Carlotta Alias

The objective of this study was to use plant models, Allium cepa and Lepidium sativum, to assess the genotoxic effects of the urban particulate matter (PM) collected in a Northern Italian town. Aqueous extracts of different particle sizes (PM_10–3, PM_3–0.5, PM_0.5) were tested alongside the organic extracts through the standard Ames test. The organic particulate matter extracts were subjected to mutagenicity testing in the Salmonella typhimurium strains TA98 and TA100 (without and with metabolic activation), whereas the aqueous extracts were evaluated for genotoxicity in the emerging seedlings of L. sativum and in the root tips of A. cepa bulbs using the comet test to detect the primary DNA damage. Furthermore, the micronuclei frequency was assessed in the bulbs of A. cepa. As expected, the organic extracts of PM_3–0.5 and PM_0.5 induced point mutations in bacteria. The aqueous extracts of the finest fractions caused a significant increase in genotoxic damage in both plant models. These findings indicate that the two plant models (L. sativum seeds and A. cepa bulbs) are able to detect the genotoxicity of aqueous extracts of air pollutants, with many potential advantages as screening-level tools to complement Ames testing for an easier assessment of urban air quality in terms of DNA toxicity.

The application of a battery of bioassays is widely recognized as a useful tool for assessing environmental hazard samples. However, the integration of different toxicity data is a key aspect of this assessment and remains a challenge. The evaluation of industrial waste leachates did not initially undergo any of the proposed integration procedures. This research addressed this knowledge gap. Twenty-five samples of waste foundry sands were subjected to a leaching test (UNI EN 12457-2) to evaluate waste recovery and landfill disposal. The leachates were evaluated using a battery of standardized toxicity bioassays composed of Aliivibrio fischeri (EN ISO 11348-3), Daphnia magna (UNI EN ISO 6341), and Pseudokirchneriella subcapitata (UNI EN ISO 8692), both undiluted and diluted. Daphnia magna and P. subcapitata were the most affected organisms, with significant effects caused by 68% and 64% of undiluted samples, respectively. The dilution of samples facilitates the calculation of EC50 values, which ranged from greater than the highest concentration tested to 2.5 g/L for P. subcapitata. The data on single-organism toxicity were integrated using three methods: the Toxicity Classification System, the toxicity test battery integrated index, and the EcoScore system. The three classifications were strongly similar. According to all applied systems, three samples were clearly nontoxic (from iron casting plants) and two were highly toxic (from steel casting plants). Moreover, the similar ranking between undiluted and diluted leachates suggests the possibility of using only undiluted leachates for a more cost-effective and time-efficient screening of waste materials. The findings of this study highlight the usefulness of integrating ecotoxicological waste assessment. Integr Environ Assess Manag 2024;20:2294–2311. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points The toxicity of waste foundry sand leachates was assessed using three ecotoxicity tests, and the results were summarized using three different synthetic indices to assess the environmental risk associated with the possible reuse of these materials. The samples of cast steel and a binder system based on sodium silicate-ester cured were very toxic and were associated with high environmental risk, whereas the samples of cast iron and different binder systems were associated with a very low level of risk. Classification systems are useful tools for responding to management and regulatory frameworks. Despite these findings, there remains a lack of development in the real-world use of these systems in the waste management industry.

The purposes of this review were to investigate the application of the comet assay in Allium cepa root cells to assess the genotoxicity of environmental samples and to analyse the experimental procedures employed. A literature search was performed selecting articles published between January 2000 and October 2023 from online databases using the combined search terms ‘comet assay’ and ‘A. cepa’. Only 18 papers met the inclusion criteria. None of these were published in the first eight years (2000–2007), highlighting the increasing interest in using the comet assay on A. cepa to analyse environmental samples over the last decade. The majority of the selected studies (15/18, 83%) were performed on samples belonging to the water compartment on onion bulbs. Half of the selected studies (9/18) were conducted to demonstrate the DNA damaging effect of the sample, while the other half of the studies not only recognized the presence of genotoxic agents but also addressed possible remediation measures. Detailed analysis of the experimental procedures revealed heterogeneity in many key steps, such as exposure time, test controls, nuclei isolation solutions, duration of electrophoresis, and number of nuclei scored. This literature review has shown that the comet assay on A. cepa, although recognized as an appropriate tool, is underutilized in environmental toxicology. Greater standardization could lead to its more widespread use, providing valuable information on the genotoxicity of environmental samples and the ability of different processes to mitigate their negative effects on plants.

