Indoor Air Quality Management Notes

Indoor Air Quality Management

Definition of Indoor Air Quality (IAQ)

• Indoor Air Quality (IAQ) is defined as the nature of air that affects the health and well-being of occupants (Industry Code of Practice on Indoor Air Quality, 2010).
• IAQ refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants (USA Environmental Protection Agency).

Primary Causes of Indoor Air Problems

• Indoor pollution sources that release gases or particles into the air.
• Inadequate ventilation increases indoor pollutant levels by:
  • Not bringing in enough outdoor air to dilute emissions.
  • Not carrying indoor air pollutants out of the area.
• High temperature and humidity levels can increase concentrations of some pollutants.

Common Indoor Air Pollutants

• Airborne particles from diesel exhaust, dust, smoke, and other sources
• Household odors & gases from outdoor air (ground level ozone is harmful to breathe)
• Formaldehyde from building materials, furniture, cooking, and smoking
• Carbon Dioxide from people exhaling and cooking

Pollutant Sources

1. Fuel-burning combustion appliances.
2. Tobacco products.
3. Building materials and furnishings:
   • Deteriorated asbestos-containing insulation.
   • Newly installed flooring, upholstery, or carpet.
   • Cabinetry or furniture made of certain pressed wood products.
4. Products for household cleaning and maintenance, personal care, or hobbies.
5. Central heating and cooling systems and humidification devices.
6. Excess moisture.
7. Outdoor sources:
   • Radon - radioactive gas that can cause lung cancer.
   • Pesticides.
   • Outdoor air pollution.

Radon

• Radioactive gas emanating from fractured bedrock.
• Enters homes through:
  • Running water.
  • Cracks in the foundation.
  • Sump drainage.

Impacts of Poor Indoor Environments

• Understanding and controlling common pollutants indoors can reduce your risk of indoor health concerns.
• Health effects may be experienced soon after exposure or years later.

Health Effects

• Some health effects show up shortly after a single exposure or repeated exposures.

  • Irritation of the eyes, nose, and throat.
  • Headaches, dizziness, and fatigue.

• Immediate effects are usually short-term and treatable.

  • Treatment involves eliminating exposure to the pollution source.

• Symptoms of some diseases such as asthma may appear, be aggravated, or worsened soon after exposure.

Particulate Matter (PM) Sizes

• Fine beach sand: $90 \, \mu m$ in diameter

• Human hair: $50-70 \, \mu m$ in diameter

• $PM_{10}: \leq 10 \, \mu m$ in diameter

• $PM_{2.5}: \leq 2.5 \, \mu m$ in diameter (not visible to the naked eye)

• Immediate reactions depend on age and preexisting medical conditions.

• Reactions can vary based on individual sensitivity.

• Some people can become sensitized to biological or chemical pollutants after repeated or high level exposures.

Effects of Indoor Air Pollution

• Confusion.

• Sneeze, Cough.

• Headache.

• Irritation in Nose and Throat.

• COPD.

• Asthma.

• Heart Ailment

• Anxiety

• Lung Infection

• Genetic Disorder

• Certain immediate effects are similar to colds or other viral diseases, making it hard to determine the cause.

• Pay attention to when and where symptoms occur.

• If symptoms fade when away from the area, identify possible indoor air sources.

Health Effects Associated with Indoor Air Pollutants

1. Irritation of the eyes, nose, and throat.
2. Headaches, dizziness, and fatigue.
3. Respiratory diseases, heart disease, and cancer.

Well-Established Links Between Indoor Air Pollutants and Health Effects

1. Radon is a known human carcinogen and the second leading cause of lung cancer.
2. Carbon monoxide is toxic; short-term exposure can be lethal.
3. Legionnaires' disease is associated with poorly maintained air conditioning or heating systems.
4. Numerous indoor air pollutants (dust mites, mold, pet dander, environmental tobacco smoke, cockroach allergens, particulate matter) are asthma triggers.

Environmental Effects

• Air pollution harms human health and the environment.

1. Acid rain: Wet or dry precipitation containing toxic amounts of nitric and sulfuric acids.
   • Acidifies water and soil.
   • Damages trees and plantations.
   • Damages buildings, sculptures, and statues.
2. Haze: Fine particles dispersed in the air reduce atmospheric transparency.
   • Caused by gas emissions from industrial facilities, power plants, automobiles, and trucks.
3. Ozone:
   • Stratospheric ozone protects from UV rays.
   • Ground-level ozone is harmful to human health and is a pollutant.
   • Ozone-depleting substances damage stratospheric ozone.
   • Thinner ozone layer leads to harmful UV radiation reaching Earth, causing skin cancer and harming crops.
   • Ozone penetrates plant stomata, causing them to close, blocking $CO_2$ transfer, and reducing photosynthesis.

Moulds Contamination

• Moulds are typical form of fungus found on earth (~25% of the Earth’s biomass).
• Moulds are essential decomposers of organic substances.
• Moulds are made up of hyphae, which grow into intertwining strings called mycelium (visible to human eye).
• Moulds reproduce via spores, or spread via broken hyphae fragments.

Types of Mould in Indoor Environment

• Cladosporium

• Penicillium

• Alternaria

• Aspergillus

• Moulds gain nutrients through decomposition of organic matter (saprotrophic).

• Eat dead moist organic matter such as wood, paper, paint, fabric, plant soil, dust, and cooked or raw foods.

