Archives of Environmental Contamination and Toxicology最新文献

Insects are impacted by pollutants in their environments and food sources. Herein, we set out a semi-field study to assess the impact of environmental heavy metal contamination on developmental parameters, energy reserves, and acidic and alkaline phosphatases in the larval Agrotis ipsilon (Lepidoptera: Noctuidae). Castor leaves from contaminated and uncontaminated (reference site) areas were fed to A. ipsilon larvae in all treatments. The heavy metal concentrations in the plant from different areas (contaminated and reference sites) and in the larvae were analyzed. Toxic effects were observed in the larvae feeding on the leaves from the metal contaminated areas. Larval and pupal weights, growth indices, and larval fitness were all significantly lower than in the reference group. Likewise, in the third and fourth instars, there was a significant decrease in both the survival and moth emergence rates. In contrast, the pupation duration was significantly longer. Total protein, lipid, and glycogen content showed significant reductions in treated larvae. Larval homogenate samples contaminated with heavy metals showed a significant increase in acid- and alkaline- phosphatase levels. The results obtained could provide a basis for a long-term evaluation of the risk associated with heavy metals and their impact on plant populations and important agricultural pests.

While in situ toxicity testing with caged organisms has been used to assess surface water and sediment contamination, no successful application to benthic organisms exposed to highly contaminated groundwater plumes discharging to surface waters has been reported. The objective of this study was to demonstrate and evaluate this application using four sets of tests performed at three previously reported contaminated groundwater sites, which include one river site affected by volatile organic contaminant plumes, and two sites, one pond and one small urban stream, impacted by landfill plumes. The study examined multiple cage designs and orientations and two test organisms: an amphipod (Hyalella azteca) and midge larvae (Chironomus riparius; only one study). Cages were deployed for between 5 and 28 days and assessed for organism survival and growth. At all sites and for some deployment conditions, cages exposed to high contaminant concentrations in the plume footprint had greater mortality compared to those exposed to lower or background concentrations. Organism growth was less clear as a metric of toxicity. Vertically oriented cages typically showed high mortality to plume contaminants, but some were also affected by other non-target groundwater conditions (e.g., low dissolved oxygen, other contaminant sources), while horizontally oriented cages were rarely responsive to either groundwater influence. A hybrid cage design showed much promise in its single study. Useful observations on the test organisms and on potentially problematic site conditions were also made. The informed use of in situ toxicity cages could be an additional beneficial tool for groundwater contaminated site assessments.

A set of quantum chemical descriptors (molecular polarization, heat capacity, entropy, Mulliken net charge of the most positive hydrogen atom, APT charge of the most negative atom and APT charge of the most positive atom with hydrogen summed into heavy atoms) was successfully used to establish the classification models for the toxicity pLC₅₀ of pesticides in Americamysis bahia. The optimal random forest model (Class Model A) yielded predictive accuracy of 100% (training set of 217 pesticides), 95.8% (test set of 72 pesticides) and 99.0% (total set of 289 pesticides), which were very satisfactory, compared with previous classification models reported for the toxicity of compounds in aquatic organisms. Therefore, it is reasonable to apply the quantum chemical descriptors associated with molecular structural information on molecular bulk, chemical reactivity and weak interactions, to develop classification models for the toxicity pLC₅₀ of pesticides in A. bahia.

Environmental stressors in aquatic organisms can be assessed using a bioenergetic approach based on the evaluation of changes in their physiological parameters. We evaluated the chronic effects of cadmium (Cd²⁺) on the energy balance as well as the survival, growth, metabolism, nitrogen excretion, hepatosomatic index, oxidized energy substrate, and osmoregulation of the shrimp Penaeus vannamei with the hypothesis that the high energy demand related to the homeostatic regulation of Cd²⁺could disrupt the energy balance and as a consequence, their physiological functions. The shrimp exposed to Cd²⁺ had higher mortality (30%), directed more energy into growth (33% of energy intake), ingested 10% more energy, and defecated less than control animals. Cd²⁺ exposure caused a tendency to decrease metabolism and ammonia excretion but did not alter the hepatosomatic index, type of energy substrate oxidized, and the hyperosmorregulatory pattern of the species. The Cd⁺² exposure may have induced a trade-off response because there was a growth rate increase accompanied by increased mortality.

