Nonattainment Area - Particulate Matter - 2.5 24 hr (2006 Standard)

The Nonattainment Area - Particulate Matter-2.5 24 hr (2006) dataset was updated on May 31, 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 24 hour (daily) particulate matter (PM2.5) levels have not met the National Ambient Air Quality Standards (NAAQS) established in 2006 for particulate matter (PM2.5) and have been designated "nonattainment areas (NAA)". 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-pm-25-2006-area-information. A data dictionary, or other source of attribute information, is accessible at https://doi.org/10.21949/1529067细颗粒物（PM2.5）24小时标准（2006年版）未达标区域数据集于2026年5月31日由美国环境保护署（Environmental Protection Agency, EPA）完成更新，隶属于美国运输部（U.S. Department of Transportation, USDOT）与美国运输统计局（Bureau of Transportation Statistics, BTS）共建的国家交通地图集数据库（National Transportation Atlas Database, NTAD）。本数据集详细收录了美国境内24小时（日均）细颗粒物（PM2.5）浓度未达到2006年版国家环境空气质量标准（National Ambient Air Quality Standards, NAAQS），且被划定为‘未达标区域（nonattainment areas, NAA）’的相关区域信息。该数据的更新周期为周度，数据源为美国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，但这并不代表数据集内容发生了变更。如需了解该未达标区域的更多详细信息，请访问官网：https://www.epa.gov/green-book/green-book-pm-25-2006-area-information。数据字典或其他属性信息可通过以下链接获取：https://doi.org/10.21949/1529067