PVC Does Not Influence Cadmium Uptake or Effects in the Mussel (Mytilus edulis)

Microplastics have become a global concern in recent years. In this study, we studied (i) whether the presence of polyvinyl chloride (PVC) microparticles may affect cadmium (Cd) uptake in mussel (Mytilus edulis); and (ii) the biological effects of PVC microparticles exposure alone or in combination with Cd. Significant Cd uptake in digestive gland was observed following Cd exposure. However, PVC did not significantly increase Cd uptake compared with Cd alone treatment. In terms of biological impacts, significantly lower neutral red retention (NRR) time and elevated expression of Metallothionein isoform 20-IV (MT-20) were observed in mussels exposed to Cd alone, or combined with microplastics, yet there was no significant difference between them. catalase (CAT) expression only showed a significant increase in mussels exposed to Cd alone. This work provides an insight into the relationship on resulting biological impacts between these two contaminants

Gonadal atresia, estrogen-responsive, and apoptosis-specific mRNA expression in marine mussels from the East China coast: a preliminary study

This preliminary survey analysed mussel atresia incidences, estrogen-responsive and apoptotic-specific molecular end points, and aqueous and gonadal levels of selected estrogens from the East China coast. Estrogen levels were low (e.g. < LOD-28.36ng/L, < LOD-3.88ng/g wet weight of tissue for BPA) relative to worldwide freshwater environments, but high oocyte follicle atresia incidences (up to 26.6%) occurred at selected sites. Expression of estrogen-responsive ER2 was significantly increased in males relative to females at sites with high atresia incidences in females. A second estrogen-responsive gene, V9, was significantly increased at two sites in April in females relative to males; the opposite was true for the remaining two sites. Apoptosis-specific genes (Bcl-2, fas) showed elevated expression in males relative to females at the site with the highest atresia incidence. These results provide coastal estrogen levels and the utility of several estrogen-specific molecular-level markers for marine mussels

Insights into technical challenges in the field of microplastic pollution through the lens of early career researchers (ECRs) and a proposed pathway forward

Early career researchers (ECR) face a series of challenges related to the inherent difficulties of starting their careers. Microplastic (MP) research is a topical field attracting high numbers of ECRs with diverse backgrounds and expertise from a wealth of disciplines including environmental science, biology, chemistry and ecotoxicology. In this perspective the challenges that could hinder scientific, professional, or personal development are explored, as identified by an international network of ECRs, all employed in MP research, that was formed following a bilateral workshop for scientists based in the UK and China. Discussions amongst the network were grouped into four overarching themes of technical challenges: in the field, in the laboratory, in the post data collection phase, and miscellaneous. The three key areas of representativeness, access to appropriate resources, training, and clean labs, and the use of databases and comparability, as well as the overarching constraint of available time were identified as the source of the majority of challenges. A set of recommendations for pathways forward are proposed based on the principles of research openness, access to information and training, and widening collaborations. ECRs have great capacity to promote research excellence in the field of MPs and elsewhere, when provided with appropriate opportunities and suitable support

Insights into technical challenges in the field of microplastic pollution through the lens of early career researchers (ECRs) and a proposed pathway forward

Early career researchers (ECR) face a series of challenges related to the inherent difficulties of starting their careers. Microplastic (MP) research is a topical field attracting high numbers of ECRs with diverse backgrounds and expertise from a wealth of disciplines including environmental science, biology, chemistry and ecotoxicology. In this perspective the challenges that could hinder scientific, professional, or personal development are explored, as identified by an international network of ECRs, all employed in MP research, that was formed following a bilateral workshop for scientists based in the UK and China. Discussions amongst the network were grouped into four overarching themes of technical challenges: in the field, in the laboratory, in the post data collection phase, and miscellaneous. The three key areas of representativeness, access t

Entanglement of <i>Daphnia magna</i> by Fibrous Microplastics through “Hook and Loop” Action

Entanglement, often associated with the interaction of large marine plastics and larger animals, has not yet been reported in the context of microplastics (MPs) and small organisms. In this study, Daphnia magna was exposed to fibrous and fragmentary MPs at concentrations ranging from 1 to 1000 items/mL for 7 days. The results revealed that fibrous MPs tended to entangle with the second antennae and tail claws of D. magna, whereas fragmentary MPs merely adhered to the surface of the daphnids but do not exhibit entanglement. Additionally, the swimming speed and projected area of swimming trajectories of daphnids significantly decreased in the 100 items/mL group compared with the control. However, the occurrence of entanglement and slow swimming was less pronounced in the 1000 items/mL group due to the aggregation of fibrous MPs. Scanning electron microscopy revealed that D. magna possessed a rich spine structure on the surface of their bodies, particularly on their antennae and tails. The entanglement of D. magna by fibrous MPs resembled the action of manufactured “hook and loop”. Overall, the results of this research revealed that entanglement is observed in small animals exposed to fibrous MPs, highlighting the direct biological effects of MPs beyond ingestion

Sinking of floating plastic debris caused by biofilm development in a freshwater lake

