scholarly journals Tests of chronic and acute toxicity of crude oil on larvae of Chironomus kiiensis Tokunaga (Diptera: Chironomidae)

2014 ◽  
Vol 74 (3 suppl 1) ◽  
pp. S070-S077 ◽  
Author(s):  
ACF Lacerda ◽  
GA Gusmão ◽  
N Hamada
Keyword(s):  
Natural Gas ◽  
Acute Toxicity ◽  
Crude Oil ◽  
Chronic Toxicity ◽  
Synergistic Effects ◽  
Aquatic Insect ◽  
Aquatic Organisms ◽  
High Tolerance ◽  
Biological Communities ◽  
The Impact

The Amazon region, known for its mega-biodiversity, also holds large reserves of petroleum and natural gas. The increasing exploitation of natural gas and crude oil in the Amazon has not been accompanied by studies evaluating the impact of these pollutants on local biological communities, particularly aquatic organisms. The aim of the present study was to determine the values of acute and chronic toxicity of crude oil from Urucu to larvae of Chironomus kiiensis Tokunaga, 1936. The LD5048hof crude oil for second-instar larvae of C. kiiensis was 26.5 mg/L, and mortality for the majority of concentrations tested was greatest during the first 24 hours of the experiment. The survival of eggs of C. kiiensis exposed to concentrations of crude oil was also evaluated but did not differ significantly among the treatments. Despite the high tolerance observed for the species in the experiments, there is a possibility that in the natural environment the oil interacts with other factors, leading to synergistic effects, so further studies are needed to assess the effects of this pollutant on aquatic insect species.

Survey for Tributyltin in Water and Sediment in Canada in 1999

2005 ◽  
Vol 40 (4) ◽  
pp. 431-447 ◽  
Author(s):  
R. James Maguire ◽  
Suzanne P. Batchelor
Keyword(s):  
Acute Toxicity ◽  
Pest Control ◽  
Marine Sediments ◽  
Chronic Toxicity ◽  
Aquatic Organisms ◽  
Benthic Organisms ◽  
Freshwater Sediments ◽  
Antifouling Paints ◽  
Water And Sediment ◽  
Small Craft

Abstract A survey of water and sediment from 152 harbours, marinas and shipping channels across Canada was conducted in 1999 to determine the extent of contamination by tributyltin (TBT) prior to the total ban on its antifouling uses being phased in over the period 2003 to 2008, and to assess the effectiveness of the 1989 regulation of antifouling uses of TBT under the Canadian Pest Control Products Act. TBT was found in sediments in this survey much more frequently than in water. The main conclusion was that by 1999 the regulation had been generally effective in reducing TBT contamination in water, but not sediment, in small-craft marinas and harbours. TBT continued to be found in some freshwater and seawater locations frequented by larger vessels, that could have been legally painted at the time with TBT antifouling paints, at concentrations that could cause chronic toxicity to aquatic organisms. TBT was also found in many marine sediments, and some freshwater sediments, at concentrations that could cause chronic toxicity to sensitive benthic organisms. In addition, TBT concentrations in many marine sediments could cause acute toxicity to sensitive benthic organisms. Because of the long persistence of TBT in sediments, it may pose a hazard to benthic organisms in some locations in Canada for many years after the total ban on antifouling uses of TBT.

scholarly journals Crude oil, natural gas, and economic growth: impact and causality analysis in Caspian Sea region

2018 ◽  
Vol 54 (3) ◽  
pp. 169-184 ◽  
Author(s):  
S M Rashed Jahangir ◽  
Betul Yuce Dural
Keyword(s):  
Economic Growth ◽  
Natural Gas ◽  
Crude Oil ◽  
Caspian Sea ◽  
Oil Price ◽  
Crude Oil Price ◽  
Causality Test ◽  
Oil And Natural Gas ◽  
Gas Price ◽  
The Impact

Abstract The main objective of this study was to investigate the impact and causality of crude oil and natural gas on economic growth in the Caspian Sea region. Here, the study applies ordinary least square (OLS) method and Granger causality test using time series data from 1997 to 2015 to ascertain the impact and causality of crude oil and natural gas on economic growth. The results, according to the OLS method, evince that crude oil and natural gas have a significant impact on economic growth of the region. Alongside, considering causality test, gross domestic product (GDP) does Granger cause (unidirectional) crude oil price and export which denotes that GDP can help to forecast crude oil price and export; however, crude oil price and export cannot help to forecast GDP. Surprisingly, this direction is unlikely for GDP and natural gas. GDP and natural gas have unidirectional, but opposite causal relationship, i.e., natural gas price and export do Granger cause GDP which signify that natural gas price and export can help to forecast GDP; however, GDP cannot help to forecast crude oil price and export.

