Mec 280 quiz 3 - Quiz 3 lecture notes PDF

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Indoor Air Pollution and Health Indoor Air Quality (IAQ) - air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants.

Immediate Effects health effects may show up shortly after a single exposure or repeated exposures to a pollutant. immediate effects are usually short-term and treatable: irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Sometimes the treatment is eliminating the person's exposure to the source of the pollution Soon after exposure to some indoor air pollutants, symptoms of some diseases such as asthma may show up, be aggravated or worsened. The likelihood of immediate reactions to indoor air pollutants depends on several factors including age and pre existing medical conditions. Depends on individual sensitivity Some people can become sensitized to biological or chemical pollutants after repeated or high level exposures. Certain immediate effects are similar to those from colds or other viral diseases, so it is often difficult to determine if the symptoms are a result of exposure to indoor air pollution. pay attention to the time and place symptoms occur. If the symptoms fade when a person is away from the area, work to identify indoor air sources that may be possible causes. Some effects may be made worse by an inadequate supply of outdoor air coming indoors or from the heating, cooling or humidity conditions prevalent indoors.

Long-Term Effects -

Other health effects may show up either years after exposure has occurred or only after long or repeated periods of exposure. These effects, which include some respiratory diseases, heart disease and cancer, can be severely debilitating or fatal. It is prudent to try to improve the indoor air quality in your home even if symptoms are not noticeable. considerable uncertainty about what concentrations or periods of exposure are necessary to produce specific health problems. People also react very differently to exposure to indoor air pollutants. Further research is needed to better understand which health effects occur after exposure to the average pollutant concentrations found in homes and which occurs from the higher concentrations that occur for short periods of time.

Primary Causes of Indoor Air Problems Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems. Inadequate ventilation - not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the area. High temperature and humidity levels - increase concentrations of some pollutants.

Pollutant Sources Indoor sources ➔ Fuel-buring combustion appliances ➔ Tobacco products ➔ Building materials and furnishings as diverse as: ◆ Deteriorated asbestos-containing insulation ◆ Newly installed flooring, upholstery or carpet ◆ Cabinetry or furniture made of certain pressed wood products ➔ Products for household cleaning and maintenance, personal care, or hobbies ➔ Central heating and cooling systems and humidification devices ➔ Excess moisture Outdoor sources ➔ Radon ➔ Pesticides ➔ Outdoor air pollution. Importance of pollutant hazardous depends on quantity, duration, age of source and if there is proper maintenance. (improperly adjusted gas stove emit significantly more carbon monoxide than one that is properly adjusted) Some sources, such as building materials, furnishings and products like air fresheners, release pollutants more or less continuously. Smoking, cleaning,redecorating or doing hobbies release pollutants intermittently. Unvented or malfunctioning appliances or improperly used products can release higher and sometimes dangerous levels of pollutants indoors Pollutant concentrations can remain in the air for long periods after some activities.

Inadequate Ventilation Unless buildings are built with special mechanical means of ventilation, those designed and constructed to minimize the amount of outdoor air that can "leak" in and out may have higher indoor pollutant levels.

