Environmental Sciences Europe最新文献

Background

The aim of environmental risk assessment (ERA) for pesticides is to protect ecosystems by ensuring that specific protection goals (SPGs) are met. The ERA follows a prospective tiered approach, starting with the most conservative and simple step in risk assessment (RA) (so-called tier 1) using the lowest available appropriate endpoint derived from ecotoxicological tests. In 2015, for the tier 1 RA of aquatic primary producers, the recommendation was changed from using the lowest of the 50% inhibition (EC50) values based on biomass (area under the curve—E_bC₅₀), increase in biomass (yield- E_yC₅₀) or growth rate (E_rC₅₀) to only using the growth rate inhibition endpoint (E_rC₅₀) because it is independent of the test design and thus more robust. This study examines the implications of this such on the level of conservatism provided by the tier 1 RA and evaluates whether it ensures a suitable minimum protection level.

Results

Our analysis shows that replacing the lowest endpoint with the growth rate inhibition endpoint while maintaining the assessment factor (AF) of 10 significantly reduces the conservatism in the tier 1 RA. Comparing protection levels achieved with different endpoints reveals that the current assessment is less protective. To maintain the previous level of protection, and since the protection goals have not changed, we recommend to multiply the default AF of 10 by an extra factor of minimum 2.4 in the tier 1 RA based on E_rC₅₀. Independently of the endpoint selected in tier 1 RA, several issues in the general RA of pesticides contribute to uncertainties when assessing the protection levels, e.g., lack of appropriate comparison of the higher tier experimental studies (i.e., best achievable approximation of field situation, so-called surrogate reference tier) with field conditions or the regulatory framework's failure to consider realistic conditions in agricultural landscapes with multiple stressors and pesticide mixtures.

Conclusions

We advise to consider adjusting the risk assessment in order to reach at least the previous protection level for aquatic primary producers. Indeed continuing using an endpoint with a higher value and without adjustment of the assessment factor is likely to jeopardize the need of halting biodiversity loss in surface waters.

Background

Tetrabromobisphenol A (TBBPA) can be characterized as an endocrine-disrupting chemical (EDCs). It has been widely used as a brominated flame retardant in industrial products. EDCs have effects on female reproduction leading to issues, such as infertility, hormone imbalance, and endometriosis. In Korea, the problems of infertility and decreasing birth rate are of significant concern. Exposure to EDCs might have a harmful effect on female fertility by mediating a decrease endometrial receptivity. This study aimed to investigate the effects of TBBPA on infertility, particularly on early implantation events in the uterine endometrium. Human endometrial adenocarcinoma and trophoblastic cell lines were used in this study. The cytotoxicity of TBBPA on Ishikawa cells and Jeg-3 cells was measured using the Cell Counting Kit-8 assay. The mRNA expression was analyzed by reverse transcription-quantitative polymerase chain reaction, and protein levels were measured by western blotting. The attachment rate was analyzed using an attachment assay, and the outgrowth area was measured using an outgrowth assay.

Results

The mRNA expression of interleukin (IL)-6, IL-1β, tumor necrosis factor-α, and leukemia inhibitory factor was significantly increased upon treatment of Ishikawa cells by TBBPA. Moreover, the outgrowth area in the TBBPA group was significantly decreased compared to that in the control. In contrast, TBBPA had a minor effect on protein levels and attachment rates.

Conclusions

In this study, TBBPA induced an inflammatory milieu in mRNA expression. An increase in inflammation-related cytokines in the endometrium can disrupt embryo implantation. TBBPA disrupted the outgrowth of spheroids in the endometrium; however, the protein levels and attachment rate were comparable to those in the control group. The effect of TBBPA on implantation events should be elucidated further.

Background

Persistence assessment is a cornerstone of chemical hazard and risk assessment in numerous regulatory frameworks, as the longevity of a substance in the environment relates to exposure and ultimately the risk it poses. A chemical that is readily biodegradable is commonly assumed to undergo rapid and ultimate biodegradation under most environmental conditions. Ready biodegradability tests (RBT), such as the OECD 301 test series, are used to quickly screen out non-Persistent substances and focus regulatory scrutiny on the most hazardous substances. The stringency of the RBT as a screen for all environmental compartments is paramount to ensure that there are no readily biodegradable yet Persistent substances. To assess this stringency in practice, we here describe a systematic comparison of substances with both RBT data and biodegradation simulation test data for soil, sediment, or water compartments to see whether there are any substances which are readily biodegradable yet meet EU REACH regulatory Persistence criteria in any specific environmental compartment.

