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Low abundance of microplastics in commercially caught fish across southern Australia Полный текст
2021
Wootton, Nina | Reis-Santos, Patrick | Dowsett, Natalie | Turnbull, Alison | Gillanders, Bronwyn M.
Plastic pollution has increased significantly in the past decades and is now a major global environmental issue. Plastic objects enter the ocean and are broken down into smaller pieces, while wastewater and runoff also carry microplastics (plastics <5 mm) into the ocean. Plastic has been found in over 700 different species of marine wildlife but little research has examined fish sold for human consumption. We determined the microplastic abundance in nine commercially important, wild-caught fish species purchased from seafood markets across 4000 km of Australia (Western Australia, South Australia, Victoria, Tasmania, New South Wales). For microplastic quantification, fish gastro-intestinal tracts were chemically digested and the amount and type of microplastic identified under a microscope and Fourier transform infrared spectrometer. Across all states, an average of 35.5% of fish samples had at least one piece of microplastic in their gastro-intestinal tract. South Australia had the highest percentage of fish with plastic (49%) and Tasmania the lowest (20%). The average microplastic load was 0.94 piece per fish but ranged from 0 to 17 pieces, with polyolefin identified as the dominant polymer group. Overall, the ingestion of microplastic was widespread across species, locations, diets and habitat niches of fish species investigated, but the average plastic ingestion was less than other similar global studies. This study provides novel insights on the use of fish species from seafood markets to assess environmental contamination by microplastic, as well as an important perspective of the potential for microplastic contamination to enter the human food chain.
Показать больше [+] Меньше [-]Preliminary results on the occurrence and anatomical distribution of microplastics in wild populations of Nephrops norvegicus from the Adriatic Sea Полный текст
2021
Martinelli, Michela | Gomiero, Alessio | Guicciardi, Stefano | Frapiccini, Emanuela | Strafella, Pierluigi | Angelini, Silvia | Domenichetti, Filippo | Belardinelli, Andrea | Colella, Sabrina
This study reports the shapes, dimensional classes, types and counts of microplastics (MPs) found in 23 individuals of N. norvegicus collected from two wild populations of the Adriatic Sea (Mediterranean basin). The focus was on three different anatomical compartments (gut, hepatopancreas and tail), which were analysed separately. MPs were found in all the investigated individuals with an average of about 17 MPs/individual. Fragments were predominant over fibers with a ratio of about 3:1. The majority of MPs were in the dimensional range 50–100 μm. The predominant polymers were polyester, polyamide 6, polyvinyl chloride and polyethylene, which together constitute about 61% of all the MPs found. Fragments were more concentrated in the hepatopancreas, with no significant difference between gut and tail, while fibers were more concentrated in the gut than in the tail with hepatopancreas somehow in between. The dimensional class of the MPs influences their anatomical distribution. There were no statistical differences among individuals from the two sampling sites. Sex of the individual did not influence the level of retained MPs, while length had a very marginal effect. The information reported here contributes to understanding of the possible risks linked to human consumption of different tissues from contaminated Norway lobsters.
Показать больше [+] Меньше [-]Stabilization of acid-rich bio-oil by catalytic mild hydrotreating Полный текст
2021
Choi, Wonjun | Jo, Hyeonmin | Choi, Jae-Wook | Suh, Dong Jin | Lee, Hyunjoo | Kim, Changsoo | Kim, Kwang-ho | Lee, Kwan Young | Ha, Jeong-Myeong
Although liquid products derived from the pyrolysis of biomass are promising for the production of petroleum-like hydrocarbon fuels, the catalytic burden of hydrodeoxygenation must be reduced to achieve feasible upgrading processes. Herein, mild hydrotreating of an acid-rich biomass pyrolysis oil (bio-oil) with an unusually high total acid number (588 mg KOH/g bio-oil) was performed to stabilize the low-quality bio-oil. Ru-added TiO₂-supported transition metal catalysts stabilized the bio-oil by reducing its acidity more compared to what could be achieved by Ru-free catalysts; this process also leads to lower loss of organic compounds compared to when using a Ru/TiO₂ catalyst. Based on the performance of transition metal catalysts, including Ni, Co, and Cu, supported on TiO₂, tungstate-zirconia, or SiO₂, supported bimetallic catalysts were prepared by adding Ru to the TiO₂-supported metal catalysts. The bimetallic catalysts Ru/Ni/TiO₂ and Ru/Co/TiO₂ exhibited good decarboxylation activity for the removal of carboxylic acids and a higher yield of organic compounds compared to that provided by Ru, which can be deemed appropriate for feedstocks when hydrodeoxygenation needs to suppress the loss of organic reactants. Using these catalysts, the carboxylic acid concentration was reduced to 319–323 mg KOH/g bio-oil with organic yields of 62–63 wt% at reaction temperatures 150–170 °C lower than the temperature required for direct conversion of carboxylic acids to alcohols or deoxygenates. The improved catalytic hydrotreating activity of Ru-added transition metals can be attributed to the high acid site densities of these catalysts along with their improved hydrogenation activities.
