Environmental risk, support and information effect: the case of polluted sludge of drainage channels in the north of Italy

The “regionalized” feature of variables is usually overlooked by the Environmental Regulation, generating an often incorrect evaluation of environmental risk. This paper presents the case study concerning the polluted sludge of a drainage channel network in Padana plane, North of Italy. The influence of “support effect” and “information effect” on the decisions are analysed in terms of environmental risks. The main risk is linked to the application of the law in force. The selection problem is studied by a sensitivity analysis of actual results to the parameters undefined by the regulation. A comparison is made between simulated and estimated pollutants contents of a bi-dimensional track. The risk analysis is developed by quantifying the misselection risk and by expressing it from an economical point of view. The influence of the selection support and estimation error is identified. The results point out the urgent need of a more rigorous approach and can be generalised to most of the current environmental regulation.