink are used specifically to describe unpleasant odors. The perception of irritation from odor sensation is hard to investigate because exposure to a volatile chemical elicits a different response based on sensory and physiological signals, and interpretation of these signals influenced by experience, expectations, personality or situational factors. Volatile organic compounds (VOCs) may have higher concentrations in confined indoor environments due to restricted infiltration of fresh air, as compared to the outdoor environment; leading to greater potential for toxic health exposures from a variety of chemical compounds. Health effects of odor are traced to the sensation of an odor or the odorant itself. Health effects and symptoms vary, including eye, nose, or throat irritation, cough, chest tightness, drowsiness, and mood change; all of which decrease as an odor ceases. Odors may also trigger illnesses such as asthma, depression, stress induced illness, or hypersensitivity.
Off-Gassing The off-gassing is the emission of especially noxious gases (as from a building material). Examples: Building materials including carpeting and plywood emit formaldehyde (H2CO) gas. Paint and solvents give off volatile organic compounds (VOCs) as they dry.
Organic chemicals An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon.
OSHA The United States Congress created the Occupational Safety and Health Administration (OSHA) with the Occupational Safety and Health Act of 1970 to assure safe and healthful working conditions for working men and women by setting and enforcing standards and by providing training, outreach, education and assistance. OSHA is part of the United States Department of Labor. The administrator for OSHA is the Assistant Secretary of Labor for Occupational Safety and Health. OSHA's administrator answers to the Secretary of Labor, who is a member of the cabinet of the President of the United States. The OSH Act covers employers and their employees either directly through federal OSHA or through an OSHA-approved state program. State programs must meet or exceed federal OSHA standards for workplace safety and health.
Ozone Ozone (O3) is a gas composed of three oxygen atoms. It is not usually emitted directly into the air, but at ground-level is created by a chemical reaction between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Ozone has the same chemical structure whether it occurs miles above the earth or at ground-level and can be "good" or "bad," depending on its location in the atmosphere. In the earth's lower atmosphere, ground-level ozone is considered "bad." Motor vehicle exhaust and industrial emissions, gasoline vapors, and chemical solvents as well as natural sources emit NOx and VOC that help form ozone. Ground-level ozone is the primary constituent of smog. Sunlight and hot weather cause ground-level ozone to form in harmful concentrations in the air. As a result, it is known as a summertime air pollutant. Many urban areas tend to have high levels of "bad" ozone, but even rural areas are also subject to increased ozone levels because wind carries ozone and pollutants that form it hundreds of miles away from their original sources. Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ground-level ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue. People with lung disease, children, older adults, and people who are active can be affected when ozone levels are unhealthy. Numerous scientific studies have linked ground-level ozone exposure to a variety of problems, including airway irritation, coughing, and pain when taking a deep breath; wheezing and breathing difficulties during exercise or outdoor activities; inflammation, which is much like a sunburn on the skin; aggravation of asthma and increased susceptibility to respiratory illnesses like pneumonia and bronchitis; and, permanent lung damage with repeated exposures.
Paint Pigments are granular solids incorporated into the paint to contribute color, toughness, texture, give the paint some special properties or simply to reduce the cost of the paint. Alternatively, some paints contain dyes instead of or in combination with pigments. Some pigments are toxic, such as the lead pigments that are used in lead paint. Recent environmental requirements restrict the use of volatile organic compounds (VOCs), and alternative means of curing have been developed, particularly for industrial purposes. In UV curing paints, the solvent is evaporated first, and hardening is then initiated by ultraviolet light. In powder coatings there is little or no solvent, and flow and cure are produced by heating of the substrate after electrostatic application of the dry powder. Volatile organic compounds (VOCs) in paint are considered harmful to the environment and especially for people who work with them on a regular basis. Exposure to VOCs has been related to organic solvent syndrome, although this relation has been somewhat controversial.
Particles "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets. Particle pollution is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, and soil or dust particles. The size of particles is directly linked to their potential for causing health problems. EPA is concerned about particles that are 10 micrometers in diameter or smaller because those are the particles that generally pass through the throat and nose and enter the lungs. Once inhaled, these particles can affect the heart and lungs and cause serious health effects.
EPA groups particle pollution into two categories:
"Inhalable coarse particles," such as those found near roadways and dusty industries, are larger than 2.5 micrometers and smaller than 10 micrometers in diameter.
