This study evaluated 210Po activity and associated risk assessment in two organs of 20 Pacific oyster (Crassostrea gigas) groups (different sizes) collected at coastal areas of Quang Ninh, Vietnam. The elevated 210Po activity in hepatopancreas compared to muscle tissue, with mean values of 108 (53.4 ± 2.0 to 201 ± 12.1) and 15.7 (9.1 ± 0.4 to 26.3 ± 1.3) Bq/kg ww, respectively. The concentration factor (CF) in hepatopancreas (1.4 × 105) was significantly higher than that in muscle tissue (1.9 × 104), reflecting the preferential accumulation of 210Po in the digestive tract. There was the inverse coefficient relationship between shell length and weight with 210Po activity in muscle tissue, while no such correlation was found in hepatopancreas. Annual effective dose (AED) assessments showed that consumption of hepatopancreas far exceeded the reference value of 1 mSv/year, with mean values for adults, children, and infants of 1.35, 2.92, and 8.98 mSv/year, respectively. Meanwhile, the AED for muscle tissue was significantly lower, with mean AED values for adults, children, and infants being 0.20, 0.42, and 1.44 mSv/year, respectively. The total radiation dose to oysters ranged from 0.82 to 2.38 µGy/h, with a mean of 1.42 µGy/h, which is much lower than the ERICA reference threshold of 10 µGy/h, suggesting no significant risk to oyster population health. The study highlights specific recommendations to limit the consumption of oyster hepatopancreas, especially for sensitive populations such as children and infants, to minimize radiation exposure risk from oyster consumption.
Holothurians are increasingly recognized as bioindicators and bioremediators in marine ecosystems. This study assessed the relationship between total mercury (THg) levels in Holothuria polii and Holothuria tubulosa from two Southern Italian coastal sites differing for ecological and anthropogenic characteristics, and those in corresponding marine sediments. THg levels in holothurians were consistently low across species and sites (0.0022–0.0146 mg kg− 1 wet mass) and showed no direct correspondence with sediment levels, which were high (1.5080 ± 1.1687 mg kg− 1 dry mass) at the Ionian site (IS), and low (0.0055 ± 0.0028 mg kg− 1 dry mass) at the Adriatic site (AS). Despite lower sediment mercury contamination, the bioconcentration factor, indicator of the efficiency of metal bioaccumulation was higher at the AS site (3.54–4.76) than at the IS site (0.021–0.022), suggesting different mercury bioavailability in the sites. Size-related analyses of THg in holothurians indicated that THg levels in individual holothurians correlated positively with body size (p < 0.05), except for H. tubulosa from AS. Results demonstrate that site-specific factors, more than species-specific ones, play a key function in controlling mercury bioavailability and uptake in the studied holothurians, supporting their potential role in environmental monitoring and their safe consumption in the studied areas.
Although fisher (Pekania pennanti) populations have stabilized due to reintroduction efforts and habitat reconstruction, they face ongoing threats from environmental stressors such as deforestation, climate change, vehicle collisions, and toxicants. This study examines the presence of heavy metals in fishers harvested in Wisconsin from 2005 to 2006, providing a foundational understanding of baseline heavy metal concentrations for future reference. Liver samples were analyzed for levels of Aluminum, Copper, Nickel, Zinc, Arsenic, Cadmium, Iron, Manganese, Cobalt, Mercury, Molybdenum, Lead, Thallium, Chromium, and Vanadium. Mass spectrometry was used to quantify the metal concentrations in parts per million and the data were analyzed using robust multiple linear regression analyses and classical linear models to assess the effects of age and sex, and a Kruskal–Wallis test to determine the effect of county of harvest on the metal concentrations. The findings suggest that fishers in Wisconsin do not have measurable levels of Ni, As, Hg, and Tl. Sex and age significantly influenced Cd levels in fishers, while county location influenced Fe and Mo concentrations.
Urban stormwater runoff introduces tire‑related contaminants such as 6PPD‑quinone (6PPD‑Q), which has been shown to exhibit acute toxicity in some salmonid species, although the underlying toxic mechanisms remain incompletely understood. To expand in vitro toxicological assessments, we evaluated the cytotoxicity of 3,4‑dichloroaniline and 6PPD‑quinone using six fish‑derived cell lines from salmonids and phylogenetically distant species, based on nominal concentrations at the time of addition. Among these cell lines, CSE‑119 cells, which are derived from coho salmon, exhibited the highest sensitivity to 6PPD‑quinone (EC50 = 8.54 µg/L), demonstrating pronounced species‑specific differences in sensitivity to quinone‑type toxicants and underscoring the value of comparative in vitro models. Using multiple fish cell lines enables the efficient, animal‑welfare–conscious screening of tire‑associated chemicals. However, further investigation is needed into evaluation methods that take into account factors such as the stability of chemicals in the culture medium.
