2019 Yes https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6486416/ Toyinbo Africa Observational Elementary (K-5) Temperature Humidity Carbon Dioxide (CO2) Carbon Monoxide (CO) Bacteria Indoor environmental quality Thermal acceptability Natural ventilation Cleaning School classrooms Educational buildings Based on the data, the quality of facilities in the buildings was low. Classroom occupancy exceeded ASRHAE 50 person/100m^2 standard in all cases indicating overcrowding. However, concentrations of C)2 remained below 1000 ppm in most classrooms. On the other hand, indoor T was about the recommended levels for thermal comfort in all classrooms. Maximum indoor CO was 6 ppm. Median ATP concentrations on the desk tops were moderately high in all school.