Department of Civil and Environmental Engineering, University of California , Berkeley, California 94720, United States.
Environ Sci Technol. 2013 Sep 17;47(18):10171-8. doi: 10.1021/es401049x. Epub 2013 Aug 27.
Ocean-going vessels burning high-sulfur heavy fuel oil are an important source of air pollutants, such as sulfur dioxide and particulate matter. Beginning in July 2009, an emission control area was put into effect at ports and along the California coastline, requiring use of lower sulfur fuels in place of heavy fuel oil in main engines of ships. To assess impacts of the fuel changes on air quality at the Port of Oakland and in the surrounding San Francisco Bay area, we analyzed speciated fine particle concentration data from four urban sites and two more remote sites. Measured changes in concentrations of vanadium, a specific marker for heavy fuel oil combustion, are related to overall changes in aerosol emissions from ships. We found a substantial reduction in vanadium concentrations after the fuel change and a 28-72% decrease in SO2 concentrations, with the SO2 decrease varying depending on proximity to shipping lanes. We estimate that the changes in ship fuel reduced ambient PM2.5 mass concentrations at urban sites in the Bay area by about 3.1 ± 0.6% or 0.28 ± 0.05 μg/m(3). The largest contributing factor to lower PM mass concentrations was reductions in particulate sulfate. Absolute sulfate reductions were fairly consistent across sites, whereas trace metal reductions were largest at a monitoring site in West Oakland near the port.
远洋船舶燃烧高硫重质燃料油是空气污染物（如二氧化硫和颗粒物）的一个重要来源。自 2009 年 7 月起，在港口和加利福尼亚海岸线实施了排放控制区，要求船舶主机使用低硫燃料替代重质燃料油。为了评估燃料变化对奥克兰港和旧金山湾区周边空气质量的影响，我们分析了来自四个城市站点和两个更偏远站点的细颗粒浓度数据。测量到的钒浓度变化（一种重质燃料油燃烧的特定标志物）与船舶气溶胶排放的总体变化有关。我们发现燃料变化后钒浓度显著降低，SO2 浓度降低了 28-72%，SO2 浓度的降低取决于与航道的距离。我们估计，船舶燃料的变化使湾区城市站点的环境 PM2.5 质量浓度降低了约 3.1±0.6%或 0.28±0.05μg/m3。降低 PM 质量浓度的最大因素是硫酸盐颗粒的减少。硫酸盐的绝对减少在各个站点都相当一致，而在奥克兰港附近的西奥克兰监测站点，痕量金属的减少最大。
