San Antonio Interstate 35 Air Monitoring Station, San Antonio, Texas

San Antonio Interstate 35 is an air monitoring station located at 9904 IH 35 N in San Antonio, Texas, within Bexar County. Operated by the Texas Commission on Environmental Quality (TCEQ), this station is part of the NEAR ROAD network, which focuses on monitoring air quality near major roadways to assess traffic-related pollution. As a roadside monitor, it plays a key role in understanding local exposure to vehicle emissions. The station operates under the regulatory framework of the U.S. Environmental Protection Agency's (EPA) Air Quality System (AQS), which sets standards for criteria pollutants such as ozone, particulate matter, carbon monoxide, nitrogen dioxide, and sulfur dioxide. NEAR ROAD stations are strategically sited to capture pollutant concentrations in high-traffic areas, providing data that supports compliance with National Ambient Air Quality Standards (NAAQS). The station's last reported sample date is August 31, 2025, indicating ongoing data collection. This monitoring station contributes to the broader environmental monitoring network in Texas, a state with significant industrial and transportation activity. The data collected helps inform public health advisories, urban planning, and regulatory decisions. By providing near-road measurements, the station fills a critical gap in understanding the impact of traffic emissions on air quality in San Antonio, a major metropolitan area.

San Antonio Interstate 35 is situated in a region with high traffic density, making it representative of urban roadside environments. The station's location along Interstate 35, a major north-south corridor, allows it to capture emissions from heavy-duty diesel trucks and passenger vehicles. This context is important for assessing exposure to nitrogen dioxide and fine particulate matter, which are linked to respiratory and cardiovascular health effects. The NEAR ROAD network design ensures siting representativeness for near-road populations.