"Fine particles," such as those found in smoke and haze, are 2.5 micrometers in diameter and smaller. These particles can be directly emitted from sources such as forest fires, or they can form when gases emitted from power plants, industries and automobiles react in the air. The size of particles is directly linked to their potential for causing health problems. Small particles less than10 micrometers in diameter pose the greatest problems, because they can get deep into your lungs, and some may even get into your bloodstream. Particle pollution - especially fine particles - contains microscopic solids or liquid droplets that are so small that they can get deep into the lungs and cause serious health problems. Numerous scientific studies have linked particle pollution exposure to a variety of problems, including increased respiratory symptoms, such as irritation of the airways, coughing, or difficulty breathing, for example; decreased lung function; aggravated asthma; development of chronic bronchitis; irregular heartbeat; nonfatal heart attacks; and premature death in people with heart or lung disease.
Perchloroethylene Perchloroethylene (also called PERC) is a colorless, nonflammable liquid. The largest user of PERC is the dry cleaning industry. It accounts for 80% to 85% of all dry cleaning fluid used. Textile mills, chlorofluorocarbon producers, vapor degreasing and metal cleaning operations, and makers of rubber coatings also use PERC. It can be added to aerosol formulations, solvent soaps, printing inks, adhesives, sealants, polishes, lubricants, and silicones. Typewriter correction fluid and shoe polish are among the consumer products that can contain PERC. Exposure to perchloroethylene can occur in the workplace or in the environment following releases to air, water, land, or groundwater. Exposure can also occur when people use products containing PERC, spend time in dry cleaning facilities that use PERC, live above or adjacent to these dry cleaning facilities, or bring dry cleaned garments into their home. PERC enters the body when breathed in with contaminated air or when consumed with contaminated food or water. Once in the body PERC can remain, stored in fat tissue.
Perfume A perfume is a mixture of fragrant essential oils and/or aroma compounds, fixatives, and solvents used to give the human body, animals, objects, and living spaces "a pleasant scent". The odoriferous compounds that make up a perfume can be manufactured synthetically or extracted from plant or animal sources. Perfume ingredients, regardless of natural or synthetic origins, may all cause health or environmental problems when used or abused in substantial quantities. Although the areas are under active research, much remains to be learned about the effects of fragrance on human health and the environment. Evidence in peer-reviewed journals shows that some fragrances can cause asthmatic reactions in some individuals, especially those with severe or atopic asthma. Many fragrance ingredients can also cause headaches, allergic skin reactions or nausea. There is scientific evidence that nitro-musk such as Musk xylene can cause cancer while common ingredients, like certain polycyclic synthetic musk, can disrupt the balance of hormones in the human body (endocrine disruption). Some natural aromatics, such as oakmoss absolutes, contain allergens and carcinogenic compounds.
Pesticides Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest. Pesticides may cause acute and delayed health effects in those who are exposed. Pesticide exposure can cause a variety of adverse health effects. These effects can range from simple irritation of the skin and eyes to more severe effects such as affecting the nervous system, mimicking hormones causing reproductive problems, and also causing cancer. A 2007 systematic review found that "most studies on non-Hodgkin lymphoma and leukemia showed positive associations with pesticide exposure" and thus concluded that cosmetic use of pesticides should be decreased. Strong evidence also exists for other negative outcomes from pesticide exposure including neurological, birth defects, fetal death, and neurodevelopmental disorder.
Phthalates Chemicals added to plastics to make them softer, pliable, durable and longer lasting; they are easily released into the environment and high levels may affect hormone levels and cause birth defects. Phthalates are esters of phthalic acid and are mainly used to soften polyvinyl chloride (PVC). Phthalates are being phased out of many products in the United States, Canada, and European Union over health concerns. In general, indoor air concentrations are higher than outdoor air concentrations due to the nature of the sources. Higher air temperatures result in higher concentrations of phthalates in the air. People are commonly exposed to phthalates, and most Americans tested by the Centers for Disease Control and Prevention have metabolites of multiple phthalates in their urine. Because phthalate plasticizers are not chemically bound to PVC, they can easily leach and evaporate into food or the atmosphere. In general, children's exposure to phthalates is greater than that of adults.
Radon Radon is a colorless, odorless gas that is widely present in the earth's surface. It comes from the radioactive breakdown of uranium. Uranium occurs naturally and can be found in small amounts in the soil, water and air. Radon seeps into a home from surrounding soil (vapor intrusion). It comes up through pores in the soil under homes and buildings through gaps and cracks in the foundation, concrete walls and floors, sumps, joints, basement drains and other openings. Unsafe levels of radon could accumulate in poorly ventilated homes and buildings. Exposure to high levels of radon increases the risk of developing lung cancer. Your risk depends on the amount of time you are exposed to radon. Radon also increases the risk of lung cancer from smoking. Since radon concentration varies from house to house even in the same area, the only way to find out if you have radon in your home is to test for it.
