Biological effects of diesel exhaust particles. I. In vitro production of superoxide and in vivo toxicity in mouse

The problem of whether or not active oxygen species are involved in pulmonary injury by diesel exhaust particles (DEP) was investigated. We found that DEP could produce superoxide O2.- and hydroxyl radical (.OH) in vitro without any biological activating systems. In this reaction system, O2.- and .OH productions were inhibited by addition of superoxide dismutase (SOD) and dimethylsulfoxide, respectively. DEP which were washed with methanol could no longer produce O2.- and .OH, indicating that active components were extractable with organic solvents. These oxygen radicals were also identified by electron spin resonance (ESR) measurement. Furthermore, DEP instilled intratracheally to mouse caused high mortality at low dose, although methanol-washed DEP did not kill any mouse. The cause of death seemed to be pulmonary edema mediated by endothelial cell damage. The instilled DEP markedly decreased the activities of SOD, glutathione peroxidase, and glutathione S-transferase in mouse lungs. On the other hand, the death rate and lung injury were markedly prevented by polyethylene glycol conjugated SOD (PEG-SOD) pretreatment prior to DEP administration. The mortality and lung injury by DEP were also suppressed by butylated hydroxytoluene (BHT) pretreatment. From these results, it was suggested that most parts of DEP toxicity in lungs are due to active oxygen radicals such as O2.- and .OH, and that the cause of death is due to pulmonary edema mediated by endothelial cell damage.

Oil sands development contributes polycyclic aromatic compounds to the Athabasca River and its tributaries

For over a decade, the contribution of oil sands mining and processing to the pollution of the Athabasca River has been controversial. We show that the oil sands development is a greater source of contamination than previously realized. In 2008, within 50 km of oil sands upgrading facilities, the loading to the snowpack of airborne particulates was 11,400 T over 4 months and included 391 kg of polycyclic aromatic compounds (PAC), equivalent to 600 T of bitumen, while 168 kg of dissolved PAC was also deposited. Dissolved PAC concentrations in tributaries to the Athabasca increased from 0.009 microg/L upstream of oil sands development to 0.023 microg/L in winter and to 0.202 microg/L in summer downstream. In the Athabasca, dissolved PAC concentrations were mostly <0.025 microg/L in winter and 0.030 microg/L in summer, except near oil sands upgrading facilities and tailings ponds in winter (0.031-0.083 microg/L) and downstream of new development in summer (0.063-0.135 microg/L). In the Athabasca and its tributaries, development within the past 2 years was related to elevated dissolved PAC concentrations that were likely toxic to fish embryos. In melted snow, dissolved PAC concentrations were up to 4.8 microg/L, thus, spring snowmelt and washout during rain events are important unknowns. These results indicate that major changes are needed to the way that environmental impacts of oil sands development are monitored and managed.

Behavioural ecotoxicology, an "early warning" signal to assess environmental quality

BACKGROUND

In this review, the position of behavioural ecotoxicology within the available means to assess the status of marine environments is described as filling the gap for the needed "early warning" signals. A few examples of studies performed since the 1960s are discussed to highlight the sensitivity of these approaches in investigating the effects of chemicals, including priority pollutants and emerging contaminants, relative to conventional toxicity tests measuring survival.

DISCUSSION

The advantage of the behavioural response is due to the integration of biochemical and physiological processes that reflect changes at higher levels of organisation with ecological relevance. Avoidance often represents a behavioural symptom easily detected in many animals exposed to contaminants and would be a useful test to explore more widely. This rapid response would reflect a defence mechanism protective against further exposure and the potential development of more pronounced deleterious effects, whilst in some cases, escape could lead to the relocation of a species with negative consequences. An investigation of the avoidance behaviour of mud shrimp, Corophium volutator, along with the chemical analyses of sediments and amphipods to assess the quality of harbour sediments is summarised. The body burden of the amphipods was 1,000 times lower than the one associated with narcosis, emphasizing the sensitivity of this endpoint. The application of this acute toxicity test is briefly compared to additional work that involved intertidal mussels collected in the field.