Urban environments are increasingly affected by heavy metal pollution originating from traffic, industrial activities, and other anthropogenic sources, which can have adverse consequences for urban ecosystems and human health. This study investigated the concentrations of heavy metals, including cadmium (Cd), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn), in the leaves of three commonly occurring urban tree species-pine (Pinus sp.), mulberry (Morus sp.), and Chinaberry (Melia azedarach)-as well as in the corresponding surface soils in Sabzevar, Iran. To assess species-specific accumulation patterns, the bioaccumulation factor (BCF) and metal accumulation index (MAI) were calculated, and non-carcinogenic health risks from soil exposure were estimated using the hazard quotient (HQ) and hazard index (HI). The results indicated significant differences in metal concentrations among tree species, with Morus sp. exhibiting the highest accumulation of Fe, Mn, and Ni, whereas Pinus sp. displayed the highest MAI values. Soil analysis revealed considerable spatial heterogeneity, with the highest Pb and Zn concentrations observed in high-traffic urban areas. HQ and HI values for all metals and age groups were below critical thresholds, although children exhibited higher values than adults. These findings underscore the importance of selecting appropriate tree species for biomonitoring and managing heavy metal pollution in semi-arid urban environments.
Baiyangdian Lake, the largest freshwater lake in the North China Plain, plays a crucial role in regional ecology and hydrology. Benthic macroinvertebrates are widely recognized as important bioindicators for assessing the ecological health of lake ecosystems. Following the establishment of the Xiong'an New Area, comprehensive ecological restoration was implemented from 2019 to 2023, yet the recovery status of benthic communities remains inadequately understood. In this study, we conducted a comprehensive analysis of the temporal and spatial dynamics of benthic macroinvertebrates using Generalized Additive Models (GAMs). A total of 449 individuals of benthic macroinvertebrates were identified, belonging to 3 phyla (Mollusca, Annelida, and Arthropoda), 6 classes, 7 orders, 7 families, and 20 genera. Five dominant species were identified: Propsilocerus akamusi, Bellamya aeruginosa, Cipangopaludina cathayensis, Chironomus flaviplumus, and Bellamya purificata. The Shannon–Wiener diversity (H') and Margalef richness (D) indices showed non-significant upward trends (p > 0.05), increasing from 0.708 to 1.854 and from 0.638 to 2.875, respectively. Biomass showed a significant increasing trend, peaking at 427.02 g/m2 in 2023 (357.9
Fish have the capacity to bioaccumulate metals such as mercury through the food web, posing potential health risks to aquatic ecosystems and humans. This study aimed to assess total mercury (THg) concentrations in different tissues of freshwater fish and evaluate the potential risk for consumers. Perch (Perca fluviatilis) and rudd (Scardinius erythrophthalmus), representing different trophic levels, were collected from Koronowo Reservoir and Lake Wierzchucińskie Duże in summer and autumn. THg accumulation followed the order: muscle > liver > gills, with significant differences observed between tissues. In perch, THg concentrations were 0.061 μg/g (muscle), 0.037 μg/g (liver), and 0.028 μg/g (gills). In rudd, THg levels were 0.050 μg/g (muscles), 0.034 μg/g (liver), and 0.022 μg/g (gills). The target hazard quotient (THQ) values were below 1, indicating that their consumption does not pose a significant health risk to humans. Estimated safe weekly intake was 1,839 g for perch and 2,249 g for rudd for dorsal muscle.
The Chodha Lake sediment core of Korba district, Chhattisgarh was investigated for 10 potentially toxic elements to asses metal pollution, their sources, past apportionment and eco-environmental risks. Geochemical analysis was performed with the help of X-ray Fluorescence spectrometer. The discrete sources of the potentially toxic elements were distinguished mainly using principal component analysis and factor analysis. The core sediments show elevated concentrations of Potentially toxic elements, with notable enrichment in Fe, Cr, Mn and Co, while Cu, V, Zn and Ni also exhibit relatively high levels. Cu, V, Pb, and Cr pollution was mainly related to the adjoining coal productions, particularly burning of coal and associated fly ash. The contamination of Mn and Fe may be attributable to coal mine tailings and allied rock fragments. On the contrary, Al, Ni and Zn indicate their geogenic origin derived largely from the weathering and erosion of soils of the study region. The various levels of contamination are interpreted based on the pollution indices. Most of the elements indicated their moderate enrichment in the sediment core, whereas moderate to substantial levels of contamination was exhibited by Fe and excessive contamination by Cobalt. The moderate to substantial degree of pollution based on the Index of geo-accumulation was revealed by Fe, Zn and Mn. However, all the core sediments confirm the consistent low potential ecological risk to aquatic life.
