Development and application of statistical models for CO concentration and duration events in the Milan urban area

Indications for the intervention strategies to be included in the context of air quality remediation plans for the Milan metropolitan area are obtained by evaluating 5 years of hourly CO concentration data. The work reports on the analysis of standard exceedances and concentration-time trends and on the development of empirical statistical models for describing relationships between annual concentration averages and air quality-related parameters. The models are applied, in combination with simple roll-back equations, for the evaluation of emissions reduction required for standards attainment. Similar statistical approaches for describing the dependence between the duration of exceedance episodes over fixed concentration levels and simple time series parameters (annual mean concentrations) are also reported.