Transfer and bioaccumulation of chemical and biological contaminants in the marine polychaete Hediste diversicolor (OF müller 1776) when reared on salmon aquaculture sludge.

Side streams from aquaculture production such as fish sludge poses ample opportunities for biological upcycling, as the sludge contains high amounts of nutrients, energy and valuable biochemicals, making it an ideal food for extractive species. Sludge has been proposed as a feed stock for polychaete production, which in turn can be utilized live in shrimp aquaculture or as an aquafeed ingredient. However, the biosafety of such value chains has not yet been addressed. We conducted an experiment exposing the polychaete Hediste diversicolor to aquaculture sludge spiked with four different fish pathogens (Mycobacterium salmoniphilum, Yersinia ruckeri, Infectious Pancreatic Necrosis (IPN) and Infectious Salmon Anaemia (ISA)) known to cause diseases in Atlantic salmon (Salmo salar L.). Moreover, we assessed whether heavy metals and other potentially hazardous elements present in fish sludge bioaccumulates in the polychaetes. Neither of the bacteria nor viruses could be detected in the polychaetes after 14 days of continuous exposure. Seven of the 15 elements we analysed showed bioaccumulation factors significantly below one, meaning biodilution, while the other eight did not differ from one, meaning no bioaccumulation. None of the elements showed a significant bioaccumulation. Further on, none of the heavy metals found in the polychaetes at the end of our experiment exceeded the EU regulatory maximum levels for fish feed ingredients. The current results suggest that a H. diversicolor can reared on aquaculture sludge, and aquaculture sludge may serve as feed stock for polychaete production without the product exceeding EU regulations for contaminants in animal feed.

Identifying pathways of pharmaceutical exposure in a mesoconsumer marine fish.

Pharmaceutical uptake involves processes that vary across aquatic systems and biota. However, single studies examining multiple environmental compartments, microhabitats, biota, and exposure pathways in mesoconsumer fish are sparse. We investigated the pharmaceutical burden in bonefish (Albula vulpes), pathways of exposure, and estimated exposure to a human daily dose. To evaluate exposure pathways, the number and composition of pharmaceuticals across compartments and the bioconcentration in prey and bonefish were assessed. To evaluate bioaccumulation, we proposed the use of a field-derived bioaccumulation factor (fBAF), due to variability inherent to natural systems. Exposure to a human daily dose was based on bonefish daily energetic requirements and consumption rates using pharmaceutical concentrations in prey. Pharmaceutical number and concentration were highest in prey, followed by bonefish, water and sediment. Fifteen pharmaceuticals were detected in common among bonefish, prey, and water; all of which bioconcentrated in prey and bonefish, and four bioaccumulated in bonefish. The composition of detected pharmaceuticals was compartment specific, and prey were most similar to bonefish. Bonefish were exposed to a maximum of 1.2 % of a human daily dose via prey consumption. Results highlight the need for multicompartment assessments of exposure and consideration of prey along with water as a pathway of exposure.

Accumulation of heavy metals from single and combined olive mill wastewater and pomace in soil and bioaccumulation in tissues of two earthworm species: Endogeic (Aporrectodea trapezoides) and Epigeic (Eisenia fetida).

Soil and earthworms are threatened by anthropogenic contamination resulting from olive mill waste dumping on the soil due to their pollutant properties. While several studies have explored the effects of olive mill waste on soil properties and the accumulation of heavy metals in soil, there is currently a gap in the literature regarding the potential bioaccumulation of heavy metals from olive mill waste in earthworms. In this study, soil with earthworms from two ecological categories (endogeic: Aporrectodea trapezoides and epigeic: Eisenia fetida) was treated with increasing doses of olive mill wastewater (OMWW) and olive mill pomace (OMP), applied individually or combined, in an indoor experiment in plastic containers, under laboratory conditions. The results revealed the presence of significant concentrations of heavy metals in the two types of wastes ranging as follows: Fe˃ Zn˃ Cu˃ Cd˃ Cr for OMWW, and Fe˃ Zn˃ Cu˃ Cr for OMP (with Cd below the detection limit). The study demonstrated distinct effects of OMWW and OMP, both individually and in combination, on soil heavy metal content, ranging as follows: soil OMWW > soil Combination > soil OMP for Cd; soil Combination > soil OMWW > soil OMP for Cr and Fe; and soil Combination > soil OMP > soil OMWW for Cu and Zn. Additionally, our investigation showed that both earthworm species exhibited significant uptake of these metals into their tissues, particularly the endogeic species. Interestingly, the most significant difference between species was in the accumulation of Cu, with the epigeic species accumulating significantly lower amounts.

