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Acute cytotoxicity, genotoxicity, and apoptosis induced by petroleum VOC emissions in A549 cell line. Toxicol In Vitro 2022; 83:105409. [DOI: 10.1016/j.tiv.2022.105409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 04/28/2022] [Accepted: 05/30/2022] [Indexed: 11/27/2022]
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2
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Bus JS, Gollapudi BB, Hard GC. Methyl-tert-butyl ether (MTBE): integration of rat and mouse carcinogenicity data with mode of action and human and rodent bioassay dosimetry and toxicokinetics indicates MTBE is not a plausible human carcinogen. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2022; 25:135-161. [PMID: 35291916 DOI: 10.1080/10937404.2022.2041516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Methyl-tert-butyl ether (MTBE) is a fuel oxygenate used in non-United States geographies. Multiple health reviews conclude that MTBE is not a human-relevant carcinogen, and this review provides updated mode of action (MOA), exposure, dosimetry and risk perspectives supporting those conclusions. MTBE is non-genotoxic and has large margins of exposure between blood concentrations at the overall rat 400 ppm inhalation NOAEL and blood concentrations in typical workplace or general population exposures. Non-cancer and threshold cancer hazard quotients range from a high of 0.046 for fuel-pump gasoline station attendants and are 100-1,000-fold lower for general population exposures. Cancer risks conservatively assuming genotoxicity for these same scenarios are all less than 1 × 10-6. The onset of MTBE nonlinear toxicokinetics (TK) in rats at inhalation exposures less than 3,000 ppm, a dose that is also not practically achievable in fuel-use scenarios, indicates that high-dose specific male rat kidney and testes (3,000 and 8,000 ppm) and female mouse liver tumors (8000 ppm) are not quantitatively relevant to humans. Mode of action analyses also indicate MTBE male rat kidney tumors, and lesser so female mouse liver tumors, are not qualitatively relevant to humans. Thus, an integrated analysis of the toxicology, exposure/dosimetry, TK, and MOA data indicates that MTBE presents minimal human cancer and non-cancer risks.
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Affiliation(s)
- James S Bus
- Toxicology and Mechanistic Biology, Exponent Inc, Apex, NC, USA
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Nour-Eldine W, Sayyed K, Harhous Z, Dagher-Hamalian C, Mehanna S, Achkouti D, ElKazzaz H, Khnayzer RS, Kobeissy F, Khalil C, Abi-Gerges A. Gasoline fume inhalation induces apoptosis, inflammation, and favors Th2 polarization in C57BL/6 mice. J Appl Toxicol 2022; 42:1178-1191. [PMID: 35001415 DOI: 10.1002/jat.4286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/11/2021] [Accepted: 12/23/2021] [Indexed: 11/10/2022]
Abstract
Gasoline exposure has been widely reported in the literature as being toxic to human health. However, the exact underlying molecular mechanisms triggered by its inhalation have not been thoroughly investigated. We herein present a model of sub-chronic, static gasoline vapor inhalation in adult female C57BL/6 mice. Animals were exposed daily to either gasoline vapors (0.86 g/animal/90 minutes) or ambient air for five days/week over seven consecutive weeks. At the end of the study period, toxic and molecular mechanisms, underlying the inflammatory, oxidative, and apoptotic effects triggered by gasoline vapors, were examined in the lungs and liver of gasoline exposed mice. Static gasoline exposure induced a significant increase (+21 %) in lungs/body weight ratio in gasoline-exposed (GE) versus control (CON) mice along with a pulmonary inflammation attested by histological staining. The latter was consistent with increases in the transcript levels of proinflammatory cytokines [Interleukins (ILs) 4 and 6], respectively by ~ 6-, 4-fold in the lungs of GE mice compared to CON. Interestingly, IL-10 expression was also increased by ~ 10-fold in the lungs of GE mice suggesting an attempt to counterbalance the established inflammation. Moreover, the pulmonary expression of IL-12 and TNF-α was downregulated by 2- and 4-fold, respectively, suggesting the skewing toward Th2 phenotype. Additionally, GE mice showed a significant upregulation in Bax/Bcl-2 ratio, caspases 3, 8 and 9 with no change in JNK expression in the lungs, suggesting the activation of both intrinsic and extrinsic apoptotic pathways. Static gasoline exposure over seven consecutive weeks had a minor hepatic portal inflammation attested by H&E staining along with an increase in the hepatic expression of the mitochondrial complexes in GE mice. Therefore, tissue damage biomarkers highlight the health risks associated with vapor exposure and may present potential therapeutic targets for recovery from gasoline intoxication.
