Impacts of Petroleum Fuels on Fertilization and Development of the Antarctic Sea Urchin Sterechinus neumayeri.

Antarctic marine environments are at risk from petroleum fuel spills as shipping activities in the Southern Ocean increase. Knowledge of the sensitivity of Antarctic species to fuels under environmentally realistic exposure conditions is lacking. We determined the toxicity of 3 fuels, Special Antarctic Blend diesel (SAB), marine gas oil (MGO), and intermediate fuel oil (IFO 180) to a common Antarctic sea urchin, Sterechinus neumayeri. Sensitivity was estimated for early developmental stages from fertilization to the early 4-arm pluteus in toxicity tests of up to 24 d duration. The effects of the water accommodated fractions (WAFs) of fuels were investigated under different exposure scenarios to determine the relative sensitivity of stages and of different exposure regimes. Sensitivity to fuel WAFs increased through development. Both MGO and IFO 180 were more toxic than SAB, with median effect concentration values for the most sensitive pluteus stage of 3.5, 6.5, and 252 µg/L total hydrocarbon content, respectively. Exposure to a single pulse during fertilization and early embryonic development showed toxicity patterns similar to those observed from continuous exposure. The results show that exposure to fuel WAFs during critical early life stages affects the subsequent viability of larvae, with consequent implications for reproductive success. The sensitivity estimates for S. neumayeri that we generated can be utilized in risk assessments for the management of Antarctic marine ecosystems. Environ Toxicol Chem 2020;39:2527-2539. © 2020 SETAC.

NADPH Oxidase-Mediated Activation of Neutral Sphingomyelinase Is Responsible for Diesel Particulate Extract-Induced Keratinocyte Apoptosis.

Human epidermis is positioned at the interface with the external environment, protecting our bodies against external challenges, including air pollutants. Emerging evidence suggests that diesel particulate extract (DPE), a major component of air pollution, leads to impairment of diverse cellular functions in keratinocytes (KC). In this study, we investigated the cellular mechanism underlying DPE-induced KC apoptosis. We first addressed cell death occurring in KC exposed to DPE, paralleled by increased activation of NADPH oxidases (NOXs) and subsequent ROS generation. Blockade of NOX activation with a specific inhibitor attenuated the expected DPE-induced KC apoptosis. In contrast, pre-treatment with a specific inhibitor of reactive oxygen species (ROS) generation did not reverse DPE/NOX-mediated increase in KC apoptosis. We next noted that NOX-mediated KC apoptosis is mainly attributable to neutral sphingomyelinase (SMase)-mediated stimulation of ceramides, which is a well-known pro-apoptotic lipid. Moreover, we found that inhibition of NOX activation significantly attenuated DPE-mediated increase in the ratio of ceramide to its key metabolite sphingosine-1-phosphate (S1P), an important determinant of cell fate. Together, these results suggest that activation of neutral SMase serves as a key downstream signal for the DPE/NOX activation-mediated alteration in ceramide and S1P productions, and subsequent KC apoptosis.

Effects of water accommodated fraction of physically and chemically dispersed heavy fuel oil on beach spawning capelin (Mallotus villosus).

Due to a northward shift in off-shore activities, including increased shipping traffic and oil and gas exploration there is a growing focus on the potential effects of oil pollution on Arctic marine ecosystems. Capelin (Mallotus villosus) is a small fish and a member of the smelt family, and is a key species in the marine food chain. Capelin are seasonally abundant in the Northern Atlantic and in coastal Arctic waters, e.g. in western Greenland and in the Barents Sea, where it undertakes aggregated spawning in the intertidal and subtidal zone. To study the possible effects of oil pollution on the physiology and development of early life stages in capelin, freshly fertilised capelin eggs were exposed to a water accommodated fraction of physically (WAF) and chemically (CEWAF) dispersed heavy fuel oil (IFO30) for 72 h. Subsequent mortality, hatching success, larvae malformations, growth and CYP1A/EROD activity was measured over a 4-week period. The nominal exposure concentrations of WAF and CEWAF were between 0.02 and 14.5 mg total hydrocarbon content (THC) L-1 and 0.5-304 mg THC L-1, respectively. Egg mortality correlated significantly with WAF exposure concentration. The proportions of hatched eggs decreased with increasing CEWAF exposure concentration. Further, the percentage of malformed larvae with craniofacial abnormalities, body axis defects, generally under developed larvae, reduced total body length (dwarfs), correlated significantly with exposure concentrations in both CEWAF and WAF treatments. The four types of the predominant malformations were distributed differently in two parallel experiments. At the biochemical level, we observed a significant relationship between CEWAF exposure concentration and CYP1A/EROD activity in newly hatched larvae and this effect persisted for 3 weeks after the 72 h exposure. We conclude that even short-term exposure to both heavy fuel oil WAF and CEWAF, at environmentally relevant THC concentrations following an oil spill, may induce adverse developmental effects on the vulnerable early life stages of capelin. The mechanisms responsible for the observed effects on mortality, growth and embryo development in capelin eggs and embryos following WAF and CEWAF exposure require further studies.

