Indoor Air Quality


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Indoor Air Quality

  1. 1. Indoor Air Quality Unit-VIII
  2. 2. Indoor Air Quality Management • Indoor Air Quality (IAQ) is a term which refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. • IAQ refers to the quality of the air inside buildings as represented by concentrations of pollutants and thermal conditions that affect the health and performance of Occupants. • It refers to the nature/ quality of the conditioned (heat/cool) air that circulates throughout closed space/ area, where we work and live and breath the air.
  3. 3. Indoor Air Quality Management
  4. 4. Indoor Air Quality Management • IAQ can be affected by gases (including carbon monoxide, radon, volatile organic compounds), particulates, microbial contaminants (mold, bacteria) etc.
  5. 5. Indoor Air Quality Management • Source control, filtration and the use of ventilation to dilute contaminants are the primary methods for improving indoor air quality in most buildings. Residential units can further improve indoor air quality by routine cleaning of carpets and area rugs.
  6. 6. Indoor Air Quality Management
  7. 7. Common Pollutants • Second-hand smoke is tobacco smoke which affects other people other than the 'active' smoker. Second-hand tobacco smoke includes both a gaseous and a particulate phase, with particular hazards arising from levels of carbon monoxide and very small particulates (at PM2.5 size) which get past the lung's natural defenses. The only certain method to improve indoor air quality as regards second-hand smoke is the implementation of comprehensive smoke-free laws.
  8. 8. Second-hand Smoke
  9. 9. Common Pollutants Radon • Radon is an invisible, radioactive atomic gas that results from the radioactive decay of radium, which may be found in rock formations beneath buildings or in certain building materials themselves. Radon is probably the most pervasive serious hazard for indoor air, probably responsible for tens of thousands of deaths from lung cancer each year
  10. 10. Radon
  11. 11. Common Pollutants Molds and Other Allergens • These biological chemicals can arise from a host of means, but there are two common classes: • (a) moisture induced growth of mold colonies and (b) natural substances released into the air such as animal dander and plant pollen. In areas where cellulosic materials (paper and wood, including drywall) become moist and fail to dry within 48 hours, mold mildew can propagate and release allergenic spores into the air. • Mold is always associated with moisture, and its growth can be inhibited by keeping humidity levels below 50%.
  12. 12. Molds and Other Allergens
  13. 13. Common Pollutants Carbon Monoxide • One of the most acutely toxic indoor air contaminants is carbon monoxide (CO), a colorless, odorless gas that is a byproduct of incomplete combustion of fossil fuels. Common sources of carbon monoxide are tobacco smoke, space heaters using fossil fuels, defective central heating furnaces and automobile exhaust. Improvements in indoor levels of CO are systematically improving from increasing implementation of smoke-free laws. By depriving the brain of oxygen, high levels of carbon monoxide can lead to nausea, unconsciousness and death.
  14. 14. Carbon Monoxide
  15. 15. Carbon Monoxide
  16. 16. Ozone • Ozone is produced by ultraviolet light from the Sun hitting the Earth's atmosphere (especially in the ozone layer), lightning, certain high-voltage electric devices (such as air ionizers), and as a by-product of other types of pollution. • Ozone exists in greater concentrations at altitudes commonly flown by passenger jets. Reactions between ozone and onboard substances, including skin oils and cosmetics, can produce toxic chemicals as by-products. Ozone itself is also irritating to lung tissue and harmful to human health.
  17. 17. Ozone
  18. 18. The Causes • Inadequate ventilation and air tightness • Variations in temperature and humidity levels • Indoor sources including combustion • Infiltration of outdoor air contaminants • Use of cleaning chemicals and building products
  19. 19. The Causes
  20. 20. Indoor Pollutants • Building Materials – Heavy Metals, VOCs, Radon, Mineral Fibers etc • Paints – Heavy Metals Electronic Equipments • Respirable Organic Particulates, Ozone and VOCs. • Carpets - VOC’S • Cleaning compounds/Cosmetics/Deodorants • : Organics and VOCs • Combustion Sources • - RSPM, NO x, SO 2 , CO
  21. 21. Indoor Pollutants
  22. 22. Health Effects
  23. 23. Health Effects
  24. 24. Health Effects • Symptoms related to poor IAQ are varied depending on the type of contaminant. They can easily be mistaken for symptoms of other illnesses such as allergies, stress, colds, and influenza. The usual clue is that people feel ill while inside the building, and the symptoms go away shortly after leaving the building, or when away from the building for a period of time (such as on weekends or a vacation).
