Health risks of human exposures to 12 Polycyclic aromatic hydrocarbons (PAHs) in coastal soils of Koh Samed Island (KSI), Thailand, were evaluated after the coastal areas were cleaned up of the 2013 oil-spill contamination. The risk assessment quantified both total cancer and non-cancer risks for four groups of receptors using average PAHs concentrations. Two exposure pathways (incidental ingestion and dermal contact) were selected to evaluate the risks, and three methods were used to calculate the total cancer risks to determine an appropriate assessment method. The non-cancer risk was represented by the total Hazard Index (HI). The contributions of each PAH to the total cancer risk and total HI were also investigated. The total cancer risk (3.53×10⁻¹⁰ to 9.12×10⁻⁸) and total HI (4.35×10⁻⁶ ᵗᵒ ².¹³×¹⁰⁻³) from this work were relatively lower than the USEPA baselines (10⁻⁶ for the cancer risk and 1 for the HI) and were quite low when compared with other works in the literature. Benzo(a)pyrene made the highest contribution to the total cancer risk (61.82%), while benzo[g,h,i]perylene made the highest contribution to the total HI (62.41%). In regard to the contributions of the two exposure routes, dermal contact contributed the most to the total cancer risk, while incidental ingestion contributed the most to the total HI.

A long-term monitoring during dredging and non-dredging periods was performed. Total and dissolved Cu and Pb concentrations, DGT-labile Pb, ultraphytoplankton abundance and structure were monitored at four sites: dredging site, dumping site (inside/outside of a geotextile bag) and reference site. During the reference period (non-dredging), an increasing contamination in Pb, Cu and a progressive shift from Synechococcus to photosynthetic picoeukaryotes dominance was observed from reference to dumping site. Pb concentrations were significantly higher during dredging period, pointing out sediment resuspension as Pb major source of contamination. Unlike Pb, Cu concentrations were not statistically different during the two periods. Dredging period did not impact on ultraphytoplankton abundance and structure but influence heterotrophic prokaryotes abundance. Sediment resuspension is therefore a major driver of chemical and biological qualities in Toulon Bay. Furthermore, although the geotextile bag reduces particulate transport of the dredged sediment, the transport in the dissolved phase remains a major problem.

In this study, we investigated the specific bacterial distribution and the response of bacterial communities to shifts in environmental factors in the subtropical Beibu Gulf, southern China. The abundances of Actinobacteria, Bacilli, Planctomycetia, Thermoleophilia, Anaerolineae, and Synechococcophycideae were significantly higher in high eutrophic samples than in medium eutrophic and oligotrophic samples. Bacterial alpha-diversity was found greater in high eutrophication samples than in the other samples. Besides, Ponticaulis koreensis, Nautella italic, Anaerospora hongkongensis, Candidatus Aquiluna rubra, and Roseovarius pacificus were sensitive to trophic variation and thus could be used as eco-markers. In addition, the relative abundances of functional genes involving carbohydrate and amino acid metabolism were very high among the samples. We also found temperature, Chl-a, TDN and NO₃⁻ were the main environmental drivers of bacterial community structure. Overall, this study provides new insight into the composition of bacterial community and function response to gradients of eutrophication in Beibu Gulf.

Tubastraea coccinea Lesson, 1830 and T. tagusensis Wells 1982 are azooxanthellate corals non-native to Brazil and introduced through fouling on oil platforms, the primary vector. They first invaded the tropical rocky reefs at Ilha Grande Bay (southwest Atlantic Ocean), during the early 1990s. Currently, at some Brazilian locations these species occupy 80% of the benthos of the shallow subtidal. They cause economic and environmental impacts by fouling shipping and modifying native communities. This study provides observations of an additional mechanism of secondary dispersal by T. coccinea and T. tagusensis that were seen attached to floating wood debris and marine litter, which are highly abundant in the region. Such rafting corals have been found adjacent to invaded reefs and stranded on beaches. These observations indicate that transport by rafting over long distances may be another mechanism of range expansion and secondary introduction of these invasive species within the region.

Prevalence of SARS-CoV-2 in the aquatic environment pertaining to the COVID-19 pandemic has been a global concern. Though SARS-CoV-2 is known as a respiratory virus, its detection in faecal matter and wastewater demonstrates its enteric involvement resulting in vulnerable aquatic environment. Here, we provide the latest updates on wastewater-based epidemiology, which is gaining interest in the current situation as a unique tool of surveillance and monitoring of the disease. Transport pathways with its migration through wastewater to surface and subsurface waters, probability of infectivity and ways of inactivation of SARS-CoV-2 are discussed in detail. Epidemiological models, especially compartmental projections, have been explained with an emphasis on its limitation and the assumptions on which the future predictions of disease propagation are based. Besides, this review covers various predictive models to track and project disease spread in the future and gives an insight into the probability of a future outbreak of the disease.

