The pollutants present in the steelworks slag are all below the legal limits and their slight toxicity is equal to that of the quarry material. This was established by a three-year research project by the University of Brescia, whose conclusions are clear: with equal effects it is better to use heavy ashes in the metallurgical sector in construction, avoiding the opening of new quarries and new landfills.
Steel mill waste can be used as building materials (road foundations, concrete production, etc.) because heavy metal concentrations are all below the legal limits. But there is more: toxicity and genotoxicity tests have shown results comparable to those performed on quarry material (sand and gravel). This is the summary of the study “Eco-health waste management” which lasted three years, which combined expertise in Medicine and Engineering and which was conducted by the interdepartmental laboratory of the University of Brescia, B + LabNet “Environment, health and sustainability”, funded from the Health & Wealth program of the University of Brescia.
The research, which studied the effects of the slag of five steelworks in Brescia and the “natural” material taken in as many sand and gravel quarries, was carried out in Brescia and saw the involvement of the engineer Sabrina Sorlini, of the Department of Civil Engineering , Architecture, Territory, Environment and Mathematics, by biologists Giovanna Piovani (project coordinator) of the Department of Molecular and Translational Medicine (DMMT), Donatella Feretti of the Department of Medical and Surgical Sciences (DSMC), Carlotta Alias (B + LabNet), Ilaria Zerbini (DSMC), from the environmental engineers Laura Benassi (B + LabNet), Alessandro Abbà (DICATAM) and from Prof. Umberto Gelatti (professor of Hygiene of the DSMC).
The basic synthesis of the research is clear: “In comparison with the natural materials normally used, the slag of a steel plant wins, because it avoids the opening of new quarries and landfills and consequently decreases the emissions of carbon dioxide”, says Prof. ssa Piovani.
Now the legislator has one more tool to be able to update and improve legislation that is now 13 years old. A holistic approach, which takes into account the context of use of the waste and at the same time clear and unambiguous tests, is the first step to solve the problem. Brescia has shown the way and will continue to develop sector studies: “However, operational guidelines are needed through the end of waste decrees, in line with the criteria proposed at European level”, concludes Prof. Sorlini.
(Corriere della Sera, Brescia)