How Outdoor Air Enters a Building -

Infiltration - outdoor air flows into buildings through openings, joints, and cracks in walls, floors, and ceilings, and around windows and doors Natural ventilation - air moves through opened windows and doors. Air movement associated with infiltration and natural ventilation is caused by air temperature differences between indoors and outdoors and by wind Mechanical ventilation - outdoor-vented fans that remove air from a single room to air handling systems that use fans and ductwork to continuously remove indoor air and distribute filtered and conditioned outdoor air to strategic points throughout the house. The rate at which outdoor air replaces indoor air is described as the air exchange rate. When there is little infiltration, natural ventilation, or mechanical ventilation, the air exchange rate is low and pollutant levels can increase. Indoor Air Quality and Environmental Justice Environmental justice (EJ) - "the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies." Agency recognizes that communities must be the impetus for implementing local solutions for environmental health problems including indoor air. However, many communities lack the capacity to affect their environmental conditions - indoor and outdoor air (climate change) Studies indicate that the following populations may be disproportionately impacted by indoor asthma triggers, secondhand smoke, mold, radon and other indoor pollutants: ➔ children ➔ elderly ➔ low-income ➔ minority ➔ Tribes and indigenous people. EPA's Indoor Environments Division (IED) provides guidance and programs to help build the capacity of communities to understand and avoid indoor and outdoor health impacts. Identifying Problems in the Indoor Environments 1. health effects can be useful indicators of an indoor air quality problem (especially if they appear after a person moves to a new residence, remodels a home, or treats a home with pesticides) 2. identify potential sources of indoor air pollution (presence of such sources does not necessarily mean that you have an indoor air quality problem) 3. lifestyle and activities. Human activities can be significant sources of indoor air pollution. 4. Home ventilation problems ● moisture condensation on windows or walls ● smelly or stuffy air (step outside and compare with inside) ● dirty central heating and air cooling equipment ● Moldy items or areas Measuring Radon Levels The federal government recommends that you measure the level of radon in your home. (colorless, odorless, radioactive gas. Inexpensive devices are available for measuring radon) For pollutants other than radon, measurements are most appropriate when there are either health symptoms or signs of poor ventilation and specific sources of pollutants have been identified as possible causes of indoor air quality problems. Testing for many pollutants can be expensive. Climate Change, Indoor Air Quality and Building Adaptation Climate change may worsen existing indoor environmental problems and indoor air quality, and it may also introduce new problems as the frequency or severity of adverse outdoor conditions change. The design, construction, operation and maintenance of buildings can impact the air we breathe, our energy consumption, and our health. T considerations for buildings should include occupant health, sustainability, energy efficiency, and changing outdoor conditions. Buildings should be constructed with future problems in minds. With use, age, changes in outdoor environmental conditions, and the drive for energy efficiency, homes and buildings will undergo renovation and repair. Modifications to buildings might be made without consideration of indoor air quality three broad approaches to moderate indoor air pollution: source control, ventilation, and air cleaning.

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When buildings and homes are modified to decrease energy use, changes can occur in ventilation, infiltration (air leakage), and pressurization, creating air flow changes that can impact indoor pollutant levels. Furthermore, building upgrades can disturb existing contaminants known to cause health problems. Some of these contaminants have specific regulatory requirements (e.g., asbestos, lead) that must be followed, while many others are not regulated. Building operational concerns to be considered with respect to climate change. provisions for increased frequency and duration of electrical power outages should be considered due to the increased frequency and severity of storms anticipated with climate change. Methods of ventilating buildings and maintaining acceptable thermal conditions using resilient or passive design strategies can be included in building design or modification strategies Severe Weather Extreme temperatures, increased precipitation and storm severity can lead to increased humidity and mold growth, droughts and wildfires and proliferation of pests. ● Areas with more precipitation, there is an increased risk of flooding and dampness indoors — the perfect environment for mold growth. Exposure to mold can lead to respiratory problems such as asthma and allergies. ● Areas with temperatures and less precipitation, resulting in more droughts and wildfires. This can result in more particulate air pollution, such as dust and smoke. The particulate air pollution can enter buildings and homes, affecting lung and heart health. ● Changes in temperature and flooding can drive pests indoors looking for shelter and food. Additionally, pest infestations are often combated with pesticides that are toxic to people, too.

