1. Marron Institute of Urban Management, New York University, New York, New York;
2. New York University Grossman School of Medicine, New York, New York;
3. Environmental Defense Fund, Washington, DC;
4. Department of Atmospheric, Oceanic and Earth Sciences and
5. Center for Spatial Information Science and Systems, George Mason University, Fairfax, Virginia; and
6. American Thoracic Society, Washington, DC