The potential impact of concrete mixtures containing steel slag (SS) as a partial replacement of natural aggregates (NA) on the terrestrial ecosystem was assessed using a battery of plant-based bioassays. Leaching tests were conducted on four concrete mixtures and one mixture containing only NA (reference concrete). Leachates were tested for phytotoxicity using seeds of Lepidium sativum, Cucumis sativus, and Allium cepa. Emerging seedlings of L. sativum and A. cepa were used to assess DNA damage (comet test). The genotoxicity of the leachates was also analyzed with bulbs of A. cepa using the comet and chromosome aberration tests. None of the samples caused phytotoxic effects. On the contrary, almost all the samples supported the seedlings; and two leachates, one from the SS-containing concrete and the other from the reference concrete, promoted the growth of C. sativus and A. cepa. The DNA damage of L. sativum and A. cepa seedlings was significantly increased only by the reference concrete sample. In contrast, the DNA damage in A. cepa bulbs was significantly enhanced by the reference concrete but also by that of a concrete sample with SS. Furthermore, all leachates caused an increase in chromosomal aberrations in A. cepa bulbs. Despite some genotoxic effects of the concrete on plant cells, the partial replacement of SS does not seem to make the concrete more hazardous than the reference concrete, suggesting the potential use of SS as a reliable recycled material. Environ Toxicol Chem 2023;42:2193–2200. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Steel slags, the main waste product from the steel industry, may have several reuse possibilities. Among others, building applications represent a crucial field. However, the potential impact of harmful substances on the environment should be assessed. The aim of this study was to assess the phytotoxicity of steel slags (SS) and concrete mixtures cast with a partial replacement of SS (CSS). Leaching tests were carried out on four SS and four CSS according to EN 12457-2 and UNI EN 15863, respectively. Each leachate was assayed using root elongation tests on 30 seeds of Allium cepa, Cucumis sativus, and Lepidium sativum, respectively, and on 12 bulbs of A. cepa. The latter also allowed the analysis of other macroscopic parameters of toxicity (turgidity, consistency, colour change and root tip shape) and the evaluation of the mitotic index on 20,000 root tip cells per sample. None of the samples induced phytotoxic effects on the organisms tested: all samples supported seedlings emergence, verified by root elongation comparable to, or even greater than, that of the negative controls, and did not affect cell division, as evidenced by mitotic index values. The absence of phytotoxicity demonstrated by the leachates allows SS and SS-derived concrete to be considered as reliable materials suitable for use in civil constructions or in other engineering applications, with economic and environmental advantages, such as the reduction of the final disposal in landfills as well as the consumption of natural resources.

The comet assay is a sensitive method for the evaluation of DNA damages and DNA repair capacity at single‐cell level. Allium cepa is a well‐established plant model for toxicological studies. The aim of this scoping review was to investigate the recent application of the comet assay in Allium cepa root cells to assess the genotoxicity. To explore the literature a search was performed selecting articles published between January 2015 and February 2023 from Web of Science, PubMed, and Scopus databases using the combined search terms “Comet assay” and “Allium cepa”. All the original articles that applied the comet assay to Allium cepa root cells were included. Of the 334 records initially found, 79 articles were identified as meeting the inclusion criteria. Some studies reported results for two or more toxicants. In these cases, the data for each toxicant were treated separately. Thus, the number of analyzed toxicants (such as chemicals, new materials, and environmental matrices) was higher than the number of selected papers and reached 90. The current use of the Allium‐comet assay seems to be directed towards two types of approach: the direct study of the genotoxicity of compounds, mainly biocides (20% of analyzed compounds) and nano‐ and microparticles (17%), and assessing a treatment's ability to reduce or eliminate genotoxicity of known genotoxicants (19%). Although the genotoxicity identified by the Allium‐comet assay is only one piece of a larger puzzle, this method could be considered a useful tool for screening the genotoxic potential of compounds released into the environment.

In this study, the agricultural digestate from anaerobic biogas production mixed with food wastes was used as a substrate to grow Trichoderma reesei RUT-C30 and Trichoderma atroviride Ta13 in solid-state fermentation (SSF) and produce high-value bioproducts, such as bioactive molecules to be used as ingredients for biostimulants. The Trichoderma spp. reached their maximum growth after 6 and 3 SSF days, respectively. Both Trichoderma species were able to produce cellulase, esterase, and citric and malic acids, while T. atroviride also produced gibberellins and oxylipins as shown by ultraperformance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) profiling. Experimental evaluation of germination parameters highlighted a significant promotion of tomato seed germination and root elongation induced by T. atroviride crude extracts from SSF. This study suggests an innovative sustainable use of the whole digestate mixed with agro-food waste as a valuable substrate in fungal biorefineries. Here, it has been applied to produce plant growth-promoting fungi and bioactive molecules for sustainable agriculture.