PURPOSE OF REVIEW: Atmospheric aerosol from both natural and anthropogenic activities has long been acknowledged as one of the important factors influencing regional and global climate change. Many regions around the globe experienced high aerosol loadings because of intensive emissions, yet the roles of atmospheric aerosols in extreme meteorological and air pollution events have not been well demonstrated due mainly to the complexity of atmospheric physical and chemical interaction at mesoscale and even microscale. Here, we present a comprehensive review of current understanding on the role of atmospheric aerosols in the development and evolution of extreme meteorological events, including monsoon circulation, heat waves, extreme rainfall, tornadoes, and severe air pollution. RECENT FINDINGS: Aerosols could participate in the development of meteorological systems through direct and indirect effects. Large-scale precipitation from shallow stratiform clouds was found to be suppressed by aerosols, while invigoration effects contribute to deep convection and even catastrophic floods in local areas. The occurrence of high-impact weather such as tornadoes and tropical cyclone is also related to aerosol concentration and distribution. Moreover, a positive feedback between aerosols and boundary layer meteorology is proposed as an important factor conducive to heavy haze pollution over urban areas. The work underscores the great importance of aerosols’ meteorological feedback in extreme weather events. Integrated observations and seamless coupling of meteorology and atmospheric chemistry in models are highlighted for future studies to fill the knowledge gap in current research.

Microplastic pollution in marine environment has been a growing public concern in recent years. This article analyzed the scientific literatures related to marine microplastics through a combination of social network analysis and bibliometrics. Researches related to microplastics have grown rapidly since 2011, with approximately two-thirds of the total number of articles published in the last three years. Researchers in United States and Europe have provided tremendous support, however, the efforts and progress of Chinese researchers cannot be ignored. Moreover, the international cooperation is getting closer, and related strategies are launched continuously. The results showed that Marine Pollution Bulletin is the most active journal. Through keyword analysis, we understand the development history and current hotspots of the whole microplastics researches, including ecological risks, interrelationship between microplastics and other pollutants, and detection methodology. Finally, some suggestions and perspectives for future microplastics research are provided.

Plastic debris provides long-lasting substrates for benthic organisms, thus acting as a potential vector for their dispersion. Its interaction with these colonizers is, however, still poorly known. This study examines fouling communities on beached, buoyant and benthic plastic debris in the Catalan Sea (NW Mediterranean), and characterizes the plastic type. We found 14 specimens belonging to two phyla (Annelida and Foraminifera) on microplastics, and more than 400 specimens belonging to 26 species in 10 phyla (Annelida, Arthropoda, Brachiopoda, Bryozoa, Chordata, Cnidaria, Echinodermata, Mollusca, Porifera and Sipuncula) on macroplastics. With 15 species, bryozoans are the most diverse group on plastics. We also report 17 egg cases of the catshark Scyliorhinus sp., and highlight the implications for their dispersal. Our results suggest that plastic polymers may be relevant for distinct fouling communities, likely due to their chemical structure and/or surface properties. Our study provides evidence that biofouling may play a role in the sinking of plastic debris, as the most abundant fouled plastics had lower densities than seawater, and all bryozoan species were characteristic of shallower depths than those sampled. More studies at low taxonomic level are needed in order to detect new species introduction and potential invasive species associated with plastic debris.

Microplastics are among the major environmental problems to be addressed because it is beginning to affect food chains and is also reaching human populations. The present study investigated the size, color, shape and abundance of microplastics in juvenile silversides (Atheriniformes) belonging to the edible species Odontesthes bonariensis, Odontesthes nigricans and Odontesthes argentinensis from shallow coastal waters. While 100 % of the sampled individuals presented microplastics in stomach contents, fibers were 95 %. There is a correlation between the size of the individuals and the maximum particle size ingested ranging from 0.2 to 1.2 mm. There is no significant difference in the number of particles ingested per individual. The plastic particles had a lower density than seawater, which is why they floated on the surface. These results imply that the protected areas of large ocean currents increase the exposure of local fauna to microplastics increasing the risk of ingestion of PMs.

This study compared the ability of Sargassum fusiforme to accumulate As, Cd, Cr, Cu, Ni, Pb and Zn in its five tissues (main branch, lateral branch, leaf, receptacles and pneumathode). The concentrations of these trace elements in seawater, surface sediments and different tissues of S. fusiforme were analyzed in different areas in Dongtong County (Wenzhou City, China). The presence of receptacle at all sites indicated that S. fusiforme had entered the mature stage. However, the proportion of each tissue in S. fusiforme in different sites was varied, indicating subtle differences in growth. S. fusiforme has a great capacity to accumulate trace elements, showing relatively high levels of As (28.2–64.2 mg kg⁻¹) and Zn (19.9–80.8 mg kg⁻¹). The elements are mainly stored in leaf, receptacles and pneumathode. Compared to element concentrations in the surrounding environment, the seaweed exhibited stronger bioconcentration capacity for As and Cd than for other elements. According to our health risk assessment results, the hazard index and carcinogenic risk were below the limit, suggesting that the S. fusiforme ingestion would not pose any health risk and the potential risk of intake branches was even lower than that of other tissues.

