Measurement of vertical concentration profiles of airborne particulate matter in indoor environments: implications for refinement of models and monitoring campaigns

Vertical concentration profiles of airborne particulate matter were measure d in four different indoor environments - library, coffee room, workshop an d undergraduate student hostel - on the University Campus at Sutton Boningt on. Measurements were carried out using an electronically-controlled liftin g platform carrying a real-time optical particle monitor for sampling air s equentially at different heights within the breathing zone. Data was automa tically logged at the different receptor levels, for the determination of t he average Vertical concentration profile of the various particle size rang es which include inhalable, thoracic, alveolic, PM10 and PM2.5. Vertical co ncentration profiles measured in these different indoor environments exhibi ted different characteristics but in almost all cases it was clear that dif ferent height groups of the population are exposed to different concentrati ons of the pollutant. This has implications on setting of air quality stand ards for the protection of public health. The results indicate that we may have to re-think the whole concept of air quality standards and develop pro tocols for indoor air quality monitoring and modelling which would take int o account the above-mentioned factor.