The stench from the polluted Tijuana River is so bad it kept a researcher up at night

"As the river flows through Baja California, it takes in untreated sewage and industrial waste from Tijuana, then crosses the U.S.-Mexico border into San Diego County, where beaches are regularly closed because the surf is filled with bacteria from the river. Researchers have now gained new insights into how that water pollution is creating air pollution that besets nearby communities."

"Using an air-quality monitor nearly half a mile from the river in the community of Nestor, scientists found extremely high levels of hydrogen sulfide, a gas linked to sewage that smells like rotten eggs. "It validates what the community has been saying for so long," said Benjamin Rico, a doctoral researcher at UC San Diego and co-author of the study. The findings show "their complaints are real and valid, and need to be listened to," he said."

Measurements near the Tijuana River detected extremely high hydrogen sulfide levels in air around nearby communities. The river takes in untreated sewage and industrial waste from Tijuana and crosses into San Diego County, contributing bacteria that prompt frequent beach closures. Air monitoring in Nestor, located about half a mile from the river, identified hydrogen sulfide concentrations linked to sewage odor and reported symptoms including eye and nasal irritation, headaches, and difficulty breathing. A foamy, churning section where water falls from culverts generates bubbles that burst and aerosolize fine pollutant particles, creating an airborne hot spot. September 2024 recordings showed exposures exceeding California air-quality standards.

Read at Los Angeles Times