Mobile Metal Aerosol Measurement in Industrially Adjacent Neighborhoods

EDWARD FORTNER, Mina Tehrani, Benjamin Werden, Megan Claflin, Conner Daube, Tara Yacovitch, Joseph Roscioli, Scott Herndon, Brian Lerner, Peter F. DeCarlo, Aerodyne Research, Inc.

     Abstract Number: 426
     Working Group: Aerosol Exposure

Abstract
This study investigates the concentration of metal aerosols in neighborhoods adjacent to industry in the Baton Rouge to New Orleans corridor in February 2023. The Aerodyne Mobile Laboratory (AML) and on-board suite of gas and particle instruments allows for mobile sampling of air quality. Measurements of aerosols chemical speciation and sizing are accomplished by an Aerodyne Soot Particle Aerosol Mass Spectrometer (SP-AMS). The SP-AMS combines conventional Aerodyne aerosol mass spectrometer (AMS) measurements of real-time, size-resolved composition of nonrefractory, aerosol particle ensembles with the ability to measure refractory particles. Nonrefractory aerosol particles are thermally vaporized at 600°C while refractory particles are vaporized by a 1064 nm laser. The resulting vapor is ionized and the ions are detected in a high-resolution mass spectrometer. Laser vaporization allows for the direct detection of metal species present in aerosols.

In this work, we compare mobile metal measurements from the SP-AMS to results from a Cooper Environmental Xact 625i ambient metals monitor also installed in the AML. The XACT 625i uses X-ray fluorescence on collected particles to accurately quantify a number of metals and was run in fast-sampling mode with five- minute resolution. The SP-AMS collected data at 1 second resolution providing superior spatial and temporal resolution but is limited in quantification and is therefore complementary to the XACT 625i. The SP-AMS and Cooper XACT625i sampled a wide variety of different metals as this campaign investigated air toxic metals in communities adjacent to industrial and metal processing facilities. We detected elevated levels of many metals including chromium, cadmium, mercury and lead during this campaign in these mixed industrial/residential areas.

This study highlights potential health risks associated with exposure to metal aerosol pollution in these neighborhoods and the need to develop effective strategies for reducing exposure in these areas.