This paper describes the ecotoxicological effects of nanomaterials (NMs) as well as their testing methods. Standard ecotoxicity testing methods are applicable to nanomaterials as well but require some adaptation. We have taken into account methods that meet several conditions. They must be properly researched by a minimum of ten scientific articles where adaptation of the method to the NMs is also presented; use organisms suitable for simple and rapid ecotoxicity testing (SSRET); have a test period shorter than 30 days; require no special equipment; have low costs and have the possibility of optimization for high-throughput screening. From the standard assays described in guidelines developed by organizations such as Organization for Economic Cooperation and Development and United States Environmental Protection Agency, which meet the required conditions, we selected as methods adaptable for NMs, some methods based on algae, duckweed, amphipods, daphnids, chironomids, terrestrial plants, nematodes and earthworms. By analyzing the effects of NMs on a wide range of organisms, it has been observed that these effects can be of several categories, such as behavioral, morphological, cellular, molecular or genetic effects. By comparing the EC50 values of some NMs it has been observed that such values are available mainly for aquatic ecotoxicity, with the most sensitive test being the algae assay. The most toxic NMs overall were the silver NMs.
Fungicides play an important role in crop protection, but they have also been shown to adversely affect non-target organisms, including those living in the aquatic environment. The aim of the present study is to combine experimental and computational approaches to evaluate the effects of flutriafol, metconazole, myclobutanil, tebuconazole, tetraconazole and triticonazole on aquatic model organisms and to obtain information on the effects of these fungicides on Lemna minor, a freshwater plant, at the molecular level. The EC50 (the half-maximum effective concentration) values for the growth inhibition of Lemna minor in the presence of the investigated fungicides show that metconazole (EC50 = 0.132 mg/L) and tetraconazole (EC50 = 0.539 mg/L) are highly toxic, tebuconazole (EC50 = 1.552 mg/L), flutriafol (EC50 = 3.428 mg/L) and myclobutanil (EC50 = 9.134 mg/L) are moderately toxic, and triticonazole (EC50 = 11.631 mg/L) is slightly toxic to this plant. The results obtained with the computational tools TEST, ADMETLab2.0 and admetSAR2.0 also show that metconazole and tetraconazole are toxic to other aquatic organisms: Pimephales promelas, Daphnia magna and Tetrahymena pyriformis. A molecular docking study shows that triazole fungicides can affect photosynthesis in Lemna minor because they strongly bind to C43 (binding energies between −7.44 kcal/mol and −7.99 kcal/mol) and C47 proteins (binding energies between −7.44 kcal/mol and −8.28 kcal/mol) in the reaction center of photosystem II, inhibiting the binding of chlorophyll a to these enzymes. In addition, they can also inhibit glutathione S-transferase, an enzyme involved in the cellular detoxification of Lemna minor.
This review seeks to highlight the issue of utilizing a widely distributed aquatic species within the broader context of the transition from a linear to a circular economy and the growing emphasis on environmental sustainability. To promote a cleaner aquatic environment and ensure compliance with current regulations, the use of bioindicators and plant bioaccumulators presents a viable alternative. Lemna minor, a small aquatic species, serves as a noteworthy example that warrants greater consideration. A review of specialized literature was conducted to provide a comprehensive overview of these issues, drawing from the most relevant sources. This paper offers a broad discussion on bioeconomy and water management, along with an in-depth examination of L. minor, its characteristics, and its practical applications. The biological characteristics, ecological significance, and useful applications of L. minor in wastewater treatment, bioenergy, and bioproduct production are summarized in this research. The analysis also identifies research gaps for further investigation and looks at how this plant fits into new frameworks for the circular economy.
