FAQ – Indoor Air Quality

1. Is indoor air quality (IAQ) a health and safety concern?

Indoor air quality has become an important occupational health and safety issue. In the past few decades, energy conservation measures have led to airtight building construction that can create problems with IAQ. Frequently the ventilation systems are set to minimize the amount of fresh air entering and circulating within the building. This restriction impacts indoor air by allowing a build-up of air contaminants within the building that are not properly removed.

People spend a lot of time indoors — for example, many office workers will spend their entire working day inside buildings. People working indoors often experience symptoms such as headaches, shortness of breath, coughing or nausea just to mention a few. However, it is rarely possible to prove that these symptoms are related to a particular indoor air contaminant. In fact, building occupants are simultaneously exposed to a wide range of indoor air contaminants. People working indoors often experience symptoms such as headaches, shortness of breath, coughing or nausea just to mention a few. However, it is rarely possible to prove that these symptoms are related to a particular indoor air contaminant. In fact, building occupants are simultaneously exposed to a wide range of indoor air contaminants.

2. What are the common causes of IAQ problems?

IAQ problems result from interactions between building materials and furnishing, activities within the building, climate, and building occupants. IAQ problems may arise from one or more of the following causes:

* Indoor environment – inadequate temperature, humidity, lighting, excessive noise
* Indoor air contaminants – chemicals, dusts, moulds or fungi, bacteria, gases, vapours, odours
* Insufficient outdoor air intake

3. What are indoor air contaminants?

Here are examples of common indoor air contaminants and their main sources:

* Carbon dioxide (CO2), tobacco smoke, perfume, body odours — from building occupants.
* Dust, fibreglass, asbestos, gases, including formaldehyde — from building materials.
* Toxic vapours, volatile organic compounds (VOCs) — from workplace cleansers, solvents, pesticides, disinfectants, glues.
* Gases, vapours, odours — off-gas emissions from furniture, carpets, and paints.
* Dust mites — from carpets, fabric, foam chair cushions.
* Microbial contaminants, fungi, moulds, bacteria, — from damp areas, stagnant water and condensate pans.
* Ozone — from photocopiers, electric motors, electrostatic air cleaners.

4. What symptoms are often linked to poor indoor air quality?

It is common for people to report one or more of the following symptoms:

* dryness and irritation of the eyes, nose, throat, and skin,
* headache,
* fatigue,
* shortness of breath,
* hypersensitivity and allergies,
* sinus congestion,
* coughing and sneezing,
* dizziness, and/or
* nausea.

People generally notice their symptoms after several hours at work and feel better after they have left the building or when they have been away from the building for a weekend or a vacation.

Many of these symptoms may also be caused by other health conditions including common colds or the flu, and are not necessarily due to poor IAQ. This fact can make identifying and resolving IAQ problems more difficult.

5. Why do only some people seem to develop symptoms?

As with any other occupational illness, not all people are affected with the same symptoms or to the same extent. Some people may be more sensitive than others. Some people may be exposed to more contaminants in the building than others and they may experience symptoms earlier than other people. As air quality deteriorates and/or the length of exposure increases, more people tend to be affected and the symptoms tend to be more serious.

6. Can a person become sensitive to IAQ contaminants as time passes?

It seems possible. Some people may not be sensitive to IAQ problems in the early years of exposure but can become sensitized as exposure continues over time.

7. When should I start suspecting that IAQ may be a problem?

When there is a problem with IAQ, people may experience various health conditions that are listed above. Since many of the symptoms are very similar to what we feel like when coming down with a cold or the flu (influenza), it is often difficult to say for sure if indoor air is the cause of the symptoms.

However, it would be prudent to investigate IAQ if people develop these symptoms within a few hours of starting the workday and feel better after leaving the building, or after a weekend or vacation. In addition, if many people report similar symptoms, or if all of the people reporting symptoms work in the same area of a building, air quality should be suspected.

8. How do I investigate possible IAQ problems?

Typicaly people will report that they are experiencing symptoms believed to be caused by IAQ. Unfortunately finding the source or cause can often be difficult. The steps taken may vary from situation to situation but will include:

* Investigate the ventilation system to make sure it is operating properly (e.g., the right mix of fresh air, proper distribution, filtration systems are working, etc.).
* Look for possible causes (e.g., source of a chemical, renovations, mould, etc.). (see a sample Inspection Checklist, below).
* Rule out common causes of the symptoms such as noise, thermal comfort, humidity, ergonomics, lighting, etc.
* Conduct a survey to help pin-point work sources and causes (see below for a sample survey).
* Consider help and/or air testing by a qualified professional.

9. What is Indoor Air Quality?

The air quality is indoor air quality. It is four comfortable data of indoor air,
1) Indoor air temperature and air flow is generated by the furnace and air conditioning.
2) Indoor air humidity is generated by the humidifier.
3) The cleanliness of indoor air is made by the filter (regular filter, medium filter or electronic filter).
4) Indoor air freshness and health is made by Heat Recovery Ventilator (HRV) and Energy Recovery Ventilator (ERV) .

Indoor Air Quality (IAQ) refers to the effect, good or bad, of the contents of the air inside a structure, on its occupants. Usually, temperature (too hot or too cold), humidity (too dry or too damp), and air velocity (draftiness or motionlessness) are considered “comfort” rather than indoor air quality issues. Unless they are extreme, they may make someone unhappy, but they won’t make a person ill. Nevertheless, most IAQ professionals will take these factors into account in investigating air quality situations.

Good IAQ is the quality of air which has no unwanted gases or particles in it at concentrations which will adversely affect someone. Poor IAQ occurs when gases or particles are present at an excessive concentration so as to affect the satisfaction or health of occupants.

In the minor instances, poor IAQ may only be annoying to one person. At the extreme, it could be fatal to all of the occupants of a structure.

It is important to note that the concentration of the contaminant or contaminants is crucial. Potentially infectious, toxic, allergenic, or irritating substances are always present in the air. There is nearly always a threshold level below which no effect occurs.