1 Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pa; Department of Rhinology, Shengjing Hospital of China Medical University, Shenyang, China.
2 Center for Biologic Imaging, School of Medicine, University of Pittsburgh Medical Center, University of Pittsburgh, Pittsburgh, Pa.
3 Department of Statistics and Operations Research, Universidad de Valladolid, Valladolid, Spain.
4 Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pa.
5 Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pa.
6 Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pa; University of Pittsburgh Asthma and Environmental Lung Health Institute @UPMC, Pittsburgh, Pa. Electronic address: swenzel@pitt.edu.