indoor pollution
TRANSCRIPT
Indoor Air Pollution
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.
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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.
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).
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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
What Causes Indoor Air Pollution??
Air tightness of buildingsPoorly designed air conditioning and
ventilation systems Indoor sources of pollutionOutdoor sources of pollution
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”.
Sources of Indoor Air Pollution in a Typical Office Building
Sources of Indoor Air Pollution in a Typical Household
Poorly Designed Air Conditioning Systems
Results into the production of fungi, molds and other sickness causing microbes.
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).
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
Relationship between Indoor and Outdoor Air Quality
Indoor Air Quality Outdoor Air Quality Indoor pollutant
concentrations may be higher or lower than outdoor air concentrations
Outdoor contaminants may be present indoors at a sufficient concentration to affect the occupants
Example : Pollen and mold spores from outdoors causes hay fever and allergies indoors
Poor IAQ Results
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
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
Sources involved in IAQ problems
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Evaluations by National Institute for Occupational Safety and Health (NIOSH) for studies on more than 500 Indoor Air quality health hazard cases
Inadequate Ventilation
53%
Bioaerosols5%
Outside Contamination
10%
Building products
4%
Unknown causes
13%
Inside contamination
15%
Problem Origin Percent Typical Sources
Inadequate Building Ventilation Systems
53%
Lack of outside air, poor air distribution, uncomfortable temperature and humidity, contaminant sources inside the system
Contaminants Originating Inside Building
15%Solvent vapors, dusts, formaldehyde, building materials, furnishings
Building Products 4% Concrete, wood, furnishings.
Unknown Causes 13% Unidentified sources
Outdoor Contaminants Entering Building
10%Motor vehicle exhaust, pollen, fungi, smoke, construction
Microbiological Agents 5% Bioaerosols, Legionella
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
Health effects due to Indoor Air Pollutants
Headaches Nausea Respiratory infections Asthma Hypersensitivity pneumonitis Humidifier fever Legionnaire’s disease Lung cancer
Health Symptoms and Possible ContaminantsSYMPTOM POSSIBLE
CONTAMINANTSPRIMARYSOURCES
ENVIRONMENTALCONDITION
· Headache · Fatigue · Poor Concentration · Dizziness · Tiredness
· Bio-aerosols · VOCs
· Ventilation systems · Humidifiers · Drip pans · Cooling coils in AHVs · Plants · Outside air
· Ergonomic Conditions · Noise and Vibration
· Headache with nausea · Ringing in ears · Pounding heart
· CO · Formaldehyde
· Incomplete Combustion (vehicle Exhaust, stoves, fireplaces) · Building products · Furnishings
· Ergonomic Conditions · Noise and Vibration
· Dry Throat · Shortness of breath or Bronchial Asthma · Irritation and Infection of Respiratory Tract
· NO2 · Formaldehyde · VOCs · Particulates
· Incomplete Combustion · Building Products · Furnishings · Smoking
· Relative humidity
To be cont……………..SYMPTOM POSSIBLE
CONTAMINANTSPRIMARYSOURCES
ENVIRONMENTALCONDITION
· Nasal Problems (Stuffiness,Irritation)
· NO2 · Formaldehyde · Bio-aerosols
· Incomplete Combustion · Building Products · Furnishings · Ventilation Systems · Humidifiers · Drip Pans · Cooling Coils in AHVs · Outside Air
· Relative Humidity · High Temperatures
· Skin Problems (Dryness, Irritation, Rashes)
· Formaldehyde · Ventilation Systems · Humidifiers · Outside Air
· Warm Air · Low Relative Humidity · Excessive Air Movement
· Eye Problems (Burning, Dry Gritty Eye)
· NO2 · Formaldehyde · VOC's · Particulates · Bio-aerosols
· Incomplete Combustion · Building Products · Furnishings · Ventilation Systems · Humidifiers · Cooling Coils in AHVs · Outside Air · Building Product Deterioration
· Artificial Light
List of Pollutants affecting IAQVolatile organic compounds (VOCs)
Dust and dirt
Radon
Environmental tobacco smoke (ETS)
Respirable Particulate Matter (RPM)
Carbon and Nitrous Oxides
Indoor Air Pollutants and Their Health EffectsPollutant Effects Limits
NO2 Type: Immediate
Causes: irritation to the skin, eyes and throat, cough etc.
0.05 ppm (avg. over one year for 8 hours exposure daily)- EPA
CO Type: ImmediateCauses: headache, shortness of breath, higher conc. May cause sudden deaths.
9.0 ppm (avg. over 8 hours period)- EPA
RSPM Type: CumulativeCauses: Lung cancer
150 µg/ m3 (24 hr. average)
SO2 Type: ImmediateCauses: lung disorders and shortness of breath
0.05 ppm (avg. over one year for 8 hours exposure daily)- EPA
Radon Type: CumulativeCauses: Lung cancer
>/ 4 pCi/ Litre of indoor air
Formaldehyde Type: Immediate
Causes: irritation to the eyes, nose and throat, fatigue, headache, skin allergies, vomiting etc.
120 g/ cu.m. (continuous exposure)- ASHRAE
Asbestos Type: CumulativeCauses: Lung cancer
>/ 2 fibers/ cu.cm. Of the indoor air (8 hrs. exposure period)- OSHA
Pesticides Type: ImmediateCauses: Skin diseases
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VOCs Type: Immediate
Causes: Liver, kidney disorders, irritation to the eyes, nose and throat, skin rashes and respiratory problems.
Not for all VOCs. For chlordane: 5 g/cu.m.(continuous exposure))
CO2 Surrogate index of ventilation 1000 ppm
O3 Type: Immediate
Causes: eyes itch, burn, respiratory disorders, lowers our resistance to colds and pneumonia.
100 g/cu.m (continuous exposure)- OSHA