Correlation of Mutagenic and Dermal Carcinogenic Activities of Mineral Oils with Polycyclic Aromatic Compound Content

Correlation of Mutagenic and Dermal Carcinogenic Activitiesof Mineral Oils with Polycyclic Aromatic Compound Content. ROY,T. A., JOHNSON, S. W., BLACKBURN, G. R., AND MACK-ERER, C. R.(1988). Fundam Appl. To.xicol. 10, 466–476. Mutagenicity,polynuclear aromatic compound content, and skin carcinogenicitywere compared for a series of complex oil mixtures derived fromthe refining and processingof petroleum. Mutagenicity in a modifiedAmes Salmonella assay showed an excellent correlation with carcinogenicity,as determined in a mouse skin-painting bioassay, for oil sampleswith median boiling points (defined as the temperature at which50%/volume of an oil sample is recovered as condensate duringdistillation—50% recovered) above {small tilde}500°F.A significant correlation was also observed between the 3–7ring polycyclic aromatic compound (PAC) content and both mutagenicand carcinogenic potencies for samples ranging from those withmedian (50% recovered) boiling points above {small tilde}500°Fto those with initial boiling points of {small tilde}1070°F.These results show that both PAC content and mutagenicity arepredictive of dermal carcinogenic activity and indicate thatPAC components are largely if not entirely responsible for boththe carcinogenic and mutagenic activities.     

Developmental toxicity of EDS recycle solvent and fuel oil

Direct coal liquefaction is one of several technologies currently under development as alternative means to produce liquid fuels. Relatively high levels of polycyclic aromatic hydrocarbons are present in distillate fractions boiling above approximately 370 degrees C. Coal-derived liquids containing substantial amounts of material from this boiling range were genotoxic in in vitro tests and carcinogenic in mouse skin. Some of the liquids were also teratogenic in rodents. The present report describes studies which assessed the potential effects of 2 coal-derived liquids, recycle solvent (nominal boiling range 200-427 degrees C) and an experimental industrial fuel oil (nominal boiling range 204-538 degrees C) on prenatal development in the rat. The test materials were produced by the EDS direct coal liquefaction process and contained substantial amounts of material boiling above 370 degrees C. Test materials were administered by gavage to pregnant female Sprague-Dawley rats from days 6 to 19 of gestation (G). Animals were sacrificed on day 20G and the uterine contents were removed and examined. Results of both studies were similar. The number of live fetuses declined in a dose-related manner, and there was evidence of intrauterine growth retardation in fetuses which survived to day 20G. Statistically significant effects were noted at doses which did not appear to be maternally toxic. The frequency of malformation was not significantly elevated in either study; however, a thorough evaluation of this endpoint was precluded by embryo lethality at the high doses. It was apparent that both of the EDS liquids examined affected prenatal survival and growth. However, in contrast to studies of other coal-derived liquids, there was no evidence of teratogenic effects at non-toxic doses.     

Studies on the dermal and systemic bioavailability of polycyclic aromatic compounds in high viscosity oil products

The assessment of skin penetration by viscous oil products is an important element in the risk assessment of these materials where skin contact is likely. Systemic bioavailability (body uptake) is viewed as a good indicator of skin penetration following cutaneous exposures. The results of this study provide quantitative information on the influence of viscosity on the bioavailability of a specific polycyclic aromatic compound (benzo(a)pyrene) in base oils, residual aromatic extracts and bitumens following skin exposures to mice. The materials studied were a base mineral oil (viscosity 32 cSt at 35 °C), a 1:1 blend of the mineral base oil and a residual aromatic extract (198 cSt), several residual aromatic extracts (ca. 5000 cSt, 35 °C) and a range of bitumens (0.65–69 × 10⁶ cSt, 35 °C). These were each spiked with 0.1% radiolabelled benzo(a)pyrene, as a representative carcinogenic polycyclic aromatic compound, then used for cutaneous exposures to mice. The results indicate that as viscosity increased in the range ca. 30 to 5000 cSt (base oil to residual aromatic extract) the uptake of the radiolabelled benzo(a)pyrene into blood was reduced by ca. fivefold. Further increases in viscosity from ca. 5000 to 69 × 10⁶ cSt (i.e. residual aromatic extract to bitumen) resulted in a further but smaller (ca. twofold) reduction in uptake. The relationship between the amounts of free benzo(a)pyrene measured in blood and viscosity showed the same trend. This trend was also mirrored by the degree of binding of benzo(a)pyrene metabolites to DNA in skin. The findings in mouse skin in vivo indicate that viscosity can significantly affect skin penetration and systemic bioavailability of polycyclic aromatic compound components of oil products. Results obtained with viable human skin in vitro also showed that the bioavailability of benzo(a)pyrene was reduced by the viscosity of the oil product matrix. It is thus necessary to take account of physical properties such as viscosity in the overall risk assessment of viscous oil products, particularly in the case of very viscous materials such as bitumens. The significantly reduced bioavailability of hazardous compounds from undiluted materials is thus an important factor to consider when assessing the risks from dermal exposures. Received: 16 December 1998 / Accepted: 16 February 1999     