This study assessed the long-term sustainability of integrating sewage sludge (SSL) with recommended (100
In Europe, agriculture has been seriously affected by the increased frequency of droughts. Agricultural fields are also exposed to traffic-related air pollution. Air pollution and drought elucidate simultaneous stress, which has been scarcely studied. The major objective of the study was to evaluate the combined effects of air pollution and drought stress on different tomato varieties/landraces. 3 commercial varieties as well as 2 Hungarian landraces were selected, effects of the combined stressors were evaluated based on biomass reduction and biochemical end-points such as photosynthetic pigments concentrations and peroxidase (POD) activity. Air pollution was simulated by treating test plants according to the No. 227 OECD Guideline. Differences were experienced in the sensitivity of varieties, landraces tested: the regional landrace ‘Tápiószelei’ proved the most tolerant to any combination of treatments. Results stress the importance of the cultivation of regional landraces to cope with environmental stress in a changing climate.
Road-killed Eastern Foxsnakes (Pantherophis vulpinus) and Eastern Gartersnakes (Thamnophis sirtalis sirtalis) from Southwestern Ontario, Canada, inclusive of samples from Point Pelee National Park (PPNP), were analysed for stable isotopes, mercury and organochlorines. Stable isotopes revealed differences in feeding ecology between the species, with foxsnakes presenting higher trophic status relative to gartersnakes at PPNP. Total Hg did not differ between location, species or body size. Foxsnakes from PPNP were enriched in ∑PCBs and ∑DDTs over gartersnakes but also distinct in chemical signatures from foxsnakes from other locations. 30
In the present study, characterisation of (nano-)biochars(NBCs) derived from agro-wastes using BET, CHNS/O, TGA/DSC, FTIR, SEM, TEM, AAS, and ICP-MS analyses confirmed physical integrity, crystalline and homogenous nature of biochars, including their elemental composition, moisture, and ash content, nanosized particles (25–100 nm), and the presence of functional groups. Maximum adsorption capacity of NBCs derived from bagasse, maize stalk, and paddy straw was found to be 66.10 ± 1.06, 75.61 ± 1.28, 73.04 ± 1.04 mg/g for lead, and 29.05 ± 0.96, 66.07 ± 1.15, 61.76 ± 1.02 mg/g for cadmium, which indicated that maize stalk biochar is the most effective. These NBCs effectively remove chromium in the range of 24.6–53.8 mg/g at a lower pH of 2.2 due to electron-donating groups; however, they were ineffective at a higher pH value of 7 because of electrostatic repulsion with negatively charged functional groups and differences in chemical speciation, surface charge, and redox potential. Pyrolysis enhanced the properties of biosorbents by increasing their porosity, surface area, and concentration of key minerals suitable for ion exchange. None of the NBCs removed ammonia and nitrite effectively. NBCs have potential applications for heavy metals removal and mitigation of stresses for climate-resilient agriculture due to their stability, recalcitrance, and water retention capacity.
Reclaimed coastal soils often exhibit low organic matter, weak nutrient-holding capacity, and salinity-related constraints that limit vegetation establishment. This study examined whether living moss inoculation induces early physicochemical changes in the surface layer of reclaimed coastal soil under controlled conditions from Taean, South Korea. The work comprised baseline site characterization followed by a 4-week controlled pot experiment using three moss species (Hypnum plumaeforme, Ceratodon purpureus, and Racomitrium lanuginosum). Moss inoculum was prepared from propagated vegetative material with visibly green tissues and applied as a slurry at 10 g fresh moss per pot (1:50 w/w). The independent variable was moss treatment, and the dependent variables were qualitative establishment and post-incubation soil chemical properties. Five independent pots were used per treatment. Visible establishment occurred within approximately 2 weeks in all moss-treated pots. Across treatments, soil pH decreased, whereas available phosphate (AP), organic matter (OM), and cation exchange capacity (CEC) increased relative to the untreated control. These findings indicate that living moss inoculation can alter fertility-related properties of reclaimed coastal soil under controlled conditions. Because the experiment was short-term, pot-based, and did not quantify moss growth, the results should be interpreted as a preliminary proof-of-concept rather than direct evidence of field-scale restoration.