Smog Smog refers to a noxious mixture of gases and particles that often appears as a haze in the air. It has been linked to a number of adverse effects on health and the environment. The two primary pollutants in smog are ground-level ozone (O3) and particulate matter(PM). High levels of smog are typically associated with the summer due to the presence of sunlight and warmer temperatures. However, the smog problem actually occurs throughout the year, with winter smog (due to particulate matter contributions rather than ozone) being a serious concern when stagnant air causes a buildup of pollutants in the air. This is usually caused by increased wood heating and vehicle usage in the winter months. Smog has been identified as contributing factors in thousands of premature deaths across the country each year, as well as increased hospital visits, doctor visits and hundreds of thousands of lost days at work and school.
Smoke Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires (including stoves, candles, oil lamps, and fireplaces), but may also be used for pest control (cf. fumigation), communication (smoke signals), defensive and offensive capabilities in the military (smoke-screen), cooking (smoked salmon), or smoking (tobacco, marijuana, etc.). Smoke inhalation is also a danger of smoke that can cause serious injury and death. Cigarette smoke is a major modifiable risk factor for lung disease, heart disease, and many cancers. Secondhand smoke is the combination of both sidestream and mainstream smoke emissions. These emissions contain more than 50 carcinogenic chemicals. According to the Surgeon General's latest report on the subject, "Short exposures to secondhand smoke can cause blood platelets to become stickier, damage the lining of blood vessels, decrease coronary flow velocity reserves, and reduce heart variability, potentially increasing the risk of a heart attack." The American Cancer Society lists "heart disease, lung infections, increased asthma attacks, middle ear infections, and low birth weight" as ramifications of smoker's emission.
Solvents Solvents are substances that are capable of dissolving or dispersing one or more other substances. Organic solvents are carbon-based solvents (i.e., they contain carbon in their molecular structure). Millions of U.S. workers are exposed to organic solvents that are used in such products as paints, varnishes, lacquers, adhesives, glues, and degreasing/cleaning agents, and in the production of dyes, polymers, plastics, textiles, printing inks, agricultural products, and pharmaceuticals. Many organic solvents are recognized as carcinogens (e.g., benzene, carbon tetrachloride, trichloroethylene), reproductive hazards (e.g., 2-ethoxyethanol, 2-methoxyethanol, methyl chloride), and neurotoxins (e.g., n-hexane, tetrachloroethylene, toluene). Many different classes of chemicals can be used as organic solvents, including aliphatic hydrocarbons, aromatic hydrocarbons, amines, esters, ethers, ketones, and nitrated or chlorinated hydrocarbons. Exposure to a massive amount of solvents can cause sudden death. Prolonged exposure to solvents can cause blindness, irregular heartbeat, and damage to the kidneys, liver, lungs, and central nervous system. Solvents anticipated to be human carcinogens include carbon tetrachloride, chloroform, 1,4-dioxane, perchloroethylene, styrene, and trichloroethylene. Regular exposure to solvents can cause memory and hearing loss, mental illness, depression, fatigue, confusion, dizziness, feeling drunk or "high," lack of coordination, headache, nausea, stomach pains, skin rashes, cracking or bleeding skin, and irritated eyes, nose, and throat.
Source capture Special attachment/hood to remove pollutants at the source. A source capture air cleaner could be used in the welding industry, for example, to provide extra protection from harmful welding fumes. Source capture units are also used in the beauty salon and spa industry, where stylists and nail salon workers are often exposed to harmful chemicals and fumes when they are applying certain hair straightening treatments, hair dyes or perms, use aerosol sprays or mousses or when they use nail polish remover, solvents, nail polish, nail glue etc. Source capture air cleaners can be used in any industry or application where chemical fumes and gases may be released at a workstation or during certain processes. Similarly, fume hoods installed in laboratories for example, could be considered source capture units.
Spores The reproductive element of fungi. Molds reproduce by means of tiny spores; the spores are invisible to the naked eye and float through outdoor and indoor air. Mold may begin growing indoors when mold spores land on surfaces that are wet. According to the EPA, inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals. It is impossible to get rid of all mold and mold spores indoors; some mold spores will be found floating through the air and in house dust. The mold spores will not grow if moisture is not present. Indoor mold growth can and should be prevented or controlled by controlling moisture indoors.
