Уточнить поиск
Результаты 2221-2230 из 7,292
Distribution and pollution risk assessment of heavy metals in the surface sediment of the intertidal zones of the Yellow River Estuary, China Полный текст
2022
Wang, Zhe | Lin, Kuixuan | Liu, Xiaoshou
Eleven heavy metals (V, Cr, Mn, Co, Fe, Ni, Cu, Zn, As, Cd, and Pb) in surface sediment in the intertidal zones of the Yellow River Estuary, China were analyzed by inductively coupled plasma-mass spectrometry in summer and autumn 2019. Results indicated that the 11 heavy metals had the same sources. Sediment particle size and total organic matter were the main factors influencing the distribution of heavy metals. Most sites in the intertidal zones of the study area were not contaminated with V, Cr, Fe, Co, Zn, Pb, Cu, As, Mn and Ni, while Cd was the priority pollutant. Heavy metal pollution risk in autumn was higher than that in summer, which may be due to hydrodynamic effects. The present study showed that the heavy metal concentrations in the study area had a temporal decreasing trend compared to previous studies, which may be due to the reduction in human activities.
Показать больше [+] Меньше [-]Evaluation of microplastic and marine debris on the beaches of Niterói Oceanic Region, Rio De Janeiro, Brazil Полный текст
2022
da Silva, Elaine Ferreira | do Carmo, Dirlane de Fátima | Muniz, Marcelo Costa | dos Santos, Camila Américo | Cardozo, Bárbara Barroso Issa | Costa, Daniel Miranda de Oliveira | dos Anjos, Roberto Meigikos | Vezzone, Mariana
The characterization of microplastics helps to improve sustainable management practices in aquatic ecosystems impacted by plastic litter. Plastic litter and microplastics from four ocean beaches in the Niterói municipality was evaluated in winter and summer. The collection and preparation of microplastic sample procedures followed on the protocol developed by the RLA7025 Project of the International Atomic Energy Agency. Marine debris followed to the United Nations Environment Program protocol. The polymer was characterized by ATR-FTIR technique.The Clean Coast Index was used to determine the degree of dirt on the beaches. Polyethylene (43%) and Polystyrene (52%) were the most abundant microplastics. The plastic is the most abundant category; representing 85% in winter and 73% in summer.The main sources are related to the consumption of drinks and food. These results emphasize the importance of reverse logistics and the value chain for packaging material and the need for effective actions managing solid waste.
Показать больше [+] Меньше [-]Heavy metals in fish nearby electronic waste may threaten consumer's health. Examples from Accra, Ghana Полный текст
2022
Steinhausen, Sophie L. | Agyeman, Narkie | Turrero, Pablo | Ardura, Alba | García Vázquez, Eva
Electronic waste sites are rich in heavy metals contained in electronic and electric equipment waste and pose a risk of pollution if metals enter in the environment nearby. The Korle lagoon, located in the center of Accra, is receiving waste effluents from industries, households and the adjacent e-waste burning site Agbogbloshie which is the biggest in the country. Thus, the risk of heavy metal contamination of the water body and subsequent uptake in the aquatic food chain is particularly relevant. Small-scale fishing, not entering the commercial chain, occurs in the lagoon despite its consideration of biologically dead. We assessed if the exposure to heavy metals through these fish consumption is posing higher health risks than fish sold on Ghanaian markets. Using ICP-MS technology, we quantified concentrations of As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn in fish caught from the Korle Lagoon (Trachinotus ovatus, Mugil curema and Mugil cephalus) and compared them to fish from the Tema Newtown fishing market (Scomber colias, Pseudotolithus senegallus). Cobalt and lead concentrations, typical e-waste metals, were higher in fish from the Korle lagoon, even though they were of lower trophic level. Calculated risk indices revealed risk of elevated arsenic and mercury exposure, particularly through T. ovatus from the Korle lagoon, if consumed daily as it is common in the region. This study suggests the need of monitoring programs of Ghanaian catch, with a special focus in environmental risk areas like Korle lagoon to ensure human food safety.