Persistent and Bioaccumulative Halogenated Natural Products in Various Tropical Reef Fish Species from the Seychelles, Western Indian Ocean.

Gas chromatography with electron capture negative ion mass spectrometry (GC/ECNI-MS) was used to quantify and compare halogenated natural products (HNPs) and selected anthropogenic persistent organic pollutants (POPs) in individual samples of 17 fish species from the Seychelles (Western Indian Ocean). The sum-HNP amounts (9.5-1100 ng/g lipid mass (lm)) were between 1 and 2 orders of magnitude higher than those of the sum of seven abundant polychlorinated biphenyl (PCB) congeners (0.2-15 ng/g lm) and dichlorodiphenyltrichloroethane-related compounds (DDTs) (<1.1-43 ng/g lm). Within the group of HNPs, the two tetrabrominated phenoxyanisoles (aka methoxylated diphenyl ethers, MeO-BDEs), 2'-MeO-BDE 68 ≫ 6-MeO-BDE 47, were predominant in most cases. Pearson correlation analysis showed that MeO-BDE levels were positively correlated with less abundant HNPs (2,2'-diMeO-BB 80, 2',6-diMeO-BDE 68, and Br6-DBP) (p < 0.01). Accordingly, HNPs, rather than PCBs and DDTs, were the predominant polyhalogenated contaminants in the current species.

Investigating the carcinogenic and non-carcinogenic health hazards of heavy metal ions in Spinacia oleracea grown in agricultural soil treated with biochar and humic acid.

This study addressed the bioaccumulation and human health risk among the consumption of Spinacia oleracea grown in agricultural soil treated with humic acid (189-2310 ppm) and biochars (0.00-5.10%.wt). The biochars came from two local feedstocks of rice-husk (RH) and sugar-beet-pulp (SBP) pyrolyzed at temperatures 300 and 600 °C. Total concentrations of Cu, Cd, and Ni found in both the soil and biomass/biochar exceeded global safety thresholds. The bioaccumulation levels of HMs in spinach leaves varied, with Fe reaching the highest concentration at 765.27 mg kg-1 and Cd having the lowest concentration at 3.31 mg kg-1. Overall, the concentrations of Zn, Cd, Pb, and Ni in spinach leaves exceeded the safety threshold limits, so that its consumption is not recommended. The assessment of hazard quotient (HI) for the HMs indicated potential health hazards for humans (HI > 1) from consuming the edible parts of spinach. The biochar application rates of 4.35%wt and 0.00%.wt resulted in the highest (3.69) and lowest (3.15) HI values, respectively. The cumulative carcinogenic risk (TCR) ranged from 0.0085 to 0.0119, exceeding the cancer risk threshold. Introducing 5.10%wt biomass/biochar resulted in a 36% rise in TCR compared to the control. The utilization of humic acid alongside HMs-polluted biochars results in elevated levels of HMs bioaccumulation exceeding the allowable thresholds in crops (with a maximum increase of 49% at 2000 ppm humic acid in comparison to 189 ppm). Consequently, this raised the HI by 46% and the TCR by 22%. This study demonstrated that the utilization of HMs-polluted biochars could potentially pose supplementary health hazards. Moreover, it is evident that the utilization of HMs-polluted biochars in treating metal-contaminated soil does not effectively stabilize or reduce pollution.

Aquatic toxicity, bioaccumulation potential, and human estrogen/androgen activity of three oxo-Liquid Organic Hydrogen Carrier (oxo-LOHC) systems.

The Liquid Organic Hydrogen Carrier (LOHC) technology offers a technically attractive way for hydrogen storage. If LOHC systems were to fully replace liquid fossil fuels, they would need to be handled at the multi-million tonne scale. To date, LOHC systems on the market based on toluene or benzyltoluene still offer potential for improvements. Thus, it is of great interest to investigate potential LOHCs that promise better performance and environmental/human hazard profiles. In this context, we investigated the acute aquatic toxicity of oxygen-containing LOHC (oxo-LOHC) systems. Toxic Ratio (TR) values of oxo-LOHC compounds classify them baseline toxicants (0.1 < TR < 10). Additionally, the mixture toxicity test conducted with D. magna suggests that the overall toxicity of a benzophenone-based system can be accurately predicted using a concentration addition model. The estimation of bioconcentration factors (BCF) through the use of the membrane-water partition coefficient indicates that oxo-LOHCs are unlikely to be bioaccumulative (BCF < 2000). None of the oxo-LOHC compounds exhibited hormonal disrupting activities at the tested concentration of 2 mg/L in yeast-based reporter gene assays. Therefore, the oxo-LOHC systems seem to pose a low level of hazard and deserve more attention in ongoing studies searching for the best hydrogen storage technologies.

