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Methyl Tertiary Butyl Ether (methyl + tertiary_butyl_ether)
Selected AbstractsThe MTBE Threat to Our Water Supply: How to Detect and Remediate ItENVIRONMENTAL QUALITY MANAGEMENT, Issue 4 2001David Kahler Methyl tertiary butyl ether, a gasoline additive once used to reduce air pollution, is now contaminating water sources around the United States. Monitoring for this chemical,and remediating it where it is found,should be an environmental priority. © 2001 John Wiley & Sons, Inc. [source] Occupational exposure to methyl tertiary butyl ether in relation to key health symptom prevalence: the effect of measurement error correctionENVIRONMETRICS, Issue 6 2003Aparna P. Keshaviah Abstract In 1995, White et al. reported that methyl tertiary butyl ether (MTBE), an oxygenate added to gasoline, was significantly associated with key health symptoms, including headaches, eye irritation, and burning of the nose and throat, among 44 people occupationally exposed to the compound and for whom serum MTBE measurements were available (odds ratio (OR),=,8.9, 95% CI,=,[1.2, 75.6]). However, these serum MTBE measurements were available for only 29 per cent of the 150 subjects enrolled. Around the same time, Mannino et al. conducted a similar study among individuals occupationally exposed to low levels of MTBE and did not find a significant association between exposure to MTBE and the presence of one or more key health symptoms among the 264 study participants (OR,=,0.60, 95% CI,=,[0.3, 1.21]). In this article, we evaluate the effect of MTBE on the prevalence of key health symptoms by applying a regression calibration method to White et al.'s and Mannino et al.'s data. Unlike White et al., who classified exposure using actual MTBE levels among a subset of the participants, and Mannino et al., who classified exposure based on job category among all participants, we use all of the available data to obtain an estimate of the effect of MTBE in units of serum concentration, adjusted for measurement error due to using job category instead of measured exposure. After adjusting for age, gender and smoking status, MTBE exposure was found to be significantly associated with a 50 per cent increase in the prevalence of one or more key health symptoms per order of magnitude increase in blood concentration on the log10 scale, using data from the 409 study participants with complete information on the covariates (95% CI,=,[1.00, 2.25]). Simulation results indicated that under conditions similar to those observed in these data, the estimator is unbiased and has a coverage probability close to the nominal value. The methodology illustrated in this article is advantageous because all of the available data were used in the analysis, obtaining a more precise estimate of exposure effect on health outcome, and the estimate is adjusted for measurement error due to using job category instead of measured exposure. Copyright © 2003 John Wiley & Sons, Ltd. [source] US braces itself for gasoline and diesel shortagesOIL AND ENERGY TRENDS, Issue 3 2006Article first published online: 9 MAR 200 New fuel regulations that are progressively being introduced in the US from the beginning of this year are likely to lead to radical changes in the gasoline and diesel fuel markets. The main change for gasoline is the replacement of methyl tertiary butyl ether (MTBE) by ethanol, whilst for diesel the principal development is the reduction in the permitted sulphur content. A shortage of the new fuels could increase price volatility and drive up prices. This is not a pleasant prospect for the White House, already under criticism for another energy plan: to cut imports of crude oil from the Middle East. [source] In situ remediation of MTBE utilizing ozoneREMEDIATION, Issue 1 2002Jeffrey C. Dey There has been a great deal of focus on methyl tertiary butyl ether (MTBE) over the past few years by local, state, and federal government, industry, public stakeholders, the environmental services market, and educational institutions. This focus is, in large part, the result of the widespread detection of MTBE in groundwater and surface waters across the United States. The presence of MTBE in groundwater has been attributed primarily to the release from underground storage tank (UST) systems at gasoline service stations. MTBE's physical and chemical properties are different than other constituents of gasoline that have traditionally been cause for concern [benzene, toluene, ethylbenzene, and xylenes (BTEX)]. This difference in properties is why MTBE migrates differently in the subsurface environment and exhibits different constraints relative to mitigation and remediation of MTBE once it has been released to subsurface soils and groundwater. Resource Control Corporation (RCC) has accomplished the remediation of MTBE from subsurface soil and groundwater at multiple sites using ozone. RCC has successfully applied ozone at several sites with different lithologies, geochemistry, and concentrations of constituents of concern. This article presents results from several projects utilizing in situ chemical oxidation with ozone. On these projects MTBE concentrations in groundwater were reduced to remedial objectives usually sooner than anticipated. © 2002 Wiley Periodicals, Inc. [source] |