خيارات البحث
النتائج 1 - 10 من 71
An Innovative Method to Allocate Air-Pollution-Related Taxes, Using Aermod Modeling (case study: Besat Power Plant).
2018
Tamjidi, Mahsa | Rashidi, Yousef | Atabi, Farideh | broomandi, parya
The present study applies the model of American Meteorological Society-Environmental Protection Agency Regulatory Model (AERMOD) to investigate NO2 emissions from Besat thermal power plant, which is fuelled by natural gas to function. Results indicate that the simulated concentration of NO2 based on AERMOD, does not exceed NO2 concentration limit, set by the Iranian Ambient Air Quality Standard. This shows that NO2 emissions from Besat power plant do not have any significant impact on nearby communities. The natural-gas-based power plant is capable of reducing the air pollution level. It also can decrease the hospital treatment costs, thus protecting public health. The modeling results shows that natural-gas-based power plant as a clean technology in power generation. Also, the AERMOD model has been used to determine the pollution source matrix of Besat power plant. An innovative idea has been implemented to not only determine air-pollution-related taxes and complexities but to solve the legal problem associated with it, also. As for the complexities, their determination entails two different methods: one, based on city's boundaries along with simulated amount of air pollutant concentrations in each receptor, and the other, based on the population of each receptor (i.e., the cities of Varamin, Eslamshahr, and Nasirshahr), which plays a vital role. According to the first approach, Varamin has the lion's share in the air pollution, caused by Best power plant. However, the second approach surprisingly shows that the largest portion belongs to Eshalmshahr, indicating the significant influence of its population.
اظهر المزيد [+] اقل [-]Survival rate and breeding outputs in a high Arctic seabird exposed to legacy persistent organic pollutants and mercury
2015
Goutte, Aurélie | Barbraud, Christophe | Herzke, Dorte | Bustamante, Paco | Angelier, Frédéric | Tartu, Sabrina | Clément-Chastel, Céline | Moe, Børge | Bech, Claus | Gabrielsen, Geir W | Ove Bustnes, Jan | Chastel, Olivier | Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols (METIS) ; Université Pierre et Marie Curie - Paris 6 (UPMC)-École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) | Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) ; Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS) | Norwegian Institute for Air Research (NILU) | LIttoral ENvironnement et Sociétés (LIENSs) ; La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS) | Norwegian Institute for Nature Research (NINA) | Norwegian Polar Institute
International audience | Chronic exposure to pollutants may represent a threat for wildlife. We tested whether adult survival rate, breeding probability and breeding success the year of sampling and the following year were affected by blood levels of mercury or persistent organic pollutants in Svalbard black-legged kittiwake Rissa tridactyla, by using capture–mark–recapture models over a five-year period. Survival rate was negatively linked to HCB levels in females, to chlordane mixture and oxychlordane, tended to decrease with increasing PCBs or DDE levels, but was unrelated to mercury. Breeding probability decreased with increasing mercury levels during the sampling year and with increasing CHL or HCB levels during the following year, especially in males observed as breeders. Surprisingly, the probability of raising two chicks increased with increasing HCB levels. Although levels of these legacy pollutants are expected to decline, they represent a potential threat for adult survival rate and breeding probability, possibly affecting kittiwake population dynamics.
