Environmental Toxicology and Chemistry最新文献

Human-managed green spaces in urban landscapes have become important focal points for insect conservation, partly because of the desirable insect diversity that these areas support, and also because exposure to nature is important for human health and wellbeing. An important issue in insect conservation is the extent to which nonpest insects are impacted by pesticide applications, but this has been relatively less examined outside of agricultural landscapes. Here, we investigated green spaces, including parks and private yards, in two urban areas (Sacramento, California, and Albuquerque, New Mexico, United States), asking if larval host plants for butterflies in the two regions contained herbicides, insecticides, and fungicides. We assayed 336 individual plants in 19 genera, including woody and herbaceous plants. Pesticide presence was ubiquitous: only 22 samples had no detectable levels of pesticides; the median number of compounds detected in the other 314 individual plants was three; and the maximum detected in any one plant was 18. Within Sacramento, azoxystrobin was detected in 84% of all samples, whereas atrazine was detected in 70% of samples within Albuquerque. Two compounds (azoxystrobin and chlorantraniliprole) were found to exceed concentrations that are known to cause lethal and sublethal effects in 71 out of 336 plants. Our results suggest that the effects of pesticides on nontarget species should be further explored in urban areas, and that nontarget effects on desirable insects are possible in these areas without thoughtful management and elimination of nonessential pesticide applications.

The bioaccumulation of metals can cause negative effects on the health status and body condition of wildlife. However, research in this field is strongly biased toward Europe and North America. Here, we investigate metal and metalloid concentrations in the feathers of a once common but now critically endangered migratory songbird, the Yellow-breasted Bunting (Emberiza aureola). Feathers were sampled in Thailand but most likely molted in China, where the species stops over during migration, and therefore likely relate to background pollution levels at these stopover sites. We detected chromium, copper, manganese, iron, lead, tin, and zinc (Zn) in 100% of the samples, whereas arsenic was detected in 9% and mercury as well as cadmium in 2% of the individuals. Most importantly, we found a weak but significant negative association of Zn concentration and individual body condition. Lower body condition could limit successful migration and ultimately lead to higher fitness costs and reduced survival in this threatened species. We call for studies to investigate whether elevated Zn exposure in Yellow-breasted Buntings is linked to mining activities or to the recent increase in Zn-biofortified rice planted in Asia to combat human Zn deficiency.

Following World Wars I and II, extensive dumping of conventional and chemical munitions in the marine environment has left a lasting impact on coastal areas, particularly those directly involved in the conflicts. Over the decades, corrosion of munition shells has resulted in the release and subsequent detection of a range of hazardous chemicals in environmental samples. These include conventional explosives and related compounds (E&RC), as well as chemical warfare agents and related compounds (CWA&RC). Despite this legacy, significant data gaps persist concerning the persistence, bioaccumulation, and toxicity of these chemicals to human and environmental health. In this study, we applied an updated and expanded suite of (quantitative) structure-activity relationship, or (Q)SAR, tools-Ecological Structure-Activity Relationships Program Version 2.2, Estimation Program Interface Suite Version 4.11, and Organisation for Economic Co-operation and Development (Q)SAR Toolbox Version 4.5-to comprehensively and simultaneously screen and prioritize a broad range of E&RC and CWA&RC detected in environmental samples from global munition dumpsites. To our knowledge, this is the first application of this combined, up-to-date toolchain to field-detected munition compounds. Our results demonstrate that (Q)SAR models can generate conservative estimations useful for the prioritization of munition-related chemicals for further investigation, although the reliability for specific endpoints may vary by the available empirical data. We underline that trinitrotoluene and its metabolites, followed by tetryl and picric acid (all E&RC), require urgent monitoring in the environment and seafood, alongside defined human health safety thresholds in key exposure sources. In addition, sulfur mustard, arsenical CWA, and their metabolites should be prioritized for targeted human health and long-term environmental studies. This comprehensive screening approach addresses long-standing data gaps, providing a valuable framework for decision makers engaged in the management and remediation of munition dumpsites.

