Ecotoxicology最新文献

(1) Background: Ecotoxicological screening evaluates the acute toxicity of WWs. The Vibrio fischeri ecotoxicological assay analyses inlet and outlet wastewater samples from two urban wastewater treatment plants in Catania, Sicily, Italy. (2) Methods: The APAT CNR IRSA 8030 Man 29 method was used as method; (3) Results: The results showed toxicity values below the limit of the Italian Legislative Decree 152/06; (4) Conclusions: This monitoring study allows to verify the efficacy, and the outlet quality of WWs discharged to sea water. This ecotoxicological assay is a valuable tool for evaluating the combined toxicity of various pollutants that underline the total damage of the studied matrices detecting the true effect of complex mixtures on the environment and its fauna.

Para-toluidine (p-toluidine) is a high production volume chemical, of which about 5,000 tons/year are imported into Korea as of the 2018 registration. This substance is mainly used as an intermediate in the manufacture of paints, azo dyes, and pigments. In this study, an ecological risk assessment of p-toluidine was performed to investigate the risk to the environment assuming the worst-case exposure scenario. Ecotoxicity data was collected from the literature and the predicted no effect concentration (PNEC) was derived. The predicted environmental concentration (PEC) was calculated using the SimpleBox Korea v2.0 model. Hazard quotient (HQ) was calculated based on PEC and PNEC. The concentration of p-toluidine was measured in soil samples from workplaces with a HQ exceeding 1 to verify the results of modeling. PNECs for surface water, sediment, and soil were 0.00022 mg/L, 0.0025 mg/kg (dw), and 0.00037 mg/kg (dw), respectively. Based on regional-scale PEC, the HQ of freshwater, sediment, and soil media were all less than 1, but the HQ exceeded 1 at some local sites. Based on the fact that the measured environmental concentration in soil samples around the workplace is below the limit of detection and that all waste is incinerated at the actual workplace, p-toluidine is not likely to pose a high risk to the environment in Korea.

The widespread presence of microplastics (MPs) in aquatic ecosystems has raised growing concerns among ecotoxicologists regarding their potential toxicity. This study explored the impacts of polylactic acid (PLA) MPs on the physiology and health of freshwater fish, Cirrhinus mrigala, by dietary exposure for 90 days. The experiment consisted of six groups: five treatment groups (0.5%, 1%, 1.5%, 2%, and 2.5% PLA-MP) and a control group (0% PLA-MP). Each group was comprised of fifteen fish, and the experiment was replicated three times. The exposure severity of PLA-MPs varied from low to high, with treatment levels ranging from 0.5% to 2.5% PLA-MPs, relative to the control group. This exposure significantly affected their growth performance. Additionally, the apparent digestibility of the SFM-based diet decreased with increasing PLA-MPs concentration. Exposure to PLA-MPs induced considerable changes in body composition, characterized by increased moisture and crude fat content and decreased ash content and crude protein. The blood profile, including MCHC, RBCs, Hb, PLT and PCV exhibited significant declines in the high treatment group (2.5% PLA-MPs), while MCH, WBCs and MCV showed notable increases. Furthermore, histopathological examination of the intestine revealed an increase in abnormalities in the intestine at 2.5% PLA-MPs level. The high treatment group (2.5% PLA-MPs) showed the lowest mineral content in the fish muscles. In summary, dietary exposure to PLA-MPs led to alterations in overall body performance across the treatment groups, ranging from low to high severity levels.

This study evaluated the toxicity of cadmium (Cd) on the green mussel Perna viridis, aiming to identify toxicological endpoints and investigate its responses across physiological, bioenergetic, and biochemical parameters. The 96-hour LC₅₀ value for Cd in P. viridis was 3.03 ± 0.12 mg L^-1, with a 95% confidence interval of 2.35-3.91 mg L^-1. Chronic toxicity tests revealed a No Observable Effect Concentration (NOEC), Lowest Observable Effect Concentration (LOEC), and chronic toxicity values of 0.20, 0.37, and 0.29 mg L^-1, respectively. Cadmium accumulation in treated mussels increased 46- to 215-fold compared to the control group. Superoxide dismutase, catalase, glutathione S-transferase, and glutathione peroxidase levels in exposed mussels exhibited a significant increase compared to the control group. The redox index ratio, acetylcholinesterase activity, and lysosomal membrane stability decreased with increasing exposure concentrations. Levels of reduced and oxidized glutathione, glutathione reductase, lipid peroxidation, and metallothionein-like proteins increased in exposed mussels. Clearance rate, respiration rate, and excretion rate decreased in a dose-dependent manner. Protein, carbohydrate, and lipid levels decreased with increasing exposure concentration (p < 0.001). Mitochondrial electron transport system activity increased, while cellular energy allocation (p < 0.001) and scope for growth decreased in a dose-dependent manner (p < 0.01). The significant increase in antioxidants suggests heightened oxidative stress in mussels under Cd exposure. The physiological activities of the mussels were severely affected, ultimately leading to a reduced scope for growth. The toxicological data generated in this study contribute to the development of seawater quality criteria for the metal Cd.

