Measuring In Door Air Quality (Health and Safety Issues) | Lee Hung Scientific Pte Ltd

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Measuring In Door Air Quality (Health and Safety Issues)


In the last several years, a growing body of scientific evidence shows that air within indoor environment such as within homes or commercial buildings can be more seriously polluted than the outdoor air. More importantly, as most people spends approximately 90% of their time indoors, they are exposed to the effects of indoor air pollutants for most parts of their daily live and may be more susceptible to the effects of indoor air pollution.

Some of the Key Indoor Air Pollutants We Are Concern With are as follows:

  • Carbon Dioxide
  • Carbon Monoxide
  • Formaldehyde
  • Ozone
  • Volatile Organic Compound
  • Total Bacteria Counts
  • Total Fungal Counts
  • Suspended Particulate Matter

This Article Touch on some of the common and Crucial In Door Air Pollutants, its source, effects and potential way of measuring them. 


Common Indoor Air Pollutants Source and Its Effects


Pollutant Sources and Its Effects

Carbon Dioxide

Pure air comprises of about approximately 0.03% in concentration. About 5% of air we breathe out is carbon dioxide and this level increases in inadequately ventilated occupied room. The level of carbon dioxide is often used to assess the efficiency of ventilation in buildings.

Moreover, when CO2 raises around 3% in our air, it may cause headage, fatigue and tiredness!

Measuring Instrumentation: Q-Track, IAQ CALC

Carbon Monoxide

Carbon Monoxide is an odorless, poisonous gas that is by product of incomplete combustion process.

When inhaled, it readily mixes with hemoglobin in the blood, inhibiting the blood’s ability to carry and exchange oxygen. Excessive exposure to carbon monoxide can starve body of oxygen and lead to death. Its sources may come from environmental tobacco smoke or vehicular exhaust.

Measurement Instrumentation: Q-Track, IAQ CALC


Formaldehyde is a type of Volatile organic compounds. It is a colorless gas that give off strong smell in high concentration and is found in many products such as adhesives, cleaning fluids, insulation material, carpet glues, pesticides, paint, ceiling tiles, office furniture etc.

It causes eye and respiratory irritation and is a suspected human carcinogen substance. 

Measurement Instrumentation: FORMALDEMETER


Ozone may be produced by equipment that utilized ultraviolet radiation, electrostatic photocopiers, laser printers, ionizers, and electrostatic precipitator devices used to clean the air by removing dust.

It aggravates asthma, damages the lining of our lungs and make breathing more difficult.

Measurement Instrumentation: OZONE MONITOR 202, OZONE MONITOR 205

Volatile Organic Compound

VOCs are a broad class of chemicals containing carbon atoms that tend to give off high levels of vapor even at room temperature. They are typically found in building materials, cleaners, solvents, paints, gasoline and other substance.

VOCs have potentially adverse health effects in certain individuals. However, the chronic and acute health effects are complicated and varies over different range of mixtures and concentrations encountered in building which are not clearly understood.

Measuring Instrumentation: Q-Track (With Optional VOC IAQ Probes)

Total Bacteria Counts

Bacteria is a form of biological microscopic life form. It may come Airborne in the form of bioaerosol. Human is also a source of bacteria. Indoor bacterial levels are normally higher than outdoor levels. Bacteria may cause hypersensitive lung disease or airway inflammation.

Sampling Instrumentation: Portable Air Microbiological Samplers

Total Fungal Counts

Fungi is a spore-producing organism. It may be singled-celled or multicellular organism without chlorophyll that reproduces by spores and lives by absorbing nutrients from organic matter. It is able to grow virtually on any material with a carbon source (i.e. wood, paper, carpet, foods & insulation, with oxygen and water) and gradually destroys the things they grow on by digesting them.

It may cause Allergic or Asthmatic reaction.

There is no practical way to eliminate all mold and mold spores in the indoor environment. The way to control indoor mold growth is to control moisture.

Sampling Instrumentation: Portable Air Microbiological Samplers

Suspended Particulate Matter

Particulate matter, also called PM consist of microscopically small solid particles or liquid droplets suspended in the air. They may come in the form of dust, fumes, mist and smoke.

Respiration of particles challenges the body’s natural defense and overexposure may strain these mechanisms, causing an adverse reaction.

Inhalable particles with aerodynamic diameter of 10 micrometers or smaller are referred to as PM 10. The smaller the particles, the deeper they can penetrate into the respiratory system and the more hazardous they are to breath.

Measuring Instrumentation: SidePAK, DustTrak II and DRX

Ultrafine particles are defined as particles less than 0.1 micrometer diameter. They are so small that they can pass easily through the body’s natural mechanisms to the deepest areas of the lungs. Certain people are extremely sensitive to ultrafine particles, sometimes regardless of chemical composition.

Measuring Instrumentation: P-Trak


Apart from Indoor Pollutants, Comfortability indoors is also an important aspect of our Indoor Air Quality.
Click here to Read On Measurement of In-door Air Quality on Comfortability.