Recent Advances in Understanding Ozone Pollution Near Large Water Bodies
EM – October 2020: The four studies highlighted in this issue of EM exemplify inter-agency and inter-state cooperative efforts to advance scientific understanding of air pollution near the land–water interface.by Susan Wierman, Leiran Biton, and Joel Dreessen
The interplay between emissions and meteorology near large water bodies requires in-depth technical analysis. Research has shown that high ozone (O3) concentrations can form over water and affect both nearby and more distant coastal areas, and that high-resolution air quality models are needed to represent local conditions more accurately. Though major regional and local reductions in O3 precursors have significantly improved air quality in the eastern United States, episodic high O3 events persist, particularly over large bodies of water and adjacent coastal areas, contributing to violations of the federal O3 standard. Motivating the four studies described in this issue were questions about the relative importance of emissions from nearby industrial or urban centers versus more distant sources of air pollution, the potential to use advanced monitoring techniques to better understand pollution episodes, and the importance of improving the ability of air quality models to simulate the fine-scale dynamics of the land–water interface. Scientists continue to stress the importance of measuring O3 aloft (as was done in studies described here) to help resolve questions about local and long-distance transport of O3 and precursor pollutants.
The U.S. Environmental Protection Agency (EPA) has recognized the value of short-term special studies, such as those described in this issue. When EPA adopted the 70 parts per billion (ppb) 8-hr O3 National Ambient Air Quality Standard (NAAQS) in 2015, the agency also substantially revised the requirements for enhanced monitoring plans for O3 and its precursors. To help states develop plans to comply with new monitoring requirements, in 2017 EPA published a “Technical Note” describing optional long-term monitoring methods, but also encouraging states to work collaboratively with other agencies to conduct short-term intensive monitoring campaigns if needed to help understand the formation of ozone in their particular areas. The results of special studies like these, along with other analytical techniques and information, can help air quality managers develop effective pollution control measures.
Continue reading the full October 2020 issue of EM.