Results

A rough assembly of data extracted from the ECHA database showed that, out of 263 substances with both RBT and simulation test data, there were 19 substances that were readily biodegradable but Persistent (based on the most conservative result and after a temperature adjustment to the half-life). However, many of the underpinning simulation study information were either not high-quality guideline studies or the substances were UVCBs. To more accurately compare the RBT and simulation testing outcomes, quality criteria on the RBT and simulation tests were applied, which limited the data set to about one-third.

Conclusions

When examining quality-screened, temperature-adjusted simulation testing half-lives for readily biodegradable substances, there were no readily biodegradable substances that were Persistent. A side-by-side comparison of the available data supports the stringency and effectiveness of RBTs to identify non-Persistent chemicals.

This study investigated the potential of utilizing both the draw and feed solutions resulting from fertilizer drawn forward osmosis for hydroponic crop cultivation. Synthetic brackish groundwater of 2500 ppm was used as the feed solution, whereas commercial hydroponic nutrients, sourced from a local supplier, were utilized as a draw solution. This study also investigated the potential of integrating nanofiltration with forward osmosis, but supplementing the water necessary for further dilution of draw solutions through nanofiltration. Two crops were selected, i.e., cherry tomatoes and spinach grown at different water salinities, for their economic values. The cherry tomatoes were grown in Deep Water Culture hydroponic systems, while the spinach was grown in Nutrient Film Technique systems. If this application is deemed feasible, it allows for providing a method to grow two different crops in areas associated with non-arable land and brackish groundwater. During desalination, it was observed that there were two groups of flux readings, the first with an average flux of 7 to 9 l/m²/h, and the other with an average flux of 4 to 6 l/m²/h. This was due to using the same draw solution twice; once to concentrate the feed solution to 5000 ppm, and then once more to concentrate the feed solution to 3500 ppm. It was found that while the 3500 ppm cherry tomatoes tables had the highest yield and highest number of tomatoes throughout the plants lifetime, tomatoes from freshwater tables on average weighed more by about 19%, while, on average, 5000 ppm tomatoes weighed less than 3500 ppm tomatoes by 10%. The results of the spinach demonstrated that while both control and experiment groups yielded similar number of leaves, the average yield per plant for the experiment group was higher than the control group (by 25%).

High soil evaporation levels are a major contributor to loss of soil moisture in arid and semiarid regions globally. Therefore, it is important to use effective measures to slow the evaporation from farmland soils. We applied various amounts of straw biochar (BC) in a soil column experiment and a field experiment to study the influence of BC on soil evaporation and moisture content, respectively, to improve the water use efficiency of cultivated soil in arid areas. The addition of BC reduced soil evaporation and delayed water loss from the soil by evaporation. In the field experiment, cumulative evaporation in the treatments declined by 9.58% (Bo-10), 10.95% (Bo-30), and 4.2% (Bo-50) compared with that in the control group, demonstrating that 30 t/hm² BC is the most effective at suppressing soil evaporation. BC also delayed the time required for the soil moisture content to drop to field capacity and increased the upward transport of water from the deeper soil layers at night. Data from continuous monitoring of moisture content for 3 days during each growth period revealed that the increases in moisture replenishment were 18.52–79.62% at the seedling stage, 55.81–202.38% at the jointing stage, 270.83–587.5% at the tassel stage, and 6.66–61.64% at the maturation stage; hence, BC was shown to work best at the tassel stage.

Membrane filtration exhibit operational limitations such as biofouling, which leads to concentration polarization and reduces permeability and selectivity, despite advantages such as low operating cost, high selectivity, and permeability. In recent years, the antibacterial properties of silver nanoparticles (AgNPs) have been investigated for improving membrane processes; however, the fouling phenomena in presence of AgNPs in the membrane matrix have not been fully discussed. Herein, the antifouling properties of a poly (acrylonitrile-styrene) copolymer incorporated with AgNPs were studied in a microfiltration membrane process. The Creighton method was used to synthesize AgNPs, and the effects of AgNPs on the porosity, morphology, pore size, mechanical strength, permeability, and selectivity of the membranes were investigated. Moreover, to investigate the biofouling of the obtained membranes, microfiltration of industrial oily wastewater was performed at constant pressure over three cycles. Using AgNPs in the membrane matrix resulted in enhanced antifouling properties of the copolymer membrane, which is related to the structure of the AgNPs in the casting solution, as proven by SAXS analysis. The results show that the CFU% for Staphylococcus aureus and E.coli reach 2% and 6%, respectively. Finally, the Derjaguin–Landau–Verwey–Overbeek (DLVO) thermodynamic model was applied to study the antifouling mechanism, correctly predict the separation behavior in the membrane, and design, simulate, and optimize the separation processes in the membrane separation plantsa. The DLVO model could predict the separation behavior in the synthesized membranes, and the poly(acrylonitrile-styrene) copolymer membranes containing AgNPs were proven have promising industrial wastewater treatment applications.

