Generally, indoor air quality or IAQ is related to pollution levels and the condition of indoor environments. The status of indoor air quality is commonly based on physical conditions, chemicals, and biological pollution. A set of factors, such as outdoor air quality, weather and climate, building design and operation, ventilation system, source of contaminants and types of activities and occupant’s behavior define it.
There are four components which determine the extent of pollutants’ effects on indoor air quality – the contaminants as the source of concern, the ventilation system, the pollutant’s pathways or air flow and the occupant exposed to the indoor environment. Improvements in one or more of these components can cause dramatic changes in the types of problems that may occur.
In recent decades, indoor air quality related issues have become more critical because people spend 70-90% of their time indoors. The main concern arising out of indoor air quality problems is the negative impact to occupant’s health, comfort, and productivity, which further become important economical considerations.
Health and Indoor Air Quality
Nowadays, people spend longer hours inside their offices and less time in the outdoors. Although this does not mean that indoor exposure will create harmful health effects, research has shown evidence of higher indoor pollutant concentration compared to those typically detected in the outside environment.
Concern about the health effects due to poor indoor air quality has been increasing worldwide. In Singapore, it is also a new concern addressed by many parties in the building and construction industry as well as authorities and researchers. Although there are no major problems due to IAQ, some symptoms and illnesses that can be attributed to indoor air conditioning and non-industrial pollution are commonly found.
The possibility that an individual will experience health related problems due to the presence of pollutants very much depends on factors, such as individual sensitivity to that contaminant, the contaminant concentration in a given air volume, proximity to the accumulated or radiated pollutant, the current state of physical health and psychological health, and duration and frequency of exposure.