The growing use of coastal areas for different economic purposes is responsible for increasing pollution by hydrocarbons in marine environments. As a consequence of these activities, accidents during fuel extraction, transport, and storage can occur, causing intense environmental degradation. Numerical modeling of the trajectory of oil stains becomes an important tool with low operational costs, providing powerful support to the government agencies in charge of risk management associated with possible oil accidents, by helping to generate scenarios and strategies for containment and cleaning of affected environments. In this sense, the aim of this study is to estimate environmental vulnerability to oil at beaches located in the Itapuã State Park (PEI), a Protection Conservation Unit. This work focused on describing a methodology to estimate the vulnerability of coastal areas, with emphasis on the fact that the study was carried out in a closed environment. For that, an approach was used based on the integration of: (1) an intrinsic variable to the environment; (2) a dynamic variable determined through diesel oil surface dispersion scenarios. Four hypothetical accident scenarios with 20 m³ of diesel oil were simulated in 2018, during five days of simulations with instant dumping in the navigation channel of the local waterway near the PEI. The results suggest the forcing of the field of intensity and direction of the local winds as preponderant for the dynamics of movement and structure of the spots, with the zonal and meridional components of the fields of superficial currents acting in this process as a secondary factor. The study showed that all beaches in the park are susceptible to contact with oil throughout the simulated year, with Pombas Beach, Pedreira Beach, and Onça Beach being affected in all simulated scenarios, which classifies them as very high vulnerability and defines them as priority protection areas.

Quantifying the sources of atmospheric particles is essential to air quality control but remains challenging, especially for the source apportionment of particles based on number concentration with wide size range. Here, particle number concentrations (PNC) with size range 19–20,000 nm involving four modes Nucleation, Aitken, Accumulation, and Coarse are used to do source apportionment of PNC at the Guangdong Atmospheric Supersite (Heshan) during July–October 2015 by nonnegative matrix factorization (NMF) with 6 factors. For July 2015, separated source apportionments for three different size ranges from collocated instruments nano scanning mobility particle sizer (NSMPS), SMPS, and aerodynamic particle sizer (APS) and for two different size ranges (below and above 100 nm) show similar quantitative source information with that for the one whole size range. The mean absolute difference of contribution percentages of total particle number concentrations (TPNC) based on 5 unique apportioned sources is 5.6 % (4.3–7.6 %) for the instrument segregated apportionment and 4.2 % (0–5.3 %) for the size range segregated apportionment respectively, relative to the one whole apportionment. Moreover, the contribution percentages of TPNC are close to the weighted sum of contribution percentages of all size bins, with a mean absolute difference of 1.1 % (0–3.4 %). In both these two aspects, the consistency among different technical paths proves the matrix factorization by NMF is practically desirable and the simplicity of reducing some steps or calculations saves time. Besides, dust can be identified with the wide size range including larger than 3000 nm. Six apportioned sources in the 4 months are Accumulation (32.4 %), Nucleation (20.0 %), Aitken (15.2 %), traffic (14.6 %), dust (10.6 %), and Coarse (7.1 %). Therefore, NMF would serve as a promising tool for PNC source apportionment with wide size range and conducting the apportionment with the whole size range in one matrix factorization procedure and using the single TPNC contribution percentage are feasible.

Mangrove sediment is a major sink for phenanthrene in natural environments. Consequently, this study investigated the effects of seasonal variation on the biodegradation rates of low (150 mg kg⁻¹), moderate (600 mg kg⁻¹), and high (1200 mg kg⁻¹) phenanthrene-contaminated mangrove sediments using a microcosm study and identified potential key phenanthrene-degrading bacteria using high throughput sequencing of 16 S rRNA gene and quantitative-PCR of the PAH-ring hydroxylating dioxygenase (PAH-RHDα) genes. The biodegradation rates of phenanthrene in all treatments were higher in the wet-season sediments (11.58, 14.51, and 8.94 mg kg⁻¹ sediment day⁻¹) than in the dry-season sediments (3.51, 12.56, and 5.91 mg kg⁻¹ sediment day⁻¹) possibly due to higher nutrient accumulation caused by rainfall and higher diversity of potential phenanthrene-degrading bacteria. The results suggested that the mangrove sediment microbiome significantly clustered according to season. Although Gram-negative phenanthrene-degrading bacteria (i.e., Anaerolineaceae, Marinobacter, and Rhodobacteraceae) played a key role in both dry and wet seasons, distinctly different phenanthrene-degrading bacterial taxa were observed in each season. Halomonas and Porticoccus were potentially responsible for the degradation of phenanthrene in the dry and wet seasons, respectively. The knowledge gained from this study contributes to the development of effective and rationally designed microbiome innovations for oil removal.

