Indoor Air Cartoon Journal, September 2019, Volume 2, #77

It is advisable to limit outdoor activities or the time spent in an outdoor environment when outdoor air pollution reached unhealthily level. Such advice is especially important for vulnerable people – the children, elderly, and people with a history of respiratory problems. However, staying indoors does not provide absolute prevention from air pollutants of outdoor origin. Exposure to pollutants of outdoor origin in the indoor environment will be reduced if the interaction between indoor with outdoor air is eliminated or significantly reduced.

The reduction in exposure can be achieved if the envelope of the indoor environment is well tightened. The lack of interaction between indoor and outdoor environment leads to a limited or ventilation. Such lack of interaction is a concern, especially if there are several active sources of air pollutants in the indoor environment. The concentration of indoor pollutants will be relatively higher with little or no ventilation. The reduction or elimination of indoor air pollutant sources will considerably lessen the concern of having limited or no ventilation. The use of air purifiers and an increase in indoor air movement will help reduce the implications of a lower or no ventilation.

Air purifiers and air movement strategies require a regular supply of electricity. Indoor occupants in developed or high-income countries with a steady supply of electricity and with the financial power to purchase air purifiers will be less vulnerable. Those in developing or low-income countries where there is irregular supply of electricity and lack the financial ability to buy air purifiers will be more vulnerable. Their vulnerability will increase with time spent in the indoor environment. Furthermore, the envelope of the indoor environment in such countries is usually not well tightened. The infiltration caused will make occupants of the indoor environment be exposed to a considerable amount of highly polluted outdoor air even if they stay indoors. An affordable and effective solution is needed for most indoor occupants in developing or low-income countries. It is essential to reduce their exposure and risk of suffering from air pollutants of indoor and outdoor sources. This issue reiterates the dilemma of many indoor occupants in developing and low-income countries.

Do you want to know more about this topic? Read Laumbach et al. (2015) and Meng et al. (2009) papers.