Estimating the air pollutant-attributable health burden of the oil and gas sector in Mexico using a TROPOMI flux-divergence approach

Background: Mexico's oil and gas (O&G) sector is a source of health relevant nitrogen dioxide (NO₂) and fine particulate matter (PM_2.5) emissions, yet the health impacts of these emissions remain unquantified. Understanding sector-specific health impacts is critical for informing methane and air quality mitigation strategies that maximize health benefits for affected communities. In this study, we conduct a full-chain health risk assessment to estimate O&G-attributable air pollution concentrations and health impacts in Mexico by leveraging satellite observations.

Methods: We derive total NO_x emissions through a flux divergence calculation that applies TROPOMI remote sensing NO₂ and ERA5 advection. Emissions specific to O&G were isolated through a land-use apportionment that integrates fine-resolution O&G infrastructure data from the Oil and Gas Infrastructure Mapping (OGIM) database. The GEOS-Chem High Performance (GCHP) model was used to perform a stretched-grid simulation over Mexico using these updated emissions to simulate the impact on NO₂ and PM_2.5 concentrations. These simulated NO₂ are further downscaled using satellite-derived estimates. Population-weighted exposure was then modeled by combining downscaled pollution concentrations with municipal and AGEB-level population data.

Results: Our methodology estimates the O&G sector contributions to ambient NO₂ and PM_2.5 concentrations across Mexico at sub-national resolution. The integration of satellite remote sensing, chemical transport modeling, and satellite-based downscaling overcomes limitations of sparse ground monitoring and enables spatially resolved exposure assessment. We find modest improvements in normalized mean bias (NMB=-4.6%) and R² value (R²=0.84) and increased surface-level NO₂ concentrations exceeding +25% in some regions of Mexico.

Conclusions: This work demonstrates a strategy for attributing sector-specific air pollution and quantifying associated health impacts in data-limited settings. By integrating satellite observations, chemical transport modeling, and epidemiological methods, we provide evidence of the public health consequences of Mexico's O&G sector.