The Decree aims at assessing in a satisfactory manner the emergency situations deriving from ambient air pollution in the city of Athens and the wider area so as to ensure that appropriate measures are taken in order to avoid adverse effects on human health and the environment, which might arise from the ambient concentrations of certain pollutants. The Decree is composed as follows: definitions (level of ambient air pollution, limit values for pollution, etc.(art. 1); determination of pollutants to be monitored (art. 2); levels of actions (art.3); limit values for air pollutants (art. 4); establishment of a timeline for the levels of actions to be applied (art. 5); duration of levels of action (art. 6); content of the various levels of action (art. 7); obligation of industries (art. 8); sanctions (art. 9).