Effective Pipeline Integrity Management in the Magallanes Region of Chile

2010 ◽  
Author(s):  
E. Salinas ◽  
A. Mun˜oz ◽  
A. Wilde ◽  
J. Healy ◽  
M. Bakayeva
Keyword(s):  
Natural Gas ◽  
Crude Oil ◽  
Operational Reliability ◽  
Management Plan ◽  
Pipeline System ◽  
Energy Company ◽  
Exploration And Production ◽  
Integrity Management ◽  
Business Line ◽  
The Impact

Empresa Nacional del Petro´leo (ENAP) is an energy company, wholly owned by the Chilean Government. With regards to overall management, the company comprises of two Business Divisions: Exploration and Production (Up-stream) and Refining and Logistic (Down-stream), complemented by corporate managerial structures. The objective of ENAP’s Exploration and Production (UpStream) business line is the exploration and exploitation of hydrocarbons (oil and natural gas) in the South of Chile (Magallanes) and abroad, as well as geo-thermal energy, in this case, associated with private entities in areas of Northern Chile. Within the Magallanes region ENAP operates approximately 2,200 km of natural gas, crude oil and refined product pipelines. These pipelines range in diameter from 4 to 20 inch and the majority of pipelines are over 30 years old. Due to operational reliability reasons, since 1998 ENAP has been regularly inspecting its pipelines using intelligent in-line inspection tools. Furthermore, since 2006, as part of an overall pipeline integrity management plan ENAP has been conducting Fitness for Service assessments on selected pipelines including a risk-based assessment considering pipeline condition and the impact on the continuity of operation. The Integrity Management Plan implemented by ENAP in the Magallanes region has been applied to all pipelines transporting gas, crude oil and refined products, including those built after 1990. This plan comprises the construction phase, from which invaluable information is gathered for later use. The primary aims of ENAP’s integrity management plan are: - To protect the public; - To protect the surrounding environment by preventing pipeline failures; - To ensure efficient usage of the budget available to conduct maintenance tasks; - To prevent damage to the pipelines, e.g. due to corrosion activity; - To provide clarity of activities being performed by ENAP in order to ensure an efficient, safe and reliable pipeline system. This paper provides a description of the integrity management strategy adopted by ENAP and includes a review of a number of the challenges encountered during its implementation.

scholarly journals Acute Toxicity and DNA Instability Induced by Exposure to Low Doses of Triclosan and Phthalate DEHP, and Their Combinations, in vitro

2021 ◽  
Vol 12 ◽  
Author(s):  
Nathalia de Assis Aguilar Duarte ◽  
Lindiane Eloisa de Lima ◽  
Flora Troina Maraslis ◽  
Michael Kundi ◽  
Emilene Arusievicz Nunes ◽  
...  
Keyword(s):  
Dna Damage ◽  
Acute Toxicity ◽  
Nuclear Division ◽  
Aquatic Organisms ◽  
Human Cells ◽  
Dna Instability ◽  
Nuclear Division Index ◽  
Mutagenic Effects ◽  
The Impact

