Silver nanoparticles (AgNPs) are expected to enter aquatic systems, but there are limited data on how they might affect microbial communities in pathogen impaired streams. We examined microbial community responses to citrate-AgNP (10.9 ± 0.7 nm) and polyvinylpyrrolidone (PVP)–AgNP (11.0 ± 0.7 nm) based on microbial concentration and enzyme activity in sediment from a pathogen impaired stream. Addition of each nanoparticle to sediment caused at least a 69% decrease in microbial concentration (1,264 ± 93.6 to 127 ± 29.5 CFU/g) and a 62% decrease in β-glucosidase activity (11.7 ± 2.1 to 1.3 ± 0.3 μg/g/h). Each AgNP reduced alkaline phosphatase activity but their effects were not statistically significant. Sediment exposed to 0.108 mg Ag/kg of AgNO₃ resulted in a 92% decrease in microbial concentration and a reduced enzyme activity which was not statistically significant. Measured total silver in sediments treated with AgNPs which exhibited significant inhibition effects on the microbial community ranged from 0.19 ± 0.02 to 0.39 ± 0.13 mg Ag/kg. These concentrations tested in this study are much lower than the expected concentrations (2–14 mg Ag/kg) in freshwater sediments. The results of this study demonstrate that AgNPs can alter microbial community activity and population size, which may lead to false negative fecal indicator bacteria detection and enumeration using methods that rely on β-glucosidase activity. We conclude that the presence of AgNPs in impaired streams and recreational waters can influence pathogen detection methods, potentially affecting public health risk estimates.

The objective of the present study was to investigate recent concentrations of perfluoroalkyl substances (PFASs) in white whales (Delphinapterus leucas) from Svalbard and compare them to concentrations found in white whales sampled from that same area 15 years ago. Plasma collected from live-captured white whales from two time periods (2013–2014, n = 9, and 1996–2001, n = 11) were analysed for 19 different PFASs. The 11 PFASs detected included seven C₈–C₁₄ perfluoroalkyl carboxylates (PFCAs) and three C₆–C₈ perfluoroalkyl sulfonates (PFSAs) as well as perfluorooctane sulfonamide (FOSA). Recent plasma concentrations (2013–2014) of the dominant PFAS in white whales, perfluorooctane sulfonate (PFOS; geometric mean = 22.8 ng/mL), was close to an order of magnitude lower than reported in polar bears (Ursus maritimus) from Svalbard. PFOS concentrations in white whales were about half the concentrations in harbour (Phoca vitulina) and ringed (Pusa hispida) seals, similar to hooded seals (Cystophora cristata) and higher than in walruses (Odobenus rosmarus) from that same area. From 1996 to 2001 to 2013–2014, plasma concentrations of PFOS decreased by 44%, whereas four C₉₋₁₂ PFCAs and total PFCAs increased by 35–141%. These results follow a similar trend to what has been reported in other studies of Arctic marine mammals from Svalbard. The most dramatic change has been the decline of PFOS concentrations since 2000, corresponding to the production phase-out of PFOS and related compounds in many countries around the year 2000 and a global restriction on these substances in 2009. Still, the continued dominance of PFOS in white whales, and increasing concentration trends for several PFCAs, even though exposure is relatively low, calls for continued monitoring of concentrations of both PFCAs and PFSAs and investigation of biological effects.

Periphyton, composed of algae, bacteria, protozoa, epiphytes, and detritus, is widely distributed on the surfaces of paddy soils. Little is known about the interactions between the periphyton and arsenic (As) in the paddy soil. In the present study, model paddy ecosystems with and without periphyton were set up to explore the effects of periphyton on As migration and transformation in soil. According to the results, periphyton played dual roles in the mobility of As in soil. Periphyton on the surface of paddy soil could significantly increase the mobility and bioavailability of As in soils in the rice tillering stage because of the increased pH and the decreased Eh. The As uptake by rice also increased in the presence of periphyton. However, a significant fraction of the released As was further entrapped by the periphyton, significantly decreasing As concentration in pore water. As biotransformation genes, including aioA, arrA, arsC, and arsM, were identified in periphyton, with arsM being the most abundant in periphyton and soil. Periphyton significantly decreased the abundance of aioA, but increased the abundance of arsC in soils. Cupriavidus and Afipia, which are involved in As(V) cytoplasmic reduction, significantly increased in the presence of periphyton. Periphyton exerted minor effects on the highly abundant and predominant bacteria but had major effects on the less abundant bacteria in the paddy soil. The results of the present study could facilitate the regulation of As contamination in paddy soil, and enhance our understanding of the role of periphyton in the As biogeochemical cycle.