The article is devoted to the study of the activity values of natural radionuclides ⁴⁰K, ²³²Th and ²²⁶Ra and technogenic radionuclide ¹³⁷Cs in the bottom sediments of the Barents Sea, which is distinguished from the rest of the Arctic seas by the fact that the largest number of radiation objects are concentrated here. The activity levels of natural radionuclides were within the range of activity values corresponding to marine sediments around the world. The highest radionuclide activities were found within the deepwater shelf of the Barents Sea. The current level of activity of the technogenic radionuclide ¹³⁷Cs is low and does not exceed 6.5 Bq·kg⁻¹. However, due to global climatic changes, the secondary source of radiation pollution of the sea may be the Novaya Zemlya ice sheet, in which huge quantities of technogenic radionuclides were deposited during atmospheric tests of the 1950s and 1960s.

Marine microbial communities might be subjected to accidental petroleum spills; however, some bacteria can degrade it, making these specific bacteria valuable for bioremediation from petroleum contamination. Thus, characterizing the microbial communities exposed to varying types of petroleum is essential. We evaluated five enriched microbial communities from the northwest Gulf of Mexico (four from the water column and one from sediments). Enrichments were performed using five types of petroleum (extra light, light, medium, heavy and extra heavy), to reveal the microbial succession using a 16S rDNA amplicon approach. Four communities were capable of degrading from extra light to heavy petroleum. However, only the community from sediment was able to degrade the extra heavy petroleum. Successional changes in the microbial communities' structures were specific for each type of petroleum where genus Dietzia, Gordonia, Microvirga, Rhizobium, Paracoccus, Thalassobaculum, Sphingomonas, Moheibacter, Acinetobacter, Pseudohongiella, Porticoccus, Pseudoalteromonas, Pseudomonas, Shewanella, and Planctomyces presented differential abundance between the treatments.

PURPOSE OF REVIEW: The objective of this review is to provide a closer check on the recent development in the thermal hydrolysis (TH) of wastewater sludge for anaerobic digestion performance enhancement with the focuses on the solubilization of sludge and macromolecules, organic micropollutants removal, TH-AD integration, and TH process (THP) energy balances. RECENT FINDINGS: The recent research has developed improved understanding of the thermal hydrolysis mechanisms of proteins, carbohydrates, and lipid components of sludge and the characteristics of soluble COD in TH-treated sludge. Studies showed that TH treatment can partially remove micropollutants, but it has limited impact on the bioavailability of those compounds. For the THP and AD integration, the post TH and intermediate TH treatment have been introduced as two alternatives of the TH pretreatment, which have demonstrated the ability to achieve higher methane yields and VSS reduction. TH is a well-established technology for anaerobic digestion performance enhancement due to its ability to improve digestion loading rate, sludge biodegradability, and sludge dewaterability. The recent studies elucidated the mechanisms of sludge TH, characteristics, and biodegradability of hydrolysis products, fate of nutrient and micropollutants in sludge TH, and the effect of AD-TH integration on methane production and VS reduction. Future work in sludge TH is still needed to reveal the mechanisms of production of refractory organics during TH treatment, optimize the design and operation of the ITHP-AD and AD-PsTHP processes, and improve the energy efficiency of TH-AD processes through energy reduction and recovery.

Spatial variations in summertime phytoplankton community structure from 1991 to 2017 in Daya Bay, China were investigated in this research. The abundance of total phytoplankton and diatoms significantly increased during the study period in all regions of the bay while an increase in dinoflagellates abundance was only significant in the inner and middle bay areas. Pseudo-nitzschia spp. were overwhelmingly dominant followed by Skeletonema costatum. Ceratium furca was the dominant dinoflagellate. Overall, species diversity and evenness indices showed downward trends during the study period. Moreover, the bloom frequency of Scrippsiella trochoidea (associated with red tides) has increased rapidly since the 2000s in the inner bay. These temporal dynamics are largely explained by enhanced dissolved inorganic nitrogen (DIN) concentrations, which increased by 64.58% during 2005–2017 relative to 1991–2004, induced by human activities, along with temperature reductions and salinity increases resulting from open oceanic seawater intrusion.

A small No. 2 fuel oil spill contaminated a Mytilus edulis population in the Cape Cod Canal, Massachusetts, USA during a three day period in April 1983. Retention and release of the fuel oil compounds were assessed over several days and months. Compounds analyzed included n-alkanes, pristane, phytane, C₂ -, C₃ –naphthalenes, flourene, phenanthrene, C₁-, C₂-, C₃ – phenanthrenes. Biological half-lives were calculated for the release of the compounds up to day 29 and ranged from 1.5 days to 9.9 days. Results compared favorably with similar data from a small No. 2 fuel oil spill contaminating the same population of Mytilus edulis at the same time of year, April 1978. Gas chromatography-mass spectrometer analyses of C₂-, and C₃- phenanthrenes documented changes in relative abundance within the isomer groupings after day 29. This suggests a within isomer grouping molecular structural control on release or enzymatic catalyzed alteration of these compounds.