The use of image analysis for PM10 characterisation of volumetric air samples taken in Cardiff since 1956

Abstract

This study investigates the size, composition andconcentration of airborne particles. These featuresare examined from continuously recorded volumetricdaily air samples, taken by Burkard and Hirst trapsfrom the center of Cardiff City and samples fromselected sites around Cardiff. The set of slides isunique as it dates from 1954 to the present day, andcontains data, which precedes any other routinemeasurements of PM10.

Image analysis has not been used previously to examinePM10 from slides taken by Hirst-type traps, but it hasbeen demonstrated as an important application inalternative projects. The advantages of being able toperform simple but tedious measurements quickly makeit an important tool for this project. It can alsomeasure a number of images simultaneously and quantifyparameters that would otherwise have been based onqualitative subjective comparisons.

Environmental data including wind speeds, rain falland temperature measurements are investigated toexamine the influence on the temporal variation of theabundance and characteristics of airborne particulatematter. Confounding factors that may have impacts oncardiovascular and respiratory illness are beingexamined. These include data on aeroallergens (pollenand fungal spore counts), nitrogen oxide, sulphurdioxide, and carbon monoxide. The project will beextended to an analysis of the results in relation tohealth data.