Plastics are synthetic organic compounds whose widespread use generates enormous waste. Different processes, such as mechanical abrasion, microbiological activity, and UVB irradiation, can fragment the plastic material and generate microplastics (MPs). MPs are ubiquitous, and various organisms, including humans, can ingest or inhale them, with potential adverse health effects. The differences between UV-aged and virgin particles were studied to evaluate the genotoxic damage and oxidative stress induced by polystyrene MPs with 1 and 5 µm sizes on the monocyte-like cell line (THP-1). Fourier transform infrared spectroscopy and Ζ-potential measurements were used to characterise MP particles after UVB exposure. Cells exposed to MPs show a widespread change in the cellular environment with the generation of reactive oxidative species (ROS), as indicated by the increased malondialdehyde level. The occurrence of genotoxic damage is correlated to the smaller size and ageing state of the MPs. The biochemical and genomic alterations observed in this in vitro study suggest that MPs, ubiquitous pollutants, following natural degradation and oxidation processes can cause various adverse effects on the health of the exposed population, making it necessary to carry out further studies to better define the real risk.

Complex mixtures of chemicals present in groundwater at legacy-contaminated industrial sites can pose significant risks to adjacent surface waters. The combination of short-term molecular and chronic apical effect assessments is a promising approach to characterize the potential hazard of such complex mixtures. The objectives of this study were to: (1) assess the apical effects (survival, growth, development, and liver histopathology) after chronic exposure of early life stages (ELSs) of fathead minnows (FHM; Pimephales promelas) to contaminated groundwater from a legacy-contaminated pesticide manufacturing and packaging plant, and (2) identify possible molecular mechanisms responsible for these effects by comparing results to mechanistic outcomes previously determined by a short-term reduced transcriptome assay (EcoToxChips). This study revealed a significant increase in mortality and prevalence of spinal curvatures, as well as a significant reduction in the length of FHMs exposed to the groundwater mixtures in a concentration-dependent manner. There was an increasing trend in the prevalence of edema in FHMs, though not significantly different from controls. Additionally, no histopathological effects were observed in the liver of FHMs exposed to the groundwater mixtures. Short-term molecular outcomes determined in a parallel study were found to be informative of chronic apical outcomes, including cardiotoxicity, spinal deformities, and liver toxicity. Overall, the results observed in this study demonstrated that short-term transcriptomics analyses could support the hazard assessment of complex contaminated sites.

Graphical Abstract

Molecular outcomes were reflective of mortality and deformities, but uncertainties remained in the prediction of hepatotoxic effects at apical level.

The present study investigated the levels of As, Ag, Al, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Pb, Se, and Zn in muscle samples of six fish species (Pygocentrus nattereri, Serrasalmus marginatus, Mylossoma duriventre, Leporinus friderici, Pimelodus argenteus, and P. pantaneiro) highly consumed by local riverine and non-resident people in middle Miranda River, southern Brazilian Pantanal. Significant differences were detected for Ba, Fe, Mn, and Zn levels among the analyzed species. Pairwise comparison detected significant differences in element levels between species with similar diets, which implies that other factors, instead of species’ feeding habits, could be involved in distinct levels of element bioaccumulation. Significant correlations between body size and concentrations were found for Ba in P. nattereri (moderate positive correlation), and for Mn in M. duriventre (weak positive correlation) and P. argenteus (moderate negative correlation). Levels exceeding tolerable daily intake (TDI) were found for Pb maximum concentrations in P. nattereri, M. duriventre, L. friderici, P. argenteus, and P. pantaneiro, and for Cd maximum concentration in P. argenteus. Health risk assessment indicated considerable risk only for the worst-case scenario (calculated from maximum concentrations) for all species. Adopting a Pb monitoring program in biotic and abiotic compartments in Miranda River is strongly recommended.

Significant amounts of tailings and oil sands process-affected water (OSPW) are generated by bitumen extraction in the Alberta Oil Sands region. These by-products are potentially toxic to aquatic organisms and require remediation. The study site was Lake Miwasin, a pilot-scale pit lake integrated into broader reclamation efforts. It consists of treated tailings overlaid with blended OSPW and freshwater, exhibiting meromictic conditions and harboring aquatic communities. This study assessed the potential toxicity of Lake Miwasin surface water (LMW) and pore water (LMP) using saline-acclimated Cladocera, including lab strains of Daphnia magna and Daphnia pulex and native Daphnia species collected in brackish Humboldt Lake (HL) and Lake Miwasin (LM). The pore water evaluation was used to represent a worst-case water quality scenario during pond stratification. Additionally, the inclusion of native organisms incorporated site-specific adaptations and regional sensitivity into the toxicity evaluation. Our results showed that LMW did not display acute or chronic toxicity to lab species and native Daphnia sp. (HL). Conversely, LMP was acutely toxic to both lab species and native D. pulex (LM). In chronic tests (12 days exposure), LMP negatively affected reproduction in D. pulex (lab), with reductions in the number of offspring. Limited ability to acclimated organisms to the high salinity levels of LMP resulted in a shortened exposure duration for the chronic toxicity test. In addition to salinity being identified as a stressor in LMP, toxicity identification evaluation (TIE) phase I findings demonstrated that the observed toxicity for D. magna (lab) and D. pulex (LM, native) might be attributed to ammonia and metals in LMP. Further investigations are required to confirm the contributions of these stressors to LMP toxicity.

This study investigated the concentrations, seasonal variations, sources, and human health risks associated with exposure to heavy elements (As, Al, Pb, Cr, Mn, Cu, Zn, and Ni) of PM_2.5 at an urban location of Delhi (28° 38′ N, 77° 10′ E; 218 m amsl), India, from January 2013 to December 2021. The average mass concentration of PM_2.5 throughout the study period was estimated as 127 ± 77 µg m⁻³, which is exceeding the National Ambient Air Quality Standards (NAAQS) limit (annual: 40 µg m⁻³; 24 h: 60 µg m⁻³). The seasonal mass concentrations of PM_2.5 exhibited at the order of post-monsoon (192 ± 110 µgm⁻³) > winter (158 ± 70 µgm⁻³) > summer (92 ± 44 µgm⁻³) and > monsoon (67 ± 32 µgm⁻³). The heavy elements, Al (1.19 µg m⁻³), Zn (0.49 µg m⁻³), Pb (0.43 µg m⁻³), Cr (0.21 µg m⁻³), Cu (0.21 µg m⁻³), Mn (0.07 µg m⁻³), and Ni (0.14 µg m⁻³) exhibited varying concentrations in PM_2.5, with the highest levels observed in the post-monsoon season, followed by winter, summer, and monsoon seasons. Six primary sources throughout the study period, contributing to PM_2.5 were identified by positive matrix factorization (PMF), such as dust (paved/crustal/soil dust: 29.9%), vehicular emissions (17.2%), biomass burning (15.4%), combustion (14%), industrial emissions (14.2%), and Br-rich sources (9.2%). Health risk assessments, including hazard quotient (HQ), hazard index (HI), and carcinogenic risk (CR), were computed based on heavy elements concentrations in PM_2.5. Elevated HQ values for Cr and Mn linked with adverse health impacts in both adults and children. High carcinogenic risk values were observed for Cr in both adults and children during the winter and post-monsoon seasons, as well as in adults during the summer and monsoon seasons. The combined HI value exceeding one suggests appreciable non-carcinogenic risks associated with the examined elements. The findings of this study provide valuable insights into the behaviour and risk mitigation of heavy elements in PM_2.5, contributing to the understanding of air quality and public health in the urban environment of Delhi.

The larval fathead minnow, Pimephales promelas, 7-day subchronic survival and growth standard toxicity test method is commonly used for research and regulatory testing of effluents and compounds, including emerging contaminants such as Perfluorooctanesulfonic Acid (PFOS). Existing feeding guidelines for testing are described in multiple methods but are open to interpretation. The current study sought to determine the impact of feeding ration on P. promelas survival and biomass during a subchronic exposure to PFOS. The study was conducted in two phases: (1) a control experiment to determine the most significant feeding ration factors that maximize biomass, with consideration to laboratory logistics, and (2) application of down-selected feeding rations in a PFOS exposure to determine toxicity reference values. The control optimization study supported that feeding ration and feeding frequency were significant factors in fish biomass. In the subsequent PFOS study, fish were fed a high or low ration of Artemia twice daily, while exposed to 0.3 to 3.4 mg/L PFOS. Fish fed a high ration of Artemia had significantly (p < 0.05) greater biomass than fish fed a low ration in all exposure concentrations except 3.4 mg/L, where survival was low in both treatments. The feeding ration was not a significant factor on the survival endpoint for either treatment, but the PFOS concentration was (p < 0.0001) (high ration LC₅₀ = 2.44 mg/L; low ration LC₅₀ = 2.25 mg/L). These findings contribute to a better understanding of the impact feeding ration has in toxicity assessments and downstream regulatory decisions.