Indoor air pollution refers to pollutants found inside homes, schools, and other buildings that can negatively impact health. Common sources of indoor air pollution include tobacco smoke, combustion appliances, building materials and furnishings, chemicals from consumer products, and outdoor air pollution entering through open windows or other means. Exposure to indoor air pollutants is an important environmental problem since people spend most of their time indoors where pollutant levels are often higher than outside. Indoor air pollution has been linked to various respiratory and other health issues.

2. Indoor Air Pollution

3. Introduction
 Although pollutant concentrations vary
significantly from building to building,
the levels of some common air
pollutants often are greater indoors
than outdoors. Since most people
spend more time indoors than outdoors,
exposure to indoor air pollutants is an
important environmental problem.

4. To be cont………..
 Air pollution is the introduction
of chemicals, particulate matter,
or biological material that cause
harm discomfort to humans or
other living organisms, or
damages the natural environment,
into the atmosphere.

5. What’s indoor air pollution?
 Indoor Air Pollution is the term used to
describe the amount of contaminants
in the air inside a building from
sources such as cigarette smoking, fuel
combustion for heating or cooking,
certain wallboards, carpets, or
insulation as well as the geology of the
area (radon in soil or rocks beneath the
structure).

6. To be cont………..
 Refers to good and bad effects of the contents of air
inside a structure on its occupants
 Good indoor air quality(IAQ) has no unwanted gases
or particles in it at concentrations which will
adversely affect someone
 Poor indoor air quality has gases or particles in
excessive concentration so as to affect the
satisfaction or health of occupants

7. What Causes Indoor Air
Pollution??
 Air tightness of buildings
 Poorly designed air conditioning and
ventilation systems
 Indoor sources of pollution
 Outdoor sources of pollution

8. Air Tightness in Buildings
Causes inadequate supply of fresh air, as a result,
negative pressure develops, which causes
 Ground level pollutants, e.g. CO, Radon etc.to be
drawn inside the buildings.
 Release of odor (Bioaerosols) and other pollutants.
 Pull outside polluted air from vents, cracks and
openings and increase dust, pollen etc.
 Causes “Sick Building Syndrome”.

9. Sources of Indoor Air Pollution
in a Typical Office Building

10. Sources of Indoor Air Pollution in a Typical
Household

11. Poorly Designed Air
Conditioning Systems
 Results into the production of fungi, molds
and other sickness causing microbes.

12. What is IAQ??
 IAQ stands for “Indoor Air Quality”.
 It refers to the nature of the conditioned
(heat/ cool) air that circulates throughout
space/area, where we work and live i.e. the
air we breathe most of the time (almost 80
% of the time).

13. Problems of IAQ
Enclosed spaces inhabited by humans produce
following effects-
 Reduction in oxygen level of spaces.
 Increase in CO2 level.
 Increase in temperature.
 Increase in humidity
 Increase in Bioaerosols and odor

14. Relationship between Indoor and Outdoor
Air Quality
Indoor Air Quality Outdoor Air Quality
 Indoor pollutant  Outdoor contaminants
concentrations may be may be present
higher or lower than indoors at a sufficient
outdoor air concentration to affect
concentrations the occupants
Example : Pollen and mold spores from outdoors
causes hay fever and allergies indoors

15. Poor IAQ Results

16. Why should you be concerned about the
quality of air that you breath?
 The contaminant indoor air could damage people’s health
 Indoor air pollutants are among the top five environmental
risk
 People spend about 90% of their time indoors and so the
health problems that result from exposure to indoor
pollution increases
 According to World Health Organization (WHO)
approximately 30% of all commercial buildings have
significant IAQ problems

17. Sources of Pollutants
 Normal Biological Processes - people and pets
generate carbon dioxide, moisture, odors and
microbes
 Combustion appliances such as wood stoves, gas
stoves, furnaces, fireplaces and gas heaters
 Use of consumer products such as spray cans, air
fresheners, spray cleaners and construction materials
 Cigarette smoking
 Soil under and around buildings
 Appliances such as humidifiers, air conditioners and
nebulizers

18. Sources involved in IAQ problems
Evaluations by National Institute for Occupational Safety
and Health (NIOSH) for studies on more than 500 Indoor
Air quality health hazard cases
Bioaerosols
5%
Inside
contamination
15%
Outside
Contamination Inadequate
10% Ventilation
Building 53%
products
4%
Unknown
causes
13%

19. Percent Typical Sources
Problem Origin
Lack of outside air, poor air
distribution, uncomfortable
Inadequate Building
53% temperature and humidity,
Ventilation Systems
contaminant sources inside the
system
Solvent vapors, dusts,
Contaminants Originating
15% formaldehyde, building materials,
Inside Building
furnishings
Building Products 4% Concrete, wood, furnishings.
Unknown Causes 13% Unidentified sources
Outdoor Contaminants Motor vehicle exhaust, pollen,
10%
Entering Building fungi, smoke, construction
Microbiological Agents 5% Bioaerosols, Legionella

