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The Ebocha-8 oil-spill-polluted site was identified as study site according to field reconnaissance surveys of oil-polluted sites in Obiobi/Obrikom prospect area of Niger Delta. A sampling area was delimited at each of the oil-spill-affected sites by the grid technique, and soils were collected at surface (0-15 cm) and subsurface (15-30 cm) depths from three replicate quadrants. A geographically similar, unaffected area, located in 50-m distance from each contaminated site, was chosen as control site. Trace heavy metals, Ni, V, Cu, Cd, and Pb, which are normal constituents of crude oil, were determined in the soils by atomic-absorption spectrophotometry after pre-extraction of cations with dithionite-citrate carbonate. Ni varied from 0.53 to 18.00 mg/kg, Cu from 0.15 to 0.30 mg/kg, and Pb from 0.32 to 0.80 mg/kg in surface and subsurface soils, respectively; Cd and V were less than 0.20 mg/kg in all sampled plots. Ni, Cu, and Pb were more enhanced (P<0.05) in the oil-spill-polluted soils, especially at surface depth, and this may be attributed to the fact that metal profiles in polluted soils penetrate a little below the 10-cm region, even after many years, thereby making the metal concentration in surface soils usually higher. Whilst the Ebocha-8 oil spillage may be responsible, at least in part, for the enhanced concentrations and paucity of variations in the metal concentrations of sampled plots, other factors such as the physicochemical characteristics of soils (e.g., soil pH and organic-matter content) and relative mobility of these metals, as well as the intense rainfall and flooding that preceded the period of sampling, may also have contributed in part. Enhanced levels of these micronutrients in the soils may result in enhanced absorption by plants, which may bring about possible bioaccumulation by such plants and the animals that depend on them for survival, and all of these may lead to toxic reactions along the food chain.
An examination of the potential of crude oil and mixtures of dispersants and crude oil to act as reproductive toxicants is reported in this article. The short-term effects of a water-accommodated fraction of crude oil (WAF) and a dispersed crude oil water-accommodated fraction (DCWAF) on selected reproductive end points were measured by conducting 3-day exposures to the crimson-spotted rainbowfish (Melanotaenia fluviatilis). Exposures were followed by 14-day depuration periods to determine the ability of fish to recover from the exposure. There were no changes to egg production, hatchability, or larval lengths for the WAF and DCWAF test periods. There were no changes to plasma estradiol or testosterone concentrations, gonadosomatic indices, or histopathological organization of gonad tissues after the exposure and depuration periods for both WAF and DCWAF. As reproductive parameters were not altered after 3 days of exposure and 14 days of depuration, crimson-spotted rainbowfish were able to endure short-term exposures to crude oil and dispersed crude oil.
The interfacial tension of four sorbitan surfactants (Span 20, sorbitan monolaurate; Span 40, sorbitan monopalmitate; Span 60, sorbitan monostearate; and Span 80, sorbitan monooleate) was determined at the water-oil interface. Seven straight-chained hydrocarbons from pentane to dodecane were used as an oil phase. From the interfacial tension measurements the following values were calculated: critical micelle concentration (cmc), the interfacial tension at the cmc (gamma(cmc)), surface pressure at the cmc (pi(cmc)), area per molecule at the cmc (A(cmc)), standard free energy of micellization (DeltaG degrees (mic)), and standard free energy of adsorption (DeltaG degrees (ad)). The shorter chained Span 20 and unsaturated Span 80 had higher cmc values and Span 80 had a larger molecular area than the other surfactants. With the same oil phase, differences between pi(cmc) values of the four sorbitan monoesters were small, but the gamma(cmc) was slightly lowered as the hydrophobicity of the surfactant was increased. DeltaG degrees (mic) was less negative for Span 20 and the DeltaG degrees (ad) value was slightly more negative for Span 80. The effect of the oil phase was obvious. Increasing the hydrocarbon chain length of the oil phase increased gamma(cmc) and cmc values while pi(cmc) and A(cmc) were decreased. As the length of the hydrocarbon chain of the oil phase was increased, DeltaG degrees (mic) and DeltaG degrees (ad) became less negative, which means a less spontaneous reaction. Copyright 2001 Academic Press.