Chitosan, chitooligosaccharides and their derivatives’ production and use in many fields may result in their release to the environment, possibly affecting aquatic organisms. Both an experimental and a computational approach were considered for evaluating the effects of these compounds on Lemna minor. Based on the determined EC50 values against L. minor, only D-glucosamine hydrochloride (EC50 = 11.55 mg/L) was considered as “slightly toxic” for aquatic environments, while all the other investigated compounds, having EC50 > 100 mg/L, were considered as “practically non-toxic”. The results obtained in the experimental approach were in good agreement with the predictions obtained using the admetSAR2.0 computational tool, revealing that the investigated compounds were not considered toxic for crustacean, fish and Tetrahymena pyriformis aquatic microorganisms. The ADMETLab2.0 computational tool predicted the values of IGC50 for Tetrahymena pyriformis and the LC50 for fathead minnow and Daphnia magna, with the lowest values of these parameters being revealed by totally acetylated chitooligosaccharides in correlation with their lowest solubility. The effects of the chitooligosaccharides and chitosan on L. minor decreased with increased molecular weight, increased with the degree of deacetylation and were reliant on acetylation patterns. Furthermore, the solubility mainly influenced the effects on the aqueous environment, with a higher solubility conducted to lower toxicity.
(1) Background: The use of pesticides, although needed to protect crops and increase production, represents an environmental and human health issue. Therefore, measures must be taken in order to develop a better understanding of the risks involved in the overuse of these compounds. Myclobutanil is a chiral triazole fungicide widely used for the protection of crops against fungal diseases. Published data have shown that, although effective in preventing fungal infections, high doses of myclobutanil can affect the soil environment. The aim of this study was to evaluate the effect of different doses of myclobutanil on soil enzyme activity, as well as the possible specificity of the interactions of the two stereoisomers of myclobutanil with these enzymes. (2) Methods: A combination of experimental and computational approaches was considered. An experimental method was applied in order to assess the effect of different doses of myclobutanil on the activity of dehydrogenase, phosphatase, catalase, urease and protease. The computational approach was based on the molecular docking of the two enantiomers of myclobutanil with the above-mentioned enzymes to assess the possible enantioselectivity of the interactions. (3) Results: High doses of myclobutanil significantly affected the enzymatic activity of dehydrogenase and led to a slight increase in the activity of catalase. Molecular docking data showed that both enantiomers of myclobutanil were able to bind to the active sites of dehydrogenase, phsosphatase and protease, with higher interacting energies observed for (S)-myclobutanil, the enantiomer known to be less active against target organisms but have a higher toxicity against non-target organisms. (4) Conclusions: The results of our study confirm the need to implement better management practices regarding the use of myclobutanil (and of pesticides in general) by using the enantiomer that is most effective on target organisms and less toxic to non-target organisms.
Triazole fungicides are widely used in agriculture but may pose risks to human health through occupational, accidental, or environmental exposure. This systematic review aimed to evaluate the toxicity of ten European Union-approved triazole fungicides in rodent models and cell lines. A total of 70 studies were included, reporting quantitative in vivo oral, dermal, or inhalation toxicity in mammals or quantitative in vitro cytotoxicity in human or mammalian cell lines; the exclusion criteria comprised publications not in English or not accessible. Literature searches were conducted in Web of Science, Google Scholar, and the Pesticide Properties DataBase (PPDB), and risk of bias in included studies was assessed using ToxRTool. Due to heterogeneity in study designs, reporting formats, and endpoints, data were synthesized descriptively. Quantitative endpoints included LD50/LC50 values for in vivo studies and LOEC, IC50, LC50, and EC50 values for in vitro studies, while mechanistic endpoints highlighted apoptosis, oxidative stress, genotoxicity, and endoplasmic reticulum stress. Difenoconazole and tebuconazole were the most extensively studied compounds, whereas several triazoles had limited data. The limitations included heterogeneity of data and incomplete reporting, which restrict cross-study comparisons. Overall, the findings provide a comprehensive overview of potential human health hazards associated with EU-approved triazole fungicides and highlight critical knowledge gaps. The review was registered in Open Science Framework.