Nonattainment Area - Sulfur Dioxide (SO2 - 2010 Standard)

The Nonattainment Area - Sulfur Dioxide (SO2-2010) dataset was updated on June 30, 2026 by the Environmental Protection Agency (EPA) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). This dataset provides detailed information about areas identified in the U.S. where sulfur oxide levels have not met the National Ambient Air Quality Standards (NAAQS) established in 2010 for sulfur oxides and have been designated "nonattainment areas (NAA)". A second round of area designations was effective September 12, 2016. A supplement to the second round of area designations was effective January 17, 2017. A third round of area designations was effective April 9, 2018. A fourth round of area designations was effective April 30, 2021. These data are weekly from an OAQPS internal database. However, that does not necessarily mean the data have changed. For more information about this non-attainment area, please see the website https://www.epa.gov/green-book/green-book-sulfur-dioxide-2010-area-information. A data dictionary, or other source of attribute information, is accessible at https://doi.org/10.21949/1529069未达标区域——二氧化硫（SO₂-2010）数据集由美国环境保护署（Environmental Protection Agency, EPA）于2026年6月30日更新，隶属于美国运输部（U.S. Department of Transportation, USDOT）、运输统计局（Bureau of Transportation Statistics, BTS）旗下的国家交通地图集数据库（National Transportation Atlas Database, NTAD）。本数据集详细记录了美国境内二氧化硫浓度未达到2010年版《国家环境空气质量标准（National Ambient Air Quality Standards, NAAQS）》所规定限值，并被划定为‘未达标区域（Nonattainment Areas, NAA）’的相关信息。该区域的划定工作共分为四轮：第二轮区域划定公告于2016年9月12日正式生效，其配套补充公告于2017年1月17日生效；第三轮区域划定公告于2018年4月9日生效；第四轮区域划定公告于2021年4月30日生效。本数据集的数据源自空气质量规划与标准办公室（Office of Air Quality Planning and Standards, OAQPS）的内部数据库，采用周度更新频率，但这并不意味着数据集内容必然发生变更。如需了解该未达标区域的更多详情，请访问以下链接：https://www.epa.gov/green-book/green-book-sulfur-dioxide-2010-area-information。属性信息相关的数据字典或其他参考资料可通过下述链接获取：https://doi.org/10.21949/1529069