Показать больше [+] Меньше [-]Seasonal distribution and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Giresun coast of southeastern Black Sea Полный текст
2022
Tepe, Yalçın | Aydın, Handan | Ustaoğlu, Fikret | Kaya, Serdal
Seasonal sediment samples were collected along the Giresun coastline of southeastern Black Sea and analyzed to detect the levels of 16 polycyclic aromatic hydrocarbons (PAHs). The PAH levels, ranging from 28.47 to 444.36 ng g⁻¹ with the mean of 102.57 ng g⁻¹ remained lower than those detected in most of the other sediment studies conducted worldwide. The percentage of three-ring PAHs (38.9%) was rather high, followed by that of 5-ring PAHs (21.8%). Detection rates revealed that PAHs in surface sediments along the Giresun coastline are mainly associated with coal combustion and local emissions. The evaluation with sediment quality guidelines (SQGs) showed that the level of PAHs was comparable to that at which the risk of adverse biological effects cannot be ruled out (≥TEL and <PEL) in some stations. The risk posed by PAHs in Giresun coastal sediments appears to be low to moderate ecological risk according to the risk quotient.
Показать больше [+] Меньше [-]Multicompartmental analysis of POPs and PAHs in Concepciόn Bay, central Chile: Part I – Levels and patterns after the 2010 tsunami Полный текст
2022
Pozo, Karla | Gomez, Victoria | Přibylová, Petra | Lammel, Gerhard | Klánová, Jana | Rudolph, Anny | Ahumada, Ramón
Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) were determined in abiotic samples from Concepción Bay in Central Chile. Samples were soxhlet extracted and injected in gas chromatography–mass spectrometry (GCMS). Polybrominated diphenyl ethers (PBDEs) showed the highest levels in air (3–1100 pg m⁻³), in water (2–64 pg L⁻¹), in sediment, and soil (1–78 ng g⁻¹ (dw)). PAHs were also high in the air (1–6 ng m⁻³), in water (1–7 ng L⁻¹), in sediment (90–300 ng g⁻¹ (dw)), and in soil (15–2300 ng g⁻¹ (dw)). The polychlorinated biphenyls (PCBs) and chlorinated pesticides were generally low and did not show clear trends along the water column, with exception of PAHs. New data are presented in this work to assess the health status of a relevant coastal area in central Chile.
Показать больше [+] Меньше [-]Pesticides in water and sediments of Chacahua-Pastoria Lagoon System, Oaxaca, Mexico Полный текст
2022
Leal-Acosta, María Luisa | de Jesús Bastidas-Bastidas, Pedro | Cruz-Acevedo, Edgar | Aguilar-Jiménez, Edgar Emmanuel | Perea-Domínguez, Xiomara Patricia | Martínez-Álvarez, Iván Guadalupe | Leyva-Morales, José Belisario
This is the first report about the presence of pesticide residues in water and sediments from Chacahua-Pastoria Lagoon System in the Oaxaca Coast, Mexico. Organochlorine and organophosphate pesticides were analyzed in water and sediment samples collected during rainy and dry seasons in 2018. The pesticides extraction was carried out by 525.2 EPA and QuEChERS methods for water and sediments samples, respectively. The quantification was done by gas chromatography coupled to electron microcapture (μECD) and flame photometric (FPD) detectors. Univariate and multivariate analysis were carried out to evaluate the distribution patterns, comparing between lagoons, seasons and matrices. The spatial distribution of malathion and organochlorines in water showed the highest values near to adjacent land with some patterns differences. DDT was the most frequent in water and sediments samples, showed the highest concentrations in the Pastoria Lagoon. These results indicate the need to establish a permanent monitoring programs to implement mitigation measures.
Показать больше [+] Меньше [-]Occurrence and accumulation of heavy metals in algal turf particulates and sediments on coral reefs Полный текст
2022
Tebbett, Sterling B. | Bellwood, David R. | Johnson, Erin R. | Chase, Tory J.
