For decades, mercury (Hg) and arsenic (As) were discharged into the Aveiro Lagoon. This study was designed to assess the natural attenuation process evolution by: (1) evaluating Hg and As concentration in sediments and in Halimione portulacoides, and assess the long-term evolution of a historically contaminated salt-marsh system; (2) evaluating the stress levels imposed by Hg and As, and the mechanisms triggered to squash oxidative damage. Concentrations of Hg and As in sediments varied considerably between sampling locations. H. portulacoides did not bioconcentrate Hg and As, restricted translocation to aerial biomass and immobilized contaminants in cell walls. The ions that reached the cytosol induced oxidative stress, restrained by antioxidant mechanisms, especially SOD and CAT activity. Results show that after 25 years of natural attenuation, contamination decreased in the sediment, but remains above non-contaminated systems and continues to induce toxicity in the saltmarsh halophyte community, evidencing the persistent effect of Hg and As contamination.

Bioplastics have emerged to minimize the ecological footprint of non-degradable plastics. However, the effect of their degradation in aquatic systems, including the interaction with toxic metals, is still unexplored. In this work, the influence of UV-aging on structure, chemistry, wettability, rigidity, and Hg-sorption of commercially available bioplastic (BIO)- and polyethylene (PE)-based films was studied. To mimetize the materials disposal in fresh-/saltwaters, non-saline/saline aqueous solutions were used in Hg-sorption studies. ATR-FTIR spectra revealed that the BIO film was a coblended starch/polyester-based material, whose microstructure, physicochemical, and mechanical properties changed after UV-aging to a higher extent than in PE film. AFM and kinetic modelling pointed out electrostatic interactions/complexation as the mechanisms involved in the increased Hg-sorption by the UV-aged BIO film. An increased salinity did not impair its Hg-sorption. Therefore, when disposed in aquatic systems, starch/polyester-based bioplastics can play a potential vector for amplifying Hg along the food chain.

Krossfjord-Kongsfjord system in the European Arctic has been assessed for abundance, source and distribution of microplastics in the surface sediments. The average abundance of microplastics in Krossfjord and Kongsfjord is 721.42 ± 217.89 (n = 5) pieces/kg and 783 ± 530.28 (n = 8) pieces/kg. Polymers like polyethylene and polypropylene are abundant in the sediment samples. Fibers are the most common shape of plastic particles. A high abundance of smaller plastic particles in the sediment may be due to the fragmentation of larger plastic particles during transportation. The microplastics' spatial distribution, shape, size, and composition suggest that the long-range transport by west Spitsbergen current and local inputs from anthropogenic activities are possible sources of microplastics found in the study area. Our results exhibit the presence of microplastic pollution, suggesting the influence of anthropogenic activity in the Arctic fjord and the need to control/reduce marine pollution which has become a potential threat to marine organisms.

The brown meagre (Sciaena umbra) is a vulnerable vocal fish species that may be affected by boat noise. The breeding site distribution along the anthropized Venice sea inlets was investigated, by using the species' chorusing activity as a proxy of spawning. Passive acoustic campaigns were repeated at 40 listening points distributed within the three inlets during three-time windows in both summer 2019 and 2020. The role of temporal, morphological, and hydrodynamic variables explaining the observed distribution patterns was evaluated using a GLM approach, considering also human-induced pressures among the candidate predictors. The GLM analysis indicates a higher probability of recording S. umbra chorus after sunset in deeper areas of the inlets, characterized by low water current, while the underwater noise overlapping the species' hearing range and boat abundance did not play any role. This suggests that the species' breeding site choice in the inlets was not influences by boat-induced pressure.

Plastics, when entering the environment, are immediately colonised by microorganisms. This modifies their physico-chemical properties as well as their transport and fate in natural ecosystems, but whom pioneers this colonisation in marine ecosystems? Previous studies have focused on microbial communities that develop on plastics after relatively long incubation periods (i.e., days to months), but very little data is available regarding the earliest stages of colonisation on buoyant plastics in marine waters (i.e., minutes or hours). We conducted a preliminary study where the earliest hours of microbial colonisation on buoyant plastics in marine coastal waters were investigated by field incubations and amplicon sequencing of the prokaryotic and eukaryotic communities. Our results show that members of the Bacteroidetes group pioneer microbial attachment to plastics but, over time, their presence is masked by other groups – Gammaproteobacteria at first and later by Alphaproteobacteria. Interestingly, the eukaryotic community on plastics exposed to sunlight became dominated by phototrophic organisms from the phylum Ochrophyta, diatoms at the start and brown algae towards the end of the three-day incubations. This study defines the pioneering microbial community that colonises plastics immediately when entering coastal marine environments and that may set the seeding Plastisphere of plastics in the oceans.

Microplastics (MPs) were collected at six locations along Kenya's marine nearshore surface waters using a 300 μm mesh-size manta net. The samples were washed over a 125-μm mesh size sieve No.120 into a glass jar and preserved in 70% ethanol. MPs were sorted, counted visually under a dissecting microscope then identified using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. A total of 1473 particles with an overall mean concentration of 0.58 ± 1.29 MPs m⁻³, were collected. Fragments were the most common types representing 55% of the total MPs, followed by films (40%) and fibers (2%). Polypropylene (PP) was dominant (52%), high-density polyethylene (HDPE) comprised 38% and low density polyethylene (LDPE) 10% of the total MPs. This study provided baseline information, in which Malindi was identified as a hot spot for MPs pollution. Furthermore, the outcomes will assist policy formulations and management strategies aimed at controlling marine plastics.

Organic ultraviolet (UV) filter compounds are crucial components of sunscreen products, which are used to absorb UV radiation. However, the increase in consumption of UV filters has led to environmental concerns about their impacts on the environment and human health. This review found that the high lipophilicity and stability of UV filters can cause bioaccumulation leading to a wide range of adverse ecological effects. UV filters’ concentration was detected in wastewater up to ppm, and their physicochemical characteristics such as the size of molecule, pKₐ, hydrophobicity, and solubility significantly control their fate in the environment. Among UV filter compounds, benzophenone 3 (BP-3) and benzophenone 4 (BP-4) are the most common in wastewater. Various removal technologies for UV filters have recently been applied, including membrane separation, adsorption, advanced oxidation processes, and phytoremediation. Among them, hybrid treatment processes such as membrane bioreactors (MBRs) can remove UV filter compounds from wastewater with a removal efficiency of up to 96% (i.e., octocrylene and benzophenone-3). Future investigation should focus on developing green/eco-friendly sunscreens to reduce hazard impacts on human health and the environment.

Microplastic pollution is an extremely emerging problem and its potential threats to the aquatic organisms were investigated worldwide. In this study, four different commercial fish species (Mullus barbatus (Linnaeus, 1758), Mullus surmuletus (Linnaeus, 1758), Mugil cephalus (Linnaeus, 1758), Saurida undosquamis (Richardson, 1848)) were used as a bioindicator to assess the microplastic pollution in the northeastern Mediterranean. The frequency of occurrence in the gastrointestinal tract (GIT) and gill was varied between 66–100% and 68–90%, respectively. The highest microplastic abundance was detected at the GIT of M. cephalus sampled from Asi River estuary. The majority of extracted microplastics were fiber, black in color and less than 1 mm in size. Fourier Transform Infrared Spectroscopy (FTIR) indicated the most common polymer type as polyethylene. This study is the first study examining the microplastic existence in gill and results obtained in this study improve the knowledge about the relationship of microplastic ingestion in fish and environmental conditions in the Northeastern Mediterranean Sea.

Haze is a well-known air pollution phenomenon linked to the severe and persistent particulate matter (PM) episodes in Southeast Asia (SEA), which significantly impacts the environment, health, and economy. This work reviewed for the first time the characteristics of haze episodes in terms of PM concentrations, chemical compositions, and the causes of haze in both Lower (Maritime) and Upper (Mainland) SEA. In addition, we carried out a systematic comparison of the frequency and intensity of haze events through SEA regions in recent years. Our finding indicated that the different trend of haze frequency and intensity between SEA cities are not only due to local air pollution sources such as biomass burning (BB) but also meteorology and long-range transport. Other sources such as secondary aerosols also play an important role in haze formation, but they have not been comprehensively investigated in previous studies. Due to the complicated formation mechanisms and the transportations of haze and its impacts on SEA’s human health and economy, more sophisticated and specific policies are needed to deal with haze issues not only for individual countries but also on a regional scale.

A literature assessment was conducted to determine the current state of microplastics research in ASEAN countries focusing on 1) microplastics in water, sediment, and water organisms; 2) microplastics' sources and dispersion; and 3) microplastics' environmental consequences, including human toxicity. ASEAN countries contributed only about 5 % of the global scholarly papers on microplastics, with Indonesia contributing the most followed by Malaysia and Thailand. The lack of standard harmonized sampling and processing methodologies made comparisons between research difficult. ASEAN contributes the most to plastic trash ending up in the ocean, indicating a need for more work in this region to prevent plastic pollution. Microplastics are found in every environmental compartment; however, their distribution and environmental consequences have not been sufficiently investigated. There are very few studies on microplastics in the human blood system as well as respiratory organs like the lungs, indicating that more research is needed.