Cadmium (Cd) is a heavy metal toxicant as a common pollutant derived from many agricultural and industrial sources. The absorption of Cd takes place primarily through Cd-contaminated food and water and, to a significant extent, via inhalation of Cd-contaminated air and cigarette smoking. Epidemiological data suggest that occupational or environmental exposure to Cd increases the health risk for osteoporosis and spontaneous fracture such as itai-itai disease. However, the direct effects and underlying mechanism(s) of Cd exposure on bone damage are largely unknown. We used primary bone marrow-derived mesenchymal stromal cells (BMMSCs) and found that Cd significantly induced BMMSC cellular senescence through over-activation of NF-κB signaling pathway. Increased cell senescence was determined by production of senescence-associated secretory phenotype (SASP), cell cycle arrest and upregulation of p21/p53/p16ᴵᴺᴷ⁴ᵃ protein expression. Additionally, Cd impaired osteogenic differentiation and increased adipogenesis of BMMSCs, and significantly induced cellular senescence-associated defects such as mitochondrial dysfunction and DNA damage. Sprague-Dawley (SD) rats were chronically exposed to Cd to verify that Cd significantly increased adipocyte number, and decreased mineralization tissues of bone marrow in vivo. Interestingly, we observed that Cd exposure remarkably retarded bone repair and regeneration after operation of skull defect. Notably, pretreatment of melatonin is able to partially prevent Cd-induced some senescence-associated defects of BMMSCs including mitochondrial dysfunction and DNA damage. Although Cd activated mammalian target of rapamycin (mTOR) pathway, rapamycin only partially ameliorated Cd-induced cell apoptosis rather than cellular senescence phenotypes of BMMSCs. In addition, a selective NF-κB inhibitor moderately alleviated Cd-caused the senescence-related defects of the BMMSCs. The study shed light on the action and mechanism of Cd on osteoporosis and bone ageing, and may provide a novel option to ameliorate the harmful effects of Cd exposure.

Cuttings are the main solid residues which are generated from drilling operations. Due to the presence of heavy and radioactive elements, the environment risk posed by cuttings has attracted increasing attention. In this work, a short-term static immersion experiment was carried out to investigate the leaching of polycyclic aromatic hydrocarbons (PAHs) from oil-based residues of shale gas drilling cuttings. Furthermore, the effects of some relevant environmental factors controlling the leaching behavior were evaluated, including the different particle sizes, pH, extraction time, solid-to-liquid (S/L) ratio and dissolved organic matter (DOM) concentration. The results showed that (1) the concentrations of leached PAHs gradually increased with prolonged leaching time, but the cumulative amount of PAHs released during leaching was less than 3% of the total. (2) The Elovich, parabolic diffusion and power function models were found to fit the experimental data better than the first-order kinetic equation, indicating that the leaching of PAHs was controlled by the coupling of diffusion and chemical reactions at the source surface. (3) Different environmental factors had different impacts on the leaching of PAHs: the shaking time and presence of DOM increased leachability, the particle size and S/L ratio decreased leachability, and the pH did not affect the leachability of PAHs. Therefore, PAHs leaching was a complex process, and it is of scientific and environmental interest to conduct the leaching tests under the simulated environmental conditions.

Despite being effective in controlling mosquito larvae and a few other target organisms, the application of insecticides into aquatic systems may cause unintended alterations to the physiology or behavioral responses of several aquatic non-target organisms, which can ultimately lead to their death. Here, we firstly evaluated whether the susceptibility of the giant water bug, Belostoma anurum (Hemiptera: Belostomatidae), a predator of mosquito larvae, to pyriproxyfen would be similar to that of its potential prey, larvae of Aedes aegypti (Diptera: Culicidae). Secondly, we recorded the nominal concentrations of pyriproxyfen in water and evaluated whether sublethal exposures would lead to physiological or behavioral alterations on the B. anurum nymphs. We characterized the activities of three major families of detoxification enzymes (i.e., cytochrome P450 monooxygenases, glutathione-S-transferase, and general esterases) and further evaluated the abilities of pyriproxyfen sublethally-exposed B. anurum to prey upon A. aegypti larvae at different prey densities. Our findings revealed that nominal pyriproxyfen concentration significantly decreased (approximately 50%) over the first 24 h. Furthermore, when applied at the concentration of 10 μg a.i./L, pyriproxyfen was approximately four times more toxic to A. aegypti larvae (LT₅₀ = 48 h) than to B. anurum nymphs (LT₅₀ = 192 h). Interestingly, the pyriproxyfen sublethally-exposed (2.5 μg a.i./L) B. anurum nymphs exhibited reduced enzyme activities (cytochrome P450 monooxygenases) involved in detoxication processes and preyed significantly less on A. aegypti larvae when compared to unexposed predators. Collectively, our findings demonstrate that mortality-based pyriproxyfen risk assessments are not always protective of aquatic non-target organisms.