CONCLUSIONS

Recent research undertaken with mud snails, Ilyanassa obsoleta, and harbour sediments confirmed the usefulness of the escape behaviour as an assessment tool. However, the limits of the state of knowledge regarding the fate of contaminants in species with the ability to metabolise contaminants is further discussed along with directions to be pursued to address questions arising from the reviewed literature.

Response of the Pacific oyster Crassostrea gigas to hydrocarbon contamination under experimental conditions

Hydrocarbon contamination perturbs the metabolism of the marine bivalve Crassostrea gigas. To understand the response of this organism to hydrocarbon exposure, a suppression subtractive hybridisation method was employed to characterise up- and down-regulated genes during hydrocarbon exposure. The number of differentially expressed gene sequences obtained via this method was 258. The expression of genes involved in hydrocarbon detoxification (cytochrome p4501A1-like protein, cytochrome b(5), flavin-containing monooxygenase 2 and glutathione S-transferase omega class), protection against oxidative stress (copper/zinc superoxide dismutase) and cell protection (heat shock protein 70 family) was analysed by RT-PCR. An increase in the mRNA level of all genes studied was observed. A quantification of HSP70 by Enzyme Linked Immunosorbent Assay (ELISA) showed a significant increase of this protein during exposure. This study provides a basis for studying hydrocarbon detoxification processes in marine bivalves, especially C. gigas.

Association between health information, use of protective devices and occurrence of acute health problems in the Prestige oil spill clean-up in Asturias and Cantabria (Spain): a cross-sectional study

BACKGROUND

This paper examines the association between use of protective devices, frequency of acute health problems and health-protection information received by participants engaged in the Prestige oil spill clean-up in Asturias and Cantabria, Spain.

METHODS

We studied 133 seamen, 135 bird cleaners, 266 volunteers and 265 paid workers selected by random sampling, stratified by type of worker and number of working days. Information was collected by telephone interview conducted in June 2003. The association of interest was summarized, using odds ratios (OR) obtained from logistic regression.

RESULTS

Health-protection briefing was associated with use of protective devices and clothing. Uninformed subjects registered a significant excess risk of itchy eyes (OR:2.89; 95%CI:1.21-6.90), nausea/vomiting/dizziness (OR:2.25; 95%CI:1.17-4.32) and throat and respiratory problems (OR:2.30; 95%CI:1.15-4.61). There was a noteworthy significant excess risk of headaches (OR:3.86: 95%CI:1.74-8.54) and respiratory problems (OR:2.43; 95%CI:1.02-5.79) among uninformed paid workers. Seamen, the group most exposed to the fuel-oil, were the worst informed and registered the highest frequency of toxicological problems.

CONCLUSION

Proper health-protection briefing was associated with greater use of protective devices and lower frequency of health problems. Among seamen, however, the results indicate poorer dissemination of information and the need of specific guidelines for removing fuel-oil at sea.

Acute effects of Benzo[a]pyrene, anthracene and a fuel oil on biomarkers of the common goby Pomatoschistus microps (Teleostei, Gobiidae)

The objective of this study was to investigate the effects of two different PAHs and a complex petrochemical mixture on the common goby, Pomatoschistus microps, using selected biomarkers as effect criteria. Benzo[a]pyrene (BaP) and anthracene were used as reference substances, while the water accommodated fraction of #4 fuel-oil (#4 WAF) was used as an example of a petrochemical mixture. P. microps was used since it is both a suitable bioindicator and a good test organism. Groups of fish were exposed to different concentrations of each of the test substances for 96 h and the activities of several enzymes commonly used as biomarkers were determined at the end of the bioassays. All the substances inhibited P. microps acetylcholinesterase (AChE) indicating that they have at least one mechanism of neurotoxicity in common: the disruption of cholinergic transmission by inhibition of AChE. An induction of lactate dehydrogenase (LDH) activity was found in fish exposed to BaP or to anthracene, suggesting an increase of the anaerobic pathway of energy production. On the contrary, inhibition of LDH was found in fish exposed to #4 WAF, suggesting a distinct effect of the mixture. An induction of P. microps glutathione S-transferase (GST) activity was found in fish exposed to BaP or to #4 WAF, while an inhibition was observed after exposure to anthracene. These results suggest that GST is involved in the detoxification of BaP and #4 WAF, but not of anthracene. All the substances increased catalase activity and isolated PAHs also increased superoxide dismutase, glutathione reductase and glutathione peroxidase activities, while #4 WAF did not cause significant alterations on these enzymes. These results suggest that all the substances may induce oxidative stress on P. microps, with BaP and anthracene apparently having more oxidative stress potential than #4 WAF.

