3 research outputs found

    Curation Decisions and Statistical Methods for Large-Scale Ecological Risk Prioritization in Surface Water: Maximizing Incomplete and Non-Optimal Data

    No full text
    Presentation to SETAC in Nov. 13-17, 2022 in Pittsburgh, PA Science Inventory, CCTE products: https://cfpub.epa.gov/si/si_public_search_results.cfm?advSearch=true&showCriteria=2&keyword=CCTE&TIMSType=&TIMSSubTypeID=&epaNumber=&ombCat=Any&dateBeginPublishedPresented=07/01/2017&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&DEID=&personName=&personID=&role=Any&journalName=&journalID=&publisherName=&publisherID=&sortBy=pubDate&count=25</p

    A Hybrid Approach to Estimating National Scale Spatiotemporal Variability of PM<sub>2.5</sub> in the Contiguous United States

    No full text
    Airborne fine particulate matter exhibits spatiotemporal variability at multiple scales, which presents challenges to estimating exposures for health effects assessment. Here we created a model to predict ambient particulate matter less than 2.5 μm in aerodynamic diameter (PM<sub>2.5</sub>) across the contiguous United States to be applied to health effects modeling. We developed a hybrid approach combining a land use regression model (LUR) selected with a machine learning method, and Bayesian Maximum Entropy (BME) interpolation of the LUR space-time residuals. The PM<sub>2.5</sub> data set included 104,172 monthly observations at 1464 monitoring locations with approximately 10% of locations reserved for cross-validation. LUR models were based on remote sensing estimates of PM<sub>2.5</sub>, land use and traffic indicators. Normalized cross-validated <i>R</i><sup>2</sup> values for LUR were 0.63 and 0.11 with and without remote sensing, respectively, suggesting remote sensing is a strong predictor of ground-level concentrations. In the models including the BME interpolation of the residuals, cross-validated <i>R</i><sup>2</sup> were 0.79 for both configurations; the model without remotely sensed data described more fine-scale variation than the model including remote sensing. Our results suggest that our modeling framework can predict ground-level concentrations of PM<sub>2.5</sub> at multiple scales over the contiguous U.S

    A Hybrid Approach to Estimating National Scale Spatiotemporal Variability of PM<sub>2.5</sub> in the Contiguous United States

    No full text
    Airborne fine particulate matter exhibits spatiotemporal variability at multiple scales, which presents challenges to estimating exposures for health effects assessment. Here we created a model to predict ambient particulate matter less than 2.5 μm in aerodynamic diameter (PM<sub>2.5</sub>) across the contiguous United States to be applied to health effects modeling. We developed a hybrid approach combining a land use regression model (LUR) selected with a machine learning method, and Bayesian Maximum Entropy (BME) interpolation of the LUR space-time residuals. The PM<sub>2.5</sub> data set included 104,172 monthly observations at 1464 monitoring locations with approximately 10% of locations reserved for cross-validation. LUR models were based on remote sensing estimates of PM<sub>2.5</sub>, land use and traffic indicators. Normalized cross-validated <i>R</i><sup>2</sup> values for LUR were 0.63 and 0.11 with and without remote sensing, respectively, suggesting remote sensing is a strong predictor of ground-level concentrations. In the models including the BME interpolation of the residuals, cross-validated <i>R</i><sup>2</sup> were 0.79 for both configurations; the model without remotely sensed data described more fine-scale variation than the model including remote sensing. Our results suggest that our modeling framework can predict ground-level concentrations of PM<sub>2.5</sub> at multiple scales over the contiguous U.S
    corecore