Oil and petroleum products are known to be among the most widespread soil pollutants. The risk of emergencies is sure to increase greatly in conditions of abnormally low temperatures. Oil and oil products are not only toxic to the environment, but can also have a negative impact on the state of the permafrost zone, accelerating the processes of permafrost degradation. The goal of the research was to study the soils and bottom sediments for oil pollution in the Arctic region of Yakutia. The research was carried out with using the complex of geochemical and microbiological methods of analysis. It had shown that at present oil pollution was mainly concentrated on the objects bearing a high technogenic load. However, some migration of hydrocarbons was observed with melt, seasonal melt and rainwaters, as a result of which the natural background of the nearby territories became technogenic character. In the Arctic conditions for the first time according to the obtained data on geochemical and microbiological studies oxidative destruction of oil pollutants in soil occurred mainly under the influence of physic and chemical environmental factors, not by microbial oxidation. Sluggish processes of mineralization of organic residues and the transformation of oil pollutants by the type of putrefaction led to the colonization of oil-polluted soils of the Arctic with putrefying and pathogenic microorganisms. The purpose of further research will be studying the possibility of intensification of soil remediation processes of technologically disturbed soils at abnormally low temperatures.

Several studies have reported the contamination of farmed fish by microcystins, however, alternations in levels of contamination resulting from seasonal changes are infrequently described. This investigation is focused on the seasonal accumulation of microcystins in farmed Nile Tilapia muscle tissue across three farms located in Zaria, Nigeria, as a means of assessing the health risks associated with the consumption of contaminated fish. Total microcystins and cyanobacteria content, respectively, in muscle tissue and gut of tilapia varied, seasonally in the farms. Microcystin levels were higher in fish tissues analyzed in the dry season than the rainy season at Nagoyi and Danlami ponds. Correlating with the levels of microcystins found in fish tissues, the highest dissolved microcystins levels in all the fish farms occurred in the dry season, where the Bal and Kol fish farm had the highest concentration (0.265 ± 0.038 μgL⁻¹). Gut analysis of fish obtained from the ponds, revealed a predominance of Microcystis spp. among other cyanobacteria. Estimation of total daily intake of consumed contaminated Nile tilapia muscles reveal values exceeding WHO recommended (0.04 μg kg⁻¹ body weight) total daily intake of MC-LR. Consumption of tilapia from Danlami pond presented the greatest risk with a value of 0.093 μg kg⁻¹ total daily intake. Results of the present study necessitate the implementation of legislation and monitoring programs for microcystins and other cyanobacteria contaminants of fish obtained from farms and other sources in Zaria and indeed several other African countries.

Environmental lead exposure has been linked with reduced kidney function. However, evidence about its role in diabetic kidney damage, especially when considering the nutritional status of vitamin D, is sparse. In this observational study, we investigated the association between low-level lead exposure and urinary albumin-to-creatinine ratio (UACR) and assessed potential impact of vitamin D among 4033 diabetic patients in Shanghai, China. Whole blood lead was measured by graphite furnace atomic absorption spectrometry. Serum 25-hydroxyvitamin D [25(OH)D] was tested using a chemiluminescence immunoassay. The associations of blood lead with UACR and albuminuria, defined as UACR ≥30 mg/g, according to 25(OH)D levels were analyzed using linear and Poisson regression models. A doubling of blood lead level was associated with a 10.7% higher UACR (95% CI, 6.19%–15.5%) in diabetic patients with 25(OH)D < 50 nmol/L, whereas the association was attenuated toward null (2.03%; 95% CI, −5.18% to 9.78%) in those with 25(OH)D ≥ 50 nmol/L. Similarly, the risk ratios of prevalent albuminuria per doubling of blood lead level between the two groups were 1.09 (95% CI, 1.03–1.15) and 0.99 (95% CI, 0.86–1.14), respectively. Joint analysis demonstrated that a combination of high blood lead and low 25(OH)D corresponded to significantly higher UACR. Among diabetic patients with 25(OH)D < 50 nmol/L, the increment of UACR relative to blood lead was more remarkable in those with reduced estimated glomerular filtration rate (<60 mL/min/1.73 m²). These results suggested that higher blood lead levels were associated with increased urinary albumin excretion in diabetic patients with vitamin D deficiency. Further prospective studies are needed to validate our findings and to determine whether vitamin D supplementation yields a benefit.

