Indoor environmental quality (IEQ) remains a global concern because it impacts people's comfort, health,
performance, and general well-being. People spend a significant amount of time in buildings or while commuting, hence
ensuring the minimal risk in indoor spaces by ensuring suitable IEQ. IEQ studies are limited regarding developing sub-Saharan
countries, whereas there is also a huge risk and concern for the current population and geometric growth as many cities in the
region will become mega-cities by 2040 (World Bank report). The absence of suitable IEQ regulations and energy poverty are
reasons to assess the IEQ gaps for increased awareness of sustainable interventions to minimize the associated risk. This study
evaluates the gaps and potential hazards that exist in the IEQ of sub-Saharan countries using empirical studies of hospital
occupants and BRT bus passengers and drivers. The Surveys were conducted in 3 cities of the Democratic Republic of Congo
and Lagos metropolis of Nigeria. The results suggest that gaps exist in IEQ for these regions. The gaps indicate existential risk
to people’s health, comfort, and well-being. The inferential conclusions are that there is a need for further scientific studies,
improvement in IEQ conditions, and ensuring suitable regulations for developing sub-Saharan countries.
Keywords: health hazards, hospitals, indoor environmental quality, indoor spaces, occupants, sub-Saharan countries, vehicles