  25. 25. Sick Building Syndrome • Sick building syndrome (SBS) is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. A 1984 World Health Organization report suggested up to 30% of new and remodeled buildings worldwide may be subject of complaints related to poor indoor air quality.
  26. 26. Sick Building Syndrome
  27. 27. Sick Building Syndrome • Sick building causes are frequently pinned down to flaws in the heating, ventilation, and air conditioning (HVAC) systems. Other causes have been attributed to contaminants produced by outgassing of some types of building materials, volatile organic compounds (VOC), molds (see mold health issues), improper exhaust ventilation of ozone (byproduct of some office machinery), light industrial chemicals used within, or lack of adequate fresh-air intake/air filtration (see Minimum Efficiency Reporting Value).
  28. 28. Sick Building Syndrome
  29. 29. Health Effects • Effects from indoor air pollutants may be experienced soon after exposure or, possibly, years later. Symptoms may include irritation of the eyes, nose, and throat; headaches; dizziness; rashes; and muscle pain and fatigue. • Diseases linked to poor IAQ include asthma and hypersensitivity pneumonitis. The specific pollutant, the concentration of exposure, and the frequency and duration of exposure are all important factors in the type and severity of health effects resulting from poor IAQ.
  30. 30. Health Effects
  31. 31. Health Effects • Age and preexisting medical conditions such as asthma and allergies may also influence the severity of the effects. Long-term effects due to indoor air pollutants may include respiratory diseases, heart disease, and cancer, all of which can be severely debilitating or fatal
  32. 32. Health Effects
  33. 33. Health Effects • Research has linked building dampness with significant health effects. Numerous species of bacteria and fungi, in particular filamentous fungi (mold), can contribute significantly to indoor air pollution. Whenever sufficient moisture is present within workplaces, these microbes can grow and affect the health of workers in several ways. • Workers may develop respiratory symptoms, allergies, or asthma. Asthma, cough, wheezing, shortness of breath, sinus congestion, sneezing, nasal congestion, and sinusitis have all been associated with indoor dampness in numerous studies. Asthma is both caused by and worsened by dampness in buildings.
  34. 34. Sources of Indoor Air Pollutants Sources of indoor air pollution may include: Building Site or Location • The location of a building can have implications for indoor pollutants. • Highways or busy thoroughfares may be sources of particulates and other pollutants in nearby buildings. Buildings sited on land where there was prior industrial use or where there is a high water table may result in leaching of water or chemical pollutants into the building.
  35. 35. Building Site or Location
  36. 36. Sources of Indoor Air Pollutants Building Design • Design and construction flaws may contribute to indoor air pollution. Poor foundations, roofs, facades, and window and door openings may allow pollutant or water intrusion. Outside air intakes placed near sources where pollutants are drawn back into the building (e.g,idling vehicles, products of combustion, waste containers, etc.) or where building exhaust reenters into the building can be a constant source of pollutants. Buildings with multiple tenants may need an evaluation to ensure emissions from one tenant do not adversely affect another tenant.
  37. 37. Building Design
  38. 38. Sources of Indoor Air Pollutants Building Systems Design and Maintenance: • When the HVAC system is not functioning properly for any reason, the building is often placed under negative pressure. In such cases, there may be infiltration of outdoor pollutants such as particulates, vehicle exhaust, humid air, parking garage contaminants, etc.
  39. 39. Building Systems Design and Maintenance
  40. 40. Renovation Activities • When painting and other renovations are being conducted, dust or other by-products of the construction materials are sources of pollutants that may circulate through a building. Isolation by barriers and increased ventilation to dilute and remove the contaminants are recommended.
