Benzo[a]pyrene (BaP) is a bio-accumulative toxic compound found in the atmosphere, water, and soil that may affect the life cycle of amphibians. In this study, a few contamination biomarkers, such as hepatic melanomacrophages (MMs), mast cells, erythrocyte micronuclei (MN) and white blood cells were used to determine how BaP acts in these cells in the anurans Physalaemus cuvieri and Leptodactylus fuscus. Animals of both species were divided into three treatment groups: 1 day, 7 days and 13 days, subcutaneously injected 2 mg/kg BaP diluted in mineral oil and control group with only mineral oil. After 7 days, BaP caused the frequency of MN to increase in both species while reducing melanin area. The micronucleus frequency increased due to the genotoxicity of BaP, while the decreasing melanin area may be related to the inhibition of tyrosinase activity, an enzyme responsible for regulating melanogenesis, decreasing the synthesis of melanin. The mast cell density increased in all groups and in both species as a response to the inflammatory action of BaP. These cells respond to nonspecific inflammatory effects leading, therefore, to this response in all treatments. The percentage of leukocytes remained unchanged probably due to great intraspecific variability. Additionally, the leukocyte profiles of both species were characterized and the differences were attributed to extrinsic factors. In short, BaP can affect the integrity of several organs and tissues, and cell functions leading to the conclusion that this compound is hepatotoxic, genotoxic and immunotoxic for anurans.

Although widespread antibiotic resistance has been mostly attributed to the selective pressure generated by overuse and misuse of antibiotics, recent growing evidence suggests that chemicals other than antibiotics, such as certain metals, can also select and stimulate antibiotic resistance via both co-resistance and cross-resistance mechanisms. For instance, tetL, merE, and oprD genes are resistant to both antibiotics and metals. However, the potential de novo resistance induced by heavy metals at environmentally-relevant low concentrations (much below theminimum inhibitory concentrations [MICs], also referred as sub-inhibitory) has hardly been explored. This study investigated and revealed that heavy metals, namely Cu(II), Ag(I), Cr(VI), and Zn(II), at environmentally-relevant and sub-inhibitory concentrations, promoted conjugative transfer of antibiotic resistance genes (ARGs) between E. coli strains. The mechanisms of this phenomenon were further explored, which involved intracellular reactive oxygen species (ROS) formation, SOS response, increased cell membrane permeability, and altered expression of conjugation-relevant genes. These findings suggest that sub-inhibitory levels of heavy metals that widely present in various environments contribute to the resistance phenomena via facilitating horizontal transfer of ARGs. This study provides evidence from multiple aspects implicating the ecological effect of low levels of heavy metals on antibiotic resistance dissemination and highlights the urgency of strengthening efficacious policy and technology to control metal pollutants in the environments.

Benzene is widely employed in the field of production, and its toxicity on biological systems has received increasing attention. Cell proliferation is a major life characteristic of living organisms. KLF15 and NOTCH1 are mature and classical genes in cell proliferation studies, particularly in the area of tumor investigation. The aim of this study was to investigate the effect and mechanism of VNN3 on cell proliferation induced by 1,4-benzoquinone (1,4-BQ), an important metabolite of benzene, and obtain a sensitive biomarker for the hazard screening and health care of benzene exposure. Normally growing AHH-1 cells were cultured in vitro and were incubated with different concentrations of 1,4-BQ (0, 10, 20, and 40 μM) for 24 h. A CCK-8 assay was used to assess the cell viability, whereas EdU was used to detect the cell proliferation of AHH-1 cells. The expression of VNN3, KLF15 and NOTCH1 was detected by real-time PCR. Moreover, a lentiviral model was constructed in AHH-1 cells to interfere with VNN3 expression. The results showed that 1,4-BQ clearly increased the expression of VNN3. Moreover, 1,4-BQ dose-dependently inhibited cell proliferation and caused increased KLF15 expression; in contrast, the NOTCH1 expression decreased in AHH-1 cells. Furthermore, following interference with the VNN3 expression, the cell proliferation inhibition and the expression of KLF15 and NOTCH1 were rescued. To further investigate the action of VNN3 in benzene hematotoxicity, we assessed it in benzene-exposed workers. The results showed that there was a remarkable correlation between the VNN3 expression and hemogram, which included RBC, NEUT and HGB. In addition, analysis of the KLF15 and NOTCH1 expression showed that the VNN3 expression was related to cell proliferation, which was consistent with the in vitro results. In conclusion, VNN3 influences cell proliferation induced by 1,4-BQ by regulating the expression of KLF15 and NOTCH1. VNN3 may represent a potential biomarker of benzene toxicity.