Polyethylene mulching films (PEM) are widely used in agriculture to improve water-use efficiency, regulate soil temperature, and enhance crop yields, but their poor degradability leads to persistent soil residues and high recovery costs. Biodegradable mulching films (BDM) offer a promising alternative by mitigating long-term plastic pollution, yet their adoption remains limited due to higher costs and uncertain field performance. To explore the key drivers of farmers’ decisions, we developed an evolutionary game-theoretic model coupled with system dynamics to simulate farmer–government interactions under varying economic and agronomic conditions. Results indicate that farmers prefer PEM under current parameters, but several tipping points can shift this equilibrium. BDM adoption becomes favorable when the price gap with PEM narrows to USD 210/ha, when crop revenues exceed USD 4400/ha, when yield losses from PEM residues reach 50
This study aimed to evaluate the accumulation of nickel (Ni) and cobalt (Co) and their associated human health risks in two guava varieties (Gola and Surahi) grown under contrasting irrigation systems. For the analysis of Ni and Co, samples of water, soil, and fruits were collected from peri-urban areas, Chak 81 S.B (Site I) and 88 S.B (Site II) of Sargodha, Pakistan, which were irrigated with tube well water and wastewater, respectively. The mean values of Ni and Co were found in the range of 0.043 to 0.217 and 0.017 to 0.040 mg/L in water, 1.070 to 1.254 and 1.032 to 1.248 mg/kg in soil, and 0.281 to 0.582 and 0.202 to 0.252 mg/kg in fruit samples, respectively. The health risk assessment revealed that only Ni exceeded the safety threshold (maximum HRI = 1.113), indicating a potential health concern associated with the consumption of wastewater-irrigated guava, whereas all Co HRI values remained below 1 and did not indicate a significant health risk. These findings suggest that prolonged use of wastewater for irrigation should be carefully monitored and managed to minimize potential health risks associated with nickel accumulation in the food chain.
Microplastics (MPs) are emerging contaminants with growing concerns about their accumulation and potential impacts on aquatic organisms. This study investigated the presence and impact of MPs in shrimp and water samples collected from three sluice gate harvest sites in Goa. MPs were found in the hepatopancreas of shrimp and water from all the sites, with St. Estevam site exhibiting the highest concentrations. Various shapes, sizes and polymers of MPs were identified with sizes ranging between 0.38 and 1168.18 μm. The CMPI highlighted minimum to average impacts. The PLI of all the sites fall under Category I indicating low hazard level. The BAF revealed low bioaccumulation (< 1). The EDI was calculated to be 0.74 ± 0.28 to 2.39 ± 0.92 particles/kg b.w/day. Although pollution indices showed low impact levels, these findings highlight the risk associated with consumption of MPs contaminated seafood.
Organophosphate esters (OPEs) are ubiquitous in various environmental matrices due to their extensive use as flame retardants and plasticizers in our daily life. Triphenyl phosphate (TPHP) and tris(2-butoxyethyl) phosphate (TBOEP), two typical analogues of OPEs, pose risk to the environment, aquatic organisms and human health. In this study, Pelophylax nigromaculatus tadpoles were selected for a 21-day exposure experiment to determine the bioaccumulation and metabolic pathways of these two substances. The logarithmic concentrations (Log C) of TBOEP in tadpoles exhibited an increase over time, while those of TPHP demonstrated a slightly declining trend. TPHP displayed higher bioconcentration factors compared to TBOEP. Differences in bioaccumulation may be attributed to biotransformation and species variability. There were four TPHP metabolites (TP-251, TP-343a, TP-343b, TP-357) and TBOEP metabolites (TB-415a, TB-415b, TB-429a, TB-429b) identified in tadpoles while three TPHP metabolites (TP-343a, TP-343b, TP-343c) and TBOEP metabolites (TB-299, TB-415a, TB-415b) in water. Among these, TB-415b exhibited the higher potential for bioaccumulation. It can be inferred that TPHP and TBOEP underwent hydrolysis (yielding TP-251 and TB-299), hydroxylation (producing TP-343a/b/c, TB-415a/b and TB-429a), and methylation reactions (generating TP-357 and TB-429b). This study provides significant insights into the bioaccumulation and biotransformation mechanisms of TPHP and TBOEP within amphibians.
Direct uptake of an element from water by an aquatic organism and its retention, leading to a higher concentration than in its surrounding water, is an environmental concern known as bioconcentration. It occurs when an organism absorbs a substance faster than it is eliminated by various metabolic processes, such as catabolism and excretion. A bioassay experiment was performed to determine the 96-hour LC50 of cadmium chloride (CdCl2), a heavy-metal salt. For experimentation, pre-acclimated Limnodrilus hoffmeisteri worms were divided into eleven treatment groups (T1 through T11) and a control group (C), each of 50 number of individuals and were exposed to 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5, 2.75 and 3.0 mg/L cadmium concentrations respectively for 96 h under semi-static condition in a closed-circuit flow-through system with complete renewal of water with the respective relevant cadmium concentration after 48 h. Post-exposure cadmium content per unit amount of tissue samples and of residual water samples was measured with atomic absorption spectrophotometry (AAS). Probit analysis revealed the 96-hour LC50 value of cadmium against L. hoffmeisteri as 1.002 mg/L. The outcome of this study established a low BCF for the experimental species for cadmium, indicating a positive correlation between BCF and exposure concentration and demonstrating the inherent bioconcentration nature of cadmium in L. hoffmeisteri. A gradual declining trend in cadmium content of the whole body was observed at exposure to a cadmium concentration higher than 2.0 mg/L. Concurrent autotomy of the caudal part of the organism has also been observed at this exposure level. Cadmium content of the autotomized tail has been estimated significantly (P < 0.05) higher. It is concluded that autotomization is a defensive mechanism evolved by L. hoffmeisteri to reduce the body’s heavy metal load and, hence, toxicity, thereby serving as an indicator species.
Fully understanding long-term liming effects on microbial dynamics requires further extensive and site-specific research. The study’s core objective was to track how the amount of viable microbial biomass (measured via PLFA) and function (measured via enzyme activity) evolve in reclaimed Northern Ontario sites over time, providing insights into the process of ecosystem recovery. Four sites were selected, encompassing both limed areas and adjacent unlimed control areas. Although all sites were monitored concurrently, the applications of limestones occurred at different times. Liming at the freshly treated Kelly Lake site caused a temporary, significant increase in microbial biomass during the first four years of monitoring. This initial surge was absent in samples from older limed areas (Wahnapitae, Hwy 17 bypass, and Sudbury Snow Dump sites) monitored 7–13 years post-treatment, which suggests the effects had plateaued. Despite this short-lived microbial response, the overall positive effects of liming such as improved soil chemistry (e.g., increased pH and increased calcium) and enhanced plant population health seems to persist long after the initial biomass increase, demonstrating lasting ecological benefits. Variations in liming effects on soil biota were linked to differences in treatment duration and site-specific environmental characteristics. Microbial biomass values showed a strong positive correlation with pH (r = 0.76) and a weak positive correlation with organic matter (OM) values (r = 0.35). Amplicon sequencing analysis revealed a significant increase in bacterial community richness, indicated by significantly higher Chao1 values in limed (4450) versus unlimed (3446) soil samples, while fungal communities showed no such changes. Enzyme activities remained stable over time in both unlimed and limed samples, with two key exceptions among the C-cycling enzymes: beta-glucosidase (BG) and cellobiohydrolase (CBH). The activities of these two enzymes increased significantly over time in the limed soils. A consistent significant increase was observed for arylsulfatase (AS), an enzyme involved in S-cycling.
This study investigates the distribution, contamination status, possible sources, and health risks of heavy metals in urban road dust from Vadodara, a rapidly developing industrial city in western India. Vadodara was selected due to its increasing traffic density, mixed land-use pattern, and growing industrial activities, which may contribute to metal accumulation in roadside environments. Road dust samples were analyzed for chromium (Cr), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn), cadmium (Cd), cobalt (Co), and copper (Cu) using microwave-assisted digestion followed by atomic absorption spectrophotometry. The mean concentrations of metals followed the order: Cr (32.87 mg/kg) > Mn (28.64 mg/kg) > Zn (7.78 mg/kg) > Ni (4.90 mg/kg) > Cu (3.85 mg/kg) > Pb (3.30 mg/kg) > Co (2.68 mg/kg) > Cd (0.40 mg/kg). Overall, metal levels were lower than those reported for highly industrialized cities, indicating moderate contamination in the study area. Contamination indices (CF, Igeo, and PLI) suggested generally low pollution, although Cd showed localized enrichment at specific high-traffic sites. Ecological risk assessment indicated low to moderate risk, mainly due to Cd. Human health risk assessment showed that ingestion is the main exposure pathway. Non-carcinogenic risk values (HI < 1) indicated no significant risk for both adults and children. However, carcinogenic risk values for children ranged from 1.59 × 10−4 to 5.63 × 10−4 at some locations, approaching or slightly exceeding recommended limits, mainly due to chromium and nickel. Source analysis indicated that traffic-related activities and resuspension of soil particles are the major contributors to metal accumulation. The findings highlight that, although overall contamination levels in Vadodara are not severe, localized hotspots and potential risks for children require attention. These results provide useful baseline data for urban environmental management and can support future monitoring and pollution control strategies in similar developing cities.