Occupational exposure to petroleum-based and oxygenated solvents and oral and oropharyngeal cancer risk in men: A population-based case-control study in France.

OBJECTIVE: To examine the association between occupational exposure to petroleum-based and oxygenated solvents and the risk of oral and oropharyngeal cancer. METHODS: The ICARE study is a large population-based case-control study conducted in France between 2001 and 2007. This present analysis was restricted to men and included 350 and 543 cases of squamous cell-carcinoma of the oral cavity and oropharynx, respectively, and 2780 controls. Lifetime tobacco, alcohol consumption and complete occupational history were assessed through detailed questionnaires. Job-exposure matrices allowed us to assess occupational exposure to five petroleum-based solvents (white spirits; diesel/fuel oils/kerosene; gasoline; benzene; special petroleum products) and five oxygenated solvents (diethyl ether; tetrahydrofuran; ketones and esters; alcohols; ethylene glycol). Odds-ratios (ORs), adjusted for age, smoking, alcohol consumption and socioeconomic status, and 95% confidence intervals (CI) were estimated using unconditional logistic models. RESULTS: Associations between oral cancer risk and exposure to white spirits and diesel/fuel oils/kerosene were suggested, but there was no exposure-response trend. Concerning exposure to oxygenated solvents, participants with the highest levels of cumulative exposure to diethyl ether had a significant excess risk of oropharyngeal cancer (OR = 7.78, 95%CI 1.42 to 42.59; p for trend = 0.04). Ever exposure to tetrahydrofuran was associated with a borderline significant increased risk of oral cancer (OR = 1.87, 95%CI 0.97 to 3.61), but no exposure-response trend was observed. Additional adjustments for exposure to other solvents did not substantially change the results. CONCLUSION: Our results do not provide evidence for a major role of petroleum-based and oxygenated solvents in the occurrence of oral and oropharyngeal cancers in men.

Biochemical and molecular alterations in freshwater mollusks as biomarkers for petroleum product, domestic heating oil.

To investigate the effect one of the oil products, domestic heating oil (DHO), on freshwater mollusks, Unio tigridis and Viviparous bengalensis were exposed to three DHO concentrations for each species (5.8, 8.7, and 17.4 ml L-1 for mussels; 6.5, 9.7, and 19.5 mlL-1 for snails, respectively). Antioxidant enzymes (superoxide dismutase, catalase), malondialdehyde, acetylcholinesterase and DNA damage in both species tissues were monitored over 21 days. The results showed that both antioxidant enzymes concentration (SOD and CAT) increased in the lowest DHO concentrations (5.8, and 8.7 ml L-1), and then decreased in the highest concentration (17.4 ml L-1) as the same pattern for Unio tigridis, but this not occurred for Viviparous bengalensis. MDA values recorded significantly increased compared to control. No reduction was observed in AChE concentrations in soft tissues of both mollusks may due to that DHO was a non-neurotoxicant to Unio tigridis and Viviparous bengalensis. The results of DNA damage parameters were showed significant differences (p≤ 0.05) between control and DHO concentrations except lowest concentration for each parameter measured in digestive gland of Unio tigridis. As well as, these significant differences were recorded between control and three concentrations of DHO exposure for comet length, and tail length parameters, and between control and highest oil concentration for tail moment in Viviparous bengalensis. DHO has the ability to prevent the reproduction of Viviparous bengalensis snail relation to control, that is what we considered strong evidence of the toxicity properties of DHO on the reproductive status of this species of snails. SOD, CAT, and MDA were useful biomarkers for evaluating the toxicity of DHO in mussel and snails, and comet assay was a good tool to assess the potential genotoxicity of DHO.

Developmental toxicity in flounder embryos exposed to crude oils derived from different geographical regions.

Crude oils from distinct geographical regions have distinct chemical compositions, and, as a result, their toxicity may be different. However, developmental toxicity of crude oils derived from different geographical regions has not been extensively characterized. In this study, flounder embryos were separately exposed to effluents contaminated by three crude oils including: Basrah Light (BLO), Pyrenees (PCO), and Sakhalin Vityaz (SVO), in addition to a processed fuel oil (MFO-380), to measure developmental toxicity and for gene expressions. Each oil possessed a distinct chemical composition. Edema defect was highest in embryos exposed to PCO and MFO-380 that both have a greater fraction of three-ring PAHs (33% and 22%, respectively) compared to BLO and SVO. Observed caudal fin defects were higher in embryos exposed to SVO and MFO-380, which are both dominated by naphthalenes (81% and 52%, respectively). CYP1A gene expressions were also highest in embryos exposed to SVO and MFO-380. Higher incidence of cardiotoxicity and lower nkx 2.5 expression were detected in embryos exposed to PCO. Unique gene expression profiles were observed in embryos exposed to crude oils with distinct compositions. This study demonstrates that crude oils of different geographical origins with different compositional characteristics induce developmental toxicity to different degrees.

Toxicity assessment of water-accommodated fractions from two different oils using a zebrafish (Danio rerio) embryo-larval bioassay with a multilevel approach.

Petroleum compounds from chronic discharges and oil spills represent an important source of environmental pollution. To better understand the deleterious effects of these compounds, the toxicity of water-accommodated fractions (WAF) from two different oils (brut Arabian Light and Erika heavy fuel oils) were used in this study. Zebrafish embryos (Danio rerio) were exposed during 96h at three WAF concentrations (1, 10 and 100% for Arabian Light and 10, 50 and 100% for Erika) in order to cover a wide range of polycyclic aromatic hydrocarbon (PAH) concentrations, representative of the levels found after environmental oil spills. Several endpoints were recorded at different levels of biological organization, including lethal endpoints, morphological abnormalities, photomotor behavioral responses, cardiac activity, DNA damage and exposure level measurements (EROD activity, cyp1a and PAH metabolites). Neither morphological nor behavioral or physiological alterations were observed after exposure to Arabian Light fractions. In contrast, the Erika fractions led a high degree of toxicity in early life stages of zebrafish. Despite of defense mechanisms induced by oil, acute toxic effects have been recorded including mortality, delayed hatching, high rates of developmental abnormalities, disrupted locomotor activity and cardiac failures at the highest PAH concentrations (∑TPAHs=257,029±47,231ng·L(-1)). Such differences in toxicity are likely related to the oil composition. The use of developing zebrafish is a good tool to identify wide range of detrimental effects and elucidate their underlying foundations. Our work highlights once more, the cardiotoxic action (and potentially neurotoxic) of petroleum-related PAHs.

Effects of exposure to oil spills on human health: Updated review.

Oil spills may involve health risks for people participating in the cleanup operations and coastal inhabitants, given the toxicological properties of the oil components. In spite of this, only after a few major oil spills (crude oil or fuel oil no. 6) have studies on effects of exposure to diverse aspects of human health been performed. Previously, Aguilera et al. (2010) examined all documents published to that date dealing with any type of human health outcome in populations exposed to oil spills. The aim of the present review was to compile all new information available and determine whether evidence reported supports the existence of an association between exposure and adverse human health risks. Studies were classified in three groups according to type of health outcome addressed: (i) effects on mental health, (ii) physical/physiological effects, and (iii) genotoxic, immunotoxic, and endocrine toxicity. New studies published on oil-spill-exposed populations-coastal residents in the vicinity of the spills or participants in cleanup operations-provide additional support to previous evidence on adverse health effects related to exposure regarding different parameters in all three categories considered. Some of the observed effects even indicated that several symptoms may persist for some years after exposure. Hence, (1) health protection in these individuals should be a matter of concern; and (2) health risk assessment needs to be carried out not only at the time of exposure but also for prolong periods following exposure, to enable early detection of any potential exposure-related harmful effects.

Evaluating toxicity of heavy fuel oil fractions using complementary modeling and biomimetic extraction methods.