Evaluation of the Relationship between PAH Content and Mutagenic Activity of Fumes from Roofing and Paving Asphalts and Coal Tar Pitch

Evalution of the Relationship between PAH Content MutagenicAcitivity of Fumes from Roofing and Paving Asphalts and CoalTar Pitch. MACHADO, M. L., BEATTY, P. W., FETZER, J. C., GLICKMAN,A. H., AND McGINNIS, E. L. (1993). Fundam. Appl. Toxicol. 21,492–499. Fume condensates from asphalt and coal tar pitch were evaluatedto determine if polycyclic aromatic hydrocarbon (PAH) composition,crude oil source, or temperature at which the fume was generatedcorrelated with mutagenic activity. The fume condensates weretested for mutagenic activity using a modified Ames Test. Benzo[a]pyrene(BP) and other PAHs were detected in all samples. The concentrationof BP in coal tar pitch was 18, 100 ppm while the concentrationin asphalt was less than 6 ppm. Coal tar fumes contained betweentwo and three orders of magnitude more BP, as well as otherPAH species, than asphalt fumes. Coal tar fume condensates werealso approximately 100 times more mutagenic than those of asphalt.Generation temperature, crude oil source, and/or process conditionsaffected the PAH concentrations but not the mutagenicity inroofing asphalt fume condensates. With paving asphalt fumes,PAH content and mutagenicity varied with crude oil source butnot with processing conditions; due to limited data, it wasnot possible to determine the effect of generation temperature.Coal tar pitch fumes generated at 316°C contained significantlyhigher concentrations of PAHs than those generated at 232°Cand the mutagenic activity generally paralleled the PAH content.A subset of the paving asphalts demonstrated good correlationbetween mutagenicity and three- to seven-ring PAH content. Theseresults indicate that asphalt fumes are far less mutagenic thancoal tar fumes. Asphalt fumes differ in their ability to inducemutagenic activity, and, most likely, in their potential carcinogenicity.     

Chronic Dermal Studies of Petroleum Streams in Mice

During petroleum refining, a large number of products are generatedwhich have varying chemical and physical properties. These areknown in the industry as petroleum streams. In order to characterize their carcinogenic activity, a number of these commercially produced streams were administered to C3H/HeJ mice inchronic dermal bioassays. The bioassays were conducted usingone of two study designs: the first set of test materials wasapplied for a lifetime and the second set for 24 months. Inthe lifetime study, the last mice in the test groups survivedfor periods of 31 to 32 months. Middle distillates, boilingin the range 115–390°C, were found to decrease thelifespan of exposed mice compared to controls or streams ofhigher and lower boiling ranges. These middle distillate streamsincluded straight run kerosine, hydrodesulfurized middle distillate,straight run middle distillate, light catalytic cracked distillate,and 90/10% and 70/30% mixtures of the last two. The middle distillatestreams also proved to be active as carcinogens, with tumorincidence ranging from 16 to 67%. Light alkylate naphtha, heavycatalytic reformed naphtha, vacuum residuum, and unleaded gasolinedid not demonstrate significant carcinogenic potency. Heavythermal cracked naphtha, heavy catalytic cracked naphtha, andhydrotreated light naphthenic distillate were dermal carcinogensof low potency in this study. Administration of light catalyticcracked naphtha led to a low incidence of very late developingtumors with a mean latency of 118 weeks. Application of the0.1% solution of catalytic cracked clarified oil in toluenedid not result in a significant incidence of tumors, but the10% solution caused almost 100% mortality and 100% tumor incidencein 12 months. There was no correlation between carcinogenicpotency and the indices of irritation, alopecia, erythema, andscabbing. Only two of the streams tested, hydrotreated lightnaphthenic distillate and 10% catalytic cracked clarified oil,contain polynuclear aromatic hydrocarbons (PNAs) and may bepresumed to be complete carcinogens. The middle distillatesand heavy naphthas are nomnutagenic and essentially free ofPNAs. Their activity may result from promotion of already-initiatedskin sites. Where comparisons could be made, reducing the exposureperiod from a lifetime (29–32 months) to 24 months didnot change the evaluations of stream carcinogenicity exceptin the case of light catalytic cracked naphtha where six ofthe seven mice that developed tumors did so after 24 months.     