Algal turfs form a critical interface on coral reefs that interacts with several key ecosystem processes. While we know these turfs have a remarkable propensity to accumulate sediments, which can have a range of ecosystem impacts, their role as sinks for heavy metals remains largely unexamined. Here we quantified the concentration of 15 metals in algal turf sediments from Lizard Island and Orpheus Island on the Great Barrier Reef, and specifically explored how the loads of arsenic, cobalt, iron and lead were related to turf length. Metal composition differed markedly between the two islands, with the composition at Orpheus Island suggesting closer links to terrestrial sediment sources. Furthermore, metal loads increased significantly with turf length, suggesting that longer turfs can accumulate these pollutants on reefs. Given that algal turfs are a crucial component of herbivorous/detritivorous trophic pathways, this could represent a key juncture at which these metals enter food chains.
Показать больше [+] Меньше [-]Mercury concentration and speciation in benthic organisms from Isfjorden, Svalbard Полный текст
2022
Korejwo, Ewa | Saniewska, Dominika | Bełdowski, Jacek | Balazy, Piotr | Saniewski, Michał
Polar regions are an important part of the global mercury cycle and interesting study sites due to different possible mercury sources. The full understanding of mercury transformations in the Arctic is difficult because this region is the systems in transition –where the effects of the global climate change are the most prominent. Benthic organisms can be valuable bioindicators of heavy metal contamination. In July 2018, selected benthic organisms: macroalgae, brittle stars, sea urchins, gastropods, and starfish were collected in Isfjorden, Spitsbergen. Two of the sampling stations were located inside the fjord system and one at the entrance to the fjord. The results showed that the starfish were the most contaminated with mercury. Total mercury concentrations in these organisms were at least 10 times higher than in other organisms. However, they effectively deal with mercury by transporting it to hard tissue. The dominant form of mercury was the labile form.
Показать больше [+] Меньше [-]A temporal assessment of microplastics distribution on the beaches of three remote islands of the Yasawa archipelago, Fiji Полный текст
2022
Al Nabhani, Khadija | Salzman, Scott | Shimeta, Jeff | Dansie, Andrew | Allinson, Graeme
This is the first study that investigated the presence, distribution, and composition of microplastics, MPs (1-5 mm) on beaches in the Yasawa Islands, Fiji. A temporal assessment over three years on six beaches was undertaken to investigate different beach traits on MP abundance. Average MP concentration was 4.5 ± 11.1 MPs·m⁻² with significantly higher concentrations were found on east-facing beaches than west (p < 0.001), and higher on the storm line compared to the high tide line (p < 0.001). No difference was found between tourist and local beaches (p = 0.21). These results demonstrate the role of current-driven ocean transport of plastic pollution in this part of The South Pacific. ATR FT-IR analysis showed that across all sites 34 % of MPs were polypropylene (PP), 33 % polystyrene (PS), 25 % polyethylene (PE), and 8 % other polymer types. Further studies are needed to assess the potential impacts of MPs on Fiji's coral reefs and marine life.
Показать больше [+] Меньше [-]In an octopus's garden in the shade: Underwater image analysis of litter use by benthic octopuses Полный текст
2022
Freitas, Tainah B.N. | Leite, Tatiana S. | de Ramos, Bruna | Di Cosmo, Anna | Proietti, Maíra C.
Benthic octopuses have been widely documented in artificial shelters for decades, and this use is apparently increasing. Despite any possible positive effects, the use of litter as shelter could have negative implications. In this work, we aimed to elucidate the interactions of octopuses with marine litter, identifying types of interactions and affected species and regions. To achieve this, we obtained 261 underwater images from ‘citizen science’ records, and identified 8 genera and 24 species of benthic octopuses interacting with litter. Glass objects were present in 41.6% of interactions, and plastic in 24.7%. Asia presented the highest number of images, and most records were from 2018 to 2021. Citizen science provided important evidence on octopus/marine litter interactions, highlighting its value and the need for more investigations on the subject. This information is fundamental to help prevent and mitigate the impacts of litter on octopuses, and identify knowledge gaps that require attention.
Показать больше [+] Меньше [-]