Background

Plastic greenhouse farming has become widespread worldwide because of its contributions to various agricultural production. However, it also generates plastic waste in large quantities and pollutes farmlands. Contrary to studies on microplastics, few studies have quantified macroplastic contamination in agricultural farmlands despite its contribution to the production of microplastics through fragmentation. Thus, there is a paucity of knowledge on the levels and characteristics of macroplastics in greenhouse environments. Thus, this study aimed to quantify and examine the macroplastic litter on soil surfaces under fallow greenhouse farmlands.

Results

The study was conducted at three sites in Southern Hungary, where the usage of plastic greenhouses is very common for cultivating vegetables. On the studied fallow plots, the overall mean abundance of macroplastics was 431 pieces/ha or 6 kg/ha. Most of the fragments had 0.5- to 5-cm sizes. The macroplastic fragmentation in the area was well detected and was an ongoing process. The dominant plastic types were polyethylene and polyvinyl chloride in the form of films and fragments. The results showed that agricultural litter comprised 90% of the total contamination, whereas nonagricultural litter (10%) due to illegal littering also appeared on the plots.

Conclusions

Given that macroplastics were found in the studied greenhouse farmlands, we recommend the following: (1) careful cleaning and disposal of plastics on greenhouse farmlands and (2) prevention of greenhouse farmland contamination by external and nonagricultural contaminants. Besides, further research is needed to elucidate the duration of macroplastic fragmentation to microplastic contaminants in greenhouse environments.

Background

Fungicides are frequently used in agriculture and can enter freshwater ecosystems through multiple pathways. The negative impacts of fungicides on microorganisms, fungi in particular, and their functions such as leaf decomposition have been repeatedly shown. In our previous microcosm experiment with three consecutive cycles of fungicide exposure and colonisation of leaf substrate, we found clear functional changes, but no differences in fungal community structure could be detected using morphological identification by analysing the spores of aquatic hyphomycetes. In this study, we examined the effects on fungal and bacterial community composition in detail using ITS and 16S metabarcoding and comparing the results to morphologically assessed community composition.

Results

While we found fewer species with metabarcoding than with morphological identification, metabarcoding also enabled the identification of several fungal species that were otherwise unidentifiable morphologically. Moreover, by distinguishing individual amplicon sequence variants (ASVs) metabarcoding provided greater taxonomic resolution. In line with the morphological results, metabarcoding neither revealed effects of fungicides on the aquatic hyphomycetes nor on the total fungal or bacterial community composition. However, several ASVs responded significantly to fungicides, demonstrating variable tolerances within species.

Conclusions

Overall, the absence of detectable effects of fungicides on the community structure despite clear functional effects, suggests a complex relationship between community structure and the ecosystem function of leaf decomposition.

Contamination of heavy metals and antibiotics would threaten the water and soil resources. Phytoremediation can be potentially used to remediate metal and antibiotics contaminated sites. The current study was carried out over a period of 12 months to assess the efficiency of the macrophytes Typha domingensis and Cyperus papyrus with different substrate materials to remove heavy metals and two antibiotics, roxithromycin and levofloxacin, from wastewater for reuse in agriculture. The concentrations of seven heavy metals (copper, nickel, iron, cadmium, zinc, lead, and chromium) in water and plant tissues were determined. The results showed that C. papyrus had a greater capacity than T. domingensis to remove biochemical oxygen demand (BOD) (80.69%), chemical oxygen demand (COD) (69.87%), and ammonium (NH⁴⁺) (69.69%). Cyperus papyrus was more effective in retaining solid pollutants. The bioaccumulation factors (BCF) roots of C. papyrus were higher levels of most metals than those of T. domingensis. The highest root–rhizome translocation factor (TF) values of C. papyrus were higher than T. domingensis. The bacterial indicators (total and fecal coliforms, as well as Faecal streptococci) and the potential pathogens (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa) showed removal efficiencies ranging between 96.9% and 99.8%. The results indicated that the two systems could significantly reduce the concentration of antibiotics in wastewater, with roxithromycin showing higher elimination rates than levofloxacin. The results showed maximum removal of the heavy metals in constructed wetlands CWs planted with T. domingensis. The presence of zeolite and C. papyrus in the effluent of CWs significantly improved treatment capacity and increased pollutant removal efficiency.