Performance of Vehicle Add-on Mobile Monitoring System PM_2.5 measurements during wildland fire episodes

Area of Science:

• Environmental Health
• Air Quality Monitoring
• Wildland Fire Science

Background:

• Wildland fire-generated fine particulate matter (PM2.5) poses a significant public health risk in the U.S.
• Current stationary monitoring networks and tools like the Air Quality Index struggle to capture the fine spatiotemporal variations in smoke exposure.
• Steep exposure gradients in wildland fire smoke plumes necessitate improved real-time monitoring solutions.

Purpose of the Study:

• To develop and evaluate a lightweight, attachable mobile PM2.5 monitoring system.
• To provide supplemental, real-time air quality data during wildland fire and prescribed burning events.
• To assess the performance of the mobile monitor against existing stationary networks.

Main Methods:

• Developed a universally attachable mobile PM2.5 monitoring system.
• Collected 1-minute averaged data during two large western U.S. wildfires and one Midwest prescribed burn.
• Compared mobile monitor performance against nearby stationary low-cost sensors and regulatory monitors.

Main Results:

• Mobile measurements showed high correlation (R² > 0.85) with stationary networks during large wildfires.
• 1-minute averaged mobile data differed by <25% from collocated stationary instruments in most passages.
• Spatial maximum concentrations measured by mobile and stationary instruments were consistent during a prescribed burn, despite challenging conditions.

Conclusions:

• Portable sensor technologies are valuable for addressing monitoring challenges posed by dynamic wildland fire conditions.
• Combining mobile monitoring with stationary data can enhance air quality assessments.
• The developed mobile system offers a promising approach for real-time wildfire smoke exposure monitoring.