The present paper reports on the interrelationships of fish, parasites and the bioaccumulation of hazardous organic compounds in the Zemplínska Šírava water reservoir in eastern Slovakia, which is heavily polluted with polychlorinated biphenyls (PCBs). The concentrations of these contaminants were measured in various fish matrices (dorsal and abdominal muscle tissues, hepatopancreas, intestine wall and adipose tissue) of the freshwater bream, Abramis brama (Cyprinidae), and in its intestinal parasite Caryophyllaeus laticeps (Cestoda), which was used for the first time as a model for a PCB bioaccumulation study. Regarding the fish, the highest concentrations of PCBs were found in the intestine, followed by hepatopancreas and muscle tissues. The amounts of PCBs were higher in abdominal muscles than in their dorsal parts. Concentrations of ∑PCBs above the limits set by European regulations were detected in both muscle parts in the fish, confirming the persistent unfavorable conditions in this locality and high risk for biota and humans. Based on bioconcentration factor values (BCFs), PCBs reached much higher levels in cestodes compared to bream matrices. Some significant differences in PCB amounts between infected and uninfected bream were determined. Fulton's condition factor (CF) significantly differed in infected and non-infected fish (p ˂ 0.05), with CF values surprisingly lower in fish free of parasites compared to parasitized fish, which suggests a “mutualistic” relationship between the parasite and its host.

Evaluation of the toxicity of pesticide residues on non-target organisms in the ecosystem is an important part of pesticide environmental risk assessment. Flupyradifurone is a new type of butenolide insecticide produced by Bayer, who claims it to be “low toxic” to non-target organisms in the environment. However, there is little evidence in the literature to show how flupyradifurone affects aquatic organism development. In the current study, zebrafish embryos were treated with 0.1, 0.15, and 0.2 mg/mL of flupyradifurone within 6.0–72 h past fertilization (hpf). We found that the half-lethal concentration (LC₅₀) of flupyradifurone for zebrafish embryos at 96 hpf was 0.21 mg/mL. Flupyradifurone decreases the heart rate, survival rate, and body length of zebrafish embryos. The flupyradifurone treatment also led to the failure of heart looping, and pericardial edema. Moreover, flupyradifurone increased the level of reactive oxygen species (ROS) and decreased the enzymatic catalysis of catalase (CAT) and superoxide dismutase (SOD). Alterations were induced in the transcription of apoptosis-related genes (bcl-2, bax, bax/bcl-2, p53 and caspase-9) and the heart development-related genes (gata4, myh6, nkx2.5, nppa, tbx2b, tbx5 and vmhc). In the current study, new evidences have been provided regarding the toxic effects of flupyradifurone and the risk of its residues in agricultural products and the environment.

The potential environmental risk of glyphosate has promoted the need for decontamination of glyphosate-polluted water bodies. These treatments should be accompanied by studies of the recovery potential of aquatic communities and ecosystems. We evaluated the potential of freshwater periphyton to recover from glyphosate exposure using microcosms under laboratory conditions. Periphyton developed on artificial substrates was exposed to 0.4 or 4 mg l⁻¹ monoisopropylamine salt of glyphosate (IPA) for 7 days, followed by translocation to herbicide-free water. We sampled the community 1, 2 and 3 weeks after the transfer. Dry weight, ash-free dry weight, chlorophyll a, and periphyton abundances were analysed. The periphyton impacted with the lowest IPA concentration recovered most of the structural parameters within 7 days in clean water, but the taxonomic structure did not entirely recover towards the control structure. Periphyton exposed to 4 mg IPA l⁻¹ could not recover during 21 days in herbicide-free water, reaching values almost four times higher in % of dead diatoms and four times lower in ash-free dry weight concerning the control at the end of the study. Results suggest a long-lasting effect of the herbicide due to the persistence within the community matrix even after translocating periphyton to decontaminated water. We conclude that the exposure concentration modulates the recovery potential of IPA-impacted periphyton. The current research is the first to study the recovery in glyphosate-free water of periphyton exposed to the most commonly used herbicide in the world. Finally, we highlight the need for more studies focused on the recovery potential of freshwater ecosystems and aquatic communities after glyphosate contamination.