In August 2016, continuous measurements of volatile organic compounds (VOCs) and trace gases were conducted at an urban site in Wuhan. Four high-ozone (O3) days and twenty-seven non-high-O3 days were identified according to the China's National Standard Level II (∼100 ppbv). The occurrence of high-O3 days was accompanied by tropical cyclones. Much higher concentrations of VOCs and carbon monoxide (CO) were observed on the high-O3 days (p < 0.01). Model simulations revealed that vehicle exhausts were the dominant sources of VOCs, contributing 45.4 ± 5.2% and 37.3 ± 2.9% during high-O3 and non-high-O3 days, respectively. Both vehicle exhausts and stationary combustion made significantly larger contributions to O3 production on high-O3 days (p < 0.01). Analysis using a chemical transport model found that local photochemical formation accounted for 74.7 ± 5.8% of the daytime O3, around twice the regional transport (32.2 ± 5.4%), while the nighttime O3 was mainly attributable to regional transport (59.1 ± 9.9%). The local O3 formation was generally limited by VOCs in urban Wuhan. To effectively control O3 pollution, the reduction ratio of VOCs to NOx concentrations should not be lower than 0.73, and the most efficient O3 abatement could be achieved by reducing VOCs from vehicle exhausts. This study contributes to the worldwide database of O3-VOC-NOx sensitivity research. Its findings will be helpful in formulating and implementing emission control strategies for dealing with O3 pollution in Wuhan.

The occurrence and transportation of antibiotics in biofilms from natural and engineered sources have attracted increasing interests. Nevertheless, the effects of extracellular polymeric substances (EPS) on the responses of biofilms to the exposure to antibiotics are not clear. In this study, the effects of EPS on the sorption and biological responses to one representative antibiotic, sulfamethizole (STZ), in model biofilms were investigated. Proteins dominated the interactions between the EPS and the STZ and the EPS from a moving bed biofilm reactor exhibited the strongest interaction with the STZ. The EPS served as important reservoirs for the STZ and the tested biofilms all showed reduced sorption capacities for the STZ after the EPS were extracted. The respiratory rates and typical enzymatic activities were reduced after the EPS were extracted. High-throughput 16S rRNA gene sequencing results confirmed that the bacterial community in the biofilm without the EPS was more vulnerable to antibiotic shock as indicated by the community diversity and richness indices. A greater increase in the abundance of susceptible species was observed in the natural biofilm. The results comprehensively suggested that the EPS played important role in biosorption of STZ and alleviated the direct damage of the antibiotic to the cells; in addition the extent of the bacterial community response was associated with the origins of the biofilms. Our study provided details on the responses of multi-species biofilms to the exposure to an antibiotic and highlighted the role of the EPS in interacting with the antibiotic, thereby providing a deeper understanding of the bioremediation of antibiotics in real-life natural and engineered biofilm systems.

Sewage sludge from a municipal wastewater treatment facility employing activated sludge process was pre-incubated with varying substrates and mixtures of substrates including metformin (MET), guanylurea (GUA) and glucose. The biomass from enriched cultures separately utilising MET and glucose/GUA was then used to investigate the kinetics of aerobic biodegradation of MET and GUA, respectively, as individual substrates in batch reactors. The results showed that GUA can be completely degraded as a nitrogen source when glucose is provided as a carbon and energy source. On the contrary, MET can be biodegraded as a sole carbon and energy source. However, formation of by-product GUA in solution, which acts as a nitrogen source, rapidly increased the degradation rate of MET resembling autocatalytic behaviour. At low starting concentration of 5 mg/L, the specific substrate utilisation rates of MET and GUA were 0.0033 day⁻¹ and 0.0013 day⁻¹, respectively, which is reported first time in this study. Out of the five biodegradation kinetic models used to describe substrate utilisation, the Quiroga-Sales-Romero (QSR) model was found to predict the measured MET and GUA degradation profile well supported by the goodness of fit parameters. Furthermore, the QSR model was able to describe the autocatalytic degradation of MET and the incomplete biodegradation of GUA in solution.

