Tijuana River Pollution Worsens San Diego Air Quality

A UC San Diego-led study published in Science Advances reveals that pollution from the Tijuana River is degrading air quality along San Diego County's coastline, reaching as far north as La Jolla. Researchers found that fine particles from untreated sewage, industrial waste, stormwater runoff, and chemicals, including drug residues like benzoylecgonine, become airborne via sea spray and river turbulence. Air and water samples collected in 2020 at the U.S.-Mexico border, Imperial Beach, and La Jolla detected these pollutants. The study highlights that the Tijuana River's pollution now poses a significant risk to air quality and public health, not just water quality. Researchers call for further study of health impacts and greater attention to the air quality aspect of cross-border contamination. The ongoing issue has been worsened by population growth, heavy rainfall, and deteriorating wastewater infrastructure on both sides of the border.