Показать больше [+] Меньше [-]Heavy metal pollution, ecological risk, spatial distribution, and source identification in sediments of the Lijiang River, China Полный текст
2021
Xiao, He | Shahab, Asfandyar | Xi, Beidou | Chang, Qixin | You, Shaohong | Li, Jieyue | Sun, Xiaojie | Huang, Hongwei | Li, Xiangkui
The Lijiang River is of great ecological and environmental importance for Guilin City, which is located in the karst area of southeast China. Given its importance, a detailed evaluation of the heavy metals (HMs) in the river sediment is required. For the first time, 61 sediment samples were collected along the entire Lijiang River to determine pollution level and ecological risk posed by 10 HMs (Co, Cr, Cu, Mn, Ni, Pb, Zn, As, Hg, and Cd). These were assessed using the geo-accumulation index, potential ecological risk index, and modified degree of contamination. The results showed that the mean concentrations of the majority of HMs exceeded their corresponding background values and followed the trend: midstream > downstream > upstream. Based on the spatial distributions and pollution indices of the 10 HMs, the Lijiang River was found to have a high accumulation of Cd, Hg, Zn, and Pb in the sediments. The midstream area was the most polluted with respect to Cd and Hg, and also posed a relatively higher potential ecological risk than the downstream and upstream areas. The sources of the assessed HMs were inferred based on a correlation analysis and principal component analysis, which identified both natural and anthropogenic sources. A higher pollution potential was associated with Cd, Hg, Pb, and Zn in the midstream and downstream areas due to higher organic and carbonate content, urbanization, agricultural activities, and leisure activities (e.g., boating and cruises). In contrast, natural erosion and weathering processes were responsible for the HM concentrations in the upstream area. The findings of this study will help the local authorities to protect the important water resource of the Lijiang River.
Показать больше [+] Меньше [-]Spatio-temporal characterization of litter at a touristic sandy beach in South Brazil Полный текст
2021
de Ramos, Bruna | Alencar, Melanie Vianna | Rodrigues, Fábio Lameiro | Lacerda, Ana Luzia de Figueiredo | Proietti, Maíra Carneiro
Litter is an ecological, economic, and social problem that impacts marine environments around the world. To create prevention and mitigation measures to solve this issue, it is necessary to understand the amounts and sources of this type of pollution. Cassino Beach is an extensive sandy beach located in South Brazil (∼220 km in length) that presents multiple uses, such as touristic, portuary and fishery activities. In order to evaluate the spatial and seasonal variation of litter amounts, types and sources at Cassino Beach, litter (>2.5 cm) was collected over 27 months at two urban and two non-urban sites. At each site, the litter present in three 200 m² areas was sampled and evaluated. A total of 19,457 items were collected, mostly composed by plastic (∼88%). Paper, metal, and cloth items were also present, but in low amounts. Fragments and cigarette butts were the major types of plastic litter, with abundances of 28.4% and 17.0%, respectively. Urban sites presented higher amounts of litter, with those related to beach use being more common, emphasizing the contribution of beachgoers to litter input at these sites. During the summer season, when beach use increases, the highest total litter concentration was found. Undefined and/or beach use-related sources were dominant in all sites and seasons. Mapping the predominant materials, types and potential sources of litter creates important baseline data that can contribute not only to beach monitoring, but also to the development of litter reduction strategies.