This study investigated the tissue distribution of phenanthrene (PHE) and the formation of monohydroxy-phenanthrene (OH-PHE) metabolites in Korean rockfish (Sebastes schlegelii). PHE was intragastrically administered to two groups of rockfish. The first group was exposed to PHE at a low dose (10 mg/kg body weight) and the second group was exposed at a high dose (30 mg/kg body weight). The rockfish were analyzed and the levels of PHE were higher in the liver, followed by muscle, and then bile. PHE concentrations in the liver, muscle, and bile were 1.4–26, 0.10–2.01, and not detected (ND)–0.13 μg/g wet weight, respectively. All five monohydroxylated PHE metabolites (1-OH-PHE, 2-OH-PHE, 3-OH-PHE, 4-OH-PHE, and 9-OH-PHE) were detected only in bile. Among these OH-PHE metabolites, 3-OH-PHE was found at the highest concentration from all fish bile samples in both PHE exposure groups, indicating that regioselective OH-PHE formation occurs in rockfish and 3-OH PHE could be a good biomarker of exposure of Korean rockfish to PHE. Suspect screening analysis of the rockfish bile was performed by LC-QTOF/MS, and the formation of two OH-PHE-DNA adducts (thymine–OH–PHE and cytosine–OH–PHE) were identified in the bile sample collected 6 h after rockfish were exposed to the high PHE dose, indicating that OH-PHE metabolites may be toxic to fish. This is the first report on the formation characteristics of OH-PHE metabolites in rockfish and their use as biomarkers of exposure of rockfish to parent PHE.

In this study, the tips of Myriophyllum aquaticum (M. aquaticum) plants were planted in open-top plastic bins and treated by simulated wastewater with various ammonium-N concentrations for three weeks. The contents of related carbohydrates and key enzyme activities of carbon metabolism were measured, and the mechanisms of carbon metabolism regulation of the ammonia tolerant plant M. aquaticum under different ammonium-N levels were investigated. The decrease in total nonstructural carbohydrates, soluble sugars, sucrose, fructose, reducing sugar and starch content of M. aquaticum were induced after treatment with ammonium-N during the entire stress process. This finding showed that M. aquaticum consumed a lot of carbohydrates to provide energy during the detoxification process of ammonia nitrogen. Moreover, ammonia-N treatment led to the increase in the activitives of invertase (INV) and sucrose synthase (SS), which contributed to breaking down more sucrose to provide substance and energy for plant cells. Meanwhile, the sucrose phosphate synthase (SPS) activity was also enhanced under stress of high concentrations of ammonium-N, especially on day 21. The result indicated that under high-concentration ammonium-N stress, SPS activity can be significantly stimulated by regulating carbon metabolism of M. aquaticum, thereby accumulating sucrose in the plant body. Taken together, M. aquaticum can regulate the transformation of related carbohydrates in vivo by highly efficient expression of INV, SPS and SS, and effectively regulate the osmotic potential, thereby delaying the toxicity of ammonia nitrogen and improving the resistance to stress. It is very important to study carbon metabolism under ammonia stress to understand the ammonia nitrogen tolerance mechanism of M. aquaticum.