Antibiotic resistance genes (ARGs) are now viewed as emerging contaminants posing a potential worldwide human health risk. The degree to which ARGs are transferred to other bacteria via mobile genetic elements (MGEs), including insertion sequences (ISs), plasmids, and phages, has a strong association with their likelihood to function as resistance transfer determinants. Consequently, understanding the structure and function of MGEs is paramount to assessing future health risks associated with ARGs in an environment subjected to strong antibiotic pressure. In this study we used whole genome sequencing, done using MinION and HiSeq platforms, to examine antibiotic resistance determinants among four multidrug resistant bacteria isolated from fish farm effluent in Jeju, South Korea. The combined data was used to ascertain the association between ARGs and MGEs. Hybrid assembly using HiSeq and MinION reads revealed the presence of IncFIB(K) and pVPH2 plasmids, whose sizes were verified using pulsed field gel electrophoresis. Twenty four ARGs and 95 MGEs were identified among the 955 coding sequences annotated on these plasmids. More importantly, 22 of 24 ARGs conferring resistance to various antibiotics were found to be located near MGEs, whereas about a half of the ARGs (11 out of 21) were so in chromosomes. Our results also suggest that the total phenotypic resistance exhibited by the isolates was mainly contributed by these putatively mobilizable ARGs. The study gives genomic insights into the origins of putatively mobilizable ARGs in bacteria subjected to selection pressure.

Considerable human data have shown that the exposure to perfluorooctane sulfonate (PFOS) correlates to the risk of metabolic diseases, however the underlying effects are not clearly elucidated. In this study, we investigated the impacts of PFOS treatment, using in-vivo, ex-vivo and in-vitro approaches, on pancreatic β-cell functions. Mice were oral-gavage with 1 and 5 μg PFOS/g body weight/day for 21 days. The animals showed a significant increase in liver triglycerides, accompanied by a reduction of triglycerides in blood sera and glycogen in livers and muscles. Histological examination of pancreases showed no noticeable changes in the size and number of islets from the control and treatment groups. Immunohistochemistry showed a reduction of staining intensities of insulin and the transcriptional factors (Pdx-1, islet-1) in islets of pancreatic sections from PFOS-treated groups, but no changes in the intensity of Glut2 and glucagon were noted. Transcriptomic study of isolated pancreatic islets treated ex vivo with 1 μM and 10 μM PFOS for 24 h, underlined perturbations of the insulin signaling pathways. Western blot analysis of ex-vivo PFOS-treated islets revealed a significant reduction in the expression levels of the insulin receptor, the IGF1 receptor-β, Pdk1-Akt-mTOR pathways, and Pdx-1. Using the mouse β-cells (Min-6) treated with 1 μM and 10 μM PFOS for 24 h, Western blot analysis consistently showed the PFOS-treatment inhibited Akt-pathway and reduced cellular insulin contents. Moreover, functional studies revealed the inhibitory effects of PFOS on glucose-stimulated insulin-secretion (GSIS) and the rate of ATP production. Our data support the perturbing effects of PFOS on animal metabolism and demonstrate the underlying molecular targets to impair β-cell functions.

Global increase in demand for food supply has resulted in surplus generation of wastes. What was once considered wastes, has now become a resource. Studies were carried out on the conversion of biowastes into wealth using methods such as extraction, incineration and microbial intervention. Agro-industry biowastes are promising sources of carbon for microbial fermentation to be transformed into value-added products. In the era of circular economy, the goal is to establish an economic system which aims to eliminate waste and ensure continual use of resources in a close-loop cycle. Biowaste collection is technically and economically practicable, hence it serves as a renewable carbon feedstock. Biowastes are commonly biotransformed into value-added materials such as bioethanol, bioplastics, biofuels, biohydrogen, biobutanol and biogas. This review reveals the recent developments on microbial transformation of biowastes into biotechnologically important products. This approach addresses measures taken globally to valorize waste to achieve low carbon economy. The sustainable use of these renewable resources is a positive approach towards waste management and promoting circular economy.

In order to better understand the environmental risks of the rare earth elements (REEs), it is necessary to determine their fate and biological effects under environmentally relevant conditions (e.g. at low concentrations, REE mixtures). Here, the unicellular freshwater microalga, Chlamydomonas reinhardtii, was exposed for 2 h to one of three soluble REEs (Ce, Tm, Y) salts at 0.5 μM or to an equimolar mixture of these REEs. RNA sequencing revealed common biological effects among the REEs. Known functions of the differentially expressed genes support effects of REEs on protein processing in the endoplasmic reticulum, phosphate transport and the homeostasis of Fe and Ca. The only stress response detected was related to protein misfolding in the endoplasmic reticulum. When the REEs were applied as a mixture, antagonistic effects were overwhelmingly observed with transcriptomic results suggesting that the REEs were initially competing with each other for bio-uptake. Metal biouptake results were consistent with this interpretation. These results suggest that the approach of government agencies to regulate the REEs using biological effects data from single metal exposures may be a largely conservative approach.

