Portable Spectrometer for Inhalable Aerosol Size Distributions.

摘要

Accurate measurement of inhalable aerosol hazards has confounded occupational health professionals since the realization that particle size plays a primary role in determining aerosol penetration into (and deposition within) the human respiratory tract. Knowledge of particle size not only determines whether a particle can enter the body and where it will deposit (oronasal vs. tracheobronchial vs. pulmonary regions) but also influences the process of hazard recognition, evaluation, and control. For example, knowing the size distribution of an aerosol hazard can reveal its source: submicron particles (<1 microm) tend to arise from vapor condensation or combustion processes, whereas, supermicron particles (>1 microm) are typically generated from abrasive, mechanical processes. Furthermore, the design and use of proper workplace control technologies (filtration, cyclone separation, ventilation) are strongly dependent on knowledge of particle size. Despite these facts, the field of occupational health lacks the technology to determine the size distribution of inhalable aerosol hazards in the workplace. Indeed, industrial hygienists currently have no means to characterize workplace aerosol size distributions above 15 microns, even though the current ACGIH/ISO criterion for inhalable aerosol extends to 100 microns in particle diameter. Many practicing professionals suspect that such particles present a significant respiratory hazard in their workplaces. Yet, the same professionals lack tools to characterize such hazards - a limitation that substantially hampers their ability to protect workers at risk. Inhalable aerosols hazards are present in virtually every NORA sector: organic dusts in agriculture, forestry, and fishing; carbonaceous and mineral dusts in construction; metal and metalworking fluid aerosols in manufacturing; and coal dust in mining, to name just a few. This project developed a new instrument to meet this need and to characterize workplace aerosol size-distributions up to 100 microns.