In China, ambient fine particulate matter (PM₂.₅) causes a large health burden and raises specific concerns for policymakers. However, assessments of the health effects associated with air pollution from industrial land layouts remain inadequate. This study established a comprehensive assessment framework to quantify the health and economic impacts of PM₂.₅ exposure at different industrial geographical locations. This framework aims to optimize the spatial distribution of industrial emissions to achieve the lowest public health costs in Changsha, a representative industrial city in China. Health effects were estimated by applying the integrated exposure-response model and a long-range pollution dispersion model (CALPUFF). The value of statistical life (VSL) was used to monetize health outcomes. It was found that implementing an optimal industrial land layout can yield considerable social and financial benefits. Compared with the current industrial space layout, in 2030, the averted contribution by Changsha’s industrial sector to PM₂.₅-related mortality and corresponding economic losses will be 60.8% and 0.69 billion US dollars (USD), respectively. The results of optimization analyses highlighted that population density and emission location are significant factors affecting the health burden. This method can identify the optimal geographical allocation of industrial land with minimal expected health and economic burden. These results will also provide policymakers with a measurable assessment of health risks related to industrial spatial planning and the associated health costs to enhance the effectiveness of efforts to improve air quality.

Contamination by potentially toxic elements (PTEs) in children’s toys and jewelry is an ongoing problem where PTEs can become bioavailable especially via oral pathway (ingestion as a whole or of parts, and mouthing) and may cause adverse health effects for children. In the present review, legislation updates from the last decade in the United States (U.S.), Canada, and the European Union (E.U.) on PTEs in toys and jewelry are presented. Then, a literature review mostly covering the last decade on the total concentration, bioavailability, children’s exposure, and bioaccessibility of PTEs in toys and jewelry is provided. The U.S. and Canadian legislations mainly focus on lead (Pb) and cadmium (Cd) total/soluble concentration limits to prevent exposure and have received several updates within the last decade, extending particularly the covered span of children’s products. It seems that the introduction, subsequent enforcement, and update of regulations in developed countries have shifted the problem towards developing countries. In terms of categories, metallic toys and children’s jewelry still have the most severe PTE contamination and the presence of Pb and Cd in these articles is an ongoing issue. Some studies suggest that color can be used as an indicator for the potential presence of PTEs (linked to chemicals such as lead chromate, cadmium sulfide) but the evidence is not always clear. Another concern is vintage/second-hand toys and jewelry as those items might have been produced before the legislation was present. As total and bioaccessible concentrations of PTEs in toys and jewelry do not always correlate, approaches considering bioaccessibility (e.g. of the E.U.) are more scientifically appropriate and help with better estimation of risk from exposure. Studies on toy and jewelry contamination using in vitro bioaccessibility techniques has become more common, however, there is still no in vitro test specifically designed and validated for toys and jewelry.

Apoptosis of vascular smooth muscle cells (VSMCs) accelerates manifestation of plaque vulnerability in atherosclerosis. Long noncoding RNA NEAT1 participates in the proliferation and apoptosis of cells. In addition, circadian clock genes play a significant role in cell apoptosis. However, whether acrolein, an environmental pollutant, affects the apoptosis of VSMCs by regulating NEAT1 and clock genes is still elusive. We established VSMCs as an atherosclerotic cell model in vitro. Acrolein exposure reduced survival rate of VSMCs, and raised apoptosis percentage through upregulating the expression of Bax, Cytochrome c and Cleaved caspase-3 and downregulating Bcl-2. Asparagus extract (AE), as a dietary supplementation, was able to protect VSMCs against acrolein-induced apoptosis. Expression of NEAT1, Bmal1 and Clock was decreased by acrolein, while was ameliorated by AE. Knockdown of NEAT1, Bmal1 or Clock promoted VSMCs apoptosis by regulating Bax, Bcl-2, Cytochrome c and Caspase-3 levels. Correspondingly, overexpression of NEAT1 inhibited the apoptosis. We also observed that silence of NEAT1 repressed the expression of Bmal1/Clock and vice versa. In this study, we demonstrated that VSMCs apoptosis induced by acrolein was associated with downregulation of NEAT1 and Bmal1/Clock. AE alleviated the effects of proapoptotic response and circadian disorders caused by acrolein, which shed a new light on cardiovascular protection.

