Assessment of contribution of internal finishing materials to indoor air VOC concentrations in UK primary school classrooms
The proposed project is a collaboration between the UCL Institutes for Environmental Design and Engineering (IEDE) and Sustainable Heritage (ISH), Architype and Historic England. In line with high-level research strategies focusing on the relationship between buildings, materials and people and the impact of environmental changes on the historic built environment, the project deals with complex interrelationships among the diverse school building stock characteristics, the classroom indoor environment, building materials, climate and the impact on the wellbeing of a vulnerable group; young children.
Approximately three quarters of purpose-built school buildings in England and Wales are equally distributed in three construction eras: 1945 to 1966, 1967 to 1976 and post-1976 (excluding new-builds, which represent 5% of the stock). Schools account for a 2% of the national carbon emissions, and for half of the emissions of local authorities. As there is great pressure towards reducing the operational energy demand of new and existing schools, a strategy on a national level is required to ensure that school buildings are fit-for-purpose, but also that designing and retrofitting for energy efficiency is not at the expense of indoor environmental quality and occupant health and wellbeing. Evidence from decades of research proves that exposure to poor indoor environmental quality in primary school classrooms is not only common but has an impact on academic performance and attendance, with indoor air pollution being the main factor. Exposure to harmful indoor air pollutants can increase the likelihood of long-term (toxic effects on liver and kidney) and acute (headaches, eye and airway irritation) health problems. Children attending schools with higher levels of pollutants are at greater risk of developing respiratory symptoms.
Indoor air quality in classrooms is evaluated with the use of a series of indicators including levels of a series of externally and internally sourced pollutants: such as carbon dioxide, fine and coarse particles and target VOCs including benzene, formaldehyde, toluene, trichloroethylene. While a small number of commonly encountered VOCs are known to be carcinogenic, over 50 different compounds can be found indoors and a study identified 24 different compounds in classroom indoor air, with many contributing to acute health effects (sick building syndrome associated) and perception of poor odour. It is thus important to know the types of VOCs as much as the quantities in which these are present. VOCs in classrooms are mainly indoor sourced. Dry finishing materials, including flooring and ceiling surfaces, are persistent sources of VOCs. Control of exposure to VOCs is achieved with ventilation (dilution) and source elimination. The required ventilation rates are adjusted to limit pollution from the occupants, the key source of pollution in high density spaces, as well as building materials.
The study will explore, for the first time, the contribution of common dry indoor finishing materials to indoor air concentrations of VOCs in UK primary school classrooms, combining exhaustive monitoring, onsite and laboratory emissions testing and modelling. The first part of the study includes non-destructive emission testing of products that will attempt to characterise emissions (type of VOCs emitted and emission rates as a function of time). A significant evidence gap is addressed, as this information is currently unavailable in existing databases. There is great variation among different products and emissions decay rates which are influenced by conditions and characteristics specific to the investigated spaces e.g. residential, offices or classrooms. The second part of the study includes indoor and outdoor (exhaustive) VOC concentrations and influencing factors (such as temperature and relative humidity) onsite monitoring. The third part of the project will use information collected from the previous two parts to optimise and also validate a methodology for the prediction of required ventilation rates, indoor air concentration of VOCs and children’s exposure, using empirical and mathematical models that enable establishing a relationship between the specified materials and the indoor air concentrations.
The project aspires to inform design and post-occupancy evaluation stages, offering important information for the determination of appropriate indoor air quality design strategies, especially with regards to indoor air quality and child health. Output from the project will inform technical guidance and policy documents over the three-year timeline and will be published in relevant to the sector journals.
- Supervisors: Dr Anna Mavrogianni and Prof Dejan Mumovic from UCL Institute for Environmental Design and Engineering, Prof Matija Strlic from UCL Institute for Sustainable Heritage, Mark Lumley from Architype, David Drewe from Historic England.
- Funding: The project is funded by the Engineering and Physical Sciences Research Council (EPSRC), through the SEAHA (Science and Engineering in Arts Heritage and Archaeology) Centre for Doctoral Training.
- Industry sponsor: Architype Ltd.
- Research Student: Chryssa Thoua