The air quality of the indoor environment such as a non-industrial office environment can significantly affect the health, comfort, and productivity of building occupants.
Indoor air quality (IAQ) in the workplace, such an office environment, is the subject of much attention recently, and for good reason. Although serious irreversible health problems related to IAQ in non-industrial office environments are rare, the perception of endangered health is increasingly common among building occupants.
To date, the causes and consequences of poor IAQ are complex and not completely understood, but there are some basic factors that in many cases address IAQ concerns.
IAQ is a problem when the air contains dust and objectionable odours, chemical contaminants, dampness, mould or bacteria.
Poor indoor air quality can lead to a number of physical symptoms and complaints. The most common of these include:
Thermal discomfort: too hot or too cold
Shortness of breath (eg. insufficient oxygen related to high carbon dioxide levels)
Eye, nose, and throat irritation
These physical symptoms and complaints are often attributed to indoor air quality, however, it is important to note that indoor air quality is not always the cause. Other factors in the indoor environment such as noise, overcrowding, improper lighting, poor ergonomic conditions, and job stress can also lead to these symptoms and complaints. In many situations, a combination of factors is to blame.
An increased likelihood of complaints is usually associated with factors such as the installation of new furnishings, uncontrolled renovation activities, poor air circulation and air flow, persistent moisture and ongoing low relative humidity. Complaints may also increase when there is a stressful work environment, such as impending layoffs, a great deal of overtime, or an ongoing conflict among staff members and management.
A number of factors can affect the indoor air quality of a building or facility, including:
The physical layout of the building
The building’s heating, ventilation, and air conditioning (HVAC) system
The outdoor climate
The people who occupy the building
Contaminants emitted inside and entered from outside the building
Poor indoor air quality and indoor air contaminants affect some people more seriously, including:
People with allergies or asthma
People with respiratory disease
People whose immune system is suppressed as a result of disease or treatment
People who wear contact lenses
Indoor air contaminants can originate within a building or be drawn in from outdoors. These contaminants can lead to indoor air quality problems, even if the HVAC system is well designed, regularly maintained, and functioning to its optimum conditions.
Sources of contaminants inside the building environment may include:
Dust, dirt, or mould in the HVAC system (eg. cooling coils, ducts, registers)
Office equipment such as laser printers and copiers (eg. airborne particulates, ozone)
Personal activities such as smoking or cooking (eg. Volatile organic compounds, nicotine)
Housekeeping activities such as cleaning and dusting
Maintenance activities such as painting (eg. Volatile organic compounds)
Spills of water or other liquids
Special use areas such as print shops and laboratories
Industrial processes such as dry cleaning
Moisture affected building materials (eg. mould and bacteria)
Sources of contaminants from outside the building may include:
Pollen and dust (eg. long term build up if cleaning regime is inadequate)
Unsanitary debris or dumpsters near the outdoor air intake
Depending on the complaint reported by building occupants, an indoor air quality investigation should include the following:
Interview with building occupants to identify potential causes such as identifiable odours, recent changes that may have caused the issue, water intrusion event, increased occupancy, cleaning regime, etc.
Assessment of the ventilation rate (generally when the indoor carbon dioxide levels are over 650 parts per million (ppm) above ambient outdoor levels)
Walkthrough inspection of the building and the ventilatio