Particulate Matter Standards and Traceability for the Quality Assurance and Quality Control of Air Quality Measurements

摘要

This work is part of an ongoing effort to identify resources for, compile, and summarize air quality standards for volume/flow, gases, particulate matter (PM) composition, and particle size and number. The effort was undertaken in part because International Standards Organization (ISO) and American Society for Testing and Materials (ASTM) procedures are dated, costly, and limited to a few observables; current definitions and specifications are imprecise and not always relevant to modern usage and technology; multiple pollutants arise from multiple sources, cause multiple effects, and standards are not widely available or accepted; and more cost-effective and easier to use preparation and implementation of air quality standards is needed, especially in developing countries. Standards and their traceability and proper use are essential components in an effective program of quality control and quality assurance in air quality measurements (which ultimately affect air quality management programs and implementation of cost-effective control strategies). This work will concentrate on particulate matter standards for composition, particle size and particle number and their traceability. In particular we will look at aerosol deposits on filters that are subjected to laboratory analyses for mass, water-soluble ions, carbon fractions, and organic compounds and at aerodynamic, optical, and mobility particle diameters that are measured by different instruments and size-selective inlet properties. Volume and flow standards used to calibrate particulate samplers have been discussed elsewhere.