  41. 41. Renovation Activities
  42. 42. Local Exhaust Ventilation Kitchens, laboratories, maintenance shops, parking garages, trash rooms, soiled laundry rooms, locker rooms, copy rooms and other specialized areas may be a source of pollutants when they lack adequate local exhaust ventilation
  43. 43. Building Materials • Disturbing thermal insulation or sprayed-on acoustical material, or the presence of wet or damp structural surfaces (e.g., walls, ceilings) • or non-structural surfaces (e.g., carpets, shades), may contribute to indoor air pollution.
  44. 44. Building Materials
  45. 45. Building Maintenance • Workers in areas in which pesticides, cleaning products, or personal-care products are being applied may be exposed to pollutants. Allowing cleaned carpets to dry without active ventilation may promote microbial growth. Occupant Activities: • Building occupants may be the source of indoor air pollutants.
  46. 46. Building Maintenance
  47. 47. Common Pollutant Categories • Although there are numerous indoor air pollutants that can be spread through a building, they typically fall into three basic categories: biological, chemical, Biological • Excessive concentrations of bacteria, viruses, fungi, dust mites, animal dander, and pollen may result from inadequate maintenance and housekeeping, water spills, inadequate humidity control, condensation, or water intrusion through leaks in the building envelope or flooding
  48. 48. Biological Pollutants
  49. 49. Common Pollutant Categories Chemical • Sources of chemical pollutants (gases and vapors) include emissions from products used in the building (e.g., office equipment; furniture, wall and floor coverings; pesticides; and cleaning and consumer products), accidental spills of chemicals, products used during construction activities such as adhesives and paints, and gases such as carbon monoxide, formaldehyde, and nitrogen dioxide, which are products of combustion
  50. 50. Chemical Pollutants
  51. 51. Common Pollutant Categories Particle (Non-biological) • Particles are solid or liquid, non- biological, substances that are light enough to be suspended in the air. • Dust, dirt, or other substances may be drawn into the building from outside. Particles can also be produced by activities that occur in buildings such as construction, sanding wood or drywall, printing, copying, and operating equipment.
  52. 52. Common Pollutant Categories
  53. 53. IAQ Management • It is recommended that building owners/managers develop and implement an IAQ management plan to address, prevent, and resolve IAQ problems in their specific buildings. The EPA’s report, • IAQ Tools for Office Buildings , provides a set of flexible and specific activities that can be useful to building owners/managers for developing such a plan. IAQ policies, assessing the current status of IAQ in buildings through periodic inspections, maintaining appropriate logs and checklists, performing necessary repairs and upgrades, and implementing follow-up assessments or other needed actions.
  54. 54. IAQ Management
  55. 55. IAQ Management • An important management strategy is to foster a team approach for problem solving and consensus building. The IAQ Team should include, but not necessarily be limited to, building occupants, administrative staff, facility operators, custodians, building healthcare staff, contract service providers, and other interested parties
  56. 56. IAQ Management
  57. 57. Identification and Assessment • Methods used in an IAQ investigation may include identifying pollutant sources, evaluating the HVAC system performance, observing production processes and work practices, measuring contamination levels and employee exposures, providing medical testing or physical examinations, conducting employee interviews, and reviewing records of medical tests, job histories, and injuries and illnesses.
  58. 58. Identification and Assessment
  59. 59. Control Methods • There are three basic control methods for lowering concentrations of indoor air pollutants • Source Management • Source management includes removal, substitution, and enclosure of sources. It is the most effective control method when it can be applied practically. • For example, the U.S. Consumer Product Safety Commission recommends installing carpets that are low-volatile organic compound (VOC) emitters, and encourages consumers to ask retailers or installers about the carpet industry’s voluntary “green label” program for new carpets. According to the carpet industry, the green and white logo displayed on carpet samples informs the consumer that the specific manufacturer’s product has been tested by an independent laboratory and has met the criteria for very low emissions
  60. 60. Source Management
  61. 61. Engineering controls Local Exhaust • Local exhaust, such as a canopy hood, is very effective in removing point sources of pollutants before they can be dispersed into the building’s indoor air. General Dilution Ventilation • General dilution ventilation systems, when properly designed, operated, and maintained, will control normal amounts of air pollutants. A well designed and functioning HVAC system controls temperature and relative humidity levels to provide thermal comfort, distributes adequate amounts of outdoor air to meet the ventilation needs of building occupants, and also dilutes and removes odors and other contaminants.
