Source Contributions to Air Pollution in the Permian Basin: Evaluating Emissions from Unconventional Oil and Gas Activities

Unconventional oil and gas development (UOGD) has enabled the extraction of previously inaccessible hydrocarbon resources, leading to a rapid proliferation of well sites across shale regions, often in close proximity to residential communities. Air emissions from UOGD pose potential health risks, yet few studies have captured their full complexity or temporal variability using long-term, high-resolution monitoring. We conducted one year of continuous stationary air pollution monitoring in Loving, New Mexico, a high-production area of the western Permian Basin. Measurements included nitrogen oxides (NO x ), sulfur dioxide (SO 2 ), hydrogen sulfide (H 2 S), methane (CH 4 ), carbon dioxide (CO 2 ), carbon monoxide (CO), radon, particle radioactivity, and 20 speciated volatile organic compounds (VOCs). We observed exceptionally high hydrocarbon concentrations and identified air quality impacts from multiple UOGD-related sources including gas flaring and midstream facilities. To characterize dominant emission sources, we applied non-negative matrix factorization to the multivariate time series. This approach resolved five distinct factors: fugitive/vented emissions, produced water, traffic, flaring, and other area sources, which together explained 95% of the variance in the combined data set. Most VOCs, along with CH 4, CO, CO 2, NO x, and radioactivity were primarily attributed to UOGD activities rather than to transportation, which itself is linked to UOGD operations in the area. Our findings provide a detailed, high-resolution source profile of UOGD-related air pollution in the Permian Basin and demonstrate the value of source apportionment modeling for disentangling overlapping emission sources in oil- and gas-producing regions.