Environmental Chemistry and Ecotoxicology最新文献

Ants (Formicidae) are ubiquitous in terrestrial ecosystems, including agricultural areas and forests. They are important for soil movement, decomposition, nutrient cycling, pollination, predation, scavenging and seed dispersal. Furthermore, they serve as a crucial food source for various wildlife. However, ants are no part of current ecotoxicity testing. Here, we systematically analyze whether and how ants can be exposed to active substances from plant protection products (PPPs) or genetically modified plants (GMPs). Like other arthropods, ants can be exposed via direct contact with PPPs after application, inhalation, uptake of contaminated drinking water or diet. For plant incorporated protectants (PIPs) expressed by GMPs, dietary exposure is the only relevant exposure route. Ants exhibit a diverse dietary spectrum, including plant material, honey dew collection, fungal cultivation, scavenging, and predation. Notably, foraging for dead or weakened arthropods, e.g., treated pest organisms, represents a significant exposure route because such food may be readily available in large amounts after spraying a field. Arthropods, alive or deceased, serve as the dominant protein source for numerous ant species, essential for larval development and the egg production of the queen(s). Consequently, exposure routes, via contaminated food items, can jeopardize entire ant colonies if it reaches the queen. However, effects arising from contaminated prey are not routinely assessed, neither for non-social nor for social insects such as the honey bee, which collects only nectar and pollen and is intensively tested in the assessment of PPPs. We conclude that ecotoxicity testing in ants would fill a gap and support the assessment of biodiversity effects. To achieve this, we recommend further research to explore the exposure of the different castes and developmental stages of ants in greater detail and to develop protocols allowing for ecological risk assessments of PPPs and PIPs via dietary uptake. This comprehensive approach will contribute significantly to our understanding of the potential consequences of PPP and GMP exposure to non-target ants.

Heavy metal contaminated soil is a common environmental pollution problem, which has a negative impact. The potential for the phytoremediation has been widely recognized. This study investigated the mechanisms of cadmium (Cd) absorption in Suaeda heteroptera Kitag., a dominant wetland plant in northern China. A hydroponic experiment was carried out to determine the Cd content in S. heteroptera roots after adding ion channel inhibitors and metabolic inhibitors. Furthermore, subcellular distribution and chemical forms of Cd in S. heteroptera were investigated. The results showed that Cd was mainly absorbed by S. heteroptera roots through calcium ion channels. Cd absorption by S. heteroptera roots was closely associated with the P-type ATPase, suggesting that Cd was actively absorbed by S. heteroptera roots. Cell wall precipitation and vacuole compartmentalization were the major mechanisms underlying absorption and tolerance to Cd. Cd in S. heteroptera root system was predominantly bound to proteins, pectinate, and phosphates, thereby reducing its toxicity. However, Cd was transformed into a highly active form and became more toxic at high concentrations.

Anodic decolorization of reactive dyes like Coomassie Brilliant Blue (CB), a triphenylmethane dye, Reactive Red 120 (RR 120) and Reactive Black 5 (RB 5), azo dyes, was investigated in a 300-ml H-type dual chamber Microbial Fuel Cell (MFC) using monoculture of a novel strain Pseudomonas gessardii DD1. The MFC setups were evaluated for power generation, electrochemical activity, dye decolorizing efficiency, and COD removal efficiency. The study revealed a maximum power density 474.06 mW/m² for RB 5 at 100 ppm concentration with 98.5% dye decolorization, while the maximum COD removal efficiency of 70% ± 2.9 was obtained. Cyclic voltammetry curves indicated the highest peak current of 1.8 mA for MFC operated using RB5. Maximum power density, in case of RR 120 and CB was 262.5 and 225.5 mW/m², with 63 and 65% COD removal, respectively. Efficient power generation and dye removal is seldom reported in the literature, as the electrons generated by exoelectrogens are consumed for dye reduction and subsequent breakdown or decolorization. The findings indicate that the MFC technology can be an easy and economical option for bioelectricity generation using dye-contaminated wastewater with simultaneous detoxification of toxic pollutants and hence sustainable treatment of industrial wastewater.

