Nonattainment Area - Particulate Matter - 2.5 Annual (1997 Standard)

The Nonattainment Area - Particulate Matter-2.5 Annual (1997) 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 annual particulate matter (PM2.5) levels have not met the National Ambient Air Quality Standards (NAAQS) established in 1997 for particulate matter (PM2.5) and have been designated "nonattainment areas (NAA)". The 1997 Primary Annual PM-2.5 NAAQS is revoked in attainment and maintenance areas for that NAAQS. For additional information see the PM-2.5 NAAQS SIP Requirements Final Rule, effective October 24, 2016 (https://www.govinfo.gov/link/fr/81/58009). 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-25-1997-area-information. A data dictionary, or other source of attribute information, is accessible at https://doi.org/10.21949/1529068本1997版年度细颗粒物（PM2.5）未达标区域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）/美国运输统计局（Bureau of Transportation Statistics, BTS）国家交通地图集数据库（National Transportation Atlas Database, NTAD）。该数据集详细记录了美国境内年度细颗粒物（PM2.5）浓度未达到1997年制定的细颗粒物国家环境空气质量标准（National Ambient Air Quality Standards, NAAQS），并被划定为“未达标区域（nonattainment areas, NAA）”的相关区域信息。针对该标准的达标与维持区域，1997年版细颗粒物一级年度国家环境空气质量标准已被废止。如需获取更多信息，请参阅2016年10月24日生效的《细颗粒物国家环境空气质量标准州实施计划要求最终规则》（https://www.govinfo.gov/link/fr/81/58009）。本数据集的数据取自美国环境保护署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，更新周期为每周一次，但这并不代表数据集内容已发生变动。如需了解该未达标区域的更多详情，请访问https://www.epa.gov/green-book/green-book-pm-25-1997-area-information。可通过https://doi.org/10.21949/1529068获取数据字典或其他属性信息来源。