Nitric AcidNitrogen DioxideSpectrophotometry, AtomicSulfur DioxideAir PollutantsNeodymiumDecalcification TechniqueAir PollutionCarbon DioxideHydrofluoric AcidOzoneOxidants, PhotochemicalSulfuric AcidsEnvironmental MonitoringNitratesGas ScavengersTrace ElementsVehicle EmissionsHydrochloric AcidParticulate MatterAir Pollution, IndoorMicrowavesSkatingCalibrationEnvironmental Exposure