Experimental Exposure to Methyltertiary-Butyl Ether

Nihlén, Annsofi; Löf, Agneta; Johanson, Gunnar

doi:10.1006/taap.1997.8333

Cited by 52 publications

(23 citation statements)

References 14 publications

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“…Nevertheless, it has been noted that the use of a specific detectors such as FID or PID to detect MTBE in complex matrices can lead to mistakes and/or false positive results, whereas MS insures high specificity in the identification of the analytes. Several papers reporting the determination of MTBE and other ethers in human blood [7,13,14,[24][25][26][27][28][29][30][31][32][33], and urine [15][16][17][18][19]26,34,35] were also found. In its latest versions MTBE is sampled by headspace SPME and analyzed by GC-MS [27,29].…”

Section: Introductionmentioning

confidence: 93%

Single-walled carbon nanotubes as an effective adsorbent in solid-phase microextraction of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether from human urine

Rastkari

Ahmadkhaniha

Yunesian

2009

Journal of Chromatography B

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Section: Introductionmentioning

confidence: 93%

Single-walled carbon nanotubes as an effective adsorbent in solid-phase microextraction of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether from human urine

Rastkari

Ahmadkhaniha

Yunesian

2009

Journal of Chromatography B

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“…As a result, most studies of MTBE's health effects have focused on exposure through inhalation rather than ingestion. Exposed-worker studies and chamber studies failed to determine any causal mechanism for acute symptoms, but they did not preclude the possibility that sensitive subpopulations could experience acute effects (13)(14)(15)(16)(17). Subsequent research suggests that MTBE does not pose an imminent human health threat, especially in comparison to other gasoline components such as benzene (18).…”

Section: The Mtbe Historymentioning

confidence: 99%

Clearing the Air: Using Scientific Information to Regulate Reformulated Fuels

Franklin

Koshland

Lucas

et al. 2000

Environ. Sci. Technol.

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The gasoline oxygenate MTBE (methyl tert-butyl ether) was widely adopted across the United States in the 1990s as a key component of federally mandated oxygenated and reformulated fuels. The regulations implementing statutory mandates for oxygenated fuels were promulgated without a comprehensive evaluation of the environmental or health consequences of using MTBE or other oxygenates in such large quantities. Policymakers only belatedly realized the environmental ramifications of increased levels of MTBE in gasoline, especially groundwater contamination resulting from leaking fuel tanks. The policy process that led to MTBE's predominance was flawed, since no systematic attempt was made a priori to evaluate multimedia implications of MTBE's widespread use. The history of MTBE in the United States illustrates several typical, but problematic, features of environmental policymaking. It reveals how the scale of chemical usage directly impacts actual and perceived environmental effects. It highlights how institutional factors constrain policymakers through statutory mandates, regulatory agency organizational structures, and the strong influence exerted by political-economic actors even in supposedly "technical" debates. Finally, the MTBE case reveals barriers to effective scientific and technical communications among policymakers, regulated industries, special-interest groups, and the public.

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“…The respiratory uptake of MTBE ranged from 40% to 53% in healthy subjects exposed to 1.39 ppm for 1 h (Buckley et al, 1997). For a wide range of exposure concentrations (5-50 ppm) the MTBE uptake of 42% to 49% was reported in 10 healthy men during 2-h exposure with light exercise (Nihlen et al, 1998a). In another study, however, the respiratory uptake was as high as 72% in 7 subjects during 1-h exposure to 3.1 ppm MTBE (Prah et al, 2004).…”

mentioning

confidence: 92%

Transport and Uptake of MTBE and Ethanol Vapors in a Human Upper Airway Model

Zhang

Kleinstreuer

Kim

2006

Inhalation Toxicology

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Potential human exposure to vapors of methyl tertiary-butyl ether (MTBE) and ethanol is of increasing concern because these materials are widely used as gasoline additives. In this study we analyzed numerically the transport and deposition of MTBE and ethanol vapors in a model of the human upper respiratory airway, consisting of an oral airway and the first four generations of the tracheobronchial tree. Airflow characteristics and mass transfer processes were analyzed at different inspiratory flow conditions using a three-dimensional computational fluid and particle dynamics method. The deposition data were analyzed in terms of regional deposition fractions (DF = regional uptake/mouth concentration) and deposition enhancement factors (DEF = local DF/average DF) at local micro surface areas. Results show that DF in the entire upper airway model is 21.9%, 12.4%, and 6.9% for MTBE and 67.5%, 51.5%, and 38.5% for ethanol at a flow rate of 15, 30, and 60 L/min, respectively. Of the total DF, 65-70% is deposited in the oral airway for both vapors. Deposition is localized at various sites within the upper airway structure, with a maximum DEF of 1.5 for MTBE and 7.8 for ethanol. Local deposition patterns did not change with inhalation conditions, but DF and the maximum DEF increased with diffusivity, solubility, and the degree of airway wall absorption of vapors, as shown by a greater deposition of ethanol than MTBE. The vapor deposition efficiency as expressed by the dimensionless mass transfer coefficient correlated well with a product of Reynolds (Re) and Schmidt (Sc) numbers. In conclusion, MTBE and ethanol vapors deposit substantially in the upper airway structure with a marked enhancement of dose at local sites, and the deposition dose may be reasonably estimated by a functional relationship with dimensionless fluid flow and diffusion parameters.

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Experimental Exposure to Methyltertiary-Butyl Ether

Cited by 52 publications

References 14 publications

Single-walled carbon nanotubes as an effective adsorbent in solid-phase microextraction of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether from human urine

Single-walled carbon nanotubes as an effective adsorbent in solid-phase microextraction of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether from human urine

Clearing the Air: Using Scientific Information to Regulate Reformulated Fuels

Transport and Uptake of MTBE and Ethanol Vapors in a Human Upper Airway Model

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