An inverse experimental approach to quantify the temporal release rate of unknown remote aerosol sources

Deploying mitigation strategies to prevent exposure to hazardous airborne particles relies firstly on identifying and characterizing the sources of pollution. As the location of aerosol sources may be unknown or variable, and their generation rates fugitive, there is a need of developing tractable methods allowing the distant characterization of such sources in the field. The present paper proposes and evaluates an inverse experimental method which enables the reconstruction of the time-varying generation rate of a single aerosol source. The method is suitable for cases where the air flow is statistically steady (forced ventilation) and requires only a reference aerosol source and a real-time concentration sensor. The underlying theory of the method is exposed and situated among existing works. The method is then applied experimentally to hand-held woodworking machines placed in a ventilated cabin, and its performances are directly evaluated by considering the mass balance of the process. Results show that the method is particularly efficient in estimating the total mass of particles released in air. This allows for instance classifying polluting processes with respect to their emission potential and building release libraries, which has important impacts on environmental and occupational hygiene