Outdoor air pollution can have many sources, both anthropogenic (power generation, vehicle emissions, industrial and agricultural emissions, etc.) and natural, for instance, volcanic eruption, wind erosion or wildfires. A key area of concern is the Suspended Particulate Matter (SPM), which can have adverse effects on health, particularly in the particle size ranges under ten microns. These are further characterized by two designations – PM10 (2.5 – 10 micron) and PM2.5 (<2.5 micron), with PM10 having the ability to penetrate deep into lungs, and PM2.5 able to permeate throughout the body and even into the brain. Particulate matter has been classified by the World Health Organization (WHO) as a Group 1 carcinogen alongside tobacco smoke and asbestos1, and the PM2.5 range has been attributed to over 3.2 million premature deaths annually2.
Many countries and regions of the world have enacted legislation setting air quality standards, such as the Clean Air Act in the United States, and the EU Air Quality Directive. The US Environmental Protection Agency (US EPA) published a comprehensive method (IO-3.3) for determining the elemental concentrations of 44 elements on air filters using energy dispersive X-ray Fluorescence (EDXRF)3.
The method was developed in 1999, and due to the performance capabilities of floor standing EDXRF spectrometers in 1999, the measurements took over 4 hours per sample to achieve the detection limits specified in the EPA method. Flash forward to 2018, the recently launched Malvern Panalytical Epsilon 4 EDXRF benchtop has the capability to achieve fully compliant results in only forty-five minutes per sample. EDXRF is non-destructive, uses minimal samples prep, and does not require a specialist operator. Air filters remain intact for further analysis such as weighing and analysis of hydrocarbons. For all these reasons, EDXRF is a low labor-intensive and less expensive analysis compared to alternative methods such as ICP and AA. To learn more about the elemental analysis of air filters according to the EPA method IO-3.3 using the Epsilon 4.