PM10 Is Not PM2.5: A Study on Fenceline Communities in Southeastern PA

SHIVANG AGARWAL, Mina Tehrani, Kirsten Koehler, Peter F. DeCarlo, Johns Hopkins University

     Abstract Number: 577
     Working Group: Aerosols Spanning Spatial Scales: Measurement Networks to Models and Satellites

Abstract
Particulate matter (PM) has a significant impact on public health, with both PM_2.5 and PM₁₀ exposure linked to adverse health outcomes. While policies and government efforts focus on PM_2.5, PM₁₀ is often overlooked despite its short-term exposure causing irritation and inflammation in the upper respiratory tract amongst other health problems. This study aimed to evaluate the spatial variability of PM₁₀ compared to that of PM_2.5 at six locations in southeastern Philadelphia.

The study validated a moderate-cost PM sensor, the Quant-AQ MODULAIR-PM, which combines nephelometry with optical particle counting (OPC), compared to filter-based Multi-Orifice Uniform Deposit Impactor (MOUDI) gravimetric measurements. Strong linear correlations were observed for both PM_2.5 (orthogonal regression slope= 1.08, r= 0.97) and PM₁₀ (1.17, 0.90), indicating that the MODULAIR-PM is an accurate measure of both pollutants.

Using the network of 6 sensors in the study area, we identified seven likely violations of 24-hour average PM₁₀ concentration (>150 µg/m³) for calendar year 2022, showing the importance of continuous PM₁₀ measurements. To understand variability of PM_2.5 and PM₁₀ spatially across the study area we compared each individual monitor to the average of all 6 monitors. We found that the slopes of the regression for the PM_2.5 measurements varied between 0.81-1.18, while the slopes comparing PM₁₀ measurements varied between 0.52-1.76, indicating higher spatial variability for PM₁₀. The study highlights the importance of studying both PM_2.5 and PM₁₀ since coarse fraction in PM₁₀ behaves differently and originates from dissimilar sources.

In conclusion, this study underscores the need to improve regulatory monitoring infrastructure for PM₁₀ and emphasizes the importance of reliable sensors for accurately measuring this pollutant. The study findings highlight the need for further monitoring in areas where violations of PM₁₀ concentrations may occur.