• Can grow on surface of damp inorganic matter such as glass and bare concrete covered by an invisible biofilm.

Factors Contributing to Mould Growth

• Mould spores (readily available in the air).

• Nutrients (dirt, dust cellulose and starch).

• Temperature range between $5°C$ to $50°C$.

• Relative Humidity consistently above 70%.

• Oxygen.

• Mould can cause health responses in humans depending on type/amount of mould and individual susceptibility.

• Humans exposed via ingestion, inhalation, and skin contact.

• Moulds produce acute health effects through toxin-induced inflammation, allergy or infection.

Sick Building Syndrome

• Illnesses among occupants due to poor indoor air quality.
• Building occupants experience acute health and/or comfort effects linked to time spent in a building, but no specific illness or cause identified.
• Complaints may be localized or spread throughout the building.

Sick Building Syndrome – Primary Causes

• Inadequate Ventilation

• Chemical Contamination from Indoor sources

• Chemical Contamination from Outdoor sources

• Biological Contaminants

• Buildings may be inadequately ventilated.

• People have less control over the indoor environment in offices.

• Symptoms do not fit any particular illness and are hard to trace to a specific source.

• Symptoms varied from eye and nose irritation, fatigue, cough, rhinitis, nausea, headache, sore throat or a combination of these.

Sick Building Syndrome - VOCs

*VOCs are a large group of carbon based toxins that are invisible and often have no odour. They are found in a number of everyday household products and furnishings including synthetic carpets and cannot be eradicated by traditional cleaning methods. VOCs are responsible for sick building syndrome and have a number of negative effects on our health, causing skin allergies including eczema, respiratory problems and even cancer.

• Examples:
  • FORMALDEHYDE
  • ACETONE
  • XYLENE
  • ETHYLENE GLYCOL
  • METHYLENE CHLORIDE
  • TOLUENE
  • BENZENE
  • PERCHLOROETHYLENE

Wool is the only fibre able to naturally absorb VOCs and reduce their presence in the
home, eradicating the risks to health and boosting wellness. These effects are observed just
through the presence of wool bedding or carpets in the home. Not only does wool
neutralise contaminants more quickly and completely than synthetic fibres, wool does not
e-emit them, even when heated. Wool beds, bedding, mattresses and 100% wool carpets
can continue to purify the air for up to 30 years.

Sources of Indoor Pollutants

• Chemicals Released from Modern Building & Furnishing Materials
• Combustion Gases from Fireplaces & Woodburning Stoves, Chemical Fumes from Paints & Solvents
• Gases including Radon seeping through foundation
• Outdoor Air Pollutants
• Molds & Bacteria
• Chemicals from Cleaning Products
• Cigarette Smoke contains some 4,000 Chemicals
• Animal Hair & Dander
• Carbon Monoxide Fumes from attached garage

Building-Related Illnesses

• Illnesses directly traced to specific building problems (e.g., Legionnaires’ disease, asthma, hypersensitivity pneumonitis, humidifier fever).
• Most can be treated, but some pose serious risks.

Legionnaires’ Disease

• A form of bacterial pneumonia with fever, chills, dry cough, muscle aches, and occasional diarrhea.

Legionella pneumophila

• Grows in environmental reservoirs meeting nutrient, water, and temperature requirements.
• Thrives in temperatures between $25°C$ and $45°C$, with an optimum around $35°C$.
• Water-cooling towers and warm water systems are major sources.
• Proliferates and distributes throughout the building via the air-handling system without treatment or maintenance.

Common sick building syndrome symptoms

• Havy breathing 9%
• Cest pain 9%
• Headaches 13%
• Dry throat 15%
• Eyes irritation 46%
• Runny nose 46%
• Stuffy nose 47%
• Flu symptoms 23%
• Lethargy 57%

MALAYSIA INDUSTRY CODE OF PRACTICE ON INDOOR AIR QUALITY 2010 (ICOP IAQ 2010)

• Introduced by the Department of Safety Health (DOSH) in 2010 to increase compliance of designated workplaces.

• Involves investigation of complaints from workers.

• Investigation includes:

  1. Preliminary site visit.
  2. Measuring the level of contaminant in the area.
  3. Data analysis.
  4. Discussions with employers.
  5. Report writing.

• Ensures employees and occupants are protected from poor indoor air quality, reducing adverse health effects and improving productivity.

• Stipulates general duties of employers and self-employed persons to employees under Section 15 of Occupational Safety and Health Act 1994 (OSHA).

• Also covers duties to persons other than employees under Section 17 and 18 of OSHA.

• Compliance can be used as evidence of good practice in court.

Acceptable Range for Specific Physical Parameters (Table 1)

• Air Temperature: $23 – 26°C$
• Relative Humidity: $40 – 70\%$
• Air Movement: $0.15 – 0.50 \, m/s$

Acceptable Limits for Indoor Air Contaminants (Table 2)

Notes:

• For chemical contaminants, the limits are eight-hour time-weighted average airborne concentrations.
• mg/m3 is milligrams per cubic meter of air at 25° Celsius and one atmosphere pressure.
• ppm is parts of vapor or gas per million parts of contaminated air by volume.
• cfu/m3 is colony forming units per cubic meter.
• C is the ceiling limit that shall not be exceeded at any time. Readings above 1000ppm are indication of inadequate ventilation.
• excess of bacterial counts does not necessarily imply health risk but serve as an indicator for further investigation