Artikel 5 bis

For the United States of America, the effects of nutrient nitrogen (eutrophication) for ecosystems are evaluated through an assessment of the sensitivity and response of ecosystems to the loading of nitrogen compounds, using peer-reviewed scientific methodologies and criteria, and accounting for uncertainties associated with nitrogen cycling within ecosystems. Adverse impacts on vegetation and ecosystems are then considered in establishing secondary national ambient air quality standards for NOx. Integrated assessment modelling and the air quality standards are used in providing guidance for setting the emission reduction commitments for the United States of America in annex II.