The effects of trophic cascades have made small-size pelagic fish species, such as Engraulicypris sardella, from Lake Malawi an important ecological and food system. However, human-induced activities can potentially pollute Lake Malawi exposing E. sardella to heavy metals contamination. This could pose a food system health risk to the population of Malawians and neighboring countries, which heavily rely on fish as a source of animal protein. Therefore, this study investigated the concentration levels of Lead (Pb), Cadmium (Cd), Zinc (Zn), Copper (Cu), Manganese (Mn), and Iron (Fe) in sun-dried E. sardella and conducted a health risk assessment associated with its consumption. E. sardella samples were collected from Karonga, Nkhata Bay, Nkhotakota, Salima, and Mangochi districts in Malawi between December 2023 and February 2024. The results revealed significant variations in Cd, Zn, Cu, Mn, and Fe concentrations among the sampled sites while Pb contamination was not detected. The concentrations of Zn, Cu, Mn, and Fe in E. sardella were within acceptable consumption limits set by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO) in 2012. However, the fish's average Cd levels (0.17 mg kg⁻¹ ww) were slightly above the recommended threshold of 0.1 mg kg⁻¹ ww by FAO/WHO (2012) but remained below the limit of 0.5 mg kg⁻¹ ww set by FAO in 1983. Furthermore, none of the analyzed heavy metals posed a health risk effect to people. Therefore, there is a need for regular monitoring of heavy metal concentrations in E. sardella and other mostly consumed fish species from Lake Malawi, both fresh and processed, for a sustained guarantee of the safety of the fish consumers.

As global surface water pollutants, tire-wear particles (TWPs) are increasingly concerning, with TWP leachate hepatotoxicity poorly understood. In this study, based on environmental TWP concentrations, TWP leachate exposure (0, 0.0005, 0.005, 0.05, and 0.5 mg/mL) in black-spotted frogs was investigated over a 21 day period. TWP leachates at realistic environmental levels disturbed intestinal microbiome homeostasis, which manifested as decreased and increased Chloroflexi and Proteobacteria abundance, respectively, and elevated lipopolysaccharide (LPS) levels in plasma. Also, the content of lipopolysaccharide-binding protein, the binding site of LPS, was increased, and downstream LPS immune pathways, such as toll-like receptor 4 (TLR4)-nuclear factor (NF)-κB (TLR4/NF-κB) signaling, were activated. Subsequently, inflammation reactions, oxidative damage, and histopathology were affected in liver samples. These results shed new light on the potential mechanisms underpinning TWP leachate-associated liver injury via the gut–liver axis, and contribute to a better understanding of emerging TWP ecotoxicology.

Liquid crystal monomers (LCMs) are synthetic organic chemicals widely used in the manufacture of liquid crystal displays (LCDs) of digital electronic devices. As human interactions with digital electronics such as computers and smartphones intensify, exposure to LCMs is a public health concern. Nevertheless, there is limited research on the occurrence of LCMs in biological and non-biological matrices. We developed a method to determine 60 LCMs in electronic-waste panels (i.e., computer monitors), indoor dust, feces, and urine using gas chromatography–mass spectrometry (GC–MS). Solid matrices (i.e., dust and feces) were extracted using a solid-liquid extraction (SLE) procedure whereas liquid matrices (i.e., urine) were extracted using solid phase extraction (SPE). Indoor dust and feces extracts were purified by passage through silica gel packed gravity columns. The method limits of detection (LODs) and quantification (LOQs) were in the ranges of 0.05–13.0 and 0.18–39.1 ng/mL, respectively. Recoveries of all target analytes fortified at concentrations of 10 and 100 ng/mL on LCD panels, dust, feces, and urine were in the range of 71–130%, with standard deviations of 0.01–33%. Repeated analyses of similarly fortified samples yielded intra-day and inter-day variations (CV) of 0.32–12.6% and 0.76–14.3%, respectively. Matrix effects, calculated from fortified matrices, ranged from −28.5% to 28.5%. The method was applied in the analysis of LCD panels, indoor dust, dog feces and urine, which were found to contain 22, 42, 46, and 18 of the 60 targeted LCMs, respectively. LCMs were found in LCD panels (∑LCM = 1780 ± 165 ng/cm² for desktop computer monitors; and 166,900 ± 80,100 ng/cm² for smartphone screens), indoor dust (∑LCM = 2030 ± 1260 ng/g), dog feces (∑LCM = 1990 ± 2000 ng/g dw), and urine (∑LCM = 24.0 ± 14.6 ng/mL). The developed method can be applied in the analysis of LCMs in a wide range of environmental and biological samples.