San Diego State University researchers unveiled early results on Tuesday of a new survey about what it’s like to live near the sewage-laced Tijuana River.
More than 500 people living in Imperial Beach, Nestor, San Ysidro and as far north as Coronado and National City took the Healthy Water, Healthy Air survey. It opened in September 2024 and closed on June 15.
“Nausea, headaches, brain fog, stomach issues, anxiety, tiredness, sleep problems: a lot of this has been reported by people taking the health survey,” said Paula Stigler Granados, one of the lead researchers behind the survey and an associate professor at SDSU.
The health survey isn’t the first to capture a snapshot of how badly the pollution is affecting people's lives. In 2024, the Centers for Disease Control and Prevention (CDC) and San Diego County surveyed about 200 households over three days. That same year, a separate branch of the CDC spent one month surveying anyone who lived, worked or visited areas near the pollution.
While they produced “incredibly valuable data,” Stigler Granados said those health surveys were taken when sewage pollution in the river was low and could not show what kind of effects major sewage spills might have on the public.
But a year and a half’s worth of data shows trends. And it confirms that even very low levels of hydrogen sulfide, a byproduct of sewage that smells like rotten eggs, can affect people’s well-being.
“People feel a one-minute spike of hydrogen sulfide just as much as they feel an elongated one-hour (spike),” she said.
Early results show that when sewage spills into the river, more hydrogen sulfide is detected, and more people feel ill. Conditions worsen depending on the weather and season.
“The beginning of fall, end of summer, is when people have more water recreational contact,” said Granados. “People are also outside more often. People tend to have, without air conditioning, more windows and doors open.”
Last year, a separate study revealed that pollution in the river becomes airborne. The Healthy Water, Healthy Air survey is the latest alert that the Tijuana River, a seasonal river running with sewage and other toxic chemicals year-round, is a top source of pollution for people living nearby.
Granados said her team’s survey further validates residents’ long-dismissed concerns and can underscore the importance of ending the decades-long crisis.
To definitively connect health issues to the pollution, the health care system will have to create a way to monitor and document low-level, chronic symptoms that don’t necessarily show up in emergency rooms, she added. A new program SDSU will lead, called ECHO and modeled after the University of New Mexico’s ECHO project, will soon train local physicians how to monitor sewage-related health issues.
“My hope is that more physicians will understand what to look for in their patient populations, what questions to ask, how to write it down in the medical records,” said Granados.
For now, the public deserves to see the survey results and feel empowered to take action, Granados said.
“If you're in a school where you feel like this is happening frequently in the mornings, talk to your school principals about, you know, making sure the filtration systems are working and making sure you have notifications going out to the families,” she said.
The findings are being peer reviewed and should be published soon, researchers said.