Vermi-remediation impacts on growth and metals bioaccumulation in tomato irrigated with wastewater.

Due to their persistence in the environment, and their highly toxic and bioaccumulative nature, heavy metals are well known to the environment. Vermicompost has gained popularity because it improves soil properties and, most importantly, remediates and immobilizes heavy metals. The present study assessed vermicompost effects on heavy metal bioaccumulation in tomato plants irrigated with wastewater. A plastic bag experiment was carried out with 5 kg of growing media in each bag. Growing media contain garden soil with four levels of vermicompost mixed at 0%, 5%, 15%, and 25%. The pots were irrigated with wastewater from different industries and tap water, which was taken as control. Wastewater was collected from the pharmaceutical industry, plastic industry, and sewage water of Hayatabad Industrial Estate, Peshawar. Vermicompost application significantly affected all tomatoes' growth attributes and heavy metals concentration. Results revealed that minimum Cd (2.48 mg kg-1), Cr (1.27 mg kg-1), Cu (4.10 mg kg-1), and Pb (0.62 mg kg-1) concentrations were recorded in tomatoes cultivated in 25 % vermicompost amended soil, while, maximum Cd (5.23 mg kg-1), Cr (2.29 mg kg-1), Cu (8.84 mg kg-1) and Pb (2.18 mg kg-1) concentrations were reported in sewage water irrigated plants., Overall, vermicompost applied at 25% significantly enhanced plant growth and yield, reducing the bioavailability and bioaccumulation of heavy metals. From the finding of this study, it is observed that wastewater irrigation of plants should be avoided because of the high level of heavy metals; in contrast, the application of vermicompost is highly recommended as compost reduces heavy metals bioaccumulation and enhances productivity.

Harnessing plant-beneficial bacterial encapsulation: A sustainable strategy for facilitating cadmium bioaccumulation in Medicago sativa.

Plant-beneficial bacteria (PBB) have emerged as a promising approach for assisting phytoremediation of heavy metal (HM)-contaminated soils. However, their colonization efficiency is often challenged by complex soil environments. In this study, we screened one rhizobacterium (Klebsiella variicola Y38) and one endophytic bacterium (Serratia surfactantfaciens Y15) isolated from HM-contaminated soils and plants for their high resistance to Cd and strong growth-promoting abilities. These strains were encapsulated individually or in combination with alginate and applied with Medicago sativa in Cd-contaminated soil pot experiments. The effectiveness of different bacterial formulations in promoting plant growth and enhancing Cd bioconcentration in M. sativa was evaluated. Results showed that PBB application enhanced plant growth and antioxidant capacity while reducing oxidative damage. Encapsulated formulations outperformed unencapsulated ones, with combined formulations yielding superior results to individual applications. Quantitative PCR indicated enhanced PBB colonization in Cd-contaminated soils with alginate encapsulation, potentially explaining the higher efficacy of alginate-encapsulated PBB. Additionally, the bacterial agents modified Cd speciation in soils, resulting in increased Cd bioaccumulation in M. sativa by 217-337 %. The alginate-encapsulated mixed bacterial agent demonstrated optimal effectiveness, increasing the Cd transfer coefficient by 3.2-fold. Structural equation modeling and correlation analysis elucidated that K. variicola Y38 promoted Cd bioaccumulation in M. sativa roots by reducing oxidative damage and enhancing root growth, while S. surfactantfaciens Y15 facilitated Cd translocation to shoots, promoting shoot growth. The combined application of these bacteria leveraged the benefits of both strains. These findings contribute to diversifying strategies for effectively and sustainably remediating Cd-contaminated soils, while laying a foundation for future investigations into bacteria-assisted phytoremediation.

Bioaccumulation of trace elements in marine mammals: New data and transplacental transfer on threatened species.

Coastal areas are affected by urban, industrial and agriculture pollutants runoff, wastewater and stormwater discharges, making this environment the final repository of chemical contaminants. These contaminants have the potential to spread out to the entire food chain, impacting marine life and the quality of their habitat. In this aspect, the concept of marine mammals as bioindicators provides an approach to the degree of contamination in the environment and to the identification and management of multiple sources of contaminants. The present study analyzed several elements like As, Ba, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, V and Zn in liver tissue from two dolphin species: Sotalia guianensis, a near-threatened species, and the vulnerable Pontoporia blainvillei. In the study, we also investigated if dolphins (population) recorded using the heaviest urban areas have higher concentrations of contaminants in their tissues. Dolphin samples (n = 40 S. guianensis; n = 97 P. blainvillei) were collected by daily monitoring carried out by Santos Basin Beach Monitoring Project (PMP-BS), from stranded individuals found in São Paulo state. The Spearman's rank correlation showed distinct correlations in the accumulation of trace elements by both species, indicating different sources of exposure to the elements studied or distinct biochemical processes between species. Interspecific and intraspecific variations were observed, possibly related to the individual distribution and feeding habits. Correlations were observed between age and concentrations of trace elements, positive for Cd, Hg and Mo. Finally, our findings indicate high levels of Cu, Zn, and concentrations of As, V and Hg in fetuses, in particular, an analysis was performed on a fetus found inside a stranded individual, indicating placental transfer as the first route of exposure for some elements.

Multi-biomarker approach reveals the effects of heavy metal bioaccumulation in the foundation species Prosopis laevigata (Fabaceae).

Mining is a major economic activity in many developing countries. However, it disturbs the environment, producing enormous quantities of waste, known as mine tailings, which can have deleterious environmental impact, due to their high heavy metals (HM) content. Often, foundation species that establish on mine tailings are good candidates to study the effects of HM bioaccumulation at different levels of biological organization. Prosopis laevigata is considered a HM hyperaccumulator which presents attributes of a foundation species (FS) and establishes naturally on mine tailings. We evaluated the bioaccumulation of Cu, Pb, and Zn in P. laevigata foliar tissue, the leaf micro- and macro-morphological characters, DNA damage, and population genetic effects. In total, 80 P. laevigata individuals (20/site) belonging to four populations: The individuals from both sites (exposed and reference) bioaccumulated HMs (Pb > Cu > Zn). However, in the exposed individuals, Pb and Cu bioaccumulation was significantly higher. Also, a significant effect of macro- and micro-morphological characters was registered, showing significantly lower values in individuals from the exposed sites. In addition, we found significant differences in genotoxic damage in P. laevigata individuals, between the exposed and reference sites. In contrast, for the micro-morphological characters, none of the analyzed metals had any influence. P. laevigata did not show significant differences in the genetic structure and diversity between exposed and reference populations. However, four haplotypes and four private alleles were found in the exposed populations. Since P. laevigata is a species that establishes naturally in polluted sites and bioaccumulates HM in its foliar tissues, the resulting genetic, individual and population effects have not been severe enough to show detrimental effects; hence, P. laevigata can be a useful tool in phytoremediation strategies for soils polluted with Pb and Cu, maintaining its important ecological functions.

Do DOM quality and origin affect the uptake and accumulation of a lipid-soluble contaminant in a filter feeding ascidian species (Ciona) that can target small particle size classes?

The widely reported increase of terrestrial dissolved organic matter (terrDOM) in northern latitude coastal areas ("coastal darkening") can impact contaminant dynamics in affected systems. One potential impact is based on differences in chemical adsorption processes of the molecularly larger terrDOM compared to marine DOM (marDOM) that leads to increased emulsification of lipophilic contaminants with terrDOM. Filter feeders filter large amounts of water and DOM daily and thus are directly exposed to associated contaminants through both respiration and feeding activity. Thus, increased exposure to terrDOM could potentially lead to an increase in bioaccumulation of lipid soluble contaminants in filter feeders. To assess the effect of DOM on bioaccumulation in filter feeders, we exposed the mucous based filter feeding ascidian Ciona intestinalis (formerly known as Ciona intestinalis Type B), to the lipophilic veterinary drug teflubenzuron (log KOW: 5.39) in combination with four DOM treatments: TerrDOM, marDOM, a mix of the two called mixDOM, and seawater without DOM addition. The exposure lasted for 15 days, after which the individuals in all DOM treatments showed a trend towards higher bioaccumulation of Teflubenzuron than those in the seawater control. However, there was considerable overlap in posterior distributions. Against our expectations, marDOM resulted in the highest bioaccumulation factor (BAF), followed by mixDOM, with terrDOM resulting in the lowest BAF except for seawater (kinetic BAF L/kg median, 2.5 %-97.5 % percentile marDOM 94, 74-118; mixDOM 82, 63-104; terrDOM 79; 61-99; seawater 61, 44-79). All BAFs were below the level of concern according to the EU REACH regulation (BAF < 2000 L / kg) and, therefore, likely not environmentally problematic in the examined context. However, the results show that DOM can act as a dietary vector; thus, different combinations of contaminants, DOM, and filter feeding organisms should be tested further.

