Lucas Lloyd, Utah Valley University
Physical Sciences
The high cost of air quality monitoring stations makes it difficult for citizens or local governments to monitor air quality in their own neighborhoods. For example, Utah County, Utah, with an area of 2141 mi2, has only four air-quality monitoring stations: (1) north Provo close to both Provo High School and Brigham Young University (2) Spanish Fork Airport (3) near State Street in Lindon (4) just south of SR-92 on 6000 W in Highland. The air-quality stations monitor levels of CO, NO2, O3, PM-2.5 (particulate matter smaller than 2.5 microns), and PM-10. The objective of this study is to find a much cheaper method of measuring air quality. The objective was addressed by measuring the magnetic susceptibilities of 10 replicates each of the leaves of 12 species of trees (cypress, crab apple, elm, flowering pear, green ash, honey locust, linden, Norway maple, pine, red maple, Russian olive, spruce) collected within a two-mile radius of each of the four air-quality monitoring stations in Utah County. After air-drying and crushing the samples, both low-frequency (0.46 kHz) and high-frequency (4.6 kHz) magnetic susceptibilities were measured with the Bartington MS3 Magnetic Susceptibility Meter. The best correlations between tree leaf magnetic susceptibilities and air-quality parameters were between the three-year average of PM-2.5 and the high-frequency magnetic susceptibility of leaves of pine (Pinus aristata) (R2 = 0.87) and Norway maple (Acer platanoides) (R2 = 0.86). The correlation was used with measured high-frequency magnetic susceptibilities of pine to estimate PM-2.5 in two unmonitored locations heavily impacted by highway traffic (corner of 800 N and I-15 and corner of University Parkway and I-15, both in Orem, Utah) on one day in August 2013. It was found that estimated levels of PM-2.5 were 9.5 µg/cm3 and 8.9 µg/cm3, respectively, which were within the EPA PM-2.5 Standard of 12.0 µg/cm3.