Estimating spatiotemporal distribution of PM_1 concentrations in China with satellite remote sensing, meteorology, and land use information

摘要

AbstractBackgroundPM1might be more hazardous than PM2.5(particulate matter with an aerodynamic diameter ≤ 1 μm and ≤2.5 μm, respectively). However, studies on PM1concentrations and its health effects are limited due to a lack of PM1monitoring data.ObjectivesTo estimate spatial and temporal variations of PM1concentrations in China during 2005–2014 using satellite remote sensing, meteorology, and land use information.MethodsTwo types of Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6 aerosol optical depth (AOD) data, Dark Target (DT) and Deep Blue (DB), were combined. Generalised additive model (GAM) was developed to link ground-monitored PM1data with AOD data and other spatial and temporal predictors (e.g., urban cover, forest cover and calendar month). A 10-fold cross-validation was performed to assess the predictive ability.ResultsThe results of 10-fold cross-validation showed R2and Root Mean Squared Error (RMSE) for monthly prediction were 71% and 13.0 μg/m3, respectively. For seasonal prediction, the R2and RMSE were 77% and 11.4 μg/m3, respectively. The predicted annual mean concentration of PM1across China was 26.9 μg/m3. The PM1level was highest in winter while lowest in summer. Generally, the PM1levels in entire China did not substantially change during the past decade. Regarding local heavy polluted regions, PM1levels increased substantially in the South-Western Hebei and Beijing-Tianjin region.ConclusionsGAM with satellite-retrieved AOD, meteorology, and land use information has high predictive ability to estimate ground-level PM1. Ambient PM1reached high levels in China during the past decade. The estimated results can be applied to evaluate the health effects of PM1.Graphical abstractDisplay OmittedHighlights•Satellite-retrieved AOD could be successfully used to predict levels of PM1.•The predicted annual mean concentration of PM1across China was 26.9 μg/m3.•The predicted PM1level in China was highest in winter while lowest in summer.Satellite-retrieved AOD could be successfully used to predict levels of PM1. The predicted annual mean concentration of PM1across China was 26.9 μg/m3.