اظهر المزيد [+] اقل [-]A meta-analysis of the distribution, sources and health risks of arsenic-contaminated groundwater in Pakistan
2018
Shāhid, Muḥammad | Niazi, Nabeel Khan | Dumat, Camille | Naidu, R. | Khalid, Sana | Rahman, Mohammad Mahmudur | Bibi, Irshad
Globally, millions of people who rely on groundwater for potable purposes and agriculture have been inadvertently exposed to toxic arsenic (As) because of its natural occurrence in groundwater in several countries of Asia, Europe and America. While the presence of As in groundwater and its impacts on human health have been documented in many countries, there is little information on As contamination in Pakistan. This review highlights, for the first time, the extent and severity of As-induced problems in Pakistan based on relevant published papers; discusses possible sources of As contamination of aquifers; and estimates As-induced potential health hazards in the country in relation to global data. Data from 43 studies (>9882 groundwater samples) were used to describe As variability in groundwater of Pakistan and for comparison with global data. The mean groundwater As content reported in these studies was 120 μg/L (range: 0.1–2090 μg/L; SD: ±307). About 73% of the values for mean As contents in the 43 studies were higher than the World Health Organization (WHO) permissible limit (10 μg/L) for drinking water, while 41% were higher than the permissible limit of As in Pakistan (50 μg/L). It was observed that groundwater samples in some areas of Punjab and Sindh provinces contained high As concentrations which were almost equal to concentrations reported in the most contaminated areas of the world. We predicted that the mean values of ADD, HQ and CR were 4.4 μg kg⁻¹day⁻¹ (range: 0–77 μg kg⁻¹day⁻¹), 14.7 (range: 0–256) and 0.0029 (range: 0–0.0512), respectively, based on mean As concentrations reported in Pakistan. In addition, this article proposes some integrated sustainable solutions and future perspectives keeping in view the regional and global context, as well as the on-ground reality of the population drinking As-contaminated water, planning issues, awareness among civil society and role of the government bodies. Based on available data, it is predicted that almost 47 million people in Pakistan are residing in areas where more than 50% of groundwater wells contain As concentrations above the WHO recommended limit of As in drinking water.
اظهر المزيد [+] اقل [-]The effect of metal pollution on the population genetic structure of brown trout (Salmo trutta L.) residing in the River Hayle, Cornwall, UK
2011
Durrant, Christopher J. | Stevens, Jamie R. | Hogstrand, Christer | Bury, Nicolas R.
The River Hayle in south-west England is impacted with metals and can be divided into three regions depending on the copper and zinc concentrations: a low-metal upper section; a highly-contaminated middle section and a moderately contaminated lower section. Hayle river water is toxic to metal-naive brown trout, but brown trout are found in the upper and lower regions. The study aimed to evaluate the population genetic structure of River Hayle brown trout and to determine if the highly-contaminated section acts as a chemical barrier to migration. Population genetic analysis indicated that metals were not a barrier to gene flow within the river, but there was a high level of differentiation observed between fish sampled at two sites in the upper region, despite being separated by only 1 km. The metal tolerance trait exhibited by this brown trout population may represent an important component of the species genetic diversity in this region.
اظهر المزيد [+] اقل [-]Consistent exposure to microplastics induces age-specific physiological and biochemical changes in a marine mysid
2021
Lee, Do-Hee | Lee, Somyeong | Rhee, Jae-Sung
In this study, a marine mysid, Neomysis awatschensis, was exposed to 1 × 10³–5 × 10⁵ particles mL⁻¹ of polystyrene microbeads (1 and 10 μm). Exposure to microplastics (MPs) resulted in ingestion and egestion in feces. MPs exposure during the early stage resulted in mortality and oxidative stress, while more mature stages were increasingly tolerant to MPs. Feeding rates were inhibited by MPs, and age-specific oxidative stress was observed. Growth parameters were significantly affected by MPs with lower 20–hydroxyecdysone (20E) concentrations and longer intermolt durations. The number of hatched juveniles from females that were exposed to MPs was significantly lower than the control treatment, but no significant differences were observed between survival rates of newly hatched juveniles in the different treatments. Our results suggest that the detrimental effects of prolonged exposure to MPs could be age- and size-specific and harmful for the maintenance of mysid populations.
اظهر المزيد [+] اقل [-]DNA strand breaks (comet assay) in blood lymphocytes from wild bottlenose dolphins
2013
Lee, Richard F. | Bulski, Karrie | Adams, Jeffrey D. | Peden-Adams, Margie | Bossart, Gregory D. | King, Lydia | Fair, Patricia A.
The comet assay was carried out on blood lymphocytes from a large number of wild dolphins (71 from Indian River Lagoon, FL, USA; 51 from Charleston Harbor, SC, USA) and provides a baseline study of DNA strand breaks in wild dolphin populations. There were no significant differences in the comet assay (%DNAintail) results between the different age and sex categories. Significant difference in DNA strand breaks were found between Charleston Harbor dolphins (median – 17.4%DNAintail) and Indian River Lagoon dolphins (median – 14.0%DNAintail). A strong correlation found between T-cell proliferation and DNA strand breaks in dolphin lymphocytes suggests that dolphins with a high numbers of DNA strand breaks have a decreased ability to respond to infection. Higher concentrations of genotoxic agents in Charleston Harbor compared with Indian River lagoon may have been one of the causes of higher DNA strand breaks in these dolphins.
