Toxic waste dumped into the Tijuana River can travel up to 7 times farther than previously thought before evaporating into the atmosphere, significantly degrading air quality across a 20-mile radius in San Diego, according to a new study from UC Riverside. Published in Scientific Reports, the research details how this untreated sewage, which is a mix of household wastewater, industrial discharge, and urban runoff, enters the Pacific Ocean at Imperial Beach. These wastewater chemicals remain submerged in ocean currents long enough to drift northward along the San Diego coastline before venting into the atmosphere. This mechanism explains why pollution linked to the Tijuana River was found near the Scripps Institution of Oceanography pier in La Jolla, approximately 22 miles north of the river’s mouth.