Toluene Toluene is a clear, colorless liquid with a strong, sweet, and pungent odor. It occurs naturally in crude oil. Toluene has a chemical formula of C7H8. Toluene is used as a solvent, and to make aviation gasoline, spray and wall paints, paint thinner, medicine, dyes, explosives, detergents, fingernail polish, spot removers, lacquers, adhesives, rubber, and antifreeze. It is also used in some printing and leather tanning processes. The largest industrial use of toluene is in the production of benzene, a chemical used to make plastics and synthetic fibers. Toluene is also used to boost the octane of gasoline. Exposure to high levels of toluene may affect your kidneys, nervous system, liver, brain, and heart. Direct, prolonged contact with liquid toluene or vapor can irritate the eyes, and cause dry skin and skin rashes. Ingesting toluene can cause vomiting, diarrhea, and difficult breathing. Inhaling high levels of toluene can cause death or unconsciousness as well as depression. Exposure to low to moderate levels of toluene can cause confusion, light-headedness, dizziness, headache, fatigue, weakness, memory loss, nausea, appetite loss, coughing, wheezing, and hearing and color vision loss.
UV Ultraviolet (some air filtration systems accommodate UV germicidal filtration, which helps neutralize bacteria, viruses and mold). The application of UV to disinfection has been an accepted practice since the mid-20th century. It has been used primarily in medical sanitation and sterile work facilities. Increasingly it was employed to sterilize drinking and wastewater, as the holding facilities were enclosed and could be circulated to ensure a higher exposure to the UV. In recent years UVGI has found renewed application in air sanitization. UVGI is a highly effective method of destroying microorganisms. When concentrated in a closed environment such as a water holding tank or duct system it is lethal over time to all micro-organisms. In many systems redundancy in exposing micro-organisms to UV is achieved by circulating the air or water repeatedly. This ensures multiple passes so that the UV is effective against the highest number of micro-organisms and will irradiate resistant micro-organisms more than once to break them down.
Vapor Intrusion Vapor intrusion generally occurs when there is a migration of volatile chemicals from contaminated groundwater or soil into an overlying building. Volatile chemicals can emit vapors that may migrate through subsurface soils and into indoor air spaces of overlying buildings in ways similar to that of radon gas seeping into homes. Volatile chemicals may include volatile organic compounds, select semi-volatile organic compounds, and some inorganic analytes, such as elemental mercury, radon, and hydrogen sulfide. In extreme cases, the vapors may accumulate in dwellings or occupied buildings to levels that may pose near-term safety hazards (e.g., explosion), acute health effects, or aesthetic problems (e.g., odors). Typically, however, the chemical concentration levels are low or, depending on site-specific conditions, vapors may not be present at detectable concentrations. In buildings with low concentrations of volatile chemicals, the main concern is whether the chemicals may pose an unacceptable risk of chronic health effects due to long-term exposure to these low levels. A complicating factor in evaluating the potential chronic risk from vapor intrusion is the potential presence of some of the same chemicals from emission sources in the building (e.g., household solvents, gasoline, cleaners) that may pose, separately or in combination with vapor intrusion, a significant human health risk.
Virus A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viral infections in animals provoke an immune response that usually eliminates the infecting virus. Immune responses can also be produced by vaccines, which confer an artificially acquired immunity to the specific viral infection. Examples of common human diseases caused by viruses include the common cold, influenza, chickenpox and cold sores. Many serious diseases such as ebola, AIDS, avian influenza and SARS are caused by viruses.
VOCs Volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids. VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects. Concentrations of many VOCs are consistently higher indoors (up to ten times higher) than outdoors. VOCs are emitted by a wide array of products numbering in the thousands. Examples include: paints and lacquers, paint strippers, cleaning supplies, pesticides, building materials and furnishings, 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. Organic chemicals are widely used as ingredients in household products. Paints, varnishes, and wax all contain organic solvents, as do many cleaning, disinfecting, cosmetic, degreasing, and hobby products. Fuels are made up of organic chemicals. All of these products can release organic compounds while you are using them, and, to some degree, when they are stored. Possible health effects are: eye, nose, and throat irritation; headaches, loss of coordination, nausea; damage to liver, kidney, and central nervous system. Some organics can cause cancer in animals; some are suspected or known to cause cancer in humans. Key signs or symptoms associated with exposure to VOCs include conjunctival irritation, nose and throat discomfort, headache, allergic skin reaction, dyspnea, declines in serum cholinesterase levels, nausea, emesis, epistaxis, fatigue, dizziness.


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