Occurrence, accumulation, ecological risk, and source identification of potentially toxic elements in multimedia in a subtropical bay, Southeast China.

Potentially toxic elements (PTEs) in seawater and sediments may be amplified along the aquatic food chain, posing a health threat to humans. This study comprehensively analyzed the concentrations, distribution, potential sources, and health risk of 7 PTEs in multimedia (seawater, sediment and organism) in typical subtropical bays in southern China. The results indicated that Zn was the most abundant element in seawater, and the average concentration of Cd in sediment was 3.93 times higher than the background value. Except for As, the seasonal differences in surface seawater were not significant. The content of Zn in fishes, crustacea, and shellfish was the highest, while the contents of Hg and Cd were relatively low. Bioaccumulation factor indicated that Zn was a strongly bioaccumulated element in seawater, while Cd was more highly enriched by aquatic organisms in sediment. According to principal component analysis (PCA), and positive matrix factorization (PMF), the main sources of PTEs in Quanzhou Bay were of natural derivation, industrial sewage discharge, and agricultural inputs, each contributing 40.4 %, 24.2 %, and 35.4 %, respectively. This study provides fundamental and significant information for the prevention of PTEs contamination in subtropical bays, the promotion of ecological safety, and the assessment of human health risk from PTEs in seafood.

Trade-offs of reproductive growth and Cd remobilization regulated Cd accumulation in wheat grains (Triticum aestivum L.).

Minimization of cadmium (Cd) accumulation in wheat grain (Triticum aestivum L.) is an important way to prevent Cd hazards to humans. However, little is known about the mechanisms of varietal variation of Cd accumulation in wheat grain. This study explores the physiological mechanisms of Cd bioaccumulation through field and hydroponic experiments on two wheat varieties of low-Cd-accumulating variety (L-6331) and high-Cd-accumulating variety (H-6049). Field study showed that average Cd accumulative rates in spikes of H-6049 were 1.57-fold of L-6331 after flowering, ultimately grain-Cd of H-6049 was 1.70-fold of L-6331 in Cd-contaminated farmland. The hydroponic experiment further confirmed that more vegetative tissues of L-6331 were involved in the remobilization of Cd, which jointly mitigated the process of Cd loaded to grains when leaf-cutting conducted after Cd stress. Additionally, the L1 and N1 of L-6331 play an especially important role in regulating Cd remobilization, and the larger EVB areas in N1 have the morphological feature that facilitates the transfer of Cd to L1. Overall results implied that low-Cd-accumulating variety initiated more trade-offs of reproductive growth and Cd remobilizatoin under Cd-stress after flowering compared with high-Cd-accumulating variety, and provided new insights into the processes of Cd loaded into wheat grains among different varieties.

Charting the microplastic menace: A bibliometric analysis of pollution in Malaysian mangroves and polypropylene bioaccumulation assessment in Anadara granosa.

According to a bibliometric analysis, studies on microplastic pollution in Malaysia are still incomprehensive. This study found microplastic contamination in sediment (97 particles/kg) and water (10,963 particles/m3) samples from Malaysian mangroves. Sediment from Matang and water from Kuala Selangor recorded the highest microplastic concentrations at 140 ± 5.13 particles/kg and 13,350 ± 37.95 particles/m3, respectively. Fragmented, blue, rayon and particles of <0.1 mm microplastic were the most abundant in sediment and water. In an experiment of polypropylene microplastic uptakes, Anadara granosa was found to uptake more 0.1 mm fiber particles. The uptake is strongly correlated to the presence of microplastics in sediment and water. The estimated dietary intake (EDI) indicates that a consumer could ingest 507 microplastic particles/year by consuming contaminated A. granosa. Therefore, mitigating measures are crucial to safeguard aquatic systems and humans from microplastic pollution.