20. How does Outdoor Air enter
Indoors
 Infiltration - outdoor air flows into the house through
openings, joints, and cracks in walls, floors, and
ceilings, and around windows and doors
 Natural Ventilation - air moves through opened
windows and doors
 Mechanical Ventilation - from outdoor-vented fans
that intermittently remove air from a single room,
such as bathrooms and kitchen, to air handling
systems that use fans and duct work to continuously
remove indoor air and distribute filtered and
conditioned outdoor air to strategic points
throughout the house

21. Health effects due to Indoor
Air Pollutants
 Headaches
 Nausea
 Respiratory infections
 Asthma
 Hypersensitivity pneumonitis
 Humidifier fever
 Legionnaire’s disease
 Lung cancer

22. Health Symptoms and Possible
Contaminants
SYMPTOM POSSIBLE PRIMARY ENVIRONMENTAL
CONTAMINANTS SOURCES CONDITION
· Headache · Bio-aerosols · Ventilation systems · Ergonomic
· Fatigue · VOCs · Humidifiers Conditions
· Poor Concentration · Drip pans · Noise and
· Dizziness · Cooling coils in AHVs Vibration
· Tiredness · Plants
· Outside air
· Headache with nausea · CO · Incomplete · Ergonomic
· Ringing in ears · Formaldehyde Combustion (vehicle Conditions
· Pounding heart Exhaust, stoves, · Noise and
fireplaces) Vibration
· Building products
· Furnishings
· Dry Throat · NO2 · Incomplete · Relative
· Shortness of breath · Formaldehyde Combustion humidity
or Bronchial Asthma · VOCs · Building Products
· Irritation and · Particulates · Furnishings
Infection of · Smoking
Respiratory Tract

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SYMPTOM POSSIBLE PRIMARY ENVIRONMENTAL
CONTAMINANTS SOURCES CONDITION
· Nasal Problems · NO2 · Incomplete Combustion · Relative Humidity
(Stuffiness,Irritation) · Formaldehyde · Building Products · High Temperatures
· Bio-aerosols · Furnishings
· Ventilation Systems
· Humidifiers
· Drip Pans
· Cooling Coils in AHVs
· Outside Air
· Skin Problems · Formaldehyde · Ventilation Systems · Warm Air
(Dryness, Irritation, · Humidifiers · Low Relative
Rashes) · Outside Air Humidity
· Excessive Air
Movement
· Eye Problems · NO2 · Incomplete Combustion · Artificial Light
(Burning, Dry Gritty · Formaldehyde · Building Products
Eye) · VOC's · Furnishings
· Particulates · Ventilation Systems
· Bio-aerosols · Humidifiers
· Cooling Coils in AHVs
· Outside Air
· Building Product
Deterioration

24. List of Pollutants affecting
IAQ
 Volatile organic compounds (VOCs)
 Dust and dirt
 Radon
 Environmental tobacco smoke (ETS)
 Respirable Particulate Matter (RPM)
 Carbon and Nitrous Oxides

25. Indoor Air Pollutants and Their Health Effects
Pollutant Effects Limits
NO2 Type: Immediate 0.05 ppm (avg. over one year for 8
hours exposure daily)- EPA
Causes: irritation to the skin, eyes and throat, cough etc.
CO Type: Immediate 9.0 ppm (avg. over 8 hours
Causes: headache, shortness of breath, higher conc. May cause sudden period)- EPA
deaths.
RSPM Type: Cumulative 150 µg/ m3 (24 hr. average)
Causes: Lung cancer
SO2 Type: Immediate 0.05 ppm (avg. over one year for 8
Causes: lung disorders and shortness of breath hours exposure daily)- EPA
Radon Type: Cumulative >/ 4 pCi/ Litre of indoor air
Causes: Lung cancer
Formaldehyde Type: Immediate 120 g/ cu.m. (continuous
exposure)- ASHRAE
Causes: irritation to the eyes, nose and throat, fatigue, headache, skin
allergies, vomiting etc.
Asbestos Type: Cumulative >/ 2 fibers/ cu.cm. Of the indoor
Causes: Lung cancer air (8 hrs. exposure period)- OSHA
Pesticides Type: Immediate -
Causes: Skin diseases
VOCs Type: Immediate Not for all VOCs.
Causes: Liver, kidney disorders, irritation to the eyes, nose and throat, skin For chlordane:
rashes and respiratory problems. 5 g/cu.m.(continuous exposure))
CO2 Surrogate index of ventilation 1000 ppm
O3 Type: Immediate 100 g/cu.m (continuous
exposure)- OSHA
Causes: eyes itch, burn, respiratory disorders, lowers our resistance to colds
and pneumonia.