Microplastics are widespread across the global oceans, yet the potential risks of the ubiquitous environmental contaminant to marine organisms has been less known. Accumulation of microplastics and ...associated contaminants in marine fish, may pose adverse impacts to human health via seafood consumption. This study evaluated microplastic contamination in 24 fish species collected from Beibu Gulf, one of the world’s largest fishing grounds in South China Sea. Microplastics were detected in 12 fish species at an abundance of 0.027–1.000 items individual−1 and found in fish stomach, intestines and gills with the count percentage of 57.7%, 34.6% and 7.7%, respectively. Transparent fibers were observed as the predominant microplastics, which might be ingested accidently by fish or transferred through other animals at lower trophic levels. Majority of microplastics were identified as polyester (44%) and nylon (38%), whereas polypropylene (6%), polyethylene (6%), and acrylics (6%) were also found. Relatively, higher microplastic abundances were found in demersal fish compared to the pelagic species. Overall, the abundance of microplastics was documented as relatively low in the commercial fish collected from the open water of Beibu Gulf, South China Sea.
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•Microplastics were present in 12 fish species from Beibu Gulf, South China Sea.•Microplastic abundance ranged from 0.027 to 1.000 items individual−1 in different species.•The polymer types were detected predominantly as polyester and nylon.•Fibers were the dominant form and accounted for 96% of microplastics.
The main finding of the work: This study documented microplastics was considerably low in commercial fish collected from Beibu Gulf, South China Sea.
Biodegradable plastics, as alternatives to conventional plastics, are increasingly used, but their interactions with organic pollutants are still unknown. In this study, the sorption and desorption ...behaviors on a type of biodegradable plastic−poly(butylene adipate co-terephtalate) (PBAT) were investigated, and at the same time two types of conventional plastics−polyethylene (PEc and PEv) and polystyrene (PS) were used for comparison. Phenanthrene (PHEN) was chosen as one of representative organic pollutants. Results indicated that the sorption and desorption capacities of PBAT were not only higher than those of the other types of microplastics, but also higher than those of carbonaceous geosorbents. The surface area normalized results illustrated that sorption and desorption of the microplastics were positively correlated with their abundance of rubbery subfraction. The sorption kinetic results showed that the sorption rates of PBAT and PEc were higher than PEv and PS. The effects of water chemistry factors including salinity, dissolved organic matter and Cu2+ ion on the sorption process displayed the same trend, but the degrees of influence on the four microplastics differed. The degrees of influence were mainly dependent on the abundance of rubbery subfraction for microplastics. These findings indicate that the biodegradable poly(butylene adipate co-terephtalate) microplastics are actually stronger vectors than the conventional microplastics, and crystallization characteristics of the microplastics have great influences on the vector effect.
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•Biodegradable microplastics sorbed/desorbed more PHEN than conventional ones.•Sorption/desorption capacities depended on the content of rubbery subfraction.•Plastic additives didn't alter the microplastics adsorption process.•High salinity and low DOM strengthen the sorption of PHEN onto microplastics.
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•Microplastics were found in 30 fish species from Zhanjiang mangrove wetland.•Microplastics could be detected in gills, stomach and intestine of the fishes.•Fiber was the dominant ...microplastic shape detected in fish bodies.•Polyethylene was the highly abundant polymer type in collected microplastics.
Microplastics (MPs) are widespread in marine and estuarine environments, but the contamination of MPs in mangrove wetlands is relatively unknown. Here, we quantify the presence of MPs in fish collected from Zhanjiang mangrove wetland, the largest mangrove in South China, which provide baseline data on MPs accumulation in fish in mangrove environment as the first evidence in China. MPs were found in 30 out of 32 fish species at an average abundance of 2.83 ± 1.84 items individual−1, ranged from 0.6 to 8.0 items individual−1 in each species. MPs were detected in gills, stomach and intestine, and not found in muscles and livers. Positive relationship was found between MPs abundance and body length or weight of mangrove fish. The dominant polymers identified by micro-FTIR were polyethylene, polyethylene terephthalate, polypropylene and cellophane. MPs consisted primarily of fibers and with the prominent size range of 0.02–1 mm. The body sizes, living habitats and feeding habits of fish are important factors affecting MPs accumulation in different fish species. This study revealed the wide presences of MPs in fish species within a mangrove wetland.
Microplastics, as emerging contaminants in the global environment, have become a cause for concern for both academics and the public. The present understanding of microplastic pollution is primarily ...focused on marine environments, and less attention has been given to freshwater environments, in particular, to urban rivers. In this study, microplastics were sampled from surface water and sediments in 14 sites located in the lower course of the Pearl River. These sampling sites are located along Guangzhou of South China, with built-up areas being the dominant land use. The abundances of microplastics in surface water and sediments ranged from 379 to 7924 items·m−3 and 80 to 9597 items·kg−1, respectively. Polyethylene and polypropylene were the common types of microplastics, together accounting for 64.3% and 73.8% of surface water and sediment samples, respectively. Fibers were the dominant microplastic shapes in both water and sediment samples. The abundances of microplastics varied in surface water and sediments with each site, which might be affected by multiple factors. Our results indicated that wastewater treatment plants (WWTP) could reduce microplastics from municipal sewage which was finally discharged into the Pearl River along Guangzhou.
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•Microplastics in the Pearl River along Guangzhou were investigated for the first time.•Fibers were detected in both surface water and sediment samples.•PE and PP were the dominant polymer types in surface water and sediments.•WWTP in Guangzhou could reduce microplastic pollution in the municipal sewage.
