Heavy metals emissions to air from industrial plants: criticalities and solutions

In the European Union, the regulation in the sector of emissions into the atmosphere from industrial plants did not evolve homogeneously. As demonstrated in this article, the sector of waste to energy plants has shown important improvements in the latest 20 years, whilst other industrial plants were subject to less stringent regulations. As consequence, the human exposure resulting from industrial plant authorisations depend on the plant to be authorised. Examples of consequent inequalities and related criticalities concern both macro and micro-pollutants. The present article concerns a category of micro-pollutants: heavy metals emissions into the atmosphere. The sector of thermo-chemical treatment of waste is presently analysed in details in the University of Insubria in the frame of a research in progress. The present article refers to some aspects emerged in that research and integrates them by a preliminary analysis of the underestimated criticalities of other industrial sectors. In both cases, the core of the problem is the demonstrable excessive simplification of the control of heavy metals emissions. Large industrial plants are controlled through an approach that does not exploit in details the available information of toxic effects of each heavy metal. Small industrial plants can be subject to simple authorisations with no analysis of the local impact of their emissions. In both cases, secondary and diffused emissions can have an impact higher than the conveyed ones, as discussed in this article. A methodology of control that integrates the present regulation, avoiding under-estimated human exposures to heavy metals is mandatory.