Bioaccumulation and Health Risk Assessment of Potentially Toxic Metals in Citrus Limetta & Citrus Sinensis Irrigated by Wastewater.

The aim of this study was to evaluate the impact of different irrigation sources on the levels of potentially toxic metals (Cd, Cr, Fe and Mn) in the edibles of citrus fruits (Citrus sinensis and Citrus limetta). The samples of fruit, soil and water were collected from two locations (fresh water irrigated-FW I and sewage water irrigated-SW II) within the city of Sargodha. The samples utilized in the study for metal analysis were prepared utilizing the wet acid digestion method. Metal determination was performed using Atomic Absorption Spectrometry (AAS). The potentially toxic metal values in the citrus samples ranged from 0.010 to 0.063, 0.015 to 0.293, 6.691 to 11.342 and 0.366 to 0.667 mg/kg for Cd, Cr, Fe and Mn, respectively. Analysis of Citrus limetta and Citrus sinensis indicated that the highest concentration of Cr, Fe and Mn is observed at the sewage water irrigation site (SW-II), whilst the minimum levels of Cr, Fe and Mn were observed at the fresh water irrigation site (FW-I). The results show that the levels of these metals in soil and fruit samples meet the acceptable guidelines outlined by USEPA and WHO. It was found that the metal pollution constitutes a potential threat to human health due to the HRI values for Cd, Cr, and Fe being above 1, despite the DIM values being below 1. Regular monitoring of vegetables irrigated with wastewater is highly recommended in order to minimise health risks to individuals.

Bioaccumulation of Cadmium in Muscle and Liver Tissues of Juvenile Yellowfin Tuna (Thunnus albacares) from the Indian Ocean.

The present study evaluated the cadmium (Cd) levels and temporal variation of Cd in dark muscle, white muscle, and liver of juvenile Thunnus albacares. 72 individuals (Standard length: 50-67 cm; weight: 0.8-2.5 kg) were collected from Indian Oceanic water around Sri Lanka during the period between April 2021 to May 2022. Total Cd levels were analyzed using an Inductively Coupled Plasma Mass Spectrophotometer. The mean Cd levels (mean ± SD mg kg-1 dry weight) in different tissues varied with significantly higher levels in the liver (13.62 ± 0.98, p < 0.05), compared to dark muscle (0.52 ± 0.05), and white muscle (0.42 ± 0.04). Cd levels in liver tissues were positively correlated (p < 0.05) with the fish weight. The Cd levels reported in dark muscles, white muscles, and liver tissues were significantly higher (p < 0.05) during 2nd inter-monsoon than in the other monsoonal regimes and exceeded the maximum permissible level (0.1 mg kg-1 wet weight) set by the European Union (EU). However, the measured Cd levels in white and dark muscles were below the maximum permissible level (0.2 mg kg-1 wet weight) set by FAO/WHO. The Cd levels in all the liver tissues were above the levels set by the EU and FAO/WHO. Accordingly, people should avoid the consumption of liver tissues of T. albacares from the Indian Ocean. A human with a body weight of 60 kg can consume white muscles up to 4.667 kg per week without exceeding the Provisional Tolerable Weekly Intake.

Wildfires Influence Mercury Transport, Methylation, and Bioaccumulation in Headwater Streams of the Pacific Northwest.

The increasing frequency and severity of wildfires are among the most visible impacts of climate change. However, the effects of wildfires on mercury (Hg) transformations and bioaccumulation in stream ecosystems are poorly understood. We sampled soils, water, sediment, in-stream leaf litter, periphyton, and aquatic invertebrates in 36 burned (one-year post fire) and 21 reference headwater streams across the northwestern U.S. to evaluate the effects of wildfire occurrence and severity on total Hg (THg) and methylmercury (MeHg) transport and bioaccumulation. Suspended particulate THg and MeHg concentrations were 89 and 178% greater in burned watersheds compared to unburned watersheds and increased with burn severity, likely associated with increased soil erosion. Concentrations of filter-passing THg were similar in burned and unburned watersheds, but filter-passing MeHg was 51% greater in burned watersheds, and suspended particles in burned watersheds were enriched in MeHg but not THg, suggesting higher MeHg production in burned watersheds. Among invertebrates, MeHg in grazers, filter-feeders, and collectors was 33, 48, and 251% greater in burned watersheds, respectively, but did not differ in shredders or predators. Thus, increasing wildfire frequency and severity may yield increased MeHg production, mobilization, and bioaccumulation in headwaters and increased transport of particulate THg and MeHg to downstream environments.