Southeast Brazilian bays have been increasingly degraded by untreated organic loads. Therefore, to assess fecal contamination status, sediment quality regarding polycyclic aromatic hydrocarbons (PAHs), and sources of organic matter (OM), we have determined fine-grained and total organic carbon (TOC) content and concentrations of PAHs and sterols in twenty-six surface sediment samples in Sepetiba Bay. The fine-grained (1–26 %), TOC (0.20–3.45 %), PAHs (<LQ – 78.27 ng g⁻¹) and sterols (0.10–21.58 μg g⁻¹) results showed a decreasing trend from the internal to the external sector of the study area. The diagnostic ratios of selected PAHs and sterols indicated a mixture with significant contribution from continental and pyrolytic OM in all stations. The fecal contamination is significant to the internal sector of Sepetiba Bay. Considering a site-specific sediment quality guidelines (SQGs) the PAHs levels with more restricted benchmark values indicate the harbor and the internal sector as contaminated.

This study was a baseline with quantitative data of marine litter along the Gulf of Nicoya, Costa Rica. The objective of the study was to quantify marine litter and its association with human activities in this estuarine gulf. A total of fourteen sandy beaches were cataloged by the degree of urbanization, tourism intensity, beach cleaning programs, and tributary rivers as possible drivers of marine litter presence. The items of the marine litter were separated and weighted by type. Analysis by the clean coastal index (CCI) and multivariate statistics were applied to find spatial patterns in marine litter in the gulf. On beaches with the highest touristic activity, cigarette butts and straws were the main components. Locations with river plume influence, less frequent cleanup, or waste cans showed more bottles, plastic parts, and sanitary waste than beaches in other conditions. A beach in a fisherman town had recently utilized plastic bags, household goods, and boat parts in the marine litter. A wildlife refuge beach showed only small plastic and coffee foam cup fragments that came with currents from other points in the estuary. River basin management, solid waste disposal programs, and environmental education to avoid single-use items combined with correct waste disposal are needed to reduce marine litter in tropical countries focused on ecological tourism.

In this study, three mangroves in the Guangdong-Hong Kong-Macao Greater Bay Area— Qi'ao Island in Zhuhai, Nansha in Guangzhou, and Futian in Shenzhen—were selected for investigating the distribution of microplastics and their characteristics The average microplastic abundance in each descended in the order: Futian (1600 n/kg) > Nansha (1100 n/kg) > Qi'ao Island (440 n/kg), with values from the forest fringe being significantly higher than those in the forest interior. The microplastics were mainly fibers, 1–5 mm in size, and white/black in color; they consisted of polypropylene and polyethylene, with foam and polystyrene accounting for a high proportion in Nansha. The exposure of humans to microplastics in the Futian forest fringe reached 35.95 ng/d·kg; it was one order of magnitude higher than the exposures in Qi'ao Island and Nansha. Furthermore, ingestion accounted for approximately 74% of the total exposure to the human body, dermal contact constitutes 25%, and sediment inhalation accounted for less than 1%.

Visual pollution is the visible deterioration and negative aesthetic quality of the landscape. Erosion, marine wrack, litter, sewage, and beach driving are affecting the coastal scenery and are generating a visual pollution problem on the Rabigh coastal area, Kingdom of Saudi Arabia. This work provides the scenic evaluation of 31 coastal sites using the Coastal Scenery Evaluation System (CSES) to determine the current state of this situation and give management inputs. The CSES assesses values from a checklist of 18 physical and 8 human parameters and allows the calculation of a scenic evaluation index (D Value), which classifies coastal sites into five classes: Class I, usually natural areas of top scenic characteristics, to Class V, poor scenic natural areas with a higher impact of human interventions. Along the study area, three sites (9.7 %) appeared in Class II; five (16.1 %) in Class III; 15 (48.4 %) in Class IV, and eight sites (25.8 %) in Class V. Class I sites were not found in the study area. Assessment presented in this work provides a complete overview of the Rabigh coastal scenery and serves as a baseline for implementing management strategies to cope the visual pollution problem.

Collected sediment samples from the cage fish farm were measured to determine carbon and nitrogen stable isotope compositions and to understand the influence of the aquaculture waste on the sediment. The average δ¹³C of the sediment organic matter was −27.2 ‰ and −26.5 ‰, and the average δ¹⁵N value was 5.6 ‰ and 6.2 ‰ in October 2017 and November 2018, respectively. A linear mixing model was used to calculate the contribution ratios of the aquaculture waste in sediment organic matter. The contribution ratio of fish feces was 53.9 % and 25.5 %, and the contribution ratio of waste feed was 18.4 % and 52.6 % in October 2017 and November 2018, respectively. The sediment in the “cage fish area” was characterized by high waste feed ratio in sediment organic matter. The sediment organic matter was affected by the aquaculture waste even at sites 1500 m away from the cage fish farm.