Despite Australia's high reliance on coal for electricity generation, no study has addressed the extent to which mercury (Hg) deposition has increased since the commissioning of coal-fired power plants. We present stratigraphic data from lake sediments in the Hunter Valley (New South Wales) and Latrobe Valley (Victoria), where a significant proportion of Australia's electricity is generated via coal combustion. Mercury deposition in lake sediments increased in the 1970s with the commissioning of coal-fired power plants, by a factor of 2.9-times in sediments of Lake Glenbawn (Hunter Valley) and 14-times in Traralgon Reservoir (Latrobe Valley). Sediments deposited after the commissioning of power plants have distinct Hg isotope compositions, similar to those of combusted coals. Mercury emission, estimated using an atmospheric model (CALPUFF), was higher in the Latrobe Valley than in the Hunter Valley. This is a result of higher Hg concentrations in lignite coal, lax regulation and older pollution-control technologies adopted by coal-fired power plants in the Latrobe Valley. Near-source deposition of Hg in Australia is significantly higher than North America and Europe, where better emission controls (e.g. wet flue gas desulfurization) have been in effect for decades. The challenge for Australia in years to come will be to ratify the Minamata Convention and develop better regulation policies to reduce Hg emissions.

Urban horticulture (UH) has been proposed as a solution to increase urban sustainability, but the potential risks to human health due to potentially elevated soil heavy metals and metalloids (HM) concentrations represent a major constraint for UH expansion. Here we provide the first UK-wide assessment of soil HM concentrations (total and bioavailable) in UH soils and the factors influencing their bioavailability to crops. Soils from 200 allotments across ten cities in the UK were collected and analysed for HM concentrations, black carbon (BC) and organic carbon (OC) concentrations, pH and texture. We found that although HM are widespread across UK UH soils, most concentrations fell below the respective UK soil screening values (C4SLs): 99 % Cr; 98 % As, Cd, Ni; 95 % Cu; 52 % Zn. However, 83 % of Pb concentrations exceeded C4SL, but only 3.5 % were above Pb national background concentration of 820 mg kg⁻¹. The bioavailable HM concentrations represent a small fraction (0.01–1.8 %) of the total concentrations even for those soils that exceeded C4SLs. There was a significant positive relationship between both total and bioavailable HM and soil BC and OC concentrations. This suggest that while contributing to the accumulation of HM concentrations in UH soils, BC and OC may also provide a biding surface for the bioavailable HM concentrations contributing to their immobilisation. These findings have implications for both management of the risk to human health associated with UH growing in urban soils and with management of UH soil. There is a clear need to understand the mechanisms driving soil-to-crop HM transfer in UH to improve potentially restrictive C4SL (e.g. Pb) especially as public demand for UH land is growing. In addition, the UH community would benefit from education programs promoting soil management practices that reduce the risk of HM exposure - particularly in those plots where C4SLs were exceeded.

Environmental water quality guidelines often work under the assumption that the toxicity of environmental pollutants is identical when present in isolation or in a complex chemical mixture. Thus, there is a crucial gap in our knowledge regarding how these toxicants interact and alter the toxicological effects in aquatic organisms. The present study examined the effects of acute (72-hr) aqueous exposures of Cadmium (Cd), a highly toxic non-essential trace metal, and Benzo[a]Pyrene (B[a]P), a prototypical polycyclic aromatic hydrocarbon (PAH) in adult zebrafish. Following a range-finding series of individual single-toxicant exposures, a second series was carried out using select concentrations in binary mixture exposures (using 5.8 or 22 μg/L for Cd; 0.44 or 1.07 μg/L for B[a]P). Our results demonstrated that tissue accumulation of both toxicants increased significantly in the presence of the second toxicant relative to single-toxicant exposures. Cd-only and B[a]P-only single toxicant exposures caused a significant downregulation of cytochrome p4501a (CYP1A1) and metallothionein-2 (MT2) mRNA in the gills, respectively, however binary co-exposures using both toxicants resulted in strong up-regulation of CYP1A1 and MT2. Additionally, co-exposures caused a strong induction of SOD1 and CAT mRNA transcript levels in the gill. The observed increase in body burden and transcript modulation did not translate into additive or more-than-additive toxic effects (oxidative stress) in zebrafish.