Spatiotemporal dynamics, bioaccumulation, and critical influencing factors of antibiotics in tilapia aquaculture: A study on source identification and environmental fate within typical farming systems.

This study investigated the spatiotemporal dynamics, bioaccumulation, and critical influencing factors of antibiotics in tilapia aquaculture, focusing on source identification and environmental fate within typical farming systems. The results revealed a progressive increase in antibiotic concentrations in pond water and sediments over the cultivation period, with suspended solids and chemical oxygen demand identified as significant environmental factors influencing the distribution and dissemination of antibiotics. The aquaculture water source was the primary contributor of antibiotics in the farming system. Furthermore, the bioaccumulation factor (BAF) calculations indicated varying degrees of antibiotic enrichment in tilapia tissues, with sulfadimethoxine exhibiting the highest BAFs. Correlation analyses, redundancy analysis, and multivariate linear regression analysis provided insights into the relationship between environmental factors and antibiotics, identifying key antibiotics and influencing factors. The study highlighted the importance of managing and treating water sources to reduce the inflow of antibiotics into aquaculture systems and emphasized the need for non-antibiotic aquaculture practices to minimize the impact on the environment and public health. In conclusion, this research contributes valuable information for the development of effective management strategies and policies aimed at curbing antibiotic pollution in aquaculture environments, ensuring the sustainability of the aquaculture industry, and protecting ecosystem and consumer health.

Organophosphate esters (OPEs) pollution characteristics, bioaccumulation and human consumption implication in wild marine organisms from the Yellow River Estuary, China.

As the substitutes of polybrominated diphenyl ethers, organophosphate esters (OPEs) with high concentrations have accumulated in the estuaries, bays, and harbors. However, limited information is available about the OPEs in the estuary organism categories, especially under the multiple industrial pressure. This study investigated the occurrence, bioaccumulation and human consumption implication in wild marine organisms from the Yellow River Estuary, where located many petroleum and chemical manufacturing industries. This study found that concentrations of Σ13OPEs ranged from 547 ng/L to 1164 ng/L in seawater (median: 802 ng/L), from 384 to 1366 ng/g dw in the sediment (median: 601 ng/g dw), and from 419 to 959 ng/g dw (median: 560 ng/g dw) in the marine organisms. The congener compositions in the organisms were dominated by alkyl-OPEs (80.7 %), followed by halogenated-OPEs (18.8 %) and aryl-OPEs (0.5 %). Based on the principal component analysis, petrochemical pollution, and industrial wastewater discharge were distinguished as the main plausible sources of OPEs to the YRE ecosystem. Most OPEs had potential or strong bioaccumulation capacity on the organisms, with a positive correlation between log BAF (Bioaccumulation Factor) and log Kow of OPEs. The highest estimated daily intake value of OPEs was tri-n-propyl phosphate, exceeding 300 ng/kg·bw/day via consuming fish. The highest hazard quotients from OPEs ranged from 0.001 to 0.1, indicating a low risk to human health by consuming marine organisms in the YRE. As the consumption of OPEs increases year by year, the risks of OPEs still cannot be ignored.

Bioaccumulation of trace metals by the gastropod Phorcus lineatus (Da Costa, 1778) from the Atlantic coast of El Jadida, Morocco.

Heavy metals in coastal ecosystems represent an issue for human and environmental health worldwide. The objective of this study was to assess the state of health of Morocco's Atlantic coastline in the El Jadida region. The study was based on metal bioaccumulation in Phorcus lineatus, a species common to Atlantic coasts. Two polluted sites were selected: Haouzia (H) and Jorf-Lasfar (J). Animals were sampled monthly for determination of trace metals in the soft tissues of P. lineatus. Except for Cr, the results show a significant variation in bioaccumulation. The highest concentrations (µg g-1 dry weight) were found in individuals from J, with 10.68 ± 2.43 Cd, 107.36 ± 21.15 Zn, 666.55 ± 143.34 Fe and 184.47 ± 49.80 Cu. The maximum Metal Pollution Index value was 37.06 at site H in spring and 65.96 at site J in autumn. The J site appears significantly more polluted than H site.