Carbapenems are used as last-resort drugs to treat infections caused by multidrug-resistant bacteria. Despite the increasing number of reports of carbapenem-resistant Enterobacteriaceae (CRE), there is still limited information on their distribution or prevalence in the environment. Our aim was to assess the occurrence of CRE in the Lis river (Portugal) and to characterize the genetic platforms linked to carbapenemase genes. We collected six water samples from sites near a wastewater treatment plant (n = 4 samples) and livestock farms (n = 2). Twenty-four CRE were characterized by BOX element-polymerase chain reaction (BOX-PCR), and thirteen representative isolates were analysed by Pulsed-Field Gel Electrophoresis (PFGE) and by sequencing the 16S rRNA gene. Antimicrobial susceptibility testing, PCR screening for carbapenemase-encoding genes, conjugation experiments and plasmid analysis were performed. Four isolates were chosen for whole-genome sequencing. All water samples contained CRE (4.0 CFU/mL on average). Representative isolates were multidrug-resistant (resistant to ciprofloxacin, trimethoprim-sulfamethoxazole and to all β-lactams tested) and were identified as K. pneumoniae, Enterobacter and Citrobacter. Isolates carried plasmids and harboured carbapenemase-encoding genes: blaKPC₋₃ in K. pneumoniae (n = 9), blaNDM₋₁ in Enterobacter (n = 3) and blaGES₋₅ in Citrobacter (n = 1). Conjugation experiments were successful in two Klebsiella isolates. Enterobacter PFGE profiles grouped in one cluster while Klebsiella were divided in three clusters and a singleton. Whole-genome sequencing analysis revealed blaGES₋₅ within a novel class 3 integron (In3-16) located on an IncQ/pQ7-like plasmid in Citrobacter freundii CR16. blaKPC₋₃ was present on IncFIA-FII pBK30683-like plasmids, which were subsequently confirmed in all K. pneumoniae (n = 9). Furthermore, blaKPC₋₃ was part of a genomic island in K. pneumoniae CR12. In E. roggenkampii CR11, blaNDM₋₁ was on an IncA/C₂ plasmid. The carbapenemase-encoding plasmids harboured other resistance determinants and mobile genetic elements. Our results demonstrate that Lis river is contaminated with CRE, highlighting the need for monitoring antibiotic resistance in aquatic environments, especially to last-resort drugs.

Activity concentrations of the radioactive cesium (¹³⁴Cs and ¹³⁷Cs) were investigated in invertebrates at two sites of moderately high and higher air radiation dose rates, 14 km and 11 km distances, respectively, from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) from 2013 to 2016. At a14-km point, the ¹³⁴⁺¹³⁷Cs concentrations of soils in coniferous and broadleaf forests increased from 2013 to 2014, and thereafter declined until 2016. The ¹³⁴⁺¹³⁷Cs concentrations of the phytophagous beetle Anomala cuprea (Hope) rapidly decreased by 76.1% from 2013 to 2014, reflecting reduction in those of broadleaves. The ¹³⁴⁺¹³⁷Cs concentration levels of the carnivorous beetle Dolichus halensis (Schaller) showed a relatively low levels. The ¹³⁷Cs concentrations of the necrophagous beetle Eusilpha japonica (Motshulsky) and coprophagous beetle Onthophagus lenzii (Harold) remained constant without reduction from 2013 to 2016. Average ¹³⁴⁺¹³⁷Cs concentrations throughout four years were the highest in the geophagous crustacean (Armadillidium vulgare Latreille), followed by necrophagous beetle and coprophagus beetle. The ¹³⁴⁺¹³⁷Cs concentrations in earthworms with gut contents were significantly correlated with those in soils at each habitat from 2014 to 2015 at a14-km point, and the concentration levels at an 11-km point in 2015 were remarkably high (898 kBq kg⁻¹). Transfer factors (TFs) in earthworms ranged from 1.02 to 2.66 at a 14-km point and 0.66 to 5.0 at an11-km point. The transfer and chronological changes of radiocesium in invertebrates were discussed in relation to food habits through trophic levels in woodlands and pasturelands.