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Affiliation(s)
- Wared Nour-Eldine
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon
| | - Katia Sayyed
- School of Arts and Sciences, Department of Natural Sciences, Lebanese American University, Byblos, Lebanon
| | - Zeina Harhous
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon
| | - Carole Dagher-Hamalian
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon
| | - Stephanie Mehanna
- Department of Natural Sciences, Lebanese American University, Chouran, Beirut, Lebanon
| | - Donna Achkouti
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon
| | - Hanan ElKazzaz
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon
| | - Rony S Khnayzer
- Department of Natural Sciences, Lebanese American University, Chouran, Beirut, Lebanon
| | - Firas Kobeissy
- Faculty of Medicine, Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
| | - Christian Khalil
- School of Arts and Sciences, Department of Natural Sciences, Lebanese American University, Byblos, Lebanon
| | - Aniella Abi-Gerges
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Byblos, Lebanon
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Romanelli L, Evandri MG. Permitted Daily Exposure for Diisopropyl Ether as a Residual Solvent in Pharmaceuticals. Toxicol Res 2018; 34:111-125. [PMID: 29686773 PMCID: PMC5903142 DOI: 10.5487/tr.2018.34.2.111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 01/29/2018] [Accepted: 02/05/2018] [Indexed: 11/20/2022] Open
Abstract
Solvents can be used in the manufacture of medicinal products provided their residual levels in the final product comply with the acceptable limits based on safety data. At worldwide level, these limits are set by the “Guideline Q3C (R6) on impurities: guideline for residual solvents” issued by the ICH. Diisopropyl ether (DIPE) is a widely used solvent but the possibility of using it in the pharmaceutical manufacture is uncertain because the ICH Q3C guideline includes it in the group of solvents for which “no adequate toxicological data on which to base a Permitted Daily Exposure (PDE) was found”. We performed a risk assessment of DIPE based on available toxicological data, after carefully assessing their reliability using the Klimisch score approach. We found sufficiently reliable studies investigating subchronic, developmental, neurological toxicity and carcinogenicity in rats and genotoxicity in vitro. Recent studies also investigated a wide array of toxic effects of gasoline/DIPE mixtures as compared to gasoline alone, thus allowing identifying the effects of DIPE itself. These data allowed a comprehensive toxicological evaluation of DIPE. The main target organs of DIPE toxicity were liver and kidney. DIPE was not teratogen and had no genotoxic effects, either in vitro or in vivo. However, it appeared to increase the number of malignant tumors in rats. Therefore, DIPE could be considered as a non-genotoxic animal carcinogen and a PDE of 0.98 mg/day was calculated based on the lowest No Observed Effect Level (NOEL) value of 356 mg/m3 (corresponding to 49 mg/kg/day) for maternal toxicity in developmental rat toxicity study. In a worst-case scenario, using an exceedingly high daily dose of 10 g/day, allowed DIPE concentration in pharmaceutical substances would be 98 ppm, which is in the range of concentration limits for ICH Q3C guideline class 2 solvents. This result might be considered for regulatory decisions.