Weatherization and Ventilation (sealing and insulating) -

offset outdoor temperature changes and to help save energy by reducing the need for heating and cooling changes. Weatherizing without maintaining proper ventilation can negatively affect indoor air. ● Without air ventilation, the humidity level remains high and can provide a breeding ground for mold, mites and bacteria (may combat with chemical products) ● Poor ventilation lead to increased indoor exposure to pollutants because there isn’t any exchange with outdoor air to dilute or remove the concentration of the pollutants: ○ carbon monoxide ○ secondhand smoke ○ volatile organic compounds (VOCs) The federal government recommends that homes be weatherized in order to reduce the amount of energy needed for heating and cooling. residents should be alert to the emergence of signs of inadequate ventilation, such as stuffy air, moisture condensation on cold surfaces, or mold and mildew growth. Additional weatherization measures should not be undertaken until these problems have been corrected. Weatherization generally does not cause indoor air problems by adding new pollutants to the air. (There are a few exceptions, such as caulking, that can sometimes emit pollutants.) However, measures such as installing storm windows, weather stripping, caulking, and blown-in wall insulation can reduce the amount of outdoor air infiltrating into a home. Consequently, after weatherization, concentrations of indoor air pollutants from sources inside the home can increase.

Asthma Asthma is a serious, sometimes life-threatening chronic respiratory disease that affects the quality of life for more than 24 million Americans, including an estimated 6 million children. Although there is no cure for asthma yet, asthma can be controlled through medical treatment and management of environmental triggers. EPA is committed to educating all Americans about asthma so that: ● Everyone knows what asthma is, ● How the environment can affect asthma patients and ● How to manage environmental asthma triggers. Who is at Risk for Asthma? Anyone can get asthma - people of all ethnic groups, male and female, young and old, city dwellers and rural dwellers. In the United States, more than 24 million people have asthma. Asthma is common among children and teens; about three students in an average classroom of 30 have asthma. While no one knows for sure why some people develop asthma and others don't, we do know that it is a combination of your family history and your environment. There is no cure for asthma. Once you have asthma, you will have the disease for the rest of your life. But with proper care, you can lead a healthy, productive, fully active life. Asthma Triggers Learn more about factors found in the indoor and outdoor environment that can cause, trigger or exacerbate asthma symptoms and what you can do to reduce their impact. You might be surprised by the list of common environmental asthma triggers and how simple it can be to eliminate them from your environment. Preventing Asthma Attacks 1. Step 1 - Talk to a doctor a. If you think that you or your child may have asthma, talk to a doctor. Your doctor will work with you to diagnose asthma and keep you or your child from having asthma attacks. b. Learn what triggers asthma attacks. c. Identify asthma triggers in your home. d. Talk about ways to get rid of triggers in your home. e. Find out what medicine(s) to take. 2. Step 2 - Make a Plan a. Ask your doctor to help you create an Asthma Action Plan to prevent asthma attacks. b. An Asthma Action Plan will help you control asthma on a regular basis. Look on the back for a list of possible asthma triggers and ways to avoid them. 3. Step 3 - Asthma-Proof Your Home Should You Have the Air Ducts in Your Home Cleaned? Duct cleaning has never been shown to actually prevent health problems. Neither do studies conclusively demonstrate that particle (e.g., dust) levels in homes increase because of dirty air ducts. This is because much of the dirt in air ducts adheres to duct surfaces and does not necessarily enter the living space (dirty air ducts are only one of many possible sources of particles that are present in homes) Pollutants that enter the home both from outdoors and indoor activities can cause greater exposure to contaminants than dirty air ducts. no evidence that a light amount of household dust or other particulate matter in air ducts poses any risk to your health. You should consider having the air ducts in your home cleaned if: There is substantial visible mold growth inside hard surface (e.g., sheet metal) ducts or on other components of your heating and cooling system. There are several important points to understand concerning mold detection in heating and cooling systems: ➔ Many sections of your heating and cooling system may not be accessible for a visible inspection, so ask the service provider to show you any mold they say exists. ➔ You should be aware that although a substance may look like mold, a positive determination of whether it is mold or not can be made only by an expert and may require laboratory analysis for final confirmation. For about $50, some microbiology laboratories can tell you whether a sample sent to them on a clear strip of sticky household tape is mold or simply a substance that resembles it. ➔ If you have insulated air ducts and the insulation gets wet or moldy it cannot be effectively cleaned and should be removed and replaced. ➔ If the conditions causing the mold growth in the first place are not corrected, mold growth will recur. Ducts are infested with vermin, e.g. (rodents or insects). Ducts are clogged with excessive amounts of dust and debris and/or particles are actually released into the home from your supply registers. Prior to any cleaning, retrofitting, or replacing of your ducts, the cause or causes must be corrected or else the problem will likely recur. -