The manual addition of lime to soil, in addition to tree planting and fertilization have been the dominant strategy described in restoration protocols for ecosystems damaged by acid rain and metal contamination. Investigations on aerial-limed soils in inaccessible lands are limited. The objective of this study was to assess the effects of aerial liming on soil pH, organic matter, microbial biomass, and enzymatic activities, and aboveground plant population quality in metal-contaminated lands in northern Ontario, Canada. Soil samples were collected from three sites around the City of Greater Sudbury with each pair being composed of a reclaimed (areal-limed) site and an adjacent undisturbed (unlimed) area. Soil physico-chemistry, microbial biomass (assessed by Phospholipid fatty acid analysis) and enzymatic activities were analyzed. Soil pH was higher in limed sites compared to unlimed at recently restored sites (Baby Lake and Wahnapitae) but not at the oldest reclaimed site (HWY 80 N). Organic matter was higher in limed areas compared to the unlimed reference site only at most recently reclaimed site at Baby Lake. Aboveground plant population health was visibly improved in limed sites compared to unlimed areas. Metal concentrations of iron (Fe) and arsenic (As), total microbial biomasses, gram-negative bacterial, fungal, and eukaryotic biomasses were all significantly increased in the limed soils compared to the unlimed samples. The same trend was observed for the activities of three of the enzymes tested, β-N-acetylglucosaminidase (BG), aryl sulfatase (AS), and glycine aminopeptidase (GAP). Interestingly, strong positive correlations between the levels of soil organic matter, microbial biomasses, and NAGase and ALP activities were observed. Although expensive, aerial liming is effective in restoring inaccessible sites impacted by smelting operations where other methods cannot easily be used.

The mode of action, bioaccumulation potential and toxicity of Rare Earth Elements (REE), with several applications in the technology, medical and agricultural fields, are still understudied. The nitrates acute effects on single exposures, binary and ternary mixtures of lanthanum (La), neodymium (Nd) and samarium (Sm) on Lactuca sativa lettuce seed germination and wet biomass in an artificial soil (AS) and an Ultisol were assessed. Germination (EC₅₀), wet biomass (IC₅₀) and germination inhibition (% GI) were evaluated. EC₅₀ values show La was the most toxic in Ultisol, Sm in AS, and Nd appears with intermediate values on both substrates. The IC₅₀, both single and mixed, decreased from 3- to 181-fold with increasing test concentrations in relation to the control in AS, while increases in Ultisol were observed, followed by decreases at higher doses which may be associated with the low-dose stimulation effect (hormesis). Our findings may be used to subsidize REE risk assessment studies and reinforce the hormesis effect to prevent the use of high application of REE fertilizers, avoiding the accumulation of REE in agricultural soils.

This study aims to assess the impact of two pesticides commonly used in Algeria (Prosaro XRT and Decis 25 EC), as well as their combinations at recommended doses, on a non-target species bioindicator of soil pollution, the earthworm Aporrectodea caliginosa, using physiological (mortality and growth) and biochemical parameters (proteins, glutathione, catalase activity and glutathione S-transferase, acetylcholine esterase, lipoxygenase). The recommended dose and its double were tested individually and in combination for this. It should be noted that the protocol used and the initial concentrations selected are the same as those used in the field. After 7 and 14 days (7D/14D) of exposure, all dosages were administered. Our findings show that the pesticides tested had no effect on earthworm survival. However, a significant decrease in their growth rates depending on the different concentrations was observed for the different treatments over the entire exposure period of 7 or 14 D. The greatest reductions (31.62%, 35.04%) are reported after 14D for the high concentrations of Decis alone (D2) as well as for the combined treatment Prosaro/Decis (P2/D2). At the same time, an increase in total protein contents (more than 50% after 14D) as well as a decrease in acetylcholine esterase activity were reported for all treatments. We were also able to identify the induction of oxidative stress after xenobiotic exposure, which is more pronounced at the end of the treatment (14D), resulting in the stimulation of the antioxidant system (gluthione, glutathione S-transférase, catalase) as well as the induction of lipoxygenase, which is responsible for the oxidation of polyunsaturated fatty acids as well as the generation of reactive oxygen species (ROS) involved in the inflammatory phenomenon. Finally, it turns out that the species Aporrectodea caliginosa is sensitive to the different concentrations applied, even those used in the open field, and that Decis (deltamethrin) seems to be more toxic than Prosaro and that the combinaison P2/D2 is as toxic as Decis alone (D2).

