It was the week that finally may have shifted the momentum to work collectively, rather than separately, to understand the health effects of the decades-long sewage crisis at the U.S.-Mexico border.
It began the first Friday of September amid a record-breaking heatwave, when researchers from UC San Diego and San Diego State University temporarily pulled their teams from the Tijuana River Valley where they were collecting data because of reportedly unhealthy levels of hydrogen sulfide, a toxic gas that emits a noxious rotten egg odor. Public health was at risk, they said.
It ended a week later with what turned out to be an inaccurate report by one of those researchers of potentially lethal levels of another gas, hydrogen cyanide. The assertion led South County schools to keep children inside, members of Congress to renew calls for a federal state of emergency and the county to immediately deploy its own hazmat team to verify the gas levels.
The county team found no evidence of hydrogen cyanide and slightly elevated levels of hydrogen sulfide. Local, state and federal agencies conferred and were in lockstep with their subsequent message to the public that their health faced no immediate threat. But the mixed messaging confused and infuriated many, both in the community and the government, who often were at odds on how best to gauge the public health risk from repeated flows of sewage.
But it appears a turning point is at hand: all of the stakeholders who have worked mostly independently in their areas of expertise for months are now making efforts to work together.
On Wednesday, county, state and federal environmental and health agencies met with Kim Prather, UCSD atmospheric chemist and Paula Stigler Granados, an environmental health professor at San Diego State University, who are spearheading cross-border pollution research. They agreed to execute several efforts:
Data sharing: Researchers are open to sharing their raw data with the agencies, but with some caveats, including whether they can agree to not openly share data without each others’ consent.
It’s uncommon for researchers to distribute what they’ve gathered before the data has been peer-reviewed and published in a scientific journal, but the county public health department argued that health departments across the nation “routinely confidentially access health records to guide public health investigations and recommendations.”
Researchers have shared snippets of preliminary data, but the county says it needs to review what’s been collected and understand researchers’ methodology to expand its response to the sewage crisis.
“As academics, we are sharing our data with the county and others out of just a courtesy because we are wanting to assist with this health emergency,” said Stigler Granados. “However, this is also our grad and doctoral students’ data so we need some sort of agreement.”
Developing an alert system: The groups want to develop a way to alert the public in advance when air quality worsens due to toxic gases, akin to when smog or smoke alerts are issued. The challenge, officials said, is that while thresholds and protocols for hydrogen sulfide exist for odor nuisances and indoor workplaces, there are no clear guidelines for this unique situation.
Setting up air monitoring: Groups also reiterated the urgent need to have a comprehensive, continuing air quality monitoring system at the Tijuana River and adjacent communities. The San Diego County Air Pollution Control District will lead the effort, which has been stalled for months due to myriad paperwork issues, district officials said last month.
Last Wednesday’s meeting, convened by county Supervisor Terra Lawson-Remer, comes after Ankita Kadakia, interim public health officer formally requested on Sept. 12 to meet with researchers.
“Our goal is to collaborate with you and others in the community in ways that complement the strengths of all individuals and organizations involved,” Kadakia wrote in her letter. “We are committed to partnering with each other to make a concentrated effort to support our South County residents.”
On Thursday, Prather said, “We’re in a much better place. It was very clear that everyone is under a lot of pressure, but everyone is doing their best to work together. Everyone acknowledged that (air quality) is sporadic in that sometimes it is healthy and sometimes it isn’t.”
The joint efforts follow what had been months of planning by a Tijuana River Valley task force, of which the researchers are a part, to investigate the exposures to polluted water and air.
It was clear the task force and the county public health department were addressing the sewage crisis separately and in their own ways. Then, earlier this summer, the Board of Supervisors directed the county to collaborate with the research group in collecting more health data.
The stakeholders had been meeting often to share updates, including on Sept. 5, when researchers told county officials they had found concerningly high levels of hydrogen sulfide. Task force members questioned why the county did not respond to their reports swiftly. So, the group decided they would announce their findings and call on the government for emergency assistance at a Sept. 9 press conference.
But things ramped up hours before the scheduled press conference.
It was nearly 5 a.m. on Sept. 9 when San Diego County and federal officials were alerted to “dangerously high” readings of hydrogen cyanide, reportedly detected in the Tijuana River Valley.
“They need help!!” Stigler Granados said in the early email to officials about the communities near where gas meter alarms indicated the presence of hydrogen cyanide and hydrogen sulfide.
By 10 a.m., Stigler Granados announced at the press conference the “spiked” levels of hydrogen cyanide. Prather shared that she had pulled her research team from the field nights prior because of high hydrogen sulfide readings and the unbearable rotten egg odors.
Local schools immediately limited outdoor activities. Some parents reportedly kept their children home from school following researchers’ reports.
And by around 3:30 p.m., members of Congress announced that they had urged in a letter to President Joe Biden and Gov. Gavin Newsom to declare the sewage crisis an emergency because of the reported “unhealthy levels of hydrogen sulfide and hydrogen cyanide (HCN) – noxious gases that have been used in chemical warfare.”
Less than 24 hours later, the public received a different announcement. This time from county Chair Nora Vargas: the air may be stinky, but it is safe.
At their own press conference on Sept. 10, officials assured the public that they were not under immediate threat after their hazardous incident response team found no hydrogen cyanide and non-threatening levels of hydrogen sulfide.
That did not sit well with the Tijuana River task force nor many of Vargas’ District 1 constituents who have repeatedly reported feeling ill due to noxious sewer gas odors.
But by Sept. 13, the state public health department and the U.S. Environmental Protection Agency said they had corroborated the county’s air quality monitoring results and concluded that “monitoring methods” for hydrogen cyanide “were flawed.”
SDSU research teams, aided by a special team from Austin, Texas, used devices designed for personal protective measures. A county report stated that these sensors are “unsuitable for use in atmospheres that contain (hydrogen sulfide)” because they have cross-sensitivities. That means they can show false readings indicating the presence of another chemical that is not actually there.
Researchers have since acknowledged that to be true.
“As a human being and not a first responder, just as an academic, I wasn’t sure what to do,” said Stigler Granados. “We’re all human and I said what I said at the time to protect my team and public health. Do I feel bad if people panicked? Of course, I do.”
Prather has been in the middle of other controversial topics for sharing some preliminary data or speculations before publishing peer-reviewed articles, particularly during the COVID-19 pandemic. But she stands by her findings of hydrogen sulfide in South County communities, and said she does not regret sharing portions of her data because they coincided with what residents have been reporting.
“We knew this was a crisis when I saw my data give validity to the complaints,” she said. “I knew enough to act and not wait to understand every part of the problem. It’s called precautionary principle and it applied during COVID.”
The collaboration also comes as the Centers for Disease Control and Prevention prepares to lead an on-the-ground investigation measuring the potential health impacts on affected communities.
On Thursday, Vargas announced she was in Washington D.C. advocating to tackle “the sewage crisis head-on.”
“I know and share the frustration we all feel—I live here too,” she said in a statement. “I understand how critical it is for our community to see real progress, and I’m committed to delivering that.”