Micronucleus test and observation of nuclear alterations in erythrocytes of Nile tilapia exposed to waters affected by refinery effluent

Micronuclei and nuclear alterations tests were performed on erythrocytes of Oreochromis niloticus (Perciformes, Cichlidae) in order to evaluate the water quality from Paraíba do Sul river, in an area affected by effluents from an oil shale processing plant, located in the city of São José dos Campos, Brazil-SP. Water samples were collected on 2004 May and August (dry season) and on 2004 November and 2005 January (rain season), in three distinct sites, comprising 12 samples. It was possible to detect substances of clastogenic and/or aneugenic potential, as well as cytotoxic substances, chiefly at the point corresponding to the drainage of oil shale plant wastes along the river. The highest incidence of micronuclei and nuclear alterations was detected during May and August, whereas the results obtained in November and January were insignificant. This work shows that the effluent treatment provided by the oil shale plant was not fully efficient to minimize the effect of cytotoxic and mutagenic substances in the test organism surveyed.

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.

The toxicity of commercial jet oils

Jet oils are specialized synthetic oils used in high-performance jet engines. They have an appreciable hazard due to toxic ingredients, but are safe in use provided that maintenance personnel follow appropriate safety precautions and the oil stays in the engine. Aircraft engines that leak oil may expose others to the oils through uncontrolled exposure. Airplanes that use engines as a source of bleed air for cabin pressurization may have this source contaminated by the oil if an engine leaks. Examination of the ingredients of the oil indicates that at least two ingredients are hazardous: N-phenyl-1-naphthylamine (a skin sensitizer) and tricresyl phosphate (a neurotoxicant, if ortho-cresyl isomers are present). Publicly available information such as labels and MSDS understates the hazards of such ingredients and in the case of ortho-cresyl phosphates by several orders of magnitude.

The role of nitroaromatic compounds in the direct-acting mutagenicity of diesel particle extracts

The Salmonella mutation assay has been adapted to a number of experimental procedures used to characterize the chemical components and molecular mechanisms involved in the direct-acting mutagenicity of diesel particle extracts. The mutagens were found to be unreactive towards purified DNA. Mutagenic activity was decreased in nitroreductase-deficient bacteria and increased in the absence of oxygen, suggesting that bacterial enzymes active the mutagens. The extract was fractionated by thin layer chromatography using both normal and reverse phase silica gel plates. On normal silica plates, a separation was made between unsubstituted PAH, nitro-PAH and the more polar aromatic compounds. About a third of the mutagenic activity in the particle extract was recovered in fractions containing monosubstituted nitro-PAH compounds. The absorption spectra and reverse phase chromatographic properties indicate 1-nitropyrene is a predominant component but not the only mutagen in these fractions. The remaining activity was in the more polar fractions, and mutagenicity assays using anaerobic conditions and nitro-reductase-deficient bacteria suggest they contain other nitro-substituted compounds.

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.

CULTEX--an alternative technique for cultivation and exposure of cells of the respiratory tract to airborne pollutants at the air/liquid interface

The assessment of cytotoxicity of air contaminants such as gaseous or particulate compounds and complex mixtures has traditionally involved animal experiments, due to the difficulties in exposing cell cultures directly to these substances. New cultivation and exposure techniques enhance the efficiency of in vitro studies, as demonstrated by a new experimental system called CULTEX which allows direct exposure of cells at the air/liquid interface. In this case, human bronchial epithelial cells are cultivated on porous transwell membranes in a device allowing intermittent medium supply. The medium is pumped into a special modular culture unit through the transwell membrane supporting the cells. At certain time intervals, the medium is completely removed and the cells can be maintained and exposed at the air/liquid interface until the next medium supply without loss of viability. In comparison to conventional submersed culture conditions, the cells have been grown on transwell membranes using the new pulse submersion technique. There are no deleterious effects on cell viability due to the direct exposure to airborne pollutants. Thus, the introduction of these new cultivation and exposure techniques offers new testing strategies for the toxicological evaluation of inhalable soluble and inert substances as well as complex mixtures.