Effect of Different Terpene-Containing Essential Oils on Percutaneous Absorption of Trazodone Hydrochloride Through Mouse Epidermis

The aim of our study was to investigate the enhancing effect of several essential oils in the percutaneous absorption of trazodone hydrochloride (TZN). For this purpose, fennel oil, eucalyptus oil, citronella oil, and mentha oil were applied on the skin membrane in three different ways: included in the transdermal device, as a pretreatment, or both. To investigate the effect of penetration enhancers used in this study on the percutaneous absorption of TZN through mouse epidermis, Keshary-Chien diffusion cells were employed. The receptor phase was constantly stirring saline phosphate buffer of pH 7.4 at 37 ± 1°C. Results showed that pretreatment of skin with essential oils increases the flux values of TZN compared with the values obtained when the same essential oils were included in the transdermal devices. The percutaneous penetration flux for TZN was increased with skin pretreatment by 10% essential oils in the following order: fennel oil > eucalyptus oil > citronella oil > mentha oil. The amount of TZN retained in the skin after pretreatment with essential oils was found to be very similar in all cases and much higher than in the experiments without skin pretreatment.     

Biological effects and toxicity of diluted bitumen and its constituents in freshwater systems

Approximately 50 billion cubic meters of bitumen resides within the oil sands region of Alberta, Canada. To facilitate the transport of bitumen from where it is extracted to where it is processed, the bitumen is diluted with natural gas condensate (‘dilbit’), synthetic crude from hydrocracking bitumen (‘synbit’), or a mixture of both (‘dilsynbit’). A primary consideration for the effects of diluted bitumen products on freshwater organisms and ecosystems is whether it will float on the water surface or sink and interact with the stream or lake sediments. Evidence from a spill near Kalamazoo, MI, in 2010 and laboratory testing demonstrate that the nature of the spill and weathering of the dilbit, synbit or dilsynbit prior to and during contact with water will dictate whether the product floats or sinks. Subsequent toxicological data on the effects of dilbit and other diluted bitumen products on freshwater organisms and ecosystems are scarce. However, the current literature indicates that dilbit or bitumen can have significant effects on a wide variety of toxicological endpoints. This review synthesizes the currently available literature concerning the fate and effects of dilbit and synbit spilled into freshwater, and the effects of bitumen and bitumen products on aquatic organisms and ecosystems. Dilbit is likely to provide ecological impacts that are similar to and extend from those that follow from exposure to lighter crude oil, but the prospect of bitumen settling after binding to suspended sediments elevates the risk for benthic impacts in streams and lakes. Copyright © 2015 John Wiley & Sons, Ltd.     

Development of a carcinogenic potency index for dermal exposure to viscous oil products

Polycyclic aromatic compounds (PACs) present in oil streams and formulated products are important determinants of possible carcinogenicity. Following dermal exposures the transport of the PACs from oil (the carrier) into the skin is a factor that may affect macromolecular (DNA) adduct formation and thus determine carcinogenicity. We have developed a mathematical model, which describes the flux into the skin for a representative carcinogenic PAC, benzo(a)pyrene. The model is based on measurements of the amount of benzo(a)pyrene bound to skin DNA or blood observed in mouse skin painting studies. The degree of adduct formation from a particular oil product, which we term the Bioavailability Index (BI), was shown to be a function of both the viscosity of the oil product, which affected the transport of the PAC through the carrier, and the aromaticity, which affected the partition of PAC between the carrier and the skin. Literature data were analysed from mouse skin painting studies with mineral oils of known carcinogenicity. A linear relationship was shown between the amount of DNA adduct formation, expressed as alkylation frequency, and the arithmetic product of the total (3–6) ring PAC content and the BI, which we have termed the Carcinogenic Potency Index (CPI). Comparison of literature data on DNA alkylation frequencies for oil products and their carcinogenicity indicated that oils giving rise to an alkylation frequency below a certain threshold (ca. 1 adduct in 10⁸ nucleotides) are non-carcinogenic to mouse skin. This threshold level can be translated into a value for the CPI, below which the genotoxic carcinogenic risk arising from skin contact with the oil product is considered to be negligible. The CPI for bitumens is well below this value, being both due to the low BI from bitumen, but more so, due to their low PAC content. For some bitumens diluted with solvents, i.e. cutback-bitumens, the CPI may exceed this value, indicating a possible carcinogenic risk for some of the cutback-bitumens. The main determining factor is the PAC content which is principally determined by the nature of the diluent used. Received: 16 December 1998 / Accepted: 16 February 1999     

The dermal carcinogenic potential of unrefined and hydrotreated lubricating oils

Unrefined lubricating oils contain relatively high levels of polycyclic aromatic hydrocarbons (PAH) and have been shown to induce tumors in mouse skin. Exxon has developed a new method of refining these materials, a severe hydrotreatment process that is optimized for PAH removal. The specific objectives of the current study were to assess PAH reduction and then to evaluate directly the dermal carcinogenic potential of the materials that spanned the range of products produced by this method. The test samples included unrefined light and heavy vacuum distillates from a naphthenic crude oil, as well as the corresponding severely hydrotreated products. Two sets of samples were prepared to assess the effects of various operating parameters in the reactor. Additionally, positive (benzo[a]pyrene), negative (white mineral oil) and vehicle (toluene) control groups were included to assess the sensitivity and specificity of the bioassay. Each sample was applied in twice-weekly aliquots to the backs of 40 male C3H mice. In the analytical studies, significant reductions in the levels of several specific PAH were demonstrated. In the dermal carcinogenesis studies, the unrefined oils and the positive control induced tumors and also significantly reduced survival. None of the mice treated with severely hydrotreated oils or with the negative or vehicle controls developed skin tumors, and survival of these mice was not significantly different from the control. Thus, the data demonstrated that this new, severe hydrotreatment process was an effective means of converting carcinogenic feedstocks to non-carcinogenic products.     

Fathead minnow (Pimephales promelas) reproduction is impaired in aged oil sands process-affected waters

Large volumes of fluid tailings are generated during the extraction of bitumen from oil sands. As part of their reclamation plan, oil sands operators in Alberta propose to transfer these fluid tailings to end pit lakes and, over time, these are expected to develop lake habitats with productive capabilities comparable to natural lakes in the region. This study evaluates the potential impact of various oil sands process-affected waters (OSPW) on the reproduction of adult fathead minnow (Pimephales promelas) under laboratory conditions. Two separate assays with aged OPSW (>15 years) from the experimental ponds at Syncrude Canada Ltd. showed that water containing high concentrations of naphthenic acids (NAs; >25 mg/l) and elevated conductivity (>2000 μS/cm) completely inhibited spawning of fathead minnows and reduced male secondary sexual characteristics. Measurement of plasma sex steroid levels showed that male fathead minnows had lower concentrations of testosterone and 11-ketotestosterone whereas females had lower concentrations of 17β-estradiol. In a third assay, fathead minnows were first acclimated to the higher salinity conditions typical of OSPW for several weeks and then exposed to aged OSPW from Suncor Energy Inc. (NAs ∼40 mg/l and conductivity ∼2000 μS/cm). Spawning was significantly reduced in fathead minnows held in this effluent and male fathead minnows had lower concentrations of testosterone and 11-ketotestosterone. Collectively, these studies demonstrate that aged OSPW has the potential to negatively affect the reproductive physiology of fathead minnows and suggest that aquatic habitats with high NAs concentrations (>25 mg/l) and conductivities (>2000 μS/cm) would not be conducive for successful fish reproduction.     

Dermal carcinogenic activity of petroleum-derived middle distillate fuels

In general, the carcinogenic potential of petroleum-derived materials is related to the polycyclic aromatic hydrocarbon (PAH) content. Thus it has been assumed that liquids which boil below the PAH distillation range (i.e., below approx. 370 degrees C (700 degrees F) would not be carcinogenic. Several early studies supported this conclusion but were of relatively short duration. Several recent and more rigorous studies have shown that repeated application of certain petroleum-derived materials boiling between approximately 177-370 degrees C (350-700 degrees F) (i.e., middle distillate fuels) can produce tumors in mouse skin. The current studies assessed the tumorigenic potential of a series of middle distillates which varied with respect to boiling range, composition, and source of blending stocks. All of the samples produced evidence of weak tumorigenic activity which was characterized by low tumor yields and long median latencies. However, the majority of the tumor yields were significantly different from the control. There were no apparent differences in response among the samples. Thus the various parameters examined did not substantially influence tumor outcome. In particular, there was no association of tumorigenic activity with aromatic carbon content; this finding, coupled with evidence that PAH levels were low, suggested that the tumorigenic responses were not PAH-dependent. In addition to the tumors, there was evidence of non-neoplastic dermal changes including hyperplasia. These may have contributed to the tumorigenic responses; however, the actual mechanism of tumor induction is unknown.     

Skin Tumorigenic Potential of Crude and Refined Coal Liquids and Analogous Petroleum Products

Skin Tumorigenic Potential of Crude and Refined Coal Liquidsand Analogous Petroleum Products. WITSCHI, H. P., SMITH, L.H., FROME, E. L., PECQUET-GOAD, M. E., GRIEST, W. H., HO. C.-H.,AND GUERIN, M. R. (1987). Fundam. Appl. Toxicol 9, 297–303.The skin tumorigenic potential of seven complex hydrocarbonmixtures was determined: a coal-derived raw blend composed oflight and heavy oils, a low- and high-severity hydrotreatedproduct of that blend, and naphthas and fuel oils from the rawblend or from natural petroleum. Male and female C3H/Bd_f micewere exposed three times per week to each test mixture by dermalapplication of 50 µl of neat, 50, or 25% (w/v) preparations.Room, vehicle, and benzo[a] control groups were run concurrently.The raw blend produced an almost 100% incidence of skin tumorsat all three doses while tuniorigenicity was considerably decreasedby hydrotreating the blend both in terms of incidence and onset.The tumongenicities of the naphthas and fuel oils derived fromthe raw blend or from petroleums were low relative to that ofthe parent mixture. Although tumorigens in the raw blend weremuch reduced by hydrotreatment, tumori genicity of the otheragents did not parallel the content of polycyclic aromatic hydrocarbonsknown to be good tumor initiators.     

Triacylglycerols of the lipid fraction from fruits of two <Emphasis Type="Italic">Echinacea</Emphasis> species

Fatty oils extracted from the fruits of Echinacea purpurea and E. pallida species have been analyzed. The extracts represent oily and readily mobile light yellow liquids. Fruits of E. purpurea contain 33.6% fatty oil; of E. pallida, 23.2%. NMR spectroscopy analyses of fatty oils from fruits of the two Echinacea species show that these substances belong to liquid plant oils such as linoleic acid, which is confirmed by the measured numerical indices. Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 43, No. 3, pp. 32 – 34, March, 2009.     