Triclosan (TCS) is an antimicrobial agent widely used in personal care products (PCP) and the di-(2-ethyl hydroxy-phthalate) (DEHP) is a chemical compound derived from phthalic acid, used in medical devices and plastic products with polyvinyl chloride (PVCs). As result of their extensive use, TCS and DEHP have been found in the environment and previous studies demonstrated the association between their exposure and toxic effects, mostly in aquatic organisms, but there is a shortage in the literature concerning the exposure of TCS and DEHP in human cells. The aim of the present study was to assess the impact of exposure to TCS and DEHP, as well as their combinations, on biomarkers related to acute toxicity and DNA instability, in HepG2 cells, by use of cytokinesis-block micronucleus cytome (CBMNCyt) assay. For that, the cultures were exposed to TCS, DEHP and combinations at doses of 0.10, 1.0, and 10 μM for the period of 4 h and the parameters related to DNA damage (i.e., frequencies of micronuclei (MN) and nuclear buds (NBUDs), to cell division (i.e., nuclear division index (NDI) and nuclear division cytotoxic index (NDCI) and to cell death (apoptotic and necrotic cells) were scored. Clear mutagenic effects were seen in cells treated with TCS, DEHP at doses of 1.0 and 10 μM, but no combined effects were observed when the cells were exposed to the combinations of TCS + DEHP. On the other hand, the combination of the toxicants significantly increased the frequencies of apoptotic and necrotic cells, as well as induced alterations of biomarkers related to cell viability (NDI and NDCI), when compared to the groups treated only with TCS or DEHP. Taken together, the results showed that TCS and DEHP are also able to induce acute toxicity and DNA damage in human cells.

scholarly journals Pregabalin induces pathological changes in cerebrum and cerebellum of Albino Rats

2021 ◽  
Author(s):  
Shaimaa Ali ◽  
Wael Abdo Hassan
Keyword(s):  
Cerebral Cortex ◽  
Acute Toxicity ◽  
Chronic Toxicity ◽  
Control Group ◽  
Albino Rats ◽  
Addictive Behaviors ◽  
Group 2 ◽  
The Impact ◽  
Cerebral Cortex Tissue ◽  
Control Group Group

Abstract Background: Pregabalin (PGB) used as analgesic in remedy of neurogenic pains of persistent diseases, is taken into consideration as one of the maximum abused anti-epileptic pills and it's been proved that it induces addictive behaviors. The current study investigated the impact of PGB management on cerebral cortex and cerebellar cortex, in each acute and chronic toxicity. Seventy- male and non-pregnant female albino rats’ 6- to 8-week-vintage divided into three principal corporations of 24 rats each had been studied. Group 1 was the control group, group 2 represented the acute toxicity group, and group three represented the hronic toxicity group. Rats had been sacrificed and examined. Result: Cerebral cortex tissue of acute toxicity group displayed astrocytosis and dystrophic changes, while the chronic toxicity group showed degeneration, necrosis and inflammatory cell infiltrates. The cerebellum of chronic toxicity group showed affection of Purkinje cells. Conclusion: Acute and chronic intoxication with pregabalin adversely altered the structure and thus the function of the cerebral cortex and cerebellum.

Acute toxicity of chemically and mechanically dispersed crude oil to juvenile sea bass (Dicentrarchus labrax): Absence of synergistic effects between oil and dispersants

2015 ◽  
Vol 34 (7) ◽  
pp. 1543-1551 ◽  
Author(s):  
Matthieu Dussauze ◽  
Karine Pichavant-Rafini ◽  
Stéphane Le Floch ◽  
Philippe Lemaire ◽  
Michaël Theron
Keyword(s):  
Acute Toxicity ◽  
Crude Oil ◽  
Synergistic Effects ◽  
Dicentrarchus Labrax ◽  
Sea Bass

scholarly journals Comparison of the Impact of Econometric Models on Hedging Performance by Crude Oil and Natural Gas

2018 ◽  
Vol 66 (2) ◽  
pp. 423-429
Author(s):  
Luděk Benada
Keyword(s):  
Natural Gas ◽  
Crude Oil ◽  
Risk Reduction ◽  
Econometric Models ◽  
Spot Price ◽  
Spot Prices ◽  
Oil And Natural Gas ◽  
Risk Protection ◽  
High Level ◽  
The Impact

The paper examines the performance of hedging spot prices in crude oil and natural gas. The subject of the research are spot prices of West Texas Intermediate and Henry Hub. The risk protection is provided by the application of futures contracts of underlying assets. In our analysis three econometric models (OLS, Copula, GARCH) and a naive portfolio are applied to obtain the optimal hedge ratio. Afterwards, the calculated weights for futures are verified for the ability to reduce the spot price risk over twelve months. The success of each model in risk reduction is measured over the test period by a conventional tool and across the models by proper metric. The results of the analysis confirm high level of risk reduction by crude oil across models. On the contrary, the results of hedging in natural gas significantly lag in comparison to crude oil. In addition, the analysis confirms a strong variability over the tested period and models.

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