Plastic pollution has been increasingly reported in both marine environment and inland waters, but their fate is not well understood. Several studies have showed that the surface of plastic debris can be colonized by microbes, leading to the sinking of floating plastic debris in marine environment. In this work, development of biofilm on polypropylene sheet (squares with a side length of 5 and 10 mm) and their buoyancy changes were studied in a freshwater lake in four seasons. Results showed that biofilm development have different growth rate and distinct algae composition in different seasons, which are mainly related to the difference in temperature, nutrient levels, and suspend solids in lake water. Biofilm development was much quicker on small plastics in all seasons. At the end of the experiment, all plastics lost buoyancy in summer while only a small portion lost buoyance in other seasons. Sinking of the floating plastics can be attributed to the development of biofilm and the trapped minerals. Our results demonstrated that biofilm development can cause the sinking of floating plastics in fresh lakes but the time required to lose buoyance can differ seasonally. Floating plastics will remain in water for a longer time in cold season but sink in a short time in warm season. Future research is required to determine the influence of plastic types and shapes, and quantitative relation between environmental variables and the sinking behavior of the fouled plastics should be established for a better prediction of their fate in the freshwater environment. (C) 2019 Elsevier Ltd. All rights reserved

Sources and distribution of microplastics in China's largest inland lake - Qinghai Lake

Microplastic pollution was studied in China&#39;s largest inland lake Qinghai Lake in this work. Micro plastics were detected with abundance varies from 0.05 x 10(5) to 7.58 x 10(5) items km(-2) in the lake surface water, 0.03 x 10(5) to 0.31 x 10(5) items km-2 in the inflowing rivers, 50 to 1292 items m(-2) in the lakeshore sediment, and 2 to 15 items per individual in the fish samples, respectively. Small microplastics (0.1-0.5 mm) dominated in the lake surface water while large microplastics (1-5 mm) are more abundant in the river samples. Microplastics were predominantly in sheet and fiber shapes in the lake and river water samples but were more diverse in the lakeshore sediment samples. Polymer types of microplastics were mainly polyethylene (PE) and polypropylene (PP) as identified using Raman Spectroscopy. Spatially, microplastic abundance was the highest in the central part of the lake, likely due to the transport of lake current. Based on the higher abundance of microplastics near the tourist access points, plastic wastes from tourism are considered as an important source of microplastics in Qinghai Lake. As an important area for wildlife conservation, better waste management practice should be implemented, and waste disposal and recycling infrastructures should be improved for the protection of Qinghai Lake. (C) 2018 Elsevier Ltd. All rights reserved.</p

Comparison of microplastic pollution in different water bodies from urban creeks to coastal waters

Although freshwater and estuary systems are recognized as origins and transport pathways of plastics to the oceans, there is a lack of comparison of microplastics in different water bodies or river networks. In the present study, the spatial distribution of microplastics was compared across different water bodies, including city creeks (Shanghai), rivers (Suzhou River and Huangpu River), an estuary (Yangtze Estuary) and coastal waters (East China Sea) in the Yangtze Delta area. Significant spatial differences of micro plastic abundances were revealed across the sampling areas. The results showed that the abundance of microplastics was higher (1.8-2.4 items/L) in freshwater bodies than that in estuarine and coastal water (0.9 items/L). In the Suzhou River and the Huangpu River, microplastics showed trends of increasing abundance downstream, where the peak of microplastic pollution is closer to the city center and the estuary. In respect of abundance, microplastics are likely to be transported from pollution sources to sink areas via river networks. The proportion of fibers was the highest in city creeks (88%), followed by the Suzhou River (85%), the Huangpu River (81%), the Yangtze Estuary (66%) and the East China Sea (37%). Similarly, polyesters dominated in city creeks and rivers. The results suggest that both the abundance and properties of microplastic pollution varies across different water bodies. Microplastic pollution in small freshwater bodies is more serious than in estuarine and coastal waters. Therefore, we support prioritization of water monitoring for microplastics within entire river networks, instead of single water body surveys. (C) 2018 Elsevier Ltd. All rights reserved

Use of the enhanced frog embryo teratogenesis assay-Xenopus (FETAX) to determine chemically-induced phenotypic effects

The frog embryo teratogenesis assay-Xenopus (FETAX) is an established method for the evaluation of the developmental toxicities of chemicals. To develop an enhanced FETAX that is appropriate for common environmental contaminants, we exposed Xenopus tropicalis embryos to eight compounds, including tributyltin, triphenyltin, CdCl2, pyraclostrobin, picoxystrobin, coumoxystrobin, all-trans-retinoic acid and 9-cis-retinoic acid. Multiple malformations were induced in embryos particularly following exposure to tributyltin, triphenyltin and pyraclostrobin at environmentally relevant concentrations. Based on the range of observed malformations, we proposed a phenotypic assessment method with 20 phenotypes and a 0–5 scoring system. This derived index exhibited concentration-dependent relationships for all of the chemicals tested. Furthermore, the phenotype profiles were characteristic of the different tested chemicals. Our results indicate that malformation phenotypes can be quantitatively integrated with the primary endpoints in conventional FETAX assessments to allow for increased sensitivity and measurement of quantitative effects and to provide indicative mechanistic information for each tested chemical

Photo-catalytic conversion of oxygenated hydrocarbons to hydrogen over heteroatom-doped TiO2 catalysts

Here we report a sustainable process for photo-induced hydrogen production from aqueous solutions of oxygenated hydrocarbons. Doping N and B into TiO2 noticeably improves its activity for hydrogen production. The addition of oxygenated hydrocarbons into water serves both as a hydrogen source and as an electron donor, which substantially enhances hydrogen production as compared with that for the photo-catalytic splitting of pure water. Other biomass-derived compounds such as glucose and sucrose are also shown to have potential for hydrogen production by this photo-catalytic conversion