title: Classification criteria and probability risk maps: limitations and perspectives.
abstract: Delineation of polluted zones with respect to regulatory standards, accounting at the same time for the uncertainty of the estimated concentrations, relies on classification criteria that can lead to significantly different pollution risk maps, which, in turn, can depend on the regulatory standard itself. This paper reviews four popular classification criteria related to the violation of a probability threshold or a physical threshold, using annual (1996-2000) nitrogen dioxide concentrations from 40 air monitoring stations in Milan. The relative advantages and practical limitations of each criterion are discussed, and it is shown that some of the criteria are more appropriate for the problem at hand and that the choice of the criterion can be supported by the statistical distribution of the data and/or the regulatory standard. Finally, the polluted area is estimated over the different years and concentration thresholds using the appropriate risk maps as an additional source of uncertainty.
authors.affiliation: Department of Chemical Engineering, National Technical University of Athens, Heroon Polytechniou 9, Zografou Campus, 15780, Greece. michaela.saisana@jrc.it
authors.forename: Michaela
authors.initials: M
authors.lastname: Saisana
authors.forename: Gregoire
authors.initials: G
authors.lastname: Dubois
authors.forename: Archontoula
authors.initials: A
authors.lastname: Chaloulakou
authors.forename: Nikolas
authors.initials: N
authors.lastname: Spyrellis
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000506:poisoning; D004777:Environment; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis* / Q000506:poisoning*; D040362:Geographic Information Systems; D015233:Models, Statistical; D009585:Nitrogen Dioxide / Q000032:analysis / Q000506:poisoning; D011050:Policy Making; D012016:Reference Values; D018570:Risk Assessment
chemical_list: D000393:Air Pollutants; D004785:Environmental Pollutants; D009585:Nitrogen Dioxide