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Affiliation(s)
- Luca Romanelli
- Department of Physiology and Pharmacology Vittorio Erspamer, University of Rome Sapienza, Rome, Italy
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Herr DW, Freeborn DL, Degn L, Martin SA, Ortenzio J, Pantlin L, Hamm CW, Boyes WK. Neurophysiological assessment of auditory, peripheral nerve, somatosensory, and visual system function after developmental exposure to gasoline, E15, and E85 vapors. Neurotoxicol Teratol 2016; 54:78-88. [DOI: 10.1016/j.ntt.2015.12.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 12/11/2015] [Accepted: 12/18/2015] [Indexed: 12/15/2022]
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Bushnell PJ, Beasley TE, Evansky PA, Martin SA, McDaniel KL, Moser VC, Luebke RW, Norwood J, Copeland CB, Kleindienst TE, Lonneman WA, Rogers JM. Toxicological assessments of rats exposed prenatally to inhaled vapors of gasoline and gasoline–ethanol blends. Neurotoxicol Teratol 2015; 49:19-30. [DOI: 10.1016/j.ntt.2015.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 02/13/2015] [Accepted: 02/16/2015] [Indexed: 01/20/2023]
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Health assessment of gasoline and fuel oxygenate vapors: Developmental toxicity in rats. Regul Toxicol Pharmacol 2014; 70:S69-79. [PMID: 24845242 DOI: 10.1016/j.yrtph.2014.05.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 05/08/2014] [Indexed: 11/22/2022]
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Roberts L, Gray T, Marr M, Tyl R, Trimmer G, Hoffman G, Murray F, Clark C, Schreiner C. Health assessment of gasoline and fuel oxygenate vapors: Developmental toxicity in mice. Regul Toxicol Pharmacol 2014; 70:S58-68. [PMID: 24979735 DOI: 10.1016/j.yrtph.2014.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 06/10/2014] [Indexed: 10/25/2022]
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Introduction: Gasoline health effects and risk management. Regul Toxicol Pharmacol 2014; 70:S1-2. [PMID: 25151183 DOI: 10.1016/j.yrtph.2014.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 08/07/2014] [Indexed: 11/15/2022]
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Clark CR, Schreiner CA, Parker CM, Gray TM, Hoffman GM. Health assessment of gasoline and fuel oxygenate vapors: subchronic inhalation toxicity. Regul Toxicol Pharmacol 2014; 70:S18-28. [PMID: 25020274 DOI: 10.1016/j.yrtph.2014.07.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/30/2014] [Accepted: 07/02/2014] [Indexed: 11/29/2022]
Abstract
Sprague Dawley rats were exposed via inhalation to vapor condensates of either gasoline or gasoline combined with various fuel oxygenates to assess whether their use in gasoline influences the hazard of evaporative emissions. Test substances included vapor condensates prepared from an EPA described "baseline gasoline" (BGVC), or gasoline combined with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA). Target concentrations were 0, 2000, 10,000 or 20,000mg/m(3) and exposures were for 6h/day, 5days/week for 13weeks. A portion of the animals were maintained for a four week recovery period to determine the reversibility of potential adverse effects. Increased kidney weight and light hydrocarbon nephropathy (LHN) were observed in treated male rats in all studies which were reversible or nearly reversible after 4weeks recovery. LHN is unique to male rats and is not relevant to human toxicity. The no observed effect level (NOAEL) in all studies was 10,000mg/m(3), except for G/MTBE (<2000) and G/TBA (2000). The results provide evidence that use of the studied oxygenates are unlikely to increase the hazard of evaporative emissions during refueling, compared to those from gasoline alone.
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Affiliation(s)
- Charles R Clark
- Phillips 66 Co., 420 S. Keeler Avenue, Bartlesville, OK, United States.
| | - Ceinwen A Schreiner
- C&C Consulting in Toxicology, 1950 Briarcliff Ave, Meadowbrook, PA 19046, United States.
| | | | - Thomas M Gray
- American Petroleum Institute, 1220 L Street NW, Washington, DC 20005, United States.
| | - Gary M Hoffman
- Huntingdon Life Sciences, Princeton Research Center, 100 Mettlers Road, East Millstone, NJ 08873, United States.
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Swick D, Jaques A, Walker JC, Estreicher H. Gasoline toxicology: overview of regulatory and product stewardship programs. Regul Toxicol Pharmacol 2014; 70:S3-S12. [PMID: 24956589 DOI: 10.1016/j.yrtph.2014.06.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Revised: 06/11/2014] [Accepted: 06/15/2014] [Indexed: 12/01/2022]
Abstract
Significant efforts have been made to characterize the toxicological properties of gasoline. There have been both mandatory and voluntary toxicology testing programs to generate hazard characterization data for gasoline, the refinery process streams used to blend gasoline, and individual chemical constituents found in gasoline. The Clean Air Act (CAA) (Clean Air Act, 2012: § 7401, et seq.) is the primary tool for the U.S. Environmental Protection Agency (EPA) to regulate gasoline and this supplement presents the results of the Section 211(b) Alternative Tier 2 studies required for CAA Fuel and Fuel Additive registration. Gasoline blending streams have also been evaluated by EPA under the voluntary High Production Volume (HPV) Challenge Program through which the petroleum industry provide data on over 80 refinery streams used in gasoline. Product stewardship efforts by companies and associations such as the American Petroleum Institute (API), Conservation of Clean Air and Water Europe (CONCAWE), and the Petroleum Product Stewardship Council (PPSC) have contributed a significant amount of hazard characterization data on gasoline and related substances. The hazard of gasoline and anticipated exposure to gasoline vapor has been well characterized for risk assessment purposes.