Показать больше [+] Меньше [-]Temporal trends and interannual variation in plastic ingestion by Flesh-footed Shearwaters (Ardenna carneipes) using different sampling strategies Полный текст
2021
Lavers, Jennifer L. | Hutton, Ian | Bond, Alexander L.
The world's oceans are under increasing pressure from anthropogenic activities, including significant and rapidly increasing inputs of plastic pollution. Seabirds have long been considered sentinels of ocean health, providing data on physical and chemical pollutants in their marine habitats. However, long-term data that can elucidate important patterns and changes in seabird exposure to marine pollutants are relatively limited but are urgently needed to identify and support effective policy measures to reduce plastic waste. Using up to 12 years of data, we examined the benefits and challenges of different approaches to monitoring plastic in seabirds, and the relationship between plastic and body size parameters. We found the mass and number of ingested plastics per bird varied by sample type, with lavage and road-kill birds containing less plastic (9.17–9.33 pieces/bird) than beach-washed or otherwise dead birds (27.62–32.22 pieces/bird). Beached birds therefore provide data for only a particular subset of the population, mostly individuals in poorer body condition, including those severely impacted by plastics. In addition, the mass and number of plastics in beached birds were more variable, therefore the sample sizes required to detect a change in plastic over time were significantly larger than for lavaged birds. The use of lavaged birds is rare in studies of plastic ingestion due to ethical and methodological implications, and we recommend future work on ingested plastics should focus on sampling this group to ensure data are more representative of a population's overall exposure to plastics.
Показать больше [+] Меньше [-]Particulate matter promotes hyperpigmentation via AhR/MAPK signaling activation and by increasing α-MSH paracrine levels in keratinocytes Полный текст
2021
Shi, Yaqian | Zeng, Zhuotong | Liu, Jiani | Pi, Zixin | Zou, Puyu | Deng, Qiancheng | Ma, Xinyu | Qiao, Fan | Xiong, Weiping | Zhou, Chengyun | Zeng, Qinghai | Xiao, Rong
Particulate matter with an aerodynamic equivalent diameter of 2.5 μm or less in ambient air (PM2.5) has become a global public and environmental problem, and the control of the PM2.5 concentration in air is an urgent problem. PM2.5 can easily penetrate the skin, activating the inflammatory response in skin, unbalancing the skin barrier function, and inducing skin aging. Hyperpigmentation is the main manifestation of skin aging and has a considerable impact on quality of life worldwide. To date, no research on the influence of PM2.5 on hyperpigmentation has been conducted. Here, we illustrate that PM2.5 can induce melanogenesis in vivo and in vitro by regulating TYR, TYRP1, TYRP2, and MITF expression via AhR/MAPK signaling activation. Furthermore, PM2.5 increased α-MSH paracrine levels, which in turn promote hyperpigmentation. Our results provide a deeper understanding of how PM2.5 disrupts skin homeostasis and function. Treatment with AhR antagonists may be a potential therapeutic strategy for hyperpigmentation induced by PM2.5.
Показать больше [+] Меньше [-]Screening ecological risk of pesticides and emerging contaminants under data limited conditions – Case study modeling urban and agricultural watersheds with OrganoFate Полный текст
2021
Parker, Nicol | Keller, Arturo A.
The increasing number of chemicals used by society requires accessible, easy to implement tools to perform screening-level ecological risk assessments. However, field data to calibrate and validate screening tools is challenging to obtain for many watersheds. Thus, the evaluation must be done under data limited conditions. Here we employ a fate and transport model, OrganoFate, to predict environmental concentrations of contaminants of emerging concern (CECs) as well as a number of pesticides. CECs evaluated include antibacterial compounds sulfamethoxazole and triclocarban and a flame-retardant tris(1,3-dichloro-2-propyl)phosphate (TDCPP). We also evaluated widely used pesticides chlorpyrifos, bifenthrin and esfenvalerate. We predict concentrations of the contaminants in high-risk watersheds which were dominated by either urban or agricultural development and have small aquatic compartments. Screening-level predictions were in good agreement with observed concentrations in surface water and sediment. Maximum predicted concentrations were close to the highest observed concentrations for CECs, only ~0.1 μg/L greater for sulfamethoxazole and triclocarban concentrations, and for TDCPP <5 μg/L higher. ChemFate was also employed to screen possible aquatic health impacts. Results demonstrated possible CEC aquatic health risk for TDCPP and triclocarban (risk quotients of 0.9 and 1.1 respectively). For pesticides, exceedance of effect (EC50) and lethal (LC50) endpoints was predicted for various taxonomic groups which include aquatic invertebrates, fish, amphibians, and benthic organisms.