Temporal ecological assessment of oil contaminated soils before and after bioremediation

Ecotoxicity methods were used to assess different soil and oil combinations before, during and after laboratory bioremediation with associated hydrocarbon analysis. Heavy, medium and light crude oil (API gravity 14, 30, and 55) was spiked (ca. 5% w/w) into two sandy soils in the laboratory having organic carbon concentrations of 0.3 (Norwood) and 4.7% (Norwood/Baccto). The earthworm (Eisenia fetida) 14-d lethality assay, the modified Microbics Microtox Solid-Phase assay, and the 14-d plant seed germination and growth assays using corn, wheat and oats, were spiked and tested during a 360-d laboratory remediation. Eisenia was the most sensitive of the three methods utilized with survival increasing throughout bioremediation with fastest toxicity reduction in the high carbon Norwood/Baccto soils where LC50's were 100% or greater at the end of 90-d whereas, > 150-d were required to achieve a similar result in the low carbon soil. Analysis of the undiluted treatments with oily soil alone showed that earthworm survival was high after 90-d in all high organic carbon soils, and after eight months in the low carbon soils, except for the Norwood soil-light oil treatment, which required 360-d to achieve 100% survival. The Microtox assay was less sensitive with EC50's 100% or greater observed after 90-d in high carbon soils and after 240-d for all low carbon soils. After bioremediation, no effects on seed germination were observed, although some plant growth inhibition effects remained. There was no direct correlation between total petroleum hydrocarbon concentrations and toxicity.

Involvement of superoxide and nitric oxide on airway inflammation and hyperresponsiveness induced by diesel exhaust particles in mice

We previously demonstrated that chronic intratracheal instillation of diesel exhaust particles (DEP) induces airway inflammation and hyperresponsiveness in the mouse, and that these effects were partially reversed by the administration of superoxide dismutase (SOD). In the present study, we have investigated the involvement of superoxide in DEP-induced airway response by analyzing the localization and activity of two enzymes: (1) a superoxide producer, NADPH cytochrome P-450 reductase (P-450 reductase), and (2) a superoxide scavenger, SOD, in the lungs of the exposed mice and controls. P-450 reductase was detected mainly in ciliated cells and clara cells: its activity was increased by the repeated intratracheal instillation of DEP. While CuZn-SOD and Mn-SOD were also present in the airway epithelium, their activity was significantly decreased following DEP instillation. Exposure to DEP doubled the level of nitric oxide (NO) in the exhaled air. DEP exposure also increased the level of constitutive NO synthase (cNOS) in the airway epithelium and inducible NO synthase (iNOS) in the macrophages. Pretreatment with N-G-monomethyl L-arginine, a nonspecific inhibitor of NO synthase, significantly reduced the airway hyperresponsiveness induced by DEP. These results indicate that superoxide and NO may each contribute to the airway inflammation and hyperresponsiveness induced by the repeated intratracheal instillation of DEP in mice.

Aerobic biodegradation potential of subsurface microorganisms from a jet fuel-contaminated aquifer