Crude oil is a complex mixture of hydrocarbons entering aquatic environments from accidental or normal marine and transportation activities. Toxicologic crude oil analysis is usually performed on the basis of the water-soluble fraction. However, this yields only a partial estimate of the damage caused by these contaminants because a substantial hydrophobic amount can be adsorbed onto suspended solids (biotic and abiotic), which directly affects filter-feeding species and permits bioaccumulation through trophic relationships. This study determined the acute toxic damage sustained after 48 hours caused by seven types of crude oil from Tabasco, Mexico on the cladoceran Daphnia magna. Comparisons were documented based on the responses of D. magna from application of the water-soluble fraction and exposure to entire crude oil samples adsorbed on kaolin clay. Oil-sorbed kaolin was more toxic than the water-soluble fraction in acute exposure. This confirms that tests of the water-soluble fraction tend to underestimate the toxic damage that can be produced in natural environments. Furthermore, chronic toxicity (21 days) was evaluated for crude oil samples adsorbed on kaolin at sublethal concentrations as established from Application Factors (AF) criteria. Results showed that in most cases, it is impossible to predict safe concentrations on the basis of LC(50) values because samples with lower acute toxicity exercised a greater influence on D. magna reproduction and survival when subjected to chronic exposure.
Oil and oil-dispersant mixtures were added to the surface waters of a series of man-made ponds. The fate of the oil and dispersant (Norman Wells crude and Corexit 9527 respectively) were studied as well as the impact of the added chemicals on the ponds' ecosystems. Elements of the ecosystems studied include bacteria, fungi, phytoplankton, periphyton , proto- and mesozooplankton , zoobenthos and surface insects. In addition a number of water quality parameters were regularly monitored. Comparisons were made between oil-treated and control ponds, as well as oil-dispersant treated and oil and/or control ponds. This paper describes the experimental set up and provides a summary of the findings reported in the following five papers.
Polar/amphiphilic oils, called lipophilic linkers, are sometimes added to oil-water-ionic surfactant microemulsions in order to increase the solubilization of hydrophobic oils. The solubilization increase has been well documented for a number of systems. However, mathematical models to calculate the solubilization increase have been proposed only for optimum microemulsions (i.e., middle phase microemulsions solubilizing equal volumes of oil and water). In this paper we propose a model, which predicts solubilization enhancement for non-optimum microemulsion systems as well. The model is an extension of the net-average curvature model of microemulsion. The net-average curvature model is combined with a surface activity model to account for the increased palisade layer solubilization due to the presence of the polar/amphiphilic oil component. New non-linear mixing rules are also incorporated to account for the optimum salinity and the characteristic length variation of the anionic surfactant microemulsion as a function of the lipophilic linker concentration. The model predicts the effect of the lipophilic linker and the electrolyte concentration on the oil solubilization in accordance with the experimental results.
Induced air flotation was used to recover oil from synthetically prepared sludge containing oil. A commercial surfactant was used as the collector and frother. The effects of various parameters, namely flotation time, initial amount of oil in the feed and the amount of surfactant used on the recovery of oil were investigated. Within the range of operating conditions studied herein, the maximum oil recovery obtained was about 55%. A detailed study of flotation kinetics based on oil recovery was carried out. It showed that the process followed first-order kinetics.
This study was undertaken to compare the effects of 1% cholesterol (Ch) on some liver mineral concentrations in rats fed with corn oil (C) or olive oil (O). Male Sprague-Dawley rats (n = 4 per group) were fed AIN76A semi-purified diets containing either 5% corn oil or 5% olive oil replacing corn oil with or without 1% cholesterol for 21 days. The analysis of minerals: Phosphorous (P), Potassium (K), Magnesium (Mg), and Sulfur (S), of liver were conducted by inductively coupled plasma (ICP) spectroscopic method. In the C fed rats addition of 1% cholesterol produced significant increase in P concentrations but not K, Mg, and S concentrations. In contrast, in O fed rats, 1% Ch significantly decreased Mg and S concentrations. There was no significant change in K and P concentrations. In conclusion, this study describes the interactions between dietary oils and cholesterol on certain mineral concentrations in liver of rats. The results obtained may have clinical significance and nutritional significance in cardiovascular health.
