Think You Are Better Breathing Indoors? | Lee Hung Scientific Pte Ltd

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Think You Are Better Breathing Indoors?

Can you breath Freely indoors?

More often than not we are usually more cautious about the air quality we face outdoors.

For many years, people working in areas with known exposure to potential hazards have had a number of options available with respect to personal protection. They could wear respirators, gloves, mask, googles etc to protect themselves.  

However, when it comes to bad indoor air quality, it often arises in situations where people are generally unaware of potential hazards and do not expect the need for protection. Since we spend more than 80% of our time indoors, the air we breathe, whether in homes, offices, schools or hospitals, can increase the risk of health problems.

Thus, the shocking truth is that the air we breathe indoors, is sometimes more polluted than the air out doors! Which is why the subject and concern of Indoor Air Quality (IAQ) have become significantly important.  


The Rise of Indoor Air Pollution

Ever since the energy crisis in 1970s, buildings were built to be air-tight with minimal fresh air intake.

The strategy is to reduce energy cost and re-circulating internal air and better insulate the buildings. Due to shortage of natural wood, developments in construction materials have resulted in use of more synthetics and composites such as usage of formaldehyde. Radical changes in technology have also led to innovations in computers and photocopiers etc which would lead to indoor air pollution.
The increase of pollutant emission from synthetic building materials and proliferation of microorganism within the building have added on to poor indoor air quality.


So What Exactly is “Indoor Air Quality?”

Indoor air quality is the air quality within and around buildings and structures, especially as it relates to the health, comfort and well-being of building occupants. New terminologies have also come into use with regard to describe bad Indoor air quality. Some examples include:

  • Sick Building Syndrome (SBS) – Where more than 30% of occupants experience adverse effects while in building, but no clinically diagnosed disease is found. Building occupants often suffer from non-specific symptoms such as headage, fatigue, drowsiness, watery eyes, runny nose, skin irritation, dry throat and cough. These symptoms are usually acute and relieved upon leaving the building.


  • Building Related Illness (BRI): Building related illness refers to a defined illness with a known causative agent resulting from exposure to the building air. While the causative agent can be chemical (e.g., formaldehyde), it is often biological.


  • Multiple Chemical Sensitivity (MCS) or Environmental Illness (EI) – a controversial condition where an individual has or develops sensitivity to even low levels of certain chemicals due to extended exposure.

There are 2 main areas to investigate a building’s indoor air quality, they are Comfortability and Health Safety issues.



Comfort is a phenomenon that is both physical and psychological, and it varies greatly from person to person. Common measurable characteristics of comfort include the following:

  • Temperature
  • Humidity
  • Air velocity
  • Air Ventilation
  • Air Volume

Factors much harder to quantify yet able to impact perceived individual comfort include light glare, odors, physical space layout, proximity to other areas, clothing, activity, and ergonomics. Even emotional or psychological stress in the workplace or at home can contribute to a person’s feeling or comfort.


Health and Safety issues

Other than Comfortability, which is important in maintaining productivity and concentration, many unwanted airborne contaminants can actually pose a threat to human health. From a Health and Safety perspective, vapors, gases or airborne particulates that are present in unhealthy concentrations can adversely affect occupants of a space.

Potentially toxic, infectious, allergenic, irritating or otherwise harmful substances are almost always around us. Usually they exist in such small concentrations that stay below a “trigger” threshold and get little attention. When concentrations rise above threshold, problems can begin. Even at relatively low concentrations, some individuals are very sensitive to certain substances and may react adversely even though other area occupants are not bothered. In very extreme cases, concentrations may be high enough to be fatal to all occupants.


Sources of Pollutants and Their Recommend Limit

Generally, there are 3 types of pollutants that would also contribute to bad indoor air quality

  • Biological - The Biological factors include the viable bacterial and fungal counts. Exposure to these microbes may cause allergy, sensitization and even infection when exposed to pathogenic strains.
  • Chemical - Cleaners, solvents, fuels, adhesives, various combustion by-products and emissions from furnishing and floor and wall coverings are typical examples of airborne chemicals. Chemical factors encompass of carbon dioxide, formaldehyde, carbon dioxide, ozone, particulate and volatile organic chemicals. Exposure to low levels of multiple chemicals might cause irritation to the mucous membrane, neurotoxic effects such as headage, fatigue and drowsiness.
  • Particles and Aerosols – are solids or liquids that are light enough to be suspended in air. Particles are classified in three general categories – coarse, fine and ultrafine – and are derived from dust, construction activities, printing, photocopying, manufacturing process, smoking, combustion and some chemical reactions in which vapors condense to form particles. These can be categorized as dust, smoke, mist, fume and condensates.

What are the Effects of In Door Air Pollutants On Us, Its Sources and How Can We Measure Them. Click Here to Find Out More!

Guidelines on Limits for Good Indoor Air Quality in Office Premises

Referencing to a publication from the Institute of Environmental Epidemiology, Ministry of the Environment, titled “Guidelines for good indoor air quality in office premises”, there are some guidelines on the recommended limits of pollutants and how to improve for our indoor air quality. The limits of the parameters are summarized in Table below.

The above guidelines’ limits were based on research data conducted locally as well as in Australia, Canada, Denmark, Norway, Sweden, United Kingdom and other European countries. In addition, a wide margin of safety was included in the recommended limits so that even if they were to be exceeded occasionally, toxic effects are unlikely to occur.


So Whats Next?

Knowing the above is only the first step to realization of our Indoor Air quality problems. Click here to read on How to Measure our Indoor Air Qualities.