Archives of Environmental Contamination and Toxicology最新文献

The contamination of soils in the urban area of Zagreb with potentially toxic elements (PTEs) was assessed by predicting their mobility and evaluating the risk to the environment and human health. Sequential extraction was performed using the optimized BCR (Community Bureau of Reference) method. The enrichment factor (EF) was calculated to assess soil contamination. The mobility risk assessment was performed using the risk assessment code (RAC) and the modified risk assessment code (mRAC). In the mobile fraction, Ca, Sr, and Mg are only weakly bound by carbonate compounds, while the other elements are strongly bound to the soils. Mn, Pb, Ba, and Cd are bound to oxides, and the least mobile elements such as Al, As, Co, Fe, Zn, K, Na, Ni, Cr, Sb, Cu and Li occurred mainly in the residual fraction. High extraction efficiency (above 40%) for Pb, Cd, and Cu was obtained when 0.43 M HNO₃ was used for extraction, and this acid is recommended for analyzing the geochemical reactivity of PTEs. The increased content of Ni, Cu, Cr, and As is accompanied by a high EF, indicating the existence of anthropogenic sources of these elements. The hazard index (HI) for adults and children is < 1.0, indicating that these PTEs have no significant non-carcinogenic effects on the human body. The cancer risk (CR) for children is highest for Ni, Cr and As and for adults for Ni. The Monte Carlo simulations show that Cd and As are the most important risk factors in the soils studied.

Environmental pollution, particularly from endocrine-disrupting chemicals (EDCs), poses a significant threat to living beings. Despite extensive research in humans, studies on companion animals like cats remain limited. This work aimed to investigate the exposure of owned male and female cats to EDCs and the residue levels in their reproductive organs. Reproductive tissues (50 ovaries, 50 uteruses, and 50 testicles) from cats presented for sterilization were analyzed for residues of organochlorinated pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) using gas chromatography-mass spectrometry. The method was validated following international standards. DDTs were the most commonly appointed contaminants, particularly in cats exposed to cigarette smoke and meat-based diets. PAHs were the second most prevalent, with higher concentrations in female reproductive organs compared to male testicles. PCBs were primarily found in testicles, potentially linked to higher meat consumption among male cats. PBDEs were the least frequently detected and only in testicles, at low concentrations. Notably, DDT concentrations were higher in ovaries than in uteruses from the same animals. These findings suggest that indoor cats are vulnerable to EDC exposure, with diet and environmental tobacco smoke as potential sources. Owners should minimize such exposures to safeguard both pet and human health. Given the shared environments and exposure risks between humans and cats, the study highlights the relevance of a One Health perspective.

The chronic toxicity of aqueous uranium (UO₂²⁺) to the early life stages of lake trout, Salvelinus namaycush, was evaluated in a 141-d static-renewal test. Eggs were obtained from wild fish from a reference lake in northern Saskatchewan and fertilized in the field. Fertilized eggs/embryos were exposed to five mean uranium concentrations ranging from 0.05 to 29.8 mg U/L and an untreated control from 6 h post-fertilization until 30 d after the swim-up fry stage had been reached. The dilution water came from a different uncontaminated lake located in the uranium mining region of northern Saskatchewan and had a mean pH of 8.0 and mean total hardness and alkalinity of 76 and 73 mg/L as CaCO₃, respectively. Test endpoints included survival, hatching and swim-up success, alevin and fry growth, general and feeding behaviour, select biochemical endpoints, and visual observations of general fish health. Of these, hatching success, mean time to hatch, and survival of those alevins/fry that did manage to hatch were the most sensitive test endpoints. No fish survived at the highest mean test concentration, 29.8 mg U/L (lowest observed effect concentration, LOEC), but none were adversely affected at the next highest mean concentration, 6.05 mg U/L (no observed effect concentration, NOEC). No significant sublethal effects were observed at any test concentration (≤ 6.05 mg/L) where fry survived.

For years, the Caspian Sea has been affected by chemical pollution resulting from human activities. More recently, Viral Nervous Necrosis (VNN) has emerged as a new threat, severely impacting fish populations in this aquatic ecosystem. The aim of this study was to evaluate differences between healthy and VNN-infected mullets along the southwestern coast of the Caspian Sea. A total of 63 individuals were randomly sampled, including 34 Chelon auratus and 29 Chelon saliens. Viral prevalence was higher in C. saliens. Statistical test revealed clear differences between healthy and infected individuals based on their elemental profiles. Infection with NNV was associated with significantly elevated concentrations of several metals, particularly Hg, Pb, Mo, V, and Cu, with Hg showing up to a tenfold increase in infected fish. These findings confirm that the southern Caspian Sea is contaminated with multiple trace elements, which not only compromise ecosystem health but may also predispose fish to viral infections such as VNN.