Peltophorum dubium, a common tree in areas close to agricultural activity in the Brazilian Cerrado, is vulnerable to damage from the drift of picloram, an herbicide widely used in pastures and agriculture in Brazil. The aim was to evaluate the application of 0.0; 19.2; 38.4; 76.8; 153.6; 307.2 g e. a. ha^-1 of picloram, in simulated drift, on P. dubium, as well as its use as a bioindicator plant for herbicide contamination. The doses of picloram applied to the plants caused symptoms typical of the action of picloram on sensitive plants and led to the death of P. dubium at the highest doses tested. At its highest dose, picloram caused a 52.86% reduction in photosynthetic rate, 42.51% in transpiration rate, and 64.28% in stomatal conductance compared to the non-treated control. Picloram at a dose of 19.2 g e. a. ha^-1 caused a reduction in N content and utilization and reduced plant protein. Picloram drift causes severe damage to P. dubium, reinforcing the concern about the risks of contamination with the herbicide. The species acted as a bioindicator of picloram in the environment and could be used in biomonitoring herbicide contamination.

Plastic production has experienced exponential growth in recent years due to its diverse industrial applications, low cost, and high availability, also causing issues, since plastic waste in aquatic ecosystems transforms into microplastics (MPs) through mechanical and weathering processes. Microplastics are distributed ubiquitously in water bodies, where they can be ingested by a wide aquatic organism range, including fish, which have been used as bioindicators to assess microplastic presence and toxicity. Research has revealed microplastic presence in various fish species worldwide; the most common characteristics are fibers and fragments of blue, black, and transparent colors, and polyethylene, terephthalate, polypropylene and cellophane chemical composition. Experimental studies under laboratory conditions have demonstrated microplastics impact on fish, showing physical, immunological, and hematological damage, and oxidative stress ultimately leading to organisms' death. However, laboratory results do not necessarily predict impacts on wild fish due to different conditions to which the organisms are exposed. Therefore, further research needs to simulate real scenarios faced by wild fish in the marine environment, providing greater certainty about microplastic impacts and negative effects.

N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and Zn²⁺, extensively used in the tire manufacturing process, are frequently detected in freshwater environments. However, the intergenerational effects of isolated 6PPD exposure and joint 6PPD and Zn²⁺ exposure at concentrations approximating environmental levels remain unknown. This study assessed the chronic toxicity and intergenerational effects of 6PPD (0.02-20 μg/L) and a mixture of 6PPD and Zn²⁺ (5 μg/L) over three generations in Daphnia magna bioassays. In the F0 generation, a dose-dependent decline in total offspring number was observed with 6PPD exposure alone, while co-exposure with Zn²⁺ exacerbated the reproductive toxicity of 6PPD. Across three generations, low-dose (0.02 µg/L) 6PPD alone and combined with Zn²⁺ induced a cumulative degenerative maternal effect. Conversely, high-dose (20 µg/L) 6PPD, both independently and in combination with Zn²⁺, exhibited an adaptive maternal effect. Notably, the grandmaternal effect emerged exclusively in the co-exposure group treated with 20 μg/L 6PPD and 5 μg/L Zn²⁺, with no such effect in the group exposed to 20 μg/L 6PPD alone, suggesting that Zn²⁺ may enhance the potential toxicity of 6PPD. Overall, this study provides novel insight into the intergenerational impacts of environmentally relevant levels of 6PPD alone and in combination with a heavy metal, elucidating the environmental risks posed by tire-derived chemicals through their synergistic effects on transgenerational toxicity.