Riparian predators integrate both nutrients and contaminants from neighboring aquatic systems through their predation of emerging aquatic insects. The reliance of some riparian taxa on aquatic subsidies has led to them to being utilized as biosentinels of aquatic contamination, often justified through stable isotope studies (δ13C, δ15N) and trophic magnification models. However, evidence suggests that both isotopic signatures and contaminant burdens can be altered during insect metamorphosis, which could propagate to riparian predators. Here, we measured total mercury and δ15N in riparian and aquatic organisms in the headwater streams of southern Appalachia to compare biomagnification in both systems. We found that biomagnification rates were similar, but that mercury concentrations in riparian organism were approximately six times higher than neighboring aquatic organisms. We propose possible ecological mechanisms, occurring separately or simultaneously, that might explain these surprising observations: (1) metamorphosis bioamplifies mercury, (2) metamorphosis enriches δ15N values, and/or (3) the fractionation of δ15N that occurs during predation is less for the observed riparian predators than for the aquatic organisms. Further study is needed to elucidate the exact mechanism driving elevated mercury concentrations in riparian predators.

Broflanilide (BFL) is a new bis-amide insecticide that binds to γ-aminobutyric acid receptor, has attracted widespread attention because of its high efficiency, broad spectrum, and novel mechanism of action. It is widely used, which may pose short or long-term safety risks to humans or the environment. This study focuses on the toxic effects of commercial BFL formulation on the human neuroblastoma cell line (SH-SY5Y) in vitro. The 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide method, flow cytometric analysis, fluorescent staining method, immunofluorescence, single-cell gel electrophoresis, and protein immunoblotting were carried out for this study. The results showed that the commercial BFL formulation could cause mitochondrial damage (the collapse of mitochondrial membrane potential and the opening of mitochondrial permeability transition pore), DNA damage (DNA single-strand breaks, DNA double-strand breaks, and oxidative DNA damage), alter the expression of related proteins, and induce mitochondria-mediated apoptosis. And the cytotoxicity of the BFL formulation is mainly caused by the active ingredient BFL. In conclusion, this study provides a theoretical basis for the damage of BFL to human cells. To our knowledge, this is the first report of the toxic effects of BFL or its formulation on human cells, which suggests the possible security risk of BFL on human beings and attracts more people's attention to its environmental toxicity effects.

A realistic release estimation is key when assessing whether the use of a chemical can be considered environmentally safe. For practically all industrial, professional, and consumer use patterns, air emission measurements are absent or available for only one or, at best, a handful of volatile chemicals. When such empirical data are used in the release estimation of other chemicals, environmental risks will be underpredicted for more volatile chemicals or unnecessarily overpredicted for less volatile chemicals. This short communication describes a pragmatic method to extrapolate release rates between chemicals with different physicochemical properties used under similar conditions. This method, which is is based on boundary layer theory and has been confirmed with empirical data, is applicable to evaporative release from liquids and semisolids. To demonstrate the value and ease of use of the boundary layer theory-based method in improving environmental risk assessments, we used this method to generate vapor pressure specific air release factors for hydrocarbons used as industrial laboratory reagents.

Phthalates (PAEs) are high-production synthetic compounds primarily used as plasticizers in plastic products to help with manufactured substance flexibility, pliability, and reduce environmental degradation. Phthalates have been detected in various manufactured goods ranging from food packaging to personal care products to water bottles. Unfortunately, recent studies have shown evidence of endocrine disruption and adverse effects on reproductive systems following PAE exposure in both males and females. This study aimed to quantify PAE residues that leached from polyethylene terephthalate bottles into drinking water over a 35-day period placed either in an indoor UV chamber or outside. Using gas chromatography/mass spectrometry coupled with direct immersion solid phase microextraction fibers, the highest total PAE concentration in bottles exposed indoors was 451 ± 366.5 µg/L with butyl benzyl phthalate (BBP) concentrations being the highest individual concentration (297.6 ± 284.3 µg/L). In the outdoor exposure group, the highest total PAE concentration was 546.7 ± 217.5 µg/L, with BBP being at the highest concentration (395.4 ± 189.3 µg/L). A subsequent risk assessment was conducted quantifying the risk associated with adults consuming leachate found in bottled water in various countries across North America, Asia, and Europe. Using standard reference values and experimental values expressed here, it was found that there was no calculated risk associated with consuming this bottled water.