اظهر المزيد [+] اقل [-]Ingestion of marine debris plastic by the wedge-tailed shearwater Ardenna pacifica in the Great Barrier Reef, Australia
2013
Verlis, K.M. | Campbell, M.L. | Wilson, S.P.
We present the first evidence of ingestion of plastic by seabirds from the southern Great Barrier Reef (GBR), Australia. The occurrence of marine debris ingestion in the wedge-tailed shearwater, Ardenna pacifica, on Heron Island was the focus of this preliminary research. Our findings indicate that 21% of surveyed chicks are fed plastic fragments by their parents, having ingested 3.2 fragments on average. The most common colours of ingested plastic fragments were off/white (37.5%) and green (31.3%). Ingested fragments had a mean size of 10.17±4.55mm and a mean weight of 0.056±0.051g. Our results indicate that further research is critical to understanding the extent of ingestion, colour preferences, and what impacts ingestion may have on these and other seabird populations in the GBR.
اظهر المزيد [+] اقل [-]Occurrence of microplastics in the gastrointestinal tract of pelagic and demersal fish from the English Channel
2013
Lusher, A.L. | McHugh, M. | Thompson, R.C.
Microplastics are present in marine habitats worldwide and laboratory studies show this material can be ingested, yet data on abundance in natural populations is limited. This study documents microplastics in 10 species of fish from the English Channel. 504 Fish were examined and plastics found in the gastrointestinal tracts of 36.5%. All five pelagic species and all five demersal species had ingested plastic. Of the 184 fish that had ingested plastic the average number of pieces per fish was 1.90±0.10. A total of 351 pieces of plastic were identified using FT-IR Spectroscopy; polyamide (35.6%) and the semi-synthetic cellulosic material, rayon (57.8%) were most common. There was no significant difference between the abundance of plastic ingested by pelagic and demersal fish. Hence, microplastic ingestion appears to be common, in relatively small quantities, across a range of fish species irrespective of feeding habitat. Further work is needed to establish the potential consequences.
اظهر المزيد [+] اقل [-]Modeling jellyfish Pelagia noctiluca transport and stranding in the Ligurian Sea
2013
Jellyfish blooms are generally attributed to a biological response to the environment, neglecting the role of transport patterns in redistributing existing populations. Here, we use high-resolution (1.25km) ocean modeling to examine the role of transport in the onshore arrival and abundance of the pelagic stinging jellyfish Pelagia noctiluca on the Ligurian Sea coast. Jellyfish are modeled as Lagrangian particles with a 0–300-m diel vertical migration typical of P. noctiluca. Over the course of a year, onshore arrivals are not restricted to the summer. Arrivals are concentrated at capes, but abundance can reach maxima in bays and in the lee of capes. Two factors impact jellyfish arrivals at the coast: the position of the Northern Current and the wind. A comparison of summer 2006 and available onshore jellyfish observations suggests a correct capture of the main stranding events by the model. These results have implications for understanding long-term fluctuations.
اظهر المزيد [+] اقل [-]Ingestion of plastic marine debris by Common and Thick-billed Murres in the northwestern Atlantic from 1985 to 2012
2013
Bond, Alexander L. | Provencher, Jennifer F. | Elliot, Richard D. | Ryan, Pierre C. | Rowe, Sherrylynn | Jones, Ian L. | Robertson, Gregory J. | Wilhelm, Sabina I.
Plastic ingestion by seabirds is a growing conservation issue, but there are few time series of plastic ingestion with large sample sizes for which one can assess temporal trends. Common and Thick-billed Murres (Uria aalge and U. lomvia) are pursuit-diving auks that are legally harvested in Newfoundland and Labrador, Canada. Here, we combined previously unpublished data on plastic ingestion (from the 1980s to the 1990s) with contemporary samples (2011–2012) to evaluate changes in murres’ plastic ingestion. Approximately 7% of murres had ingested plastic, with no significant change in the frequency of ingestion among species or periods. The number of pieces of plastic/bird, and mass of plastic/bird were highest in the 1980s, lowest in the late 1990s, and intermediate in contemporary samples. Studying plastic ingestion in harvested seabird populations links harvesters to conservation and health-related issues and is a useful source of large samples for diet and plastic ingestion studies.
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