A small experimental oil spill was conducted on the northern tip of Baffin Island Nunavut, Canada (72 degrees 31' N, 79 degrees 50' W) in August 1981, and the natural weathering of the oil has been followed by periodic visits. This paper reports on the chemical composition of oil collected in August 2001. The vast majority of the initial oil has gone, but small patches remain. Some samples remain essentially unaltered despite their 20 years of exposure to the elements, while others show that biodegradation and photooxidation can play important roles in removing the majority of the components of the oil. Using 17alpha(H)21beta(H)hopane as a conserved marker within the oil, we show that the most biodegraded sample has lost more than 87% of the hydrocarbons initially present, while another has lost a substantial proportion of its initial chrysene and alkylated congeners. Potential explanations for the different weathering patterns seen in samples collected from this small site are briefly discussed.
Low-field (< 50 mT) nuclear magnetic resonance (NMR) well-logging measurements are beginning to be used to obtain estimates of oil viscosity in situ. To build an interpretive capability, we made laboratory T1 and T2 relaxation measurements on a suite of high-density, high-viscosity crude oils. These measurements were also used to estimate oil viscosity and water fraction from T1 and T2 measurements on stable, water-in-oil emulsions. High-density, high-viscosity oils have components that relax faster than can be measured by nuclear magnetic resonance logging tools. This requires corrections to T2 logging measurements for accurate estimates of oil saturation and porosity.
The present study was performed to investigate the effect of zinc deficiency on the activities of lipoprotein lipase in postheparin serum and tissues of rats fed diets containing either coconut oil or fish oil as dietary fat, using a bifactorial experimental design. To ensure an adequate food intake, all the rats were force-fed by gastric tube. Experimental diets contained either 0.8 mg zinc/kg (zinc-deficient diets) or 40 mg zinc/kg (zinc-adequate diets). The effects of zinc deficiency on the activities of lipoprotein lipase in postheparin serum and postprandial triglyceride concentrations and distribution of apolipoproteins in serum lipoproteins depended on the type of dietary fat. Zinc-deficient rats fed the coconut oil diet exhibited a reduced activity of lipoprotein lipase in postheparin serum and adipose tissue, markedly increased concentrations of triglycerides in serum, and a markedly reduced content of apolipoprotein C in triglyceride-rich lipoproteins and high density lipoproteins compared with zinc-adequate rats fed coconut oil. By contrast, zinc-deficient rats fed the fish oil diet did not exhibit reduced activities of lipoprotein lipase in postheparin serum and adipose tissue and increased concentrations of serum lipids compared with zinc-adequate rats fed the fish oil diet. This study suggests that a reduced activity of lipoprotein lipase might contribute to increased postprandial concentrations of serum triglycerides observed in zinc-deficient animals. However, it also demonstrates that the effects of zinc deficiency on lipoprotein metabolism are influenced by dietary fatty acids.
We report the stereospecific (sn-1, sn-2, sn-3) distribution of fatty acids in subcutaneous adipose tissue triacylglycerols of male weaned Wistar rats fed either a standard diet or diets containing, in addition to 20 g corn oil/kg feed, 120 g/kg feed, each, of canola-type rapeseed oil, olive oil, conventional or high oleic sunflower oil or high petroselinic coriander oil for 10 wk. The regiospecific distribution of the major acyl moieties in the sn-1 (3) vs. sn-2 positions of the adipose tissue triacylglycerols broadly reflected that of the dietary oils. The saturated palmitoyl and stearoyl moieties were more abundant in the sn-1 and sn-3 positions compared with the sn-2 position of the adipose tissue triacylglycerols, and both occurred at a higher proportion in the sn-1 than in the sn-3 position. Oleoyl moieties were abundant in all the three positions of the adipose tissue triacylglycerols, whereas petroselinoyl moieties were more abundant in the sn-1 and sn-3 positions compared with the sn-2 position. Linoleoyl moieties occurred predominantly in the sn-2 position compared with the sn-1 and sn-3 positions of the adipose tissue triacylglycerols; however, they were more abundant in the sn-3 than in the sn-1 position. Despite widely varying proportions of the palmitoyl, oleoyl and linoleoyl moieties at the three positions of the dietary triacylglycerols, the ratios of each of these acyl moieties at the sn-1, sn-2, and sn-3 positions in adipose tissue triacylglycerols were essentially constant for all groups, with the exception of the group fed coriander oil, indicating a rigid stereospecific incorporation.
