San Francisco — More than a half century after the U.S. ignited 67 atomic weapons in the the central Pacific Ocean, a former Navy base in the Bay Area continues to carry that nuclear legacy.

Last week, residents were informed by the San Francisco Department of Health that a test taken in November 2024 at the former site of Hunters Point Naval Shipyard showed radiation levels of airborne Plutonium-239 had exceeded the Navy’s “action level,” requiring the military to further investigate.

The city and the residents were not informed until 11 months after that initial reading.

Hunters Point, a 500-acre peninsula jutting out into San Francisco Bay, served as a military laboratory to study the effects of nuclear weapons from 1946-69 following World War II. Although the research largely focused on how to decontaminate U.S. warships and equipment targeted with atomic bombs, the experimentation left much of the shipyard laced with radioactive contaminants and toxic chemicals.

For the last 30 years, the Navy has sought to clean up the area — now a U.S. Superfund site — with the long-term goal of redeveloping it into new housing and parkland.

But some Bay Area community leaders say haphazard remediation work and lackluster public outreach have endangered the health and safety of residents of the Bayview-Hunters Point neighborhood that sits beside the former shipyard. And they point to the Navy’s nearly year-long delay in informing them of the elevated Plutonium-239 reading, taken in November 2024, as just the latest example.

Plutonium-239 is a radioactive isotope and byproduct of nuclear bomb explosions. The elevated readings from November 2024 came from a 78-acre tract of land on the northeast portion of the shipyard, known as Parcel C.

“The City and County of San Francisco is deeply concerned by both the magnitude of this exceedance and the failure to provide timely notification,” wrote San Francisco Health Officer Susan Philip in an Oct. 30 letter to Navy officials. “Such a delay undermines our ability to safeguard public health and maintain transparency. Immediate notification is a regulatory requirement and is critical for ensuring community trust and safety.”

Navy officials and some health experts insist the radiation levels detected at the site, while above the Navy’s action level, did not pose an imminent or substantial threat to public health. Exposure to this level of Plutonium-239 every day for one year would be less than one-tenth the dose of radiation from a chest X-ray, according to a Navy spokesperson.

“The San Francisco Department of Public Health’s letter references a single outlier air sample that detected Plutonium-239 above the regulatory action level,” a Navy spokesperson said in a statement to The Times. “Regulatory action levels are deliberately and conservatively established below levels of health concern, and a single detection of Pu-239 at this level does not pose a risk to human health or public safety.”

The Navy said it has collected more than 200 ambient air monitoring samples from Parcel C since it began performing fieldwork there in 2023. The November 2024 sample was the only reading with elevated Plutonium-239, the Navy spokesperson told The Times.

Plutonium isotopes emit alpha radiation that is relatively benign outside the body, because it cannot travel through solid objects. However, if these radioactive particles are inhaled, they can damage the lungs and increase the long-term risk of developing certain cancers, according to the Centers for Disease Control and Prevention.

“What we generally are concerned about for alpha emitters is if you get them into your body, and either through inhalation, ingestion, inadvertent injection — like somebody gets a cut and it gets into their body,” said Kathryn Higley, a professor of nuclear science at Oregon State University.

But it’s the lack of transparency and the 11-month delay in reporting the reading that has fomented community mistrust and raised questions regarding the military’s competency to safely clean up the polluted shipyard. In 2000, the EPA admonished naval officials for neglecting to inform residents that a fire had broken out at a hazardous landfill at Hunters Point. In 2017, two employees of the consulting firm Tetra Tech, who were hired by the Navy to assess radiation levels at Hunters Point, pleaded guilty to falsifying data in an effort to avoid having to perform additional cleanup on some areas of the shipyard.

The presence of radioactive air contaminants — at any level — compounds the health risks of the Bayview-Hunters Point neighborhood, which already faces high exposure to toxic diesel particles from big rigs traveling on nearby freeways and cargo ships visiting the Port of San Francisco.

Hunters Point Biomonitoring Foundation, a local nonprofit, has found concerning levels of toxic substances in urine screenings it has provided to several residents of the neighborhood, especially among older individuals and those living closer to the former Naval shipyard.

“Now, you’re talking about adding one of the most devastating radionuclides known to the human cardiopulmonary system to the chemical burden,” said Dr. Ahimsa Porter Sumchai, the foundation’s medical director and principal investigator.

“The particulate load is enough to kill people,” Sumchai added. “But you add … a little Plutonium-239, and it’s a recipe for death.”

Philip, the San Francisco health officer, said in a statement that she met with Navy officials Oct. 31 and received assurances that air and dust monitoring is “ongoing” and that the military agency is “reviewing their duct control methods to ensure they are fully protective of public health.”

As a result, “no immediate action is required from a public health safety standpoint,” she said, adding that her office will continue to closely monitor the situation.

Other experts argued the situation was overblown. Phil Rutherford, a radiological risk expert and corporate consultant, called the delayed notification “unacceptable” but said the San Francisco health department’s letter was “a storm in a teacup” considering the low levels of radioactive material.

Higley, the Oregon State professor, said the site’s long history of delays and scandals likely added to backlash from community members. “I understand [residents’] frustration that they want to see this place cleaned up so that they can safely use it,” Higