4
Quality-Assurance Procedures in Low- and Middle-Income Countries
To better estimate the exposure of their citizens to particulate matter with an aerodynamic diameter less than or equal to 2.5 microns (PM2.5 ) and the associated health effects, and to design policies to minimize these effects, low- and middle-income countries (LMICs) are working to begin, expand, and improve their air-quality monitoring efforts. However, some LMICs (Type I) currently have no air-quality data. Other LMICs (Type II) have air-quality data, but, because instrument maintenance and other “quality-assurance” procedures have not been fully followed, their data are potentially inaccurate. Still other LMICs (Type III) have accurate data but with insufficient spatial coverage. Satellites have been suggested as a way to reduce or eliminate the need for a ground-level-monitoring (GLM) network. However, accurate GLM data are needed to determine the performance of the satellite approaches to air-quality monitoring and to use the statistical and hybrid satellite approaches. Thus, to evaluate the ability of satellites to assist with air-quality monitoring in LMICs (chapter 5), this chapter discusses the issues affecting the availability and accuracy of GLM data in LMICs in the first main section, the potential of automated methods to flag potentially incorrect GLM data in the second, and the need to examine the metadata, warning files, and operator logs for the GLM instruments to ensure the data are of sufficient accuracy to be used to develop and evaluate satellite approaches to PM2.5 monitoring.
ISSUES AFFECTING THE AVAILABILITY AND ACCURACY OF GLM DATA IN LMICs Recent high-air-pollution events in many LMICs have highlighted the need for improved dissemination of PM2.5 concentrations obtained via GLM. Currently, one of the most promising dissemination mechanisms for real-time air-quality information in LMICs is the open-access web platform OpenAQ (see box 4.1). In the research underlying this report, we used data from OpenAQ for several LMICs to evaluate the ability of satellites to estimate daily average ground-level PM2.5 concentrations in cities within LMICs. OpenAQ, and similar accessible 21