In the oil refining and petrochemical industries exposure to cancer-causing asbestos particles, especially during equipment repair and maintenance, is very high. Up to 90% of workers in the oil refining industry had direct and/or indirect contact with asbestos, and more than half of this contact occurred without the use of any kind of precaution, thus these workers are in high risk of developing lung cancer and mesothelioma, both fatal diseases. The hazards include: inadequate health and safety training for both company personnel and workers, failure to inform about the dangers and diseases (cancers) resulting from exposure to asbestos; excessive use of large numbers of untrained and uninformed contract workers; lack of use of protective equipment; and archaeological approaches and responses to repairing asbestos breaks and replacement of asbestos in oil refining facilities. For a better understanding of practices and policies in the oil refining industry, refer to Rachel Scott's Muscle and Blood, in particular the chapter "Oil" (E.P. Dutton, New York, 1974), as well as to an editorial which appeared in the Oil and Gas Journal, April, 1968.
OBJECTIVE: To investigate the influence of different processing methods on fatty oils in yolk oil. METHOD: The contents of fatty oils and fatty acids were determined by ROESS GOTTILE and GC respectively, and the physicochemical properties of fatty oils were identified by pharmacopoeial method. RESULTS AND CONCLUSION: The yolk oils processed by daking and dry distillation are almost similar in the contents of fatty oils, type of fatty acids, acid value, iodine value, saponification value, relative density and refractive index, while obvious differences were found in the products processed by chloroform extraction.
The formation of water-in-crude oil emulsions occurs when crude oils are spilled into sea. The water-in-crude oil emulsions significantly change the properties of the spilled crude oils and in turn influence the choices made relating to oil spill countermeasures. The water-in-crude oil emulsions were characterized using various techniques in this study. The environmental scanning electron microscopy observation of water droplets in the emulsions is also presented. It is a powerful tool in emulsion observations.
In 1981 a massive food-borne epidemic, termed the toxic oil syndrome (TOS), occurred in Spain. Eight years later a closely related disease, the eosinophilia myalgia syndrome (EMS), was reported in the USA with many additional cases being reported worldwide. Although EMS was linked to the ingestion of contaminated L-tryptophan and TOS to aniline denatured rapeseed oil, the etiological agent(s) responsible for both diseases remains unknown. However, contaminants in both the oil and the dietary supplement are believed to have triggered these diseases, and there has been much speculation that a common contaminant may have caused both epidemics. In this report, methods for the facile preparation and HPLC analysis of EMS-implicated L-tryptophan and adulterated rapeseed oil samples associated with TOS are described which allow a direct comparison between the contaminants of both foodstuffs. A combination of solvent and solid phase extraction methods are demonstrated along with the application of C18 reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with on-line UV and MS detection. These methods have allowed us to determine for the first time, based upon this work, that there are no detectable common contaminants that possess a UV response, between EMS implicated L-tryptophan and TOS implicated rapeseed oil samples.
Diets rich in linoleic acid (CO) from corn oil, or in linoleic acid and either alpha-linolenic acid (LO) based on linseed oil or n-3 fatty acids (MO) from menhaden oil were fed to male and female Cynomolgus monkeys for 15 wk. In the liver a 40% reduction of alpha-tocopherol occurred in the MO group relative to the CO and LO groups followed by increased formation of lipofuscin in vivo. A four-fold increase of alpha-tocopherol in the MO diet (MO + E) brought the level in the liver to that found with CO and LO. The increased peroxidation in the MO group in the liver phospholipids was associated with the replacement of 60% of the n-6 fatty acids by n-3 fatty acids from menhaden oil. Similar fatty acid profiles were found in groups fed MO and MO + E, respectively. Compared to the CO fed group, feeding alpha-linolenic acid only resulted in a slight incorporation of n-3 fatty acids in the liver membranes mainly due to a direct incorporation of alpha-linolenic acid. However, in monkeys fed menhaden oil more than 30% of the total fatty acids in the liver phospholipids were n-3 fatty acids. The various diets did not influence the activity of liver catalase (EC 1.11.1.6) nor superoxide dismutase (EC 1.15.1.1), but glutathione-peroxidase activity (EC 1.11.1.9) was higher in monkeys fed the MO diet. The catalase activity in females was 20% higher than in males.(ABSTRACT TRUNCATED AT 250 WORDS)