USC Environmental Health Centers

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PM2.5 PurpleAir Data Visualization Project: Long Beach and South/Southeast Los Angeles

Project Background

This data visualization project focuses on atmospheric PM2.5 monitoring data from low cost PurpleAir PA-II outdoor sensors made publicly available on the PurpleAir website. PurpleAir sells low cost air quality sensors that can be installed indoors or outdoors, and rely on WiFi to transmit data to the open source map hosted on the PurpleAir website.

Sensors used in this project were located near the 710 freeway corridor, extending from Long Beach in the south to Huntington Park and Bell Gardens in the north. The east-west boundaries of the sensor group were between the 110 freeway SR-19. 

Data from calendar years 2019 and 2020 were included. A total of 26 sensors were used in the final 2019 data set, and 41 sensors in the final 2020 data set. Of these sensors, 25 had usable data for both years. All data were combined and analyzed using R statistical software. 

Analyses were done for 2019 and 2020 for all respective sensors, sensors were also split into smaller groupings using the I-405 and I-105 as rough boundaries. Visualizations available using the tool on this webpage include: 

Particulate Matter

Particulate matter, or PM for short, is composed of solid or liquid airborne pollutants. PM can contain dust, ash, soot, metallic particles, cement, pollen, smoke and other pollutants. These pollutants are inhalable by humans and span a diameter of 10 microns or less. 

The most common types are PM2.5 (fine particulate matter), which refers to particles that are 2.5 microns or less in diameter, and PM10 (coarse particulate matter), which includes particles with diameters of 10 microns or less. Contributors to PM2.5 levels include combustion of common energy sources, including gasoline, oil, diesel fuel and wood. Because of its small size, PM2.5 is more likely than PM10 to be inhaled deep into human lungs.

The Ambient Air Quality Standard for PM2.5 concentration in California, and nationally, is 12 µg/m3 annually and 35µg/m3 daily.

References and resources
USC Environmental Health Centers
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