Impact of a new gasoline benzene regulation on ambient air pollutants in Anchorage, Alaska. (May 2016)

• Record Type: Journal Article
• Authors: Yano, Yuriko; Morris, Stephen S.; Salerno, Christopher; Schlapia, Anne M.; Stichick, Mathew
• Is Part Of: Atmospheric environment. Volume 132(2016)
• Page Start: 276
• Page End: 282
• Publication Date: 2016-05
• Subjects: Ambient air benzene concentration -- Anchorage Alaska -- Gasoline benzene content -- Gasoline fuel standard -- Hazardous urban air pollutants -- Mobile source air toxics; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2016.02.039
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: The purpose of this study was to quantify the impact of a new U.S. Environmental Protection Agency (EPA) standard that limits the amount of benzene allowed in gasoline on ambient benzene concentrations. This new standard, together with two companion regulations that limit cold-temperature automotive emissions and the permeability of portable fuel containers, was expected to lower the levels of ambient benzene and other volatile organic compounds (VOCs) nationwide. In this study the impact of the gasoline benzene standard was evaluated in Anchorage, Alaska in a two-phase ambient air monitoring study conducted before and after the new gasoline standard was implemented. Gasoline sold by Anchorage retailers was also evaluated in each phase to determine the content of benzene and other gasoline components. The average benzene content in Anchorage gasoline was reduced by 70%, from 5.05% (w/w) to 1.53% (w/w) following the implementation of the standard. The annual mean ambient benzene concentration fell by 51%, from 0.99 ppbv in Phase 1 to 0.49 ppbv in Phase 2. Analysis suggests the change in gasoline benzene content alone reduced benzene emissions by 46%. The changes in toluene, ethylbenzene, and xylene content in gasoline between Phase 1 and 2 were relatively small and the differences in the mean ambient concentrations of these compounds between phases were modest. Our results suggest that cold winter communities in high latitude and mountainous regions may benefit more from the gasoline benzene standard because of high benzene emissions resulting from vehicle cold start and a tendency to develop atmospheric stagnation conditions in the winter. Graphical abstract: Highlights: The impact of a new EPA limit on benzene in gasoline on ambient air was evaluated. Average gasoline benzene content was reduced by 70% as a result of the new limit. The new benzene limit alone reduced the ambient benzene concentration by 46%.