In 1975, a leak of 83,000 gallons (314,189 liters) of jet fuel (JP-4) contaminated a shallow water-table aquifer near North Charleston, S.C. Laboratory experiments were conducted with contaminated sediments to assess the aerobic biodegradation potential of the in situ microbial community. Sediments were incubated with 14C-labeled organic compounds, and the evolution of 14CO2 was measured over time. Gas chromatographic analyses were used to monitor CO2 production and O2 consumption under aerobic conditions. Results indicated that the microbes from contaminated sediments remained active despite the potentially toxic effects of JP-4. 14CO2 was measured from [14C]glucose respiration in unamended and nitrate-amended samples after 1 day of incubation. Total [14C]glucose metabolism was greater in 1 mM nitrate-amended than in unamended samples because of increased cellular incorporation of 14C label. [14C]benzene and [14C]toluene were not significantly respired after 3 months of incubation. With the addition of 1 mM NO3, CO2 production measured by gas chromatographic analysis increased linearly during 2 months of incubation at a rate of 0.099 mumol g-1 (dry weight) day-1 while oxygen concentration decreased at a rate of 0.124 mumol g-1 (dry weight) day-1. With no added nitrate, CO2 production was not different from that in metabolically inhibited control vials. From the examination of selected components of JP-4, the n-alkane hexane appeared to be degraded as opposed to the branched alkanes of similar molecular weight. The results suggest that the in situ microbial community is active despite the JP-4 jet fuel contamination and that biodegradation may be compound specific.(ABSTRACT TRUNCATED AT 250 WORDS)

Sea-urchin (Paracentrotus lividus) glutathione S-transferases and cholinesterase activities as biomarkers of environmental contamination

Activities of glutathione S-transferases (GST) and cholinesterase (ChE) from Paracentrotus lividus were investigated as possible biomarkers of environmental contamination in the coastal zone. In the first phase of the study, the activity of both enzymes was determined in various tissues in order to select the most appropriate ones to be used in the following assays. In the second phase, the ChEs present in ambulacra were characterized using different substrates and selective inhibitors. In the next phase, laboratory bioassays were performed with dilutions of water-accommodated fraction of #4 fuel-oil (WAF) and benzo[a]pyrene (BaP) to determine the response of those enzymes to these pollutants and, finally, the activity of both enzymes was determined during a year in indigenous specimens from six sites on the Northwest coast of Portugal, with different pollution levels, to determine basal values and seasonal variations of ChE and GST activities. Among the several tissues tested, ambulacra and the anterior portion of the intestine were selected for ChE and GST assays, respectively. The determination of ChE in ambulacra tissue may be performed in a non-destructive way. Ambulacra ChE hydrolysed acetylthiocholine preferentially to propionylthiocholine and butyrylthiocholine and, inhibition by excess of substrate was observed. Enzymatic activity was almost fully inhibited by eserine sulfate (>98%) at concentrations equal or higher than 6.25 microM. Sensitivity to both BW284C51 (reaching 98% at 200 microM) and iso-OMPA (73% at 8 mM) was found. In laboratory bioassays, GSTs activity was inhibited by WAF and induced by BaP, whereas ChE activity was not affected by any of these environmental contaminants. Seasonal variations in enzymatic activities were found. For example, in a reference site, ChE values changed from 52.2 +/- 9.3 U mg(-1) protein in autumn to 71.8 +/- 13.3 U mg(-1) protein in spring, while GST activity changed from 129.9 +/- 29.8 U mg(-1) protein in winter to 279.0 +/- 48.0 U mg(-1) protein in autumn. Sea-urchins from reference sites presented significantly higher values of both ChE and GST than animals from contaminated sites in all seasons. In conclusion, the results of this study indicate that (i) ambulacra and the anterior portion of intestine are the most suitable tissues to measure ChE and GST activities, respectively; (ii) only one form of ChE seems to be present in ambulacra, showing properties of both typical acetylcholinesterase (AChE) and pseudocholinesterase (PChE); (iii)P. lividus GST is sensitive to both WAF and BaP even after acute exposures while ChE is not, and (iv) in spite of the significant seasonal variations observed in both enzymes in the field, P. lividus ChE and GST were capable of discriminate sites with different contamination levels and, thus, they are suitable for use as biomarkers in biomonitoring studies in the coastal zone.

