The heinously polluted Tijuana River, which has sickened residents and even researchers with its hydrogen sulfide fumes, is gaining attention, and now a coalition of politicians, activists, physicians and economists are pushing California Gov. Gavin Newsom to declare the fetid and toxic river valley a public health emergency.

They’ve also put together a plan to clean it up and are pleading with state lawmakers to fund it, even as the state faces a multibillion-dollar deficit.

“We’re only starting to understand the full reach of the environmental and health impacts and they’re getting worse every day,” Sarah Davidson, clean border water manager for the ocean protection group Surfrider, said at a news conference Thursday. “There’s no saying how far-reaching they are or how far-reaching they will be. So every lawmaker and resident in California should be concerned.”

In 2024, Newsom said in an interview that a state emergency declaration “would not have availed us to any real benefit except symbolism and then ultimately frustration that it didn’t mean anything.”

Four of the gubernatorial candidates — Katie Porter, Antonio Villaraigosa, Tom Steyer and Xavier Becerra — have pledged to treat the issue as a top priority.

Despite his resistance, Newsom has secured funding for the river and region, including $38 million for water quality improvements in 2019 and an additional $100 million in federal funds for the area’s infrastructure in 2025.

Among the elements in the package announced Thursday: state Senate Bill 58, which would establish air quality standards for hydrogen sulfide, a toxic pollutant emitted from the river, and Senate Bill 1046, which would set standards and guidelines for workers employed near the river.

They’re also pushing for $23 million in state transportation funds to upgrade the Saturn Boulevard crossing near San Ysidro, where the river cascades through a small channel and is considered a hot spot for spewing toxic air pollutants. Other items include $5 million for air purifiers for people in heavily affected ZIP Codes, and $2 million to update a boom on the river that collects trash moving downstream.

Support for addressing the Tijuana River crisis has been bipartisan.

Last summer, Environmental Protection Agency Administrator Lee Zeldin committed the Trump administration to “a permanent, 100% solution to the decades-old Tijuana River sewage crisis,” signing a memorandum of understanding with Mexico.

“I smelled for myself that foul smell that so many residents of Southern California have been complaining about for so long,” Zeldin said, adding that President Trump was highly motivated after hearing from Navy SEALs who must train in the polluted waters of the Pacific Ocean where the Tijuana River meets the sea.

A recent Department of Defense report showed 1,100 reported cases of illness among Navy SEALs and other service members exposed to high levels of bacteria when they trained in and around the mouth of the river near the border.

In 2024, California voters also approved Proposition 4, which allocated nearly $50 million for projects addressing water quality problems along the Mexico border and coastal areas. But most of that money has yet to be released, waiting for various agency reviews and approvals.

Trump also took an interest in the river during his first administration, committing $300 million in federal funding to the San Diego region for a new U.S. facility to capture Tijuana sewage spills before they foul shorelines.

Advocates for an emergency declaration, including those representing local communities, say an emergency declaration could help release those funds and prompt interagency action. For example, funds could be used for road and tunnel construction to improve the flow of the river, addressing several public health issues plaguing the region.

Nearly three-quarters of the Tijuana River watershed is in Mexico, with the last five miles flowing into the U.S. before emptying into the Pacific Ocean at Imperial Beach.

Pollution in the 120-mile-long river has been so egregious that recent studies have shown that even the air above the river, or the spray where it reaches the surf, is dangerous.

Using an air quality monitor nearly half a mile from the river in the community of Nestor, Calif., last year, scientists found extremely high levels of hydrogen sulfide, a gas linked to sewage that smells like rotten eggs. Their paper was published in the journal Science.

Last year, American Rivers, an environmental group, declared the Tijuana River the second-most endangered river in the nation.

A couple of years ago, in the middle of the night, I crept downstairs to find my father sitting at the kitchen table, sobbing like a child.

My mother was beside him, trying to comfort him, an activity that took up more and more of her time. He was 87 and had dementia. It wasn’t unusual to find him upset or confused. But on this night, something seemed to be happening to him in real time — in 1941.

He was 6 years old, and was leaving Pittsburgh, the only home he had ever known, for an Air Force base in San Antonio, where his father had been ordered for duty. He and his parents were traveling there by train, transferring in Chicago.