Assessment of the potential reproductive and subchronic toxicity of EDS coal liquids in Sprague-Dawley rats

The EDS direct coal liquefaction process is one of several methods of producing liquid fuels from coal which have reached the pilot or demonstration stage of development. Relatively high levels of polycyclic aromatic hydrocarbons are present in distillate fractions boiling above approximately 370 degrees C, and unrefined coal-derived liquids which contain substantial amounts of material from this boiling range are relatively potent dermal carcinogens. Because coal-derived liquids containing high boiling (i.e., greater than 370 degrees C) material may pose a variety of toxic hazards, efforts have been made to evaluate the potential effects on biological endpoints other than cancer. The present studies assessed the potential for reproductive and subchronic toxicity following repeated oral administration of 2 coal-derived liquids, recycle solvent and fuel oil, which contained substantial amounts of high boiling material. Few biologically important differences were found in any of the experimental parameters. In the reproductive toxicity study, frequency of fertilization and implantation, mean number of live births, fraction of litter surviving through the lactation period and mean weight gain of the litters during the lactation period were not affected by treatment; in addition, there was no evidence of increased frequency of malformation. In the subchronic toxicity study, weight gain was reduced in animals from the high dose groups, but was not significantly different from controls. Liver weights were significantly elevated, but there was no microscopic evidence of pathologic changes. Erythrocyte counts, hemoglobin levels and hematocrits were significantly reduced suggesting a tendency towards anemia. These findings suggested that repeated exposure to EDS recycle solvent and fuel oil at levels of up to 0.5 g/kg per day had no detectable effect on reproductive capacity or performance and did not induce substantial systemic toxicity.     

Genotoxicity studies in the ST cross of the Drosophila wing spot test of sunflower and soybean oils before and after frying and boiling procedures

Sunflower and soybean oils were tested for genotoxicity in the Drosophila wing somatic mutation and recombination assay. Results indicate that both oils produce genotoxic effects when tested without any previous frying or boiling processes. Boiling sunflower oil during fifteen, thirty and sixty minutes significantly increased its genotoxic response; nevertheless, after frying potatoes this oil showed a significant decrease in the genotoxic activity. On the other hand, boiling and frying soybean oil in the same conditions results in a decrease of its genotoxic potential. We have also detected that the amount of total polar materials increases significantly in oils submitted to frying or boiling process. Nevertheless, in oils obtained after frying potatoes, the amount of TPM was higher than after boiling. It is suggested that this effect is probably due to the amount of non-volatile TPM, the fatty acid composition of the oils, the types of frying oil, the high frying temperature and time, and the number of boiling and frying. This is the first study reporting genotoxicity data in Drosophila for the boiling and frying of both sunflower and soybean oils.     

Characteristics and thermal behavior of fresh and waste oil blends as supplement in diesel engines

This study deals with the combustion characteristics of base oil-based blends called number 10 lubes (NTLs), a blend of virgin/nonstandard base oils with low taxation petroleum products and/or wastes, used as diesel additive or substitute using thermogravimetric analysis with Fourier Transform Infrared Spectroscopy. Basic compositional analyses (i.e. elemental analysis, calorific value, sulfated ash) were also conducted with relevant methods in an accredited fuel analysis laboratory. In general, samples yielded exceptional characteristics in terms of sulfated ash content. Oxidation reactions were found to compose of one decomposition stage whilst up to three-stages were also observed outstandingly. Thermographs vary slightly in shape and position, similarly shaped to that for mineral oil, base oil or waste engine oil, and exhibited lower mass loss rates at low temperatures when compared to diesel. Quantitatively, combustion reactions occur between 236 ± 42.2 °C and 362 ± 39.0 °C yielding a maximum combustion rate and mass loss of 17.4 ± 3.87%/min and 98.4 ± 1.29%, respectively, on average, with major gases released carbon dioxide, water vapour, and the others complicating the interpretation of spectral bands. The combustion characteristic indices (ignition, flammability, burnout and comprehensive combustion index) also showed the combustion performance in favor of diesel > NTLs > mineral oil > waste engine oil > base oil > waste vegetable oil. Thus, this problem needs to be handled carefully via waste to fuel projects adopting the circular economy approach if sufficient knowledge on all of the technical and market aspects of such fuels would be obtained.     