The toxicity of chemically dispersed heavy fuel oil (HFO) and 3 distillate fractions to rainbow trout (Oncorhynchus mykiss) embryos was evaluated using the PETROTOX model and a biomimetic extraction technique that involved passive sampling of oil-contaminated test media with solid-phase microextraction (SPME) fibers. Test solutions for toxicity testing were generated using a combination of dispersant and high-energy mixing. The resulting water accommodated fractions (WAF) provided complex exposure regimens that included both dissolved hydrocarbons and oil droplets. The toxicity of the various fractions differed by approximately 3 orders of magnitude when expressed on the basis of WAF dilution. Using detailed compositional data, the PETROTOX model predicted the speciation of hydrocarbons between dissolved and oil droplet phases and explained observed toxicity based on computed dissolved phase toxic units (TUs). A key finding from model calculations was that dissolved hydrocarbon exposures and associated TUs were a nonlinear function of WAF dilution, because dissolved hydrocarbons were largely controlled by the dissolution of oil droplets that were transferred in WAF dilutions. Hence, oil droplets served to "buffer" dissolved concentrations in WAF dilutions at loadings greater than 1 mg/L, resulting in higher dissolved concentrations and TUs than expected based on dilution. The TUs computed at each WAF dilution explained the observed toxicity among the HFO and fractions to within a factor of 3. Dissolved material measured by SPME showed a consistent relationship with model-predicted TUs, confirming the utility of this approach for providing an integrated measure of exposure to bioavailable hydrocarbons. These 2 approaches provide complementary tools for better defining bioavailability of complex petroleum substance.

Natural sunlight and residual fuel oils are an acutely lethal combination for fish embryos.

The majority of studies characterizing the mechanisms of oil toxicity in fish embryos and larvae have focused largely on unrefined crude oil. Few studies have addressed the toxicity of modern bunker fuels, which contain residual oils that are the highly processed and chemically distinct remains of the crude oil refinement process. Here we use zebrafish embryos to investigate potential toxicological differences between unrefined crude and residual fuel oils, and test the effects of sunlight as an additional stressor. Using mechanically dispersed oil preparations, the embryotoxicity of two bunker oils was compared to a standard crude oil from the Alaska North Slope. In the absence of sunlight, all three oils produced the stereotypical cardiac toxicity that has been linked to the fraction of tricyclic aromatic compounds in an oil mixture. However, the cardiotoxicity of bunker oils did not correlate strictly with the concentrations of tricyclic compounds. Moreover, when embryos were sequentially exposed to oil and natural sunlight, the bunker oils produced a rapid onset cell-lethal toxicity not observed with crude oil. To investigate the chemical basis of this differential toxicity, a GC/MS full scan analysis was used to identify a range of compounds that were enriched in the bunker oils. The much higher phototoxic potential of chemically distinct bunker oils observed here suggests that this mode of action should be considered in the assessment of bunker oil spill impacts, and indicates the need for a broader approach to understanding the aquatic toxicity of different oils.

Western Canada study of animal health effects associated with exposure to emissions from oil and natural gas field facilities. Study design and data collection I. Herd performance records and management.

Beef cow-calf herds are the most common livestock operation in Western Canada. Beef cows also have the greatest opportunity for direct contact with their environment through continuous sampling of the air, water, vegetation, and soil. These factors combine to make cow-calf herds a potentially useful sentinel of environmental change. Researchers individually tracked more than 33,000 cows in 205 beef cow-calf herds from spring 2001 to the end of the calving season in 2002 to examine the potential effects of emissions from the oil and gas industry on productivity. This article describes the study design and methodology of the Western Canada Study, with emphasis on herd-selection criteria and study implementation, the collection of herd-production data, and the challenges of tracking individual animals in a large prospective observational study-as the Western Canada Study is the largest on-farm study of its kind in North American cow-calf herds to date. The primary objective of this project was to examine the potential association between reproductive success and cumulative chronic exposure to sulfur dioxide, hydrogen sulfide, and volatile organic compounds in beef herds. Herd-selection criteria included potential exposure to oil and gas facilities, herd size, quality of available records, an established relationship with a local veterinary clinic, and participant interest. With the cooperation of local herd owners and veterinarians, on-farm collection of detailed individual animal data was successful in this group of cow-calf operations. Of the 212 herds initially selected to participate, complete calving season data for 2002 were available for 203 herds (96%). Individual animal records were available for more than 98% of eligible cows for each measurement period throughout the study. Herd-production records were rated as satisfactory or better in 94% of the herds. These process outcomes confirm the practicality of using cow-calf herds as sentinel populations for environmental exposures and support the validity of subsequent research on these animal populations.

