Measurement and Modelling of Short-Term Variations in Particle Concentrations in UK Homes

Abstract

The causes of short-term variations in particle number concentrations were examined in 7 homes in northern England. Cooking, smoking and physical activity led to high short-term peak concentrations, while the loss rate of particles after emissions ceased was clearly depen dent on the particle size range. Simultaneous measure ments of particle number concentration and air ex change rate were used to quantify the relative impor tance of deposition and air exchange in particle loss rates; while air exchange was the dominant process in the size range 1-2 μm, deposition was the dominant pro cess in the size range 7.5-10 μm. The loss rate is critically important in determining the impacts of short-term em issions on longer-term particle exposures indoors.