Correlation of 32P-postlabelling-detection of DNA adducts in mouse skin in vivo with the polycyclic aromatic compound content and mutagenicity in Salmonella typhimurium of a range of oil products

The in vivo genotoxic activities in mouse skin of the dimethyl sulphoxide (DMSO) extracts of a range of oil products [residual aromatic extract; untreated heavy paraffinic distillate aromatic extract; mildly refined light naphthenic base oil; bitumen (vacuum residue); high viscosity index base oil obtained by catalytic hydrogenation] were evaluated by ³²P-postlabelling DNA analysis. The results of quantitative ³²P-postlabelling analyses of epidermal DNA from mice treated with the DMSO extracts showed linear relationships with the total polycyclic aromatic compound (PAC) contents, determined by the Institute of Petroleum method IP 346 and also the 3–6 ring PAC contents, measured by on-line liquid-liquid extraction using flow injection analysis. The ³²P-postlabelling data also showed a linear relationship with the mutagenicity indices of these oil products determined in S. typhimurium TA98 using the modified Ames Salmonella microsome test. The in vivo genotoxicity of the DMSO extracts from the oil products was low, judged by ³²P-postlabelling analysis of DNA adducts measured in epidermal DNA of treated mouse skin, and ranging from 2 to 723 attomole/μg DNA per mg oil product. The in vivo ³²P-postlabelling data from this study are consistent with these materials expressing low genotoxicity in mouse skin in vivo. The DMSO extraction procedure coupled with ³²P-postlabelling DNA analysis is useful for ranking the relative genotoxic potency in vivo of a wide range of oil products. In general the trend observed is similar to rankings based on physicochemical measurements of␣total PAC contents or 3–6 ring PAC contents of the oil products. Received: 11 February 1998 / Accepted: 2 April 1998     

Final report on the safety assessment of Juniperus communis Extract, Juniperus oxycedrus Extract, Juniperus oxycedrus Tar, Juniperus phoenicea extract, and Juniperus virginiana Extract

The common juniper is a tree that grows in Europe, Asia, and North America. The ripe fruit of Juniperus communis and Juniperus oxycedrus is alcohol extracted to produce Juniperus Communis Extract and Juniperus Oxycedrus Extract, respectively. Juniperus Oxycedrus Tar is the volatile oil from the wood of J. oxycedrus. Juniperus Phoenicea Extract comes from the gum of Juniperus phoenicea, and Juniperus Virginiana Extract is extracted from the wood of Juniperus virginiana. Although Juniperus Oxycedrus Tar is produced as a by-product of distillation, no information was available on the manufacturing process for any of the Extracts. Oils derived from these varieties of juniper are used solely as fragrance ingredients; they are commonly produced using steam distillation of the source material, but it is not known if that procedure is used to produce extracts. One report does state that the chemical composition of Juniper Communis Oil and Juniperus Communis Extract is similar, each containing a wide variety of terpenoids and aromatic compounds, with the occasional aliphatic alcohols and aldehydes, and, more rarely, alkanes. The principle component of Juniperus Oxycedrus Tar is cadinene, a sesquiterpene, but cresol and guaiacol are also found. No data were available, however, indicating the extent to which there would be variations in composition that may occur as a result of extraction differences or any other factor such as plant growth conditions. Information on the composition of the other ingredients was not available. All of the Extracts function as biological additives in cosmetic formulations, and Juniperus Oxycedrus Tar is used as a hair-conditioning agent and a fragrance component. Most of the available safety test data are from studies using oils derived from the various varieties of juniper. Because of the expected similarity in composition to the extract, these data were considered. Acute studies using animals show little toxicity of the oil or tar. The oils derived from J. communis and J. virginiana and Juniperus Oxycedrus Tar were not skin irritants in animals. The oil from J. virginiana was not a sensitizer, and the oil from J. communis was not phototoxic in animal tests. Juniperus Oxycedrus Tar was genotoxic in several assays. No genotoxicity data were available for any of the extracts. Juniperus Communis Extract did affect fertility and was abortifacient in studies using albino rats. Clinical tests showed no evidence of irritation or sensitization with any of the tested oils, but some evidence of sensitization to the tar. These data were not considered sufficient to assess the safety of these ingredients. Additional data needs include current concentration of use data; function in cosmetics; methods of manufacturing and impurities data, especially pesticides; ultraviolet (UV) absorption data; if absorption occurs in the UVA or UVB range, photosensitization data are needed; dermal reproductive/developmental toxicity data (to include determination of a no-effect level); two genotoxicity assays (one in a mammalian system) for each extract; if positive, a 2-year dermal carcinogenicity assay performed using National Toxicology Program (NTP) methods is needed; a 2-year dermal carcinogenicity assay performed using NTP methods on Juniperus Oxycedrus Tar; and irritation and sensitization data on each extract and the tar (these data are needed because the available data on the oils cannot be extrapolated). Until these data are available, it is concluded that the available data are insufficient to support the safety of these ingredients in cosmetic formulations.     