Western Canada study of animal health effects associated with exposure to emissions from oil and natural gas field facilities. Study design and data collection II. Location of study herds relative to the oil and gas industry in Western Canada.

During the late part of 2000 and early months of 2001, project veterinarians recruited 205 beef herds to participate in a study of the effects of emissions from the upstream oil and gas industry on cattle reproduction and health. Researchers developed herd-selection criteria to optimize the range of exposure to facilities, including oil and gas wells, battery sites, and gas-gathering and gas-processing facilities across the major cattle-producing areas of Western Canada. Herds were initially selected on the basis of a ranking system of exposure potential on the basis of herd-owner reports of the locations of their operations in relation to oil and gas industry facilities. At the end of the study, researchers summarized data obtained from provincial regulatory agencies on facility location and reported flaring and venting volumes for each herd and compared these data to the original rankings of herd-exposure potential. Through this selection process, the researchers were successful in obtaining statistically significant differences in exposure to various types of oil and gas facility types and reported emissions among herds recruited for the study.

Western Canada study of animal health effects associated with exposure to emissions from oil and natural gas field facilities. Study design and data collection III. Methods of assessing animal exposure to contaminants from the oil and gas industry.

Researchers measured exposure to oil and gas industry emissions in 205 cow-calf herds located in Western Canada. They measured airborne concentrations of sulfur dioxide, hydrogen sulfide, and volatile organic compounds with passive monitors placed in each pasture, wintering, or calving area that contained study animals from the start of the breeding season in the spring of 2001 until June 30, 2002. Researchers continued air monitoring in a subset of herds to the end of the study in fall 2002. Each sampling device was exposed for 1 month and then shipped to the laboratory for analysis. New samplers were installed and the shelters relocated, as necessary, to follow the movements of herd-management groups between pastures. Researchers linked the results of the air-monitoring analysis to individual animals for the relevant month. For the 205 herds examined at pregnancy testing in 2001, monthly mean exposures on the basis of all available data were as follows: sulfur dioxide, geometric mean (GM)=0.5 ppb, geometric standard deviation (GSD)=2.2; hydrogen sulfide, GM=0.14 ppb, GSD=2.3; benzene, GM=0.247 microg/m3, GSD=2.5; and toluene, GM=0.236 microg/m3, GSD=2.7. Benzene and toluene were surrogates for volatile organic compound exposure. In addition to passive measurements of air quality, researchers obtained data from provincial regulatory agencies on the density of oil and gas field facilities and on flaring and venting from the surrounding facilities. They developed the data into additional measures of exposure that were linked to each animal at each location for each month of the study.

The association between exposure to the oil and gas industry and beef calf mortality in Western Canada.

Researchers assessed the association between exposure to emissions from oil and gas field facilities and newborn calf survival and health status by determining the risks of calf mortality and treatment reported for 27,511 beef calves born to cows in 203 herds, which were followed from the beginning of the 2001 breeding season through the 2002 calving season. They prospectively measured exposures to sulfur dioxide, hydrogen sulfide, and volatile organic compounds (VOCs) by using data from passive air monitors. They also used the density of oil and gas well sites surrounding each pasture as an additional measure of exposure. The researchers found that well-site density as well as exposures to hydrogen sulfide and VOCs measured as benzene or toluene were not associated with the odds of calf mortality in the first 3 months of life. After adjusting for cow-and herd-level risk factors, they found that exposure to sulfur dioxide near the time of calving was associated with an increased risk of calf mortality during this period. Exposure to sulfur dioxide in the 3-month period before calving was most suggestive of a causal exposure-response relationship (the odds ratio for every 1 ppb increase in sulfur dioxide=1.32; 95% confidence interval=1.13-1.54; p=0004). Exposure to sulfur dioxide, hydrogen sulfide, and VOCs measured as benzene or toluene during gestation was not associated with the odds of calf treatment in the first 3 months of life. However, exposure to sulfur dioxide, hydrogen sulfide, and VOCs measured as benzene or toluene, and sulfur dioxide in the first month after calving, was associated with a small increase in the odds of calf treatment after the first month of life when risk was compared across quartiles for exposure; only the association between hydrogen sulfide exposure and the odds of treatment was consistent with a causal exposure.

