Environ Sci Pollut Res Int. 2026 Jul 28. doi: 10.1007/s11356-026-38083-2. Online ahead of print.
ABSTRACT
Air pollution remains an environmental health risk, with particulate matter (PM2.5) disproportionately affecting vulnerable communities. Allegheny County, Pennsylvania, a high-PM2.5 region, requires assessment of exposure variability and risk. This study evaluated spatial and seasonal variation in PM2.5-equivalent concentrations using community monitoring from 290 homes across Allegheny County (2016-2021). Particle counts (> 0.5 µm) from the ROCIS Low-Cost Monitoring Project were converted to estimated PM2.5-equivalent mass concentrations, and census tracts were classified by environmental justice (EJ) status and proximity to industrial sources using GIS. Generalized estimating equation (GEE) models assessed spatial and seasonal patterns, and noncancer risks were estimated using hazard quotients (HQs). Overall, 33.8% of the study sites (n = 290) exceeded the WHO 2021 24-h guideline (15 µg/m3) and the 66.6% EPA annual reference (9 µg/m3), based on 3-week site medians-screening-level comparisons rather than regulatory determinations. Compared to the WHO 2021 24-h guideline, median (mean ± SD) PM2.5 concentrations were highest in Sewickley-median 19.3 µg/m3, range = 6.1-22.8 µg/m3 (16.1 ± 8.8 µg/m3), with GEE estimated at 62% above the Etna baseline, though this rests on only three homes and should be read as exploratory. Winter concentrations were significantly elevated (p < 0.001), with the combined cold season (winter and fall) exceeding the warm season (p < 0.05). Although EJ differences were not statistically significant, 42% of municipalities had HQ ≥ 1, indicating potential noncancer risks. These results highlight fine-scale pollution variability not captured by regulatory monitors and underscore the need for spatially resolved assessments to guide public health interventions.
PMID:42521969 | DOI:10.1007/s11356-026-38083-2
