Conclusions
Potential sources of the extremely high levels of air pollution found in the classrooms
The in-depth analysis resulted in the identification of the following possible sources of indoor air pollutants:
- overcrowding in the classrooms and carpets on the floor (benzene)
- water-resistant paints used on the walls (ethylbenzene)
- cleaning chemicals (toluene and formaldehyde)
- ineffective air conditioning (CO2)
The results highlight that:
- air conditioning can only be effective in combination with a continuous supply of fresh air
- fewer cleaning chemicals should be used to clean the classrooms
- increasing the frequency and effectiveness of ventilation in school buildings could significantly contribute to improving IAQ
- NO2 is a typical ambient pollutant, while formaldehyde and CO2 can be considered potential indoor air pollutants
Associations between extremely high levels of indoor air pollution and health impacts on schoolchildren
The in-depth analysis suggests that:
- there is a high chance that polluted classroom air plays a role in causing symptoms among children
- xylenes and NO2 are among the factors causing allergies, and NO2 may also contribute to fatigue, attention deficit disorder, irritability, anxiety and symptoms of depression
- there is a significant association between PM10 and coughing every morning, and between formaldehyde and chronic cough symptoms in the last 12 months and anxiety
- xylenes significantly increase the incidence of sleep disorders
- toluene and ethylbenzene contribute to the development of conjunctivitis, sinusitis and earache complications