Identifying new contaminants of emerging concern remains a complex task due to the sheer number of chemical substances potentially released into the environment, the scattered sources of information, and often the lack of adequate data. Environmental screening and monitoring programs are designed to map the presence, sources, and potential environmental impacts of contaminants, yet prioritizing which chemicals to include in such efforts remains resource-intensive and technically challenging. PikMe is a modular, open-access prioritization tool that integrates information from major data bases and evaluates the concern and reliability of the data for more than one million substances. PikMe is built in a modular way so that prioritization can be done based on specific chemical properties relevant to a given scenario (i.e., drinking water contaminants or bioaccumulation in biota) rather than assigning only a global risk score. PikMe scores substances based on persistence, bioaccumulation, mobility, environmental toxicity, and human toxicity, assigning individual score per property. Additionally, PikMe is designed for flexibility by allowing the integration of external lists of chemicals and supporting optional add-ons. Different scenarios of use are described in this article, including the selection of chemicals for environmental monitoring and screening in Norway and the assessment of the implications of the new classifications according to the regulation for classification, labelling and packaging of substances and mixtures on persistent chemicals.

In a previous article, we developed quantitative ion character-activity relationships (QICARs) to relate the intrinsic properties of a metal to its acute toxicity towards freshwater aquatic organisms. These predictive tools were developed for a set of data-rich training elements and then applied to a representative selection of technology-critical elements (TCEs). The toxicity of the TCEs was reasonably well predicted, with most values located within the 95% prediction intervals. In this work, we have extended this approach to use the calculated metal speciation. Linear free energy relationships were used to estimate some of the needed thermodynamic constants. Using this information, we expressed the concentration resulting in a 50% effect level value as free metal activities and performed regression analyses. For the training metals, the determination coefficients slightly increased compared with those obtained using the total dissolved metal. As before, the log-transformed composite value of the covalent index (χm2r) was the best predictor of their acute toxicity towards algae and daphnids (χm = metal's electronegativity; r = ionic radius). However, for the TCEs, the regressions were much poorer, particularly when the predicted free metal ion concentrations were very low (e.g., < 10-18 M). We suggest that this result reflects the distinctive speciation of these metals, where (i) the free metal ion is present only at vanishingly low concentrations (the calculation of which is problematic) and (ii) in all but one case (Au(CN)2-), the metal's calculated speciation is dominated by neutral polyhydroxo species (e.g., Au(OH)30, Ge(OH)40…). In our view, this result does not undermine the use of QICARs. Rather, the use of QICARs revealed that free-ion activity could be inadequate for predicting the toxicity of the studied data-poor metals.

Approximately 30% of global food production relies on crops that depend on pollinators. In the Neotropics, Meliponini bees are generalist pollinators, contributing to the pollination of up to 90% of the native flora. Partamona helleri is a eusocial stingless bee that plays a crucial role in pollinating several economically significant plants. However, various factors, particularly exposure to insecticides, are driving the population decline of these insects. Thiamethoxam is a neurotoxic neonicotinoid that acts on nicotinic acetylcholine receptors but can also affect other organs, such as the midgut, through ingestion. This study assessed the effects of acute oral exposure to thiamethoxam on the behavior, midgut, and oxidative stress of P. helleri workers. The bees were orally exposed for 72 hr to sublethal concentrations (LC) of thiamethoxam corresponding to LC5 and LC50. The results revealed that thiamethoxam exposure altered the bees' behavior, affecting their traveled distance and meandering activity. Additionally, the insecticide caused histopathological alterations in the midgut epithelium of workers, including cytoplasmic vacuolization, nuclear pyknosis, and release of cell fragments to the gut lumen secretion. Both LC5 and LC50 concentrations induced oxidative stress, as evidenced by changes in detoxification enzyme activity and antioxidant markers. These findings indicate that sublethal concentrations of thiamethoxam negatively impact P. helleri workers, potentially compromising individual survival and colony health.