  62. 62. Engineering Controls
  63. 63. Air Cleaning • Air cleaning primarily involves the removal of particles from the air as the air passes through the HVAC equipment. • Most HVAC system filtration is provided to keep dirt off of coil surfaces to promote heat transfer efficiency. • Most smudging observed around air supply diffusers in a ceiling result from entrainment (trapping) of dirt particles in the space that accumulate there because of poor housekeeping
  64. 64. Air Cleaning
  65. 65. Administrative Controls Work Schedule • Through scheduling, managers can significantly reduce the amount of pollutant exposure in their buildings. • For instance: • 1. Eliminate or reduce the amount of time a worker is exposed to a pollutant (i.e., scheduling maintenance or cleaning work to be accomplished when other building occupants are not present). • 2.Reduce the amount of chemicals being used by or near workers (i.e., limit the amount of chemicals being used by the worker during maintenance or cleaning activities). • 3. Control the location of chemical use (i.e., perform maintenance work on moveable equipment in a maintenance shop as opposed to the general area, or locate the equipment (e.g., printers, copiers) in a separate room)
  66. 66. Administrative Controls
  67. 67. Administrative Controls b. Education • Education of building occupants regarding IAQ is important. If occupants are provided with information about the sources and effects of pollutants under their control, and about the proper operation of the ventilation system, they can alert their employer and/or take action to reduce their personal exposure. c. Housekeeping • Housekeeping practices should include preventing dirt from entering the environment (using, for example, walk-off mat systems), removing dirt once it is in the building, disposing of garbage,
  68. 68. Education
  69. 69. Housekeeping
  70. 70. Seeking Professional Assistance • Some indoor air problems can be resolved when good practices are put in place to control contaminants and building personnel follow good housekeeping approaches. Other problems may be difficult to resolve, however, and may require outside assistance.
  71. 71. Seeking Professional Assistance Examples of experts include: Structural engineers - address issues with structural elements such as corrosion problems in a building’s foundation; Architects - responsible for designing the building envelope and can mitigate water intrusion problems by designing vapor barriers; Mechanical engineers - test and balance HVAC systems and may be able to assess and recommend repairs/replacement of HVAC systems and local exhaust ventilation systems; and Industrial hygienists - assess general IAQ parameters such as air changes in a building, carbon dioxide levels, carbon monoxide levels, and other indoor pollutants, and also evaluate contaminant levels
  72. 72. Seeking Professional Assistance
  73. 73. Applicable Standards and Regulations OSHA Standards • All OSHA regulations, interpretations, and the OSH Act can be found on Important OSHA statues and standards include: • Occupational Safety and Health Act of 1970 • Section 5(a)(1), • often referred to as the General Duty Clause, requires employers to “furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.” • Section 5(a)(2) • requires employers to “comply with occupational safety and health standards promulgated under this Act.”
  74. 74. Applicable Standards and Regulations
  75. 75. Applicable Standards and Regulations • Some of the applicable OSHA Standards are: • 29 CFR 1904, Recording and Reporting Occupational Injuries and Illnesses. • • 29 CFR 1910.94, Ventilation. • • 29 CFR 1910.1000, Air Contaminants. • • 29 CFR 1910.1048, Formaldehyde. • • 29 CFR 1910.1450, Occupational exposure to hazardous chemicals in laboratories.