Risk of nonpregnancy, risk of disposal for pregnant cows, and duration of the calving interval in cow-calf herds exposed to the oil and gas industry in Western Canada.

To determine potential associations between emissions from oil and gas field facilities and the reproductive success of cow-calf herds in Western Canada, researchers followed approximately 33,000 beef cows from the beginning of the breeding season in 2001 through pregnancy testing in 2002. They prospectively measured exposure to sulfur dioxide, hydrogen sulfide, and volatile organic compounds (VOCs) by using data from passive air monitors installed in pastures and linked to the locations of individual animals. They used the density of oil and gas well sites surrounding each pasture as an additional measure of exposure. The researchers measured the risk of nonpregnancy in cattle in 205 herds in fall 2001 and 200 herds in fall 2002, and they determined the interval between the dates of calving in 2001 and 2002 for all cows calving in both years from 202 herds. The risk of disposal in pregnant cows was measured as the risk of removal from inventory for any reason other than nonpregnancy between pregnancy testing in 2001 and calving in 2002. There was no evidence that exposure to sulfur dioxide or VOCs measured as benzene and toluene increased the odds of nonpregnancy or disposal for pregnant cows. Density of oil and gas well sites was not related to the odds of nonpregnancy in either 2001 or 2002 or the odds of disposal for pregnant cows. During the first month after bull contact, exposures to increasing concentrations of sulfur dioxide, VOCs measured as toluene, and the density of oil and gas well sites were also not associated with an increase in the 2001-2002 breeding-to-calving interval. However, there was an estimated 3.0-day increase in the breeding-to-calving interval for mature cows exposed to benzene concentrations in the highest quartile of exposure (>0.236 microg/m3) compared with those cows exposed to benzene concentrations in the lowest quartile of exposure (<0.082 microg/m3).

Effects of heavy fuel oil on the bacterial community structure of a pristine microbial mat.

The effects of petroleum contamination on the bacterial community of a pristine microbial mat from Salins-de-Giraud (Camargue, France) have been investigated. Mats were maintained as microcosms and contaminated with no. 2 fuel oil from the wreck of the Erika. The evolution of the complex bacterial community was monitored by combining analyses based on 16S rRNA genes and their transcripts. 16S rRNA gene-based terminal restriction fragment length polymorphism (T-RFLP) analyses clearly showed the effects of the heavy fuel oil after 60 days of incubation. At the end of the experiment, the initial community structure was recovered, illustrating the resilience of this microbial ecosystem. In addition, the responses of the metabolically active bacterial community were evaluated by T-RFLP and clone library analyses based on 16S rRNA. Immediately after the heavy fuel oil was added to the microcosms, the structure of the active bacterial community was modified, indicating a rapid microbial mat response. Members of the Gammaproteobacteria were initially dominant in the contaminated microcosms. Pseudomonas and Acinetobacter were the main genera representative of this class. After 90 days of incubation, the Gammaproteobacteria were superseded by "Bacilli" and Alphaproteobacteria. This study shows the major changes that occur in the microbial mat community at different time periods following contamination. At the conclusion of the experiment, the RNA approach also demonstrated the resilience of the microbial mat community in resisting environmental stress resulting from oil pollution.

Effects of three biodiesels and a low sulfur diesel in male rats--a pilot 4-week oral study.