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Affiliation(s)
- Derek Swick
- American Petroleum Institute, 1220 L Street, N.W., Washington, DC 20005, United States.
| | - Andrew Jaques
- RegNet, 1250 Connecticut Avenue, N.W., Suite 700, Washington, DC 20036, United States.
| | - J C Walker
- Keller and Heckman LLP, 1001 G Street, N.W., Suite 500W, Washington, DC 20001, United States.
| | - Herb Estreicher
- Keller and Heckman LLP, 1001 G Street, N.W., Suite 500W, Washington, DC 20001, United States.
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Henley M, Letinski DJ, Carr J, Caro ML, Daughtrey W, White R. Health assessment of gasoline and fuel oxygenate vapors: generation and characterization of test materials. Regul Toxicol Pharmacol 2014; 70:S13-7. [PMID: 24852493 DOI: 10.1016/j.yrtph.2014.05.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 05/08/2014] [Indexed: 10/25/2022]
Abstract
In compliance with the Clean Air Act regulations for fuel and fuel additive registration, the petroleum industry, additive manufacturers, and oxygenate manufacturers have conducted comparative toxicology testing on evaporative emissions of gasoline alone and gasoline containing fuel oxygenates. To mimic real world exposures, a generation method was developed that produced test material similar in composition to the re-fueling vapor from an automotive fuel tank at near maximum in-use temperatures. Gasoline vapor was generated by a single-step distillation from a 1000-gallon glass-lined kettle wherein approximately 15-23% of the starting material was slowly vaporized, separated, condensed and recovered as test article. This fraction was termed vapor condensate (VC) and was prepared for each of the seven test materials, namely: baseline gasoline alone (BGVC), or gasoline plus an ether (G/MTBE, G/ETBE, G/TAME, or G/DIPE), or gasoline plus an alcohol (G/EtOH or G/TBA). The VC test articles were used for the inhalation toxicology studies described in the accompanying series of papers in this journal. These studies included evaluations of subchronic toxicity, neurotoxicity, immunotoxicity, genotoxicity, reproductive and developmental toxicity. Results of these studies will be used for comparative risk assessments of gasoline and gasoline/oxygenate blends by the US Environmental Protection Agency.
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Affiliation(s)
- Michael Henley
- Chevron Energy Technology Company, 100 Chevron Way, Richmond, CA 94801-2016, USA.
| | - Daniel J Letinski
- ExxonMobil Biomedical Sciences, Inc., 1545 US Highway 22, East Annandale, NJ 08801-3059, USA.
| | - John Carr
- Chevron Energy Technology Company, 100 Chevron Way, Richmond, CA 94801-2016, USA.
| | - Mario L Caro
- Chevron Energy Technology Company, 100 Chevron Way, Richmond, CA 94801-2016, USA.
| | - Wayne Daughtrey
- ExxonMobil Biomedical Sciences, Inc., 1545 US Highway 22, East Annandale, NJ 08801-3059, USA.
| | - Russell White
- American Petroleum Institute, 1220 L. Street NW, Washington, DC 20005, USA.
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Health assessment of gasoline and fuel oxygenate vapors: immunotoxicity evaluation. Regul Toxicol Pharmacol 2014; 70:S43-7. [PMID: 24793263 DOI: 10.1016/j.yrtph.2014.04.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 04/19/2014] [Indexed: 11/23/2022]
Abstract
Female Sprague Dawley rats were exposed via inhalation to vapor condensates of either gasoline or gasoline combined with various fuel oxygenates to assess potential immunotoxicity of evaporative emissions. Test articles included vapor condensates prepared from "baseline gasoline" (BGVC), or gasoline combined with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA). Target concentrations were 0, 2000, 10,000 or 20,000mg/mg(3) administered for 6h/day, 5days/week for 4weeks. The antibody-forming cell (AFC) response to the T-dependent antigen, sheep erythrocyte (sRBC), was used to determine the effects of the gasoline vapor condensates on the humoral components of the immune system. Exposure to BGVC, G/MTBE, G/TAME, and G/TBA did not result in significant changes in the IgM AFC response to sRBC, when evaluated as either specific activity (AFC/10(6) spleen cells) or as total spleen activity (AFC/spleen). Exposure to G/EtOH and G/DIPE resulted in a dose-dependent decrease in the AFC response, reaching the level of statistical significance only at the high 20,000mg/m(3) level. Exposure to G/ETBE resulted in a statistically significant decrease in the AFC response at the middle (10,000mg/m(3)) and high (20,000mg/m(3)) exposure concentrations.
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