San Diego State University researchers, bolstered by a grant from the Prebys Foundation, are launching an environmental monitoring system to detect pathogens in the Tijuana River, along with a community survey to determine the effect on public health.
The initiative, part of a broader $872,000 commitment, involves SDSU’s School of Public Health and SDSU Imperial Valley in addressing this escalating environmental and public health threat, according to a press release from the university.
With $260,000 in initial funding, SDSU researchers aim to close knowledge gaps about the contaminants flowing from the Tijuana River into the air and water of Coronado, Imperial Beach, San Ysidro and other South Bay communities.
This research will focus on the presence of dangerous pathogens and chemicals, many of which pose significant risks to the health of local residents, including children, pregnant women and frontline workers.
Closing the gap
The Tijuana River’s pollution has long been a source of concern, with evidence of antibiotic-resistant microbes and hazardous chemicals making their way into the ocean, where currents transport contaminants north to San Diego County beaches.
However, comprehensive data on how these pollutants affect air quality and public health remains elusive.
“This grant is pivotal in advancing our understanding of how pollutants travel from water to air in the Tijuana River region,” said SDSU School of Public Health associate professor Paula Stigler Granados in a press release.
The findings, she notes, could be instrumental in pushing for much-needed upgrades to sewage treatment facilities along the border.
As the school’s chair of environmental health and the study’s principal investigator, Stigler Granados said researchers will gather survey responses to identify health patterns for at least a year, which could lead to a comprehensive epidemiological investigation.
The community survey is set to go out in about three weeks.
Stigler Granados said that her lab will also conduct non-targeted chemical analyses and metagenomic sequencing to detect various chemicals and pathogens in air, water and soil samples.
A group effort
In collaboration with SDSU environmental health professor Eunha Hoh, the researchers will test silicone wristbands for airborne chemicals and analyze DNA from pathogens to identify potential contaminants.
The wristbands, Stigler Granados explained, “absorb chemicals in the atmosphere and what people are being exposed to. We’ll go out and hang them on fences to see what’s in the air.”
Stigler Granados said the research team is “very interested in antibiotic-resistant bacteria” and viruses like norovirus, which are highly contagious but often not reported.
Additionally, the team will be looking at school absences, clinic records and other health data to identify patterns related to environmental exposure and illness.
On August 19, the San Diego State University HealthLINK Center received a $22 million grant from the National Institutes of Health that will support a study in San Ysidro, where researchers will collect dust and air samples and test for environmental contaminants, particularly those linked to pollution from the Tijuana River.
“[Our study] is sort of the pilot to that HealthLINK grant,” Stigler Granados said.
Her lab is also partnering with Kim Prather, the University of California San Diego’s chair in atmospheric chemistry and professor at Scripps Institution of Oceanography, who has a lab conducting a 30-day air sampling study to measure hydrogen sulfide levels.
Stigler Granados said UCSD is currently sampling and anticipates having her lab support them with preliminary sampling this week.
“Hopefully our data will complement [Prather’s lab’s findings],” Stigler Granados said.
In sum, Stigler Granados said, at least 10-15 scientists are working on this research, not including the doctoral and master students involved.
“We’re also going to rely on the data that we’re collecting from multiple partners and agencies, and some of the county and state agencies as well, to put all the data together,” Stigler Granados said. “It’s sort of a paint-by-number… until we get the full picture.”
Partners of the study include but are not limited to The Surfrider Foundation, YMCA, Imperial Beach Mayor Paloma Aguirre’s office, UCSD, Casa Familiar and the California Department of Public Health.
From data to action
Stigler Granados emphasized that while quick data release is important, analyzing complex chemical samples can take three to six months due to the need to accurately identify thousands of chemical fingerprints.
“The question of the day is, ‘How fast can the data come out?’ I think the release of data needs to be pretty immediate, however, a deep dive into the data is going to take some time,” she said. “Our team is trying to figure out how we explain the findings without creating panic and empower people to have the ability to do something about it.”
A national disaster
As faculty and graduate students at SDSU delve into this research, Stigler Granados said, she hopes their work will not only inform local policymakers and advocacy groups but also strengthen the community’s ability to respond to the ongoing pollution crisis.
“My hope is that we are able to communicate a better picture of what’s going on,” Stigler Granados said. “Ultimately, what we’re really asking for is for them [policymakers] to call this [Tijuana River Pollution] a national disaster.”
Last month, Congress approved $210 million in the 2024 Water Resources Development Act for San Diego County and the Tijuana River Valley watershed.
This funding aims to alleviate the financial shortfall for rehabilitating the South Bay International Wastewater Treatment Plant. That project is designed to prevent sewage overflows that routinely contaminate beaches from Tijuana to Coronado.
A $42.4 million dollar contract was awarded in August to a contractor to begin the design for repair at the plant.
Grant Oliphant, CEO of the Prebys Foundation, emphasized the nonprofit organization’s commitment to supporting SDSU’s School of Public Health in addressing this critical public health issue.
In the press release, he said “This partnership underscores our dedication to advancing research that helps to protect and enhance the health and wellbeing of our communities.”
