Indoor Air Cartoon Journal, March 2019, Volume 2, #49

Greenhouses gases like carbon dioxide (CO2), methane (CH4), and nitrous oxides (N2O) exist naturally in the atmosphere. They control the temperature of the earth. They allow solar heat (light energy) pass through them to the earth’s atmosphere but prevent the heat from leaving it. In natural quantity, they provide the warmth earth needs. However, an excessive amount of these GHG causes more heat trapped in the earth thereby causing global warming. The excessive demand for energy and the adoption of a non-renewable source of energy production increase human exposure to pollutants of outdoor origin and pose a threat to public health.

The extreme solar heat (light energy) trapped in the atmosphere serves as a catalyst that increases the rate of chemical reaction of pollutants in the atmosphere to produce secondary pollutants which include ozone, oxidation products, like formaldehyde and acetaldehyde, and secondary organic aerosols (SOAs). SOAs are formed from newly formed particles (solid and liquid droplets) adsorbing and absorbing on existing particles to change particle size, chemical composition and characteristics. When outdoor air is polluted, the indoor environment is not safe for building occupants due to the potential outdoor to indoor transport of pollutants.

The implications of photochemical reaction occurrence, aided by GHG, mean that the campaign to reduce energy demand or adopt non-renewable sources of energy is not only crucial in reducing global warming, but it also helps to reduce human exposure to pollutants with mortality and morbidity implications. What does this information mean to policymakers and people responsible for delivering energy and healthy indoor environment, especially that of buildings? How should the design, construction, and maintenance and operation of buildings be done to reduce energy consumption?

Do you want to know more about this topic? Read Ebi and McGregor (2008), Fang et al. (2013), and Ma and Birmili (2015) papers.