122 A New Dichotomic Personal Sampler for Semi-Volatile Aerosols Named “Ppas” for a Better Exposure Assessment of the Workers

Abstract

Abstract Semi-volatile organic compounds (SVOCs) are airborne pollutants present as a mixture of airborne particles and their vapour. Evaluating the exposure of workers to SVOCs represents a major challenge to occupational hygienists due to different toxicological effects regarding the particles and the vapour phases on human health. Therefore, the exposure assessment requires sampling these phases separately. In this regard, several methods were proposed to separate the two phases. However, all these methods have biased measurements of the concentration of the particulate and vapour phases. As an alternative, we propose a new personal SVOCs sampler named PPAS for “Préleveur Personnel d’Aérosols Semi-volatils”. The PPAS was built on the virtual impactor concept but with an inverted ratio between the major and minor flow. The development of the PPAS was first carried out using computational fluid dynamics (CFD) and then using experiments to estimate the actual performances. A great attention was paid to reduce at their minimum the pressure drops between the inlet and the two exits to allow 8 hours samplings using personal pumps classically used for assessing the exposure of the workers in workplaces. The transmission efficiency η of the PPAS was evaluated by CFD calculations for particles size ranging between 0.05 and 20 µm and measured experimentally with mono-dispersed aerosols consisted of a mixture of glycerol and fluorescein particles of 0.15, 2, 3 and 4.5 µm. The aim of the presentation is to focus on the CFD and experimental tests that permit to develop the PPAS.