U.S. flag An official website of the United States government.
Official websites use .gov

A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS

A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

i

Deducing Atmospheric Conditions That Contribute to Elevated Pollution Events in the Salton Sea Air Basin



Select the Download button to view the document
Please click the download button to view the document.

Details

  • Personal Author:
  • Description:
    The Salton Sea Air Basin (SSAB) has struggled to comply with National Ambient Air Quality Standards (NAAQS) for three federally regulated air pollutants: ozone, PM2.5, and PM10. Seasonal and diurnal patterns are presented along with their long-term decadal trends to better understand the relationship between the meteorological setting and air pollution levels as well as their deviations. This analysis revealed that ozone exceedances are no longer dominated by regulated NOx emissions but rather are primarily controlled by regional agricultural soil emissions. These emissions are also likely influenced by stratospheric ozone transport to the deep convective boundary layers unique to the area. Observed peak ozone levels are still approx. 2-5 ppb lower on weekends indicative of a NOx-limited regime during the warm season. This implies that local ozone production is directly dependent on NOx levels, which emphasizes the need to address unregulated sources of NOx pollution such as those from heavily fertilized, arid agricultural soils. Additionally, strong correlations of PM2.5 with NOx, PM10, and CO, indicate that influences from combustion sources as well as agricultural soils, secondary formation, and mechanical processes are all important sources of PM2.5 production in Calexico, the main city of PM2.5 nonattainment on the southern border with Mexico. These PM2.5 exceedances occur in winter months, when low ventilation accumulates localized PM2.5 precursor emissions. Source apportionment of PM2.5 was assessed using non-negative matrix factorization of data from the Chemical Speciation Network (CSN) site in Calexico. The CSN data analysis for Calexico identifies biomass burning as the dominant source of high PM2.5 concentrations, followed by agricultural soil emissions and wind-blown dust. In the immediate vicinity of the Salton Sea, less frequent PM2.5 exceedances seem to be associated with occasional windstorms. Further, analysis of PM10 exceedance days indicates that high winds, primarily westerly, are a critical factor, and the low PM2.5/PM10 ratios suggest minimal contribution from photochemical or combustion sources. Furthermore, the correlation of PM10 with wind speed across various sites underscores the importance of dust resuspension and soil erosion. This comprehensive assessment highlights the complexity of air quality problems in the SSAB. Additionally, it emphasizes the need for targeted and localized air quality management strategies for this region which, despite its low population, suffers some of the worst air pollution impacts in the state of California. [Description provided by NIOSH]
  • Subjects:
  • Keywords:
  • ISSN:
    1352-2310
  • Document Type:
    Text
  • Funding:
    Cooperative Agreement
  • Genre:
    Journal Article
  • Place as Subject:
  • CIO:
    National Institute for Occupational Safety and Health (NIOSH)
  • Topic:
    Workplace Safety & Health
  • Location:
    North America
  • Volume:
    352
  • NIOSHTIC Number:
    nn:20070859
  • Citation:
    Atmos Environ 2025 Jul; 352:121191
  • Email:
    icfaloona@ucdavis.edu
  • CAS Registry Number:
    Ozone (CAS RN 10028-15-6)
  • Federal Fiscal Year:
    2025
  • NORA Priority Area:
    Agriculture, Forestry and Fishing
  • Performing Organization:
    University of California - Davis
  • Peer Reviewed:
    True
  • Start Date:
    20010930
  • Source Full Name:
    Atmospheric Environment
  • End Date:
    20270929
  • Collection(s):
  • Main Document Checksum:
    urn:sha-512:d5a93dc32679a63d449f1db4023f1084e3663c49feded955d92b1d09f6b9334c96dd0887f25e78b32bd5dc1ba4e336e1f5befa2e14ad36a9c01293e3618efa90
  • Download URL:
  • File Type:
    Filetype[PDF - 11.01 MB ]
PREVIOUS
ON THIS PAGE
Details
CDC STACKS serves as an archival repository of CDC-published products including scientific findings, journal articles, guidelines, recommendations, or other public health information authored or co-authored by CDC or funded partners.

As a repository, CDC STACKS retains documents in their original published format to ensure public access to scientific information.
BACK TO TOP