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.

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.

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).

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

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

Click icon to add picture

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

-

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