Evaluation of toxicity and genotoxicity of concrete cast with steel slags using higher terrestrial plants [post]

Carlotta Alias, Giovanna Piovani, Laura Benassi, Alessandro Abbà, Sabrina Sorlini, Umberto Gelatti, Ilaria Zerbini, Donatella Feretti
2022 unpublished
Steel slags (SS), by-products of the steel industry, may be used as recycled materials. However, their reuse may generate the potential release of harmful compounds into the environment. The aim of this study was to assess the potential impact of concrete mixtures cast with SS as partial replacement of natural aggregate on the terrestrial ecosystem, in terms of toxicity and genotoxicity, by using a battery of bioassays composed of higher plants. Four concrete mixtures, each one cast with the
more » ... lacement of natural aggregates by 30% of four different SS and a mixture with natural aggregates only (reference concrete) were submitted to the monolithic leaching test (UNI EN 15863). The leachates were assayed for phytotoxicity by using seeds of Lepidium sativum, Cucumis sativus, and Allium cepa. The emerged seedlings of L. sativum and A. cepa were used for the evaluation of the DNA damage through the Comet test. The genotoxicity of the leachates was also analysed by means of bulbs of A. cepa applied through the Comet and the chromosomal aberrations tests. None of the samples caused phytotoxic effects towards the tested seeds. Rather, almost all the samples support the seedlings emergence, demonstrated by germination indexes (GI%) between 90% and 120%. Moreover, two leachates from concrete cast with SS and the one from the reference concrete were able to promote the germination and root elongation of C. sativus and A. cepa. DNA damage in L. sativum and A. cepa seedlings was significantly increased only by the sample from reference concrete, while the four leachates from concrete cast with SS did not differ by the controls. Conversely, the DNA damage on A. cepa bulbs was significantly improved by leachate from reference concrete, but also by that from a sample of concrete with SS. Moreover, all the leachates caused the rise of chromosomal aberrations in bulbs of A. cepa. Despite some genotoxic effects of concrete on plant cells, the partial replacement of SS does not seem to make concrete any more hazardous than the reference one in terms of global toxicological assessment, suggesting the potential use of SS as reliable recycled material, leading to a reduction of the impact of the anthropic activities on the environment.
doi:10.21203/rs.3.rs-2041011/v1 fatcat:3f2z2bedq5hhtcobqjid4aduxe