Effects of Indoor Air Quality

Indoor Air Quality and Its Effects on Health

Enhanced alertness and understanding about Indoor Air Quality will empower the public to shift towards prolific interventions.

Indoor air pollution has an alarming impact on the social wellbeing of occupants of any building, be it commercial, residential, school, college, mall, or health care units. As per the analysis by the existing body of published literature, Indoor Air Pollution has been ranked among the top 10 health risk factors. The concentration of pollutants in urban indoor air is much higher than in the outdoor ambient environment.

Poor indoor air quality not just affects the health of occupants of a building but also, reduces their productivity at work. The situation can be highly vulnerable to specific groups such as children, the elderly, and those with cardiovascular and chronic respiratory diseases viz. asthma.

The concentration of pollutants and CO2 inside the buildings

The CO2 concentration in an occupied indoor space indicates whether the building’s air exchange balance is appropriate i.e., whether the optimal amount of filtered outside air is being mixed with air that has been circulating in the building or not. ASHRAE (The American Society of Heating, Refrigerating, and Air Conditioning Engineer), recommends that CO2 levels of indoor air should be less than 650 ppm contrasted to the outdoor air concentration of CO2. Indoor air pollution is caused by harmful gases, particulate matter (PM10 and PM 2.5), viruses, molds, volatile organic compounds, and other outdoor pollutants penetrating the enclosed environments. Therefore, it is essential to monitor and control the concentration of CO2 and other pollutants in the air inside.

Key factors affecting IAQ-

Some of the critical factors affecting the indoor air quality are –

  1. The concentration of gases and pollutants
  2. The ventilation of building structure
  3. VOCs released from resins, paints, polishing materials, glues, spray propellants, perfumes, and cleaning agents
  4. Living space and occupancy of a building
  5. Use of equipment such as heaters, refrigerators, photocopiers
  6. The customs and habits of occupants

IAQ vs. Energy Efficiency-

Heating and cooling the outside air for the comfort of the building occupants require a significant amount of energy. A considerable energy saving is possible by minimizing the outdoor air used for ventilation. However, this deteriorates the indoor air quality if active air-filtration systems are not installed. On the other hand, is a naturally ventilated building, the concentration levels of PM10 and PM 2.5 are expected to be much higher in urban areas where the outside air is polluted. Thus, achieving IAQ and energy efficiency simultaneously is a challenging game for engineers.


In the present scenario, it is crucial to create mass awareness regarding exposure and the health impacts of indoor air quality among the general population. Enhanced alertness and understanding about IAQ will empower the public to shift towards prolific interventions. It is crucial to monitor air circulation inside a building for at least a year to develop a seasonal plan to improve the air quality and foster maximum output and social well-being of the occupants.

There is a need to set benchmarks and form best practices for maintaining good IAQ in buildings in an energy-efficient manner. There must be a core focus on installing air filtration systems in new constructions to ensure proper ventilation and enhanced air quality. Other novel approaches need to be adopted to address the challenges posed in front of engineers to take possible measures.


The Cotocon Group consists of a team of skilled sustainability engineers that can help and consult you in maintaining proper Indoor Air Quality. Contact us to know more!

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