Because of the accessible and renewable nature of feedstock and the potential for the reduction of harmful combustion emissions and greenhouse gases, biodiesels have received increasing interest as an alternate fuel. Oral exposure to biodiesels is a concern because of contact during refuelling, accidental ingestion and exposure through ground water contamination. Although biodiesels from various feedstock are in use commercially and experimentally, very little is known about their potential adverse effects and no data is available on their potential for ground water contamination. A study was performed on male rats following oral treatment with experimental biodiesels (dissolved in corn oil) derived from canola oil (Bio-C), soy oil (Bio-S) and fish oil (Bio-F), at 500 mg/kg body weight/day, 5 days per week, for 4 weeks. Separate groups of animals were treated with low sulfur diesel (LSD) for comparison purpose, and with corn oil alone to serve as control. The potential for ground water contamination by biodiesels was investigated by the preparation of water-accommodated fractions (WAF) followed by gas chromatographic analysis. WAF from Bio-F and Bio-S was found to have the highest level of dichloromethane extractable materials. Gas chromatographic analysis indicated that the extractable materials from biodiesels contained much higher proportion of C15-C30 materials than LSD. Increased liver weight was observed in animal treated with Bio-C, Bio-S and LSD and decreased thymus weight was found in those treated with Bio-S. Histopathological changes typical of male-rat specific hyaline-droplet nephropathy were detected in kidney tubules of animals treated with LSD, Bio-S and Bio-C. Mild adaptive changes were observed in thyroids of animals treated with LSD, Bio-S and Bio-F. Clinical chemical and biochemical changes were confined to Bio-S and LSD treated rats and included elevation in some hepatic phase-I and phase-II drug metabolizing enzymes and hepatic palmitoyl Co-A oxidase, and elevated urinary concentrations of ascorbic acid and albumin. At the given dose level of 500 mg/kg bw/day, the overall treatment-related effects of biodiesels and LSD are mild, and the severity of the treatment effects may be ranked as: LSD>Bio-S>Bio-C>Bio-F. Considered together with the presence of a higher level of water extractable materials, Bio-S may be more of a concern for potential human health than Bio-C and Bio-F in an oral exposure scenario. Further studies are needed to identify and characterize the constituents contributing to the treatment-related effects specific to these experimental biodiesels.

Mortality of UK oil refinery and petroleum distribution workers, 1951-2003.

BACKGROUND: The health of UK petroleum industry workers has been monitored for many years. AIM: To identify any long-term adverse health outcomes from occupational exposures in this industry. METHODS: The mortality (1951-2003) and cancer morbidity (1971-2003) experienced by cohorts of 28,555 oil refinery workers and 16,477 petroleum distribution workers has been investigated. Study subjects were all those males first employed in the period 1946-74 at one of eight UK oil refineries or 476 UK petroleum distribution centres; all subjects had a minimum of 12 months employment with some employment after 1 January 1951. Observed numbers of cause-specific deaths and site-specific cancer registrations were compared with expectations based on national mortality and cancer incidence rates. RESULTS: Standardized mortality ratios (SMRs) were significantly <100 for all causes both in oil refinery workers (Obs 11,156, SMR 89) and in petroleum distribution workers (Obs 7320, SMR 96). Significantly elevated SMRs were shown in oil refinery workers for cancer of the pleura (mesothelioma) (Obs 64, SMR 261) and melanoma (Obs 48, SMR 168). Significantly elevated SMRs were not found in petroleum distribution workers for any site of cancer. Significantly elevated standardized registration ratios (SRRs) were only shown in oil refinery workers and for cancer of the pleura (mesothelioma) (Obs 115, SMR 274), melanoma (Obs 85, SMR 129) and other skin cancer (Obs 983, SRR 117). CONCLUSIONS: The only findings that showed clear evidence of an occupational cancer hazard were those for mesothelioma in oil refinery workers.

Formation of methanol and formate in Wistar rats after oral administration of methylated rapeseed oil: a fuel for lamps.

Low viscosity, low surface tension and low volatility are features of lamp oils contributing to chemical pneumonia that can occur after ingestion. Because lamp oils with such physico-chemical properties have been forbidden in the European Community from July 2000 onward, industry has developed different products, mostly based upon rapeseed oil. The fatty acids of these oils are methylated. The goal of this study is to demonstrate whether methanol is released in Wistar rats after oral administration of these new lamp oils. Applying a dose of 1 ml/kg body weight lamp oil, peak levels of methanol were reached at 1 h (54.6 +/- 18.6 microg/ml), methanol was not detectable at 8 h. After the instillation of 4 ml/kg of lamp oil peak levels occurred at 2 h (189.2 +/- 24.9 microg/ml). The metabolite formate increased with time, and was highest at 8 h after the administration of 1 ml/kg body weight lamp oil (32.9 +/- 2.9 microg/ml). Starvation before the administration of 1 ml/kg body weight lamp oil decreased the methanol serum concentrations, but the differences were not significant. Based upon these experimental data in rats, it can be concluded that in humans small amounts of methanol will be released after ingestion of these lamp oils. As these products are mainly ingested accidentally by toddlers in low quantities, the risk of a methanol intoxication seems to be very low.