  76. 76. Applicable Standards and Regulations WHO Guidelines • Concentration based - PM10, PM2.5, CO, NO2, SO2, O3, • Asbestos, Formaldehyde (Reference: WHO, 2006) • New WHO guidelines are formed on the basis of exposure levels, which gives an objective measure of health risk and is used as reference point for design and maintenance of safe indoor environments - Benzene, CO, Formaldehyde, Naphthalene, NO2 , PAH, Radon, Ethylene, dampness and Moulds (Reference: WHO, 2010)
  77. 77. Applicable Standards and Regulations
  78. 78. AQ: Indian Context • A standard IAQ Protocol is under process of development The protocol is a check list for establishing a IAQ study in India that includes sampling, monitoring, and analysis and prediction of IAQ similar to NAAQM programme • The Protocol Team • IIT Delhi • : Prof. Mukesh Khare • NEERI • : Dr. Anjali Shrivastava, Dr. Radha Goyal, Dr. S.K. Goyal • CPCB • : Dr. D. Saha • Delhi University • : Dr. Priyanka Kulshrestha
  79. 79. AQ: Indian Context
  80. 80. Fan Death An Urban Legend • Fan death is death supposedly caused by sleeping in a closed room containing a running electric fan Origins of belief • The genesis of the misconception is unclear, but fears about electric fans date almost to their introduction to Korea, with stories dating to the 1920s and 1930s warning of the risks of nausea, asphyxiation, and facial paralysis from this "new technology”
  81. 81. Fan Death An Urban Legend
  82. 82. Fan Death An Urban Legend Proposed causes • Hypothermia • Is abnormally low body temperature caused by inadequate thermoregulation. • As the metabolism slows down at night, one becomes more sensitive to temperature, and thus supposedly more prone to hypothermia. People who believe this theory think a fan operating in a closed room all night can lower temperature to the point of causing hypothermia
  83. 83. Hypothermia
  84. 84. Fan Death An Urban Legend Asphyxiation • It is alleged that fans may cause asphyxiation by oxygen displacement and carbon dioxide intoxication. In the process of human respiration, inhaled fresh air is exhaled with a lower concentration of oxygen gas (O2) and higher concentration of carbon dioxide gas (CO2), causing a gradual reduction of O2 and build-up of CO2 in a completely unventilated room.
  85. 85. Asphyxiation
  86. 86. Fan Death An Urban Legend • Other indoor sources of carbon dioxide include burning fossil fuels, such as a gas-fuelled water heater, and seepage through foundations in areas of high CO2 soil content. Carbon dioxide is a colourless, odourless gas, and because it weighs 1.5 times more than normal air, it tends to concentrate toward the floor, depending on temperature and air currents. In South Korea, some people sleep on traditional floor mats called yos, while others prefer Western-style beds, and floor vents may be absent in rooms equipped with radiant underfloor heating, called ondol
  87. 87. Fan Death An Urban Legend
  88. 88. Fan Death An Urban Legend Actual hazard • The American Environmental Protection Agency (EPA) does not warn of fan death, but discourages people from using fans in closed rooms without ventilation during excessive heat, specifically when the heat index is above 99 °F (37 °C). The EPA does, however, approve of using a fan if a window is open and it's cooler outside, such as during overnight conditions, or when the heat index in a closed room is below 90 °F (32 °C).
  89. 89. Fan Death An Urban Legend
  90. 90. Fan Death An Urban Legend Professional Opinion • Dr. John Linton, of Yonsei University's Severance Hospital, who is licensed to practice medicine in South Korea, has said: There are several things that could be causing the fan deaths, things like pulmonary embolisms, cerebrovascular accidents or arrhythmia. There is little scientific evidence to support that a fan alone can kill you if you are using it in a sealed room. Although it is a common belief among Koreans, there are other explainable reasons for why these deaths are happening
  91. 91. Fan Death An Urban Legend
  92. 92. Fan Death An Urban Legend • Dr. Lee Yoon-song is a professor at Seoul National University's medical school and works with the school's Institute of Scientific Investigation. He has conducted autopsies on some of the people who have been described in Korean media as having succumbed to fan death, and said: • “When someone's body temperature drops below 35 degrees, they do start to lose judgment ability. So if someone was hiking and later found dead, that could be part of the reason. But we can't really apply this to fan accidents. I found most of the victims already had some sort of disease like heart problems or serious alcoholism. So hypothermia is not the main reason for death, but it may contribute”.
  93. 93. Fan Death An Urban Legend
  94. 94. References Environmental Management Bala Krishnamoorthy- PHI publication Wikipedia- The online free Encyclopedia
  95. 95. Think Global Act Local Thanks …