The oxidative degradation of azo dye, Orange G (OG), in aqueous solutions by the persulfate/Fe
2+ reagent has been investigated. Effects of pH, dosages of persulfate and Fe
2+, temperature, and the ...presence of inorganic ions (Cl
−, NO
3
−, HCO
3
− and H
2PO
4
−) on OG degradation were examined in batch experiments. The OG degradation by the persulfate/Fe
2+ reagent was found to follow the first-order kinetic model. Under an optimum condition (persulfate
=
4
mM, Fe
2+
=
4
mM and pH 3.5), the OG degradation in aqueous solutions with an initial concentration of 0.1
mM was achieved by 99% within 30
min. The OG degradation increased with an increased dosage of both persulfate and Fe
2+. The experimental results showed that increasing the reaction temperature from 293 to 313
K was beneficial to the OG degradation, but not as efficient as chemical activation with Fe
2+ at ambient temperature. In the meantime, the apparent activation energy for the OG degradation was determined to be 92.2
kJ
mol
−1. Furthermore, the results demonstrated that the OG degradation could be significantly inhibited due to the existence of inorganic ions in a sequence of NO
3
−
<
Cl
−
<
H
2PO
4
−
<
HCO
3
−. The experiments also demonstrated that the persulfate/Fe
2+ reagent can degrade OG in aqueous solutions to a higher degree than the Fenton's reagent, which is beneficial to the mineralization of azo dyes.
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•67 studies on microplastic pollution undertook in China were reviewed.•Sampling, extraction, identification and quantification procedures were compared.•A standardised methodology ...for microplastic research is suggested.
China is the world’s largest plastic producer and has been a focus of research on microplastic pollution. An increasing number of studies have documented plastics in the sediment, water and biota of China over the past decades. This systematic review compares different methodologies adopted by microplastic studies in China, including sampling equipment and methods; laboratory procedures in microplastic extraction and identification; and the characterisation and quantification of particles. In general, sediment samples were primarily collected with a grab sampler, while water samples were mostly taken from the surface using trawl nets. Different techniques, including density separation, chemical digestion, sieving and filtration, were applied to extract microplastics from the sample matrix. Visual sorting was an obligatory step that identifies microplastics by their morphological characteristics, such as size, shape and colour. Most studies in China reported the prevalence of irregular-shaped particles with sizes smaller than 1 mm. The chemical properties of microplastics were also assessed using infrared and Raman spectroscopy. Quantitative units commonly used for sediment, water and biota samples were “items per kg”, “items per m3” and “items per individual”, respectively. The inconsistencies in methods have marked the urgent warrant of a standardised methodology. It is believed that the findings of the present review can serve as an important waypoint contributing towards a more efficient and long-acting methodology for microplastic research, that can enable meaningful inter-study comparisons.
•Recent advances in OIS mechanisms are discussed.•The role of the p38 MAPK pathway in OIS is highlighted.•The role of the PI3K/AKT/mTOR pathway in OIS is explored.
Oncogene-induced senescence (OIS) ...is a tumor-suppressing response that must be disrupted for cancer to develop. Mechanistic insights into OIS have begun to emerge. Activation of the p53/p21WAF1 and/or p16INK4A tumor-suppressor pathways is essential for OIS. Moreover, the DNA damage response, chromatin remodeling, and senescence-associated secretory phenotype (SASP) are important for the initiation and maintenance of OIS. This review discusses recent advances in elucidating the mechanisms of OIS, focusing on the roles of the p38 mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/cellular homolog of murine thymoma virus AKT/mammalian target of rapamycin (mTOR) pathways. These studies indicate that OIS is mediated by an intricate signaling network. Further delineation of this network may lead to development of new cancer therapies targeting OIS.
► Antioxidant activities and total phenolic contents of 62 fruits were evaluated. ► The relations between FRAP value and TEAC value as well as total phenolic content were studied. ► Several fruits ...possessing strongest antioxidant activities have been screen out. ► This study supplied new information for consumers, nutritionists and food policy makers.
In order to supply new information on the antioxidant function of selected fruits for nutritionists and the general public, antioxidant activities and total phenolic contents of 62 fruits were evaluated using ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays as well as the Folin–Ciocalteu method, respectively. The correlations between the FRAP value and the TEAC value as well as total phenolic content were also assessed. The results showed that different fruits had diverse antioxidant capacities and the variation was very large, and seven fruits, Chinese date, pomegranate, guava, sweetsop, persimmon, Chinese wampee and plum, possessed the highest antioxidant capacities and total phenolic contents among tested fruits, and could be important dietary sources of natural antioxidants for prevention of diseases caused by oxidative stress.
The estuaries of populated catchments have been documented as hotspots of plastic pollution. In this study, microplastics (0.355–5.0 mm) and large plastic debris (>5.0 mm) of surface water collected ...from the Inner Lingding Bay of the Pearl River Estuary (PRE) were quantified and categorized according to their size, shape, colour and composition. Both microplastics and large plastic debris were detected at all sampling sites with mean abundances of 2.376 ± 0.700 n/m3 and 0.110 ± 0.039 n/m3, respectively. Microplastics constitute 95.4% of the total abundance by number. The average microplastic concentration in the inner PRE was almost 3.5 times higher than that in the central PRE, indicating a positive correlation between plastic concentration and proximity to the river mouth. This result reveals the important role of rivers in transporting plastic debris from land to the oceans.
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•Plastic debris and MPs were detected in the Pearl River Estuary.•MPs accounted for 95.4% of total identified plastic debris.•Sites with high MP concentrations were located near the estuarine mouth.•The distribution of MPs within the estuary was influenced by tidal currents.
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