Arnold West Air Monitoring Station, Arnold, Missouri | United States Environmental Monitoring

Arnold West is an air monitoring station located at 1709 Lonedell Drive in Arnold, Missouri, within Jefferson County. Operated under the Missouri Laboratory Services Program, this station is part of the broader US EPA Air Quality System (AQS) network, which monitors criteria pollutants and other atmospheric parameters to ensure compliance with National Ambient Air Quality Standards (NAAQS). The station's last reported sample date was May 31, 2025, indicating recent operational activity. As an air monitoring station, Arnold West likely measures pollutants such as ozone, particulate matter (PM2.5 and PM10), nitrogen dioxide, sulfur dioxide, carbon monoxide, and lead, though specific parameters are not detailed. The station operates within the regulatory framework of the Clean Air Act, with data used by state and federal agencies for air quality management and public reporting. In Missouri, air monitoring is coordinated by the Missouri Department of Natural Resources, which oversees a network of stations to assess regional air quality trends. The environmental significance of Arnold West lies in its contribution to long-term air quality surveillance in the St. Louis metropolitan area. Data from this station supports health advisories, regulatory compliance, and research on pollution sources and transport. Continuous monitoring helps track progress toward reducing emissions and protecting public health, particularly in communities near industrial and urban areas.

Arnold West operates in a suburban setting within the St. Louis metro area, where air quality is influenced by transportation emissions, industrial activity, and meteorological conditions. The station's siting is representative of residential exposure, providing data on population-level pollutant concentrations. Monitoring at this location supports assessment of compliance with NAAQS and contributes to regional air quality trend analysis. The station's parameter coverage, though unspecified, typically includes criteria pollutants and may extend to speciation or meteorological measurements depending on network objectives.