Показать больше [+] Меньше [-]A systematic review of the leaf traits considered to contribute to removal of airborne particulate matter pollution in urban areas Полный текст
2021
Corada, Karina | Woodward, Huw | Alaraj, Hiba | Collins, C Matilda | de Nazelle, Audrey
Global urban planning has promoted green infrastructure (GI) such as street trees, shrubs or other greenspace in order to mitigate air pollution. Although considerable attention has been paid to understanding particulate matter (PM) deposition on GI, there has been little focus on identifying which leaf traits might maximise airborne PM removal. This paper examines existing literature to synthesize the state of knowledge on leaf traits most relevant to PM removal. We systematically reviewed measurement studies that evaluated particulate matter accumulated on leaves on street trees, shrubs green roofs, and green walls, for a variety of leaf traits. Our final selection included 62 papers, most from field studies and a handful from wind tunnel studies. The following were variously promoted as useful traits: coniferous needle leaves; small, rough and textured broadleaves; lanceolate and ovate shapes; waxy coatings, and high-density trichomes. Consideration of these leaf traits, many of which are also associated with drought tolerance, may help to maximise PM capture. Although effective leaf traits were identified, there is no strong or consistent evidence to identify which is the most influential leaf trait in capturing PM. The diversity in sampling methods, wide comparison groups and lack of background PM concentration measures in many studies limited our ability to synthesize results. We found that several ancillary factors contribute to variations in the accumulation of PM on leaves, thus cannot recommend that selection of urban planting species be based primarily on leaf traits. Further research into the vegetation structural features and standardization of the method to measure PM on leaves is needed.
Показать больше [+] Меньше [-]A toxicity pathway-oriented approach to develop adverse outcome pathway: AHR activation as a case study Полный текст
2021
Jin, Yuan | Feng, Meiyao | Ma, Wanli | Wei, Yanhong | Qi, Guangshuai | Luo, Jiao | Xu, Lin | Li, Xinmei | Li, Chuanhai | Wang, Ying | Li, Daochuan | Chen, Jing | Zhao, Yanjie | Hou, Yufei | Zhao, Qianwen | Jiang, Lidan | Xie, Mengyue | Zheng, Yuxin | Yu, Dianke
With numerous new chemicals introduced into the environment everyday, identification of their potential hazards to the environment and human health is a considerable challenge. Developing adverse outcome pathway (AOP) framework is promising in helping to achieve this goal as it can bring In Vitro testing into toxicity measurement and understanding. To explore the toxic mechanism underlying environmental chemicals via the AOP approach, an integration of adequate experimental data with systems biology understanding is preferred. Here, we describe a novel method to develop reliable and sensible AOPs that relies on chemical-gene interactions, toxicity pathways, molecular regulations, phenotypes, and outcomes information obtained from comparative toxicogenomics database (CTD) and Ingenuity Pathway Analysis (IPA). Using Benzo(a)pyrene (BaP), a highly studied chemical as a stressor, we identified the pivotal IPA toxicity pathways, the molecular initiating event (MIE), and candidate key events (KEs) to structure AOPs in the liver and lung, respectively. Further, we used the corresponding CTD information of multiple typical AHR-ligands, including 2,3,7,8-tetrachlorodibenzoparadioxin (TCDD), valproic acid, quercetin, and particulate matter, to validate our AOP networks. Our approach is likely to speed up AOP development as providing a time- and cost-efficient way to collect all fragmented bioinformation in published studies. It also facilitates a better understanding of the toxic mechanism of environmental chemicals, and potentially brings new insights into the screening of critical paths in the AOP network.
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