The widely used Di-(2-ethylhexyl) phthalate (DEHP) has been reported to exhibit ubiquitous environmental and global health hazards. The bioaccumulation and environmental persistence of DEHP can cause serious health hazards in wildlife animals and human. However, DEHP-induced nephrotoxicity in bird is remained unknown. Thus, this study explored the related mechanism of DEHP nephrotoxicity in quail. For this purpose, quail were exposed with DEHP at doses of 0, 250, 500, and 1000 mg/kg body weight daily by gavage administration for 45 days. The results showed that DEHP exposure induced renal injury, oxidative stress, and endoplasmic reticulum (ER) degeneration. Low level DEHP (250 mg/kg) exposure inhibited Nrf2 signaling pathway and induced renal injury via oxidative stress and suppressed the unfolded protein response (UPR) signaling pathway and induced ER stress in the kidney. But surprisingly, high level DEHP (500 mg/kg and 1000 mg/kg) exposure activated Nrf2 and UPR signaling pathways and protected kidney, but they still couldn't resist the toxicity of DEHP. Our study demonstrated that DEHP-induced nephrotoxicity in quail was associated with activating Nrf2-mediated antioxidant defense response and UPR signaling pathway.

Heavy metal pollution of urban stormwater poses potential risks to human and ecosystem health. The design of reliable pollution mitigation strategies requires reliable stormwater modelling approaches. Current modelling practices do not consider the influence of urbanisation characteristics on stormwater quality. This could undermine the accuracy of stormwater quality modelling results. This research study used a database consisting of over 1000 datasets to compare the characteristics of heavy metal build-up (one of the most important stormwater pollutant processes) on urban surfaces under the influence of anthropogenic and natural factors specific to different urban regions from China (Shenzhen) and Australia (Gold Coast), using Bayesian Networks. The outcomes show that the differences in heavy metals build-up loads between the two regions (mean value for Shenzhen – mean value for Gold Coast)/mean value for Shenzhen) were 0.45 (Al), 0.88 (Cr), 0.99 (Mn), 0.68 (Fe), 0.98 (Ni), 0.24 (Cu), 0.47 (Zn) and 0.13 (Pb), respectively. The research outcomes also confirmed that the influence of traffic on the build-up of different sized particles varies between Shenzhen and Gold Coast, and traffic plays distinct roles as a source and as a factor that drives heavy metal re-distribution. The road surface roughness was also found to influence build-up process differently between the two regions. More importantly, the assessment of inherent process uncertainty revealed that heavy metal build-up between different road sites in Shenzhen varies over a wider range than in Gold Coast. The study highlighted a clear distinction in the influence of sources and key anthropogenic factors on the variability of particle-bound heavy metals build-up between geographically different urban regions. The study outcomes provide new knowledge to enhance the accuracy of urban stormwater quality modelling.

Five Descriptors (D) of Marine Strategy Framework Directive (MSFD): marine litter (D10), non-indigenous species (D2) and organic and inorganic pollutants (D8), were estimated in a coastal area of GSA 16 (Augusta harbour, Central Mediterranean Sea) in order to study their effects on the biodiversity (D1) of the benthic community D6) and to improve data for the MSFD. Investigation of plastic debris had led to the identification of 38 fragments divided into four categories, among which microplastics resulted as the most abundant. Six non-indigenous species, belonging to Polychaeta (Kirkegaardia dorsobranchialis, Notomastus aberans, Pista unibranchia, Pseudonereis anomala, Branchiomma bairdi) and Mollusca (Brachidontes pharaonis) were found. Biodiversity and benthic indices suggested a generalised, slightly disturbed ecological status. Anthracene, Zinc and Chrome were the most abundant chemical compounds in analysed sediments. Significant correlations were found between the abundance of trace elements vs biotic indices and between plastic debris vs biodiversity and benthic indices. This study represents the first report about the abundance of plastic debris and its relationship to contaminants and infauna in Augusta harbour. Our results can provide useful information for national and international laws and directives.

Polar regions are fragile ecosystems threatened by both long-range pollution and local human contamination. In this context, the environmental distribution of the Personal Care Products (PCPs) represent a major knowledge gap. Following preliminary Antarctic studies, Fragrance Materials (FMs) were analyzed in the seawater and snow collected in the area of Ny-Ålesund, Svalbard, to investigate local and long-range contamination. Polycyclic Aromatic Hydrocarbons (PAHs), including Retene, were determined in parallel to help the identification of the governing processes. Concentrations of FMs up to 72 ng L⁻¹ were detected in the surface snow near the settlement and at increasing distances, in relation to the prevailing winds. PAHs follow a similar scheme, with levels of Retene up to 1.8 μg L⁻¹, likely deriving from the occurrence of this compound in the coal dust due to the previous mining activities in the area. The snow seasonal deposition of FMs and PAHs was estimated in a snowpit dug at the top of the Austre Brøggerbreen glacier, indicating the long-range atmospheric transport (LRAT) of these compounds.