Mutagenicity of Diesel Exhaust Particle Extracts: Influence of Fuel Composition in Two Diesel Engines

Mutagenicity of Diesel Exhaust Particle Extracts: Influenceof Fuel Composition in Two Diesel Engines. Clark, C.R., Royer,R.E., Brooks, A.L., Henderson, T.R., McClellan, R.O., Marshall,W.F. and Naman, T.M. (1982). Fundam. Appl. Toxicol. 2:38–43.The influence of diesel fuel composition on mutagenicity ofexhaust particle associated organic compounds has been investigatedusing nine fuels varying in aromatic content and distillationproperties. The tests were conducted with Oldsmobile Delta-88and Peugot 504 diesel cars operated according to the EPA FederalTest Procedure. The particulate exhaust from each test was collectedon a filter, extracted in dichloromethane and the resultingextract evaluated for mutagenicity in Salmonella strain TA-100.Mutagenicity of extracts of particles collected from the Oldsmobilewere highest in the higher aromatic content fuels (> 30%)but similar for intermediate (20%) and low (13%) aromatic contentfuels. No influence of aromaticity on mutagenicity was observedin samples collected from the Peugeot under the same conditions.Thus, fuel aromatic content may enhance the production of mutageniccombustion products at higher concentrations, but may be dependentupon engine type. A good correlation was observed between mutagenicityof the particle extracts and the initial boiling point of thefuel (r = 0.89). Gas chromatog-raphy/mass spectrometric analysisof the aromatic fraction of the fuels showed that the fuel producingthe most muta-genic combustion products was highest in phenanthrenetype compounds.     

Ingestion of Soil Contaminated with 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) Alters Hepatic Enzyme Activities in Rats

Ingestion of Soil Contaminated with 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD) Alters Hepatic Enzyme Activities in Rats. LUCIER, G.W., RUMBAUGH, R. C., MCCOY, Z., HASS, R., HARVAN, D., AND ALBRO,P. (1986). Fundam. Appl. Toxicol. 6, 36.4–371. Femalerats were treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)in either corn oil or contaminated soil from the Minker sitein Missouri. Eight doses ranging from 0.015 to 5 µg TCDD/kgwere used in the corn oil group; the range was 0.015 to 5.5TCDD/kg in the TCDD-contaminated soil group. Rats in a thirdgroup were given equal amounts of soil uncontaminated with TCDD.No acute toxicity or effects on body weight gain were observedat these doses. In general, equivalent doses of TCDD in cornoil or TCDD in soil produced similar increases in hepatic arylhydrocarbon hydroxylase activity (AHH) and UDP glucuronyltransferaseactivity although effects were slightly greater in the TCDD–cornoil groups. In the corn oil groups, the induction of AHH rangedfrom about 30-fold at the highest dose to twofold at the lowestdose studied. TCDD also caused an increase in cytochrome P-450concentration and a shift in spectral peak from 450 to 448 nm.There was no effect of TCDD on ethylmorphine N-demethylase,consistent with previous reports. Liver concentrations of TCDD(mean ± SD) in the 5-µg/kg groups were 40.8 ±6.3 ppb in the TCDD- corn oil group and 20.3 ± 12.9 ppbin the TCDD-contaminated soil group. Our results suggest thatthe bioavailability of TCDD in soil in rats is approximately50%. Therefore, ingestional exposure to TCDD-contaminated soilmay constitute a significant health hazard in view of its extremelyhigh toxicity and relatively high bioavailability.