Air pollution in schools

March 2017

Air monitoring equipment lines the wall in a Wellington primary school classroom. Photo: Dr Bill Trompetter, GNS Science.

Researchers from the University of Otago, Massey University and GNS Science are investigating air pollution sources in school classrooms as part of the BRANZ-funded Warmer, Drier, Healthier Buildings programme. The research team has been monitoring indoor and outdoor air quality in a Wellington primary school and say the study is providing valuable information that will be used to improve future building design and ventilation.

Exposure to indoor air pollution can have significant negative short-term and long-term health effects. Children are more sensitive to the negative health effects of air pollution. They breathe more rapidly than adults and do not have fully developed respiratory systems. Around one-quarter will suffer from asthma, in addition, there is also growing evidence that air pollution is associated with slower cognitive development and behavioural problems in children. For these reasons, air pollution in classrooms is of great concern. In previous studies, pollution levels two to five times higher than outdoors have been recorded in New Zealand classrooms, much of this attributable to poor ventilation.

Measurements of indoor and outdoor air pollution at the case study school were taken inside and outside two classrooms – one directly beside the road and one further away.  Measurements included fine particulate matter, carbon monoxide, carbon dioxide, nitrogen dioxide, volatile organic compounds, temperature, and humidity. Dust samples from the floor were collected in both classrooms to investigate the connection between airborne and dustborne pollutants.  

The school is located at a busy intersection in Newtown, Wellington and is currently operating out of typical school prefabricated buildings that are poorly insulated, ventilated and not designed to minimise exposure to air pollution or noise. In addition to the main study, a pilot study measuring traffic related air pollution was run over six weeks in mid-2016.  Results from this pilot indicated that air pollution levels were often elevated well above World Health Organization (WHO) guidelines.

The results of the main study are still being analysed, but already the pilot study has supported the case for a mechanical ventilation system to be installed to the new school buildings which are currently being built, this will ensure the health of students and staff.

Dr Julie Bennett, a Research Fellow in the Housing and Health Programme at the University of Otago, says the study will lead to confirmation of the sources of the pollution. “It will fill knowledge gaps about how outdoor air pollution interacts with the indoor environment in poorly built buildings situated near busy roads.”

“Collecting hourly indoor and outdoor air pollution samples will allow us to explore the dynamic of indoor-outdoor air pollution in prefabricated buildings in high-risk areas. How outdoor sources infiltrate into classrooms and how to get rid of these pollutants from the children’s environment are particularly important to explore.”

The social costs associated with air pollution in New Zealand are estimated to be $4.28 billion per year or $1,061 per person.

For more information about the study, please see Build 158: School rules – flexible, healthy, safe spaces.