Nitrogen dioxide (\(NO_{2}\))
Beyond its contribution to secondary \(PM_{2.5}\) formation and the associated health impacts, recent epidemiological evidence has shown that there are health impacts of exposure to \(NO_{2}\) itself. [6] The recently revised GAINS-Europe transfer coefficients from 2022 have allowed the calculation of exposure to \(NO_{2}\) well enough to attempt a quantification of \(NO_{2}\)-related mortality in GAINS. These impact assessments have been included in the Clean Air Outlook 3 [8] but are not yet operational in the GAINS model.