Some research suggests that cleaning heating and cooling system components (e.g., cooling coils, fans and heat exchangers) may improve the efficiency of your system, resulting in a longer operating life, as well as some energy and maintenance cost savings. However, little evidence exists that cleaning only the ducts will improve the efficiency of the system. EPA does recommend that if you have a fuel burning furnace, stove or fireplace, they be inspected for proper functioning and serviced before each heating season to protect against carbon monoxide poisoning. Air duct cleaning service providers may tell you that they need to apply chemical biocide to the inside of your ducts as a means to kill bacteria (germs) and fungi (mold) and prevent future biological growth. They may also propose the application of a "sealant" to prevent dust and dirt particles from being released into the air or to seal air leaks. While the targeted use of chemical biocides and sealants may be appropriate under specific circumstances, research has not demonstrated their effectiveness in duct cleaning or their potential adverse health effects. No chemical biocides are currently registered by EPA for use in internally-insulated air duct systems

Duct cleaning These services typically — but not always — range in cost from $450 to $1,000 per heating and cooling system, depending on: ➔ the size of the system to be cleaned ➔ system accessibility ➔ climatic region ➔ level of contamination Duct cleaning - cleaning of various heating and cooling system components of forced air systems, including the supply and return air ducts and registers, grilles and diffusers, heat exchangers heating and cooling coils, condensate drain pans (drip pans), fan motor and fan housing, and the air handling unit housing

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If not properly installed, maintained and operated, these components may become contaminated with particles of dust, pollen or other debris. If moisture is present, the potential for microbiological growth (e.g., mold) is increased and spores from such growth may be released into the home's living space. Some of these contaminants may cause allergic reactions or other symptoms in people if they are exposed to them. If you decide to have your heating and cooling system cleaned, it is important to make sure the service provider agrees to clean all components of the system and is qualified to do so. Failure to clean a component of a contaminated system can result in re-contamination of the entire system, thus negating any potential benefits. Methods of duct cleaning vary, although standards have been established by industry associations concerned with air duct cleaning. Typically, a service provider will use specialized tools to dislodge dirt and other debris in ducts, then vacuum them out with a high-powered vacuum cleaner. In addition, the service provider may propose applying chemical biocides, designed to kill microbiological contaminants, to the inside of the duct work and to other system components. Some service providers may also suggest applying chemical treatments (sealants or other encapsulants) to encapsulate or cover the inside surfaces of the air ducts and equipment housings because they believe it will control mold growth or prevent the release of dirt particles or fibers from ducts. These practices have yet to be fully researched and you should be fully informed before deciding to permit the use of biocides or chemical treatments in your air ducts. They should only be applied, if at all, after the system has been properly cleaned of all visible dust or debris. Note: Use of sealants to encapsulate the inside surfaces of ducts is a different practice than sealing duct air leaks. Sealing duct air leaks can help save energy on heating and cooling bills. Deciding Whether or Not to Have Your Air Ducts Cleaned Knowledge about the potential benefits and possible problems of air duct cleaning is limited. Since conditions in every home are different, it is impossible to generalize about whether or not air duct cleaning in your home would be beneficial. If no one in your household suffers from allergies or unexplained symptoms or illnesses and if, after a visual inspection of the inside of the ducts, you see no indication that your air ducts are contaminated with large deposits of dust or mold (no musty odor or visible mold growth), having your air ducts cleaned is probably unnecessary. It is normal for the return registers to get...