This study assesses heavy metal accumulation in water, sediment, feeds, and farmed shrimp-tilapia (Penaeus monodon, Macrobrachium rosenbergii, Oreochromis mossambicus) from aquaculture hotspots in Satkhira and Khulna, Bangladesh, to apportion potential metal sources and evaluate associated human health risks. Metal concentrations were quantified using flame atomic absorption spectrometry (AAS) and hydride generation AAS (HG-AAS). The determined average content of As, Cr, Pb, Mn, and Ni in fish species exceeded FAO permissible levels, indicating significant contamination. As, Cr, Pb, and Mn concentrations in water; As, Cr, Pb, Cu, Mn, and Ni content in sediment; and Cr, Pb, Cu levels in fish feeds surpassed FAO and USEPA maximum safe limits. Self-organizing maps (SOM) and positive matrix factorization (PMF) revealed that fish feed inputs were the dominant contributors to Cu (68.1%), Pb (40.1%), Cr (36.1%), Cd (31.6%), As (30%), and Ni (26.1%) accumulation. Principal component analysis (PCA) supported likely shared anthropogenic and natural sources, while cluster analysis (CA) indicated sampling stations’ homogeneity. Target hazard quotient (THQ) values for children indicated potential non-carcinogenic risks from As and Cr exposure, with hazard index (HI) scores for adults (1.22–1.44 > 1) and children (4.77–5.20 > 1), inferring possible cumulative effects in consuming all these fishes. Target risk (TR) assessment suggested a likelihood of carcinogenic risks from As, Cd, Cr, and Pb exposure, with As posing the highest potential risk for both children (TR = 1.36 × 10⁻³) and adults (TR = 3.75 × 10⁻⁴). These findings underscore the necessity of developing strong regulatory structures to ensure sustainable aquaculture by controlling sources of toxic metal contamination.

Graphical Abstract

As a key economic marine aquaculture species in China, sea cucumbers (Apostichopus japonicus) were widely cultured in coastal regions, where were susceptible to crude oil pollution threatening their survival and population recruitment, and the impact of crude oil on non-specific immune functions of sea cucumbers was still limited. Therefore, this study exposed sea cucumbers to water-accommodated fractions (WAFs) of Oman crude oil for 7 d to investigate the effects of crude oil on non-specific immune functions, which were composed of cellular and humoral immune responses. Results showed that WAFs exposure caused oxidative stress and lipid peroxidation, evidenced by elevated reactive oxygen species levels in coelomocytes and initially increased and then reduced malondialdehyde content in coelomic fluid of sea cucumbers. For cellular immune, results showed that WAFs exposure caused dysregulation of phagocytic activity, and a rough reduction in total cell count and an obvious increase in respiratory burst capacity in coelomocytes in a dose-dependent manner, indicating coelomocytes dysfunction and suppression of cellular immune function. Regarding humoral immune function, an obvious decrease in the lysozyme content, total nitric oxide synthase, acid phosphatase and alkaline phosphatase activities, was observed in coelomic fluid with the increase in total petroleum hydrocarbons concentrations, indicating lysosomal dysfunction and suppression of humoral immune function. These findings revealed adverse effects on both cellular and humoral immune responses, suggesting acute immunotoxicity of crude oil in sea cucumbers.

Crude oil and its water-soluble fractions (WSF) are highly toxic to early life stages of fishes, while exposed adults are often considered more resilient. However, research suggests that parental exposure can result in toxic effects in subsequent generations. This study investigated the impact of a crude oil WSF on Atlantic cod (Gadus morhua) broodstock and the subsequent maternal effects on their offspring. Mature Atlantic cod at late gametogenesis were exposed for 20 days to either a crude oil WSF or to control conditions. Over the following month, fish from both groups were repeatedly strip-spawned, and egg batches were fertilized in vitro using pooled sperm from control males. Maternally exposed offspring had accumulated levels of petroleum-derived aromatic hydrocarbons, including monoaromatic and polyaromatic hydrocarbons (PAHs). However, the profile of accumulated compounds was skewed towards lower-molecular weight compounds compared to the exposure water. Crude oil WSF exposure appeared to accelerate spawning readiness in females, resulting in smaller egg diameters in strip-spawned eggs. Additionally, sperm from oil-exposed males showed reduced curvilinear velocity and linearity. Despite these impacts, no significant differences in larval malformations or cardiac activity were observed. Our findings highlight the importance of advancing our understanding of intergenerational impacts of crude oil contamination on key fish species to accurately assess the long-term ecological consequences of petroleum pollution.

Many national and international initiatives aim to control and limit the use of mercury (Hg) in gold extraction. However, the feasibility of Hg eradication from the environment depends on understanding the extent of its distribution. This case study focuses on the spatial and vertical distribution of total mercury (THg) residues at five artisanal mining sites in Tanzania namely, Mgongo, Sekenke, Nyarugusu, Rwamgasa, and Mugusu to assess the feasibility of remediating the problem. The trend showed presence of THg residues in surface layers (0–20 cm), decreasing with depth but still detectable in deeper layers (> 20–100 cm). A horizontal distribution in surface-layer concentrations was also observed along the Mabubi River, which drains across Mugusu mine into Lake Victoria. Among all sites, the highest surface-layer (20 cm) total mercury (THg) concentration was 1.48 ± 0.02 mg/kg, measured from a sample collected at the Nyarugusu mine site, with a moderate decrease to 0.12 ± 0.001 mg/kg at a depth of 100 cm. Other soil samples from the Rwamgasa mine site showed THg concentrations of 0.048 ± 0.012 mg/kg and 0.082 ± 0.01 mg/kg at depths of 70 and 80 cm, respectively. These findings suggest that significant THg residues are detected from surface to deeper layers and wide area of river sediment distribution, mediated by physical, environmental, biological and chemical processes that support simultaneous Hg transport and suspension. The THg residues in soils and sediments challenge the feasibility of remediation efforts in areas with similar wide contamination extents. They demonstrate a long-term legacy of contamination that will continue to impact environmental quality in many regions affected by artisanal mining.