Identification of compounds in heavy fuel oil that are chronically toxic to rainbow trout embryos by effects-driven chemical fractionation

The present study isolated and identified compounds in heavy fuel oil 7102 (HFO 7102) that are bioavailable and chronically toxic to rainbow trout embryos (Oncorhynchus mykiss). An effects-driven chemical fractionation combined the chemical separation of oil with toxicity testing and chemical analyses of each fraction to identify the major classes of compounds associated with embryo toxicity. Toxicity was assessed with 2 exposure methods, a high-energy chemical dispersion of oil in water, which included oil droplets in test solutions, and water accommodated fractions which were produced by oiled gravel desorption columns, and which did not contain visible oil droplets. Fractions of HFO with high concentrations of naphthalenes, alkanes, asphaltenes, and resins were nontoxic to embryos over the range of concentrations tested. In contrast, fractions enriched with 3- to 4-ringed alkyl polycyclic aromatic hydrocarbons (PAHs) were embryotoxic, consistent with published studies of crude oils and individual alkyl PAHs. The rank order of fraction toxicity did not vary between the exposure methods and was consistent with their PAH content; fractions with higher-molecular weight alkyl PAHs were the most toxic. Exposure of juvenile trout to most fractions of HFO induced higher activities of cytochrome P450 enzymes, with a rank order of potency that varied with exposure method and differed somewhat from that of embryotoxicity. Induction reflected the bioavailability of PAHs but did not accurately predict embryotoxicity.

Toxicity and phototoxicity of water-accommodated fraction obtained from Prestige fuel oil and Marine fuel oil evaluated by marine bioassays

Acute toxicity and phototoxicity of heavy fuel oil extracted directly from the sunken tanker Prestige in comparison to a standard Marine fuel oil were evaluated by obtaining the water-accommodated fraction (WAF) and using mussel Mytilus galloprovincialis and sea urchin Paracentrotus lividus embryogenesis bioassays, and copepod Acartia tonsa and fish Cyprinodon variegatus survival bioassays. Aromatic hydrocarbon (AH) levels in WAF were measured by gas chromatography. Prestige WAF was not phototoxic, its median effective concentrations (EC50) were 13% and 10% WAF for mussel and sea urchin respectively, and maximum lethal threshold concentrations (MLTC) were 12% and 50% for copepod and fish respectively. Marine WAF resulted phototoxic for mussel bioassay. EC50s of Marine WAF were 50% for sea urchin in both treatments and 20% for mussel under illumination. Undiluted Marine WAF only caused a 20% decrease in mussel normal larvae. Similar sensitivities were found among sea urchins, mussels and copepods, whilst fish were less sensitive. Unlike Marine WAF, Prestige WAF showed EC50 values at dilutions below 20%, and its toxicity was independent of lighting conditions. The differences in toxicity between both kinds of fuel could not be explained on the basis of total AH content.

The wreckage of the oil tanker 'Erika'--human health risk assessment of beach cleaning, sunbathing and swimming

In December 1999 the oil tanker 'Erika', carrying approximately 30 tons of heavy fuel oil, wrecked before the coast of Brittany (France), polluting the local beaches and rocks over a distance of some 500 km. Also numerous birds were affected. During the first months of 2000 the coastal area and many birds were cleaned. The health risk for people involved in these cleaning activities and for tourists was evaluated with emphasis on the carcinogenic properties of this oil. The outcome indicates that the risks were limited to people who had been in bare-handed contact with the oil. Firstly they had an increased risk for developing skin irritation and dermatitis, however, these effects are in general reversible. Secondly they had an increased risk for developing skin tumours, but since the dermal contacts with the oil were of relative short duration, this risk is considered to be very limited.

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.

Characterization of automotive emissions by bacterial mutagenesis bioassay: a review

Due to the growing numbers of diesel passenger automobiles in the United States, there has been an expanded effort to understand the health effects of airborne pollutants arising from increased automotive emissions. Bacterial mutagenicity testing has played an important role in the characterization of genotoxic effects and components arising from these combustion products. This review examines published material concerning the bacterial mutagenicity of automotive emissions. In addition, the paper explores factors that modify the mutagenicity of mobile-source emissions, the use of bacterial tests for the comparison of various mobile source emissions, and the use of bacterial tests to examine the phenomena of mammalian uptake and metabolism.

Toxicity to freshwater organisms from oils and oil spill chemical treatments in laboratory microcosms

Toxicity and temporal changes in toxicity of freshwater-marsh-microcosms containing South Louisiana Crude (SLC) or diesel fuel and treated with a cleaner or dispersant, were investigated using Chironomus tentans, Daphnia pulex, and Oryzias latipes. Bioassays used microcosm water (for D. pulex and O. latipes) or soil slurry (for C. tentans) taken 1,7, 31, and 186 days after treatment. SLC was less toxic than diesel, chemical additives enhanced oil toxicity, the dispersant was more toxic than the cleaner, and toxicities were greatly reduced by day 186. Toxicities were higher in the bioassay with the benthic species than in those with the two water-column species. A separate experiment showed that C. tentans' sensitivity was intermediate to that of Tubifex tubifex and Hyallela azteca. Freshwater organisms, especially benthic invertebrates, thus appear seriously effected by oil under the worst-case-scenario of our microcosms. Moreover, the cleaner and dispersant tested were poor response options under those conditions.

Cytokine induction as a measure of cutaneous toxicity in primary and immortalized porcine keratinocytes exposed to jet fuels, and their relationship to normal human epidermal keratinocytes

The purpose of this study was to identify biomarkers of toxicity in primary porcine keratinocytes (PKC) and an immortalized porcine keratinocyte cell line (MSK3877) exposed to jet fuels Jet A, JP-8, and JP-8+100. Cells were exposed to 0.1% jet fuels and assayed for interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-alpha) mRNA using the TaqMan real time quantitative reverse transcriptase PCR assay. IL-8 and TNF-alpha protein release was measured using an ELISA. PKC exposed to jet fuels caused a slight upregulation of TNF-alpha mRNA at early time points, but no significant differences in TNF-alpha protein production were detected. IL-8 mRNA was increased at 4 h following exposure, and IL-8 protein was increased at 8 h. In MSK 3877 cells, jet fuels were shown to increase the production and expression of TNF-alpha mRNA and protein at 30 min and 1 h following exposure, respectively. IL-8 mRNA was only slightly induced compared to control. IL-8 protein release was suppressed by jet fuel exposure. These results were compared with those of a previous study in our laboratory to evaluate the utility of using porcine cells in lieu of normal human epidermal keratinocytes (NHEK). Similarities exist between PKC and NHEK with respect to both TNF-alpha and IL-8 production. The expression profile of TNF-alpha in MSK3877 cells mimics that of NHEK. In contrast, the profile of IL-8 expression opposes that of PKC and NHEK. These results suggest that porcine keratinocytes are susceptible to jet fuel toxicity. However, the responses of immortalized cells may vary from those of PKC and NHEK necessitating cautious interpretation of such data.

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.

Long-term recovery of a Louisiana brackish marsh plant community from oil-spill impact: vegetation response and mitigating effects of marsh surface elevation

Oil spills can have significant, short-term, negative impacts on coastal marshes, but the long-term effects and eventual recovery are not well documented, particularly in brackish marshes. The goals of this investigation were to: (1) document the long-term recovery of a Louisiana brackish marsh plant community impacted by a 1985 oil spill; (2) separate the effect of the oil spill on marsh deterioration from ambient rates of marsh deterioration; and (3) assess the relative importance of residual oil in the sediment and decreased marsh surface elevation in the failure of certain areas to recover. A total of 68 permanent plots previously established in 1985 were re-surveyed for plant and soil recovery in the fall of 1989. Although substantial (and near total) vegetative recovery was evident by significant increases in live and total vegetative cover, many of the plots that were initially heavily impacted by oil still displayed elevated levels of total saturated hydrocarbons in the soil. August 1990 measurements of plant photosynthetic response and edaphic variables revealed no significant differences between control plots and plots heavily impacted by oil that displayed vegetative regrowth. Rates of wetland land loss in the oiled marsh during an 8-year period that bracketed the time of the spill were within the historical range measured for this site and similar to the land loss rates of adjacent reference marshes. Results from a manipulative field transplant experiment indicated that the long-term failure of certain small areas to revegetate was primarily due to a decrease of marsh surface elevation (increased flooding stress), not a residual oil effect.