United States National Aeronautics and Space AdministrationAtmosphereOzoneSaturnOxidants, PhotochemicalAir PollutantsOzone DepletionAir PollutionNitrogen DioxideEnvironmental MonitoringChlorine CompoundsSmogEnvironmental ExposureParticulate MatterInhalation ExposureSulfur DioxideStratospheric OzoneChlorofluorocarbonsIndigo CarmineLungPentanesSeasonsDisinfectionCitiesDisinfectantsWeatherBronchoalveolar Lavage Fluid