It was the beginning of a lonely, difficult time for my father’s family, moving between Air Force bases in the South, where landlords sometimes turned them away because they were Catholic. An only child, he had been allowed to take one pet with him, a canary he was carrying in a birdcage.

As they were changing trains in Chicago, the bottom fell out of the cage. The canary flew out, up into the vaulted atrium of the station’s Great Hall. There was no way to get the bird — there was no time, they had to board a train to Texas. So my 6-year-old father shuffled after his parents, holding an empty cage.

In the years that had elapsed, he had negotiated arms treaties with the Soviets, had advised presidents, had served as a U.S. ambassador, all with the same watchful, wisecracking reserve. I thought I knew who he was. I could count on one hand the times I had seen him cry. Now here he was, sobbing over the canary as if it were yesterday.

This was all, it seemed, because of his brain. He had fallen hard in their house in Washington, D.C., smacking his head on the hardwood floor. Blood rushed into spaces in his brain, and cells starved of oxygen began to die. Eventually, he was diagnosed with vascular dementia, which is most often caused by strokes.

For five years after that, my parents lived with my family outside Boston, and we learned firsthand how brain injury affects behavior. My father recovered in some ways, but he became chaotic, his thoughts broken into mirror shards.

The biggest problem was that he had no idea where he was. Specifically, he did not know why he was living with us in Massachusetts, and no matter how many times we tried to remind him, over and over, he tried to leave. We would catch him packing the car, and gently — or not so gently — guide him back into the house.

This child-father was full of surprises. He bought surprising things: Five laptops! A cruise on the Norwegian fjords! Recurring $2 donations to every Democrat running for any office, anywhere! Once, in a weeklong cascade of Amazon deliveries, we received seven identical birdbaths from China.

With each step you take, coordinated contractions in your abdominal muscles help keep you stable and upright.

Now, new research finds that those gentle changes in tension and pressure also affect your brain, and may play a role in the organ’s overall health.

Imaging in humans and other animal species has long shown that the brain gently moves inside the fluid-filled skull cavity, but it’s never been clear what, exactly, is propelling this motion, said neuroscientist Patrick Drew, a Penn State University professor and associate director of the Huck Institutes of the Life Sciences.

Using advanced imaging, Drew’s team observed mice brains before and after the animals began walking. They realized that the brain actually moved just milliseconds before a mouse took a step — the brief moment when the animal’s abdominal muscles contracted in preparation for movement.

To test the observation, they strapped pressure sensors around the bellies of lightly anesthetized mice and observed the brain when slight pressure was applied only to the abdominal muscles. The same motion followed. Breathing or cardiac activity didn’t trigger the same response.

The connection, Drew and his colleagues determined, is the vertebral venous plexus, a network of veins that connects the abdomen to the spine in mice and humans alike.

“It’s like a hydraulic system. It really is very much like the jacks that push your car up, or something that an excavator might have,” Drew said. “Whenever you tense those muscles, which you do whenever you make a movement … that pushes blood into the spinal cord, it increases the pressure on your brain, and it moves your brain forward.”

The paper, which was published April 27 in Nature Neuroscience, answers a puzzling question about the mechanism controlling this long-observed cerebral movement.

It also puts forward hypotheses about why this belly-brain choreography exists.

Drew and his team ran computer simulations of fluid’s motion in and around mouse brains. The kind of contraction generated by walking moves cerebrospinal fluid out of the brain, leading Drew to hypothesize that the mechanism plays an important role in flushing out protein waste and other unnecessary material.

“It’s more speculative, but using simulations, we can see that this sort of motion should drive fluid movement and could help clear waste in the brain,” Drew said.

In future research, Drew said, the team would like to explore whether the brain is detecting these mechanical signals, and how physical conditions like obesity affect the hydraulic relationship between the abdominal muscles and the brain.

These current findings clarify the relationship between the brain and physical movement, illuminating fundamental mechanics that can apply to other research, said Michael Goard, an associate professor at UC Santa Barbara who studies sensory and spatial processing.

“He did, what I think is a very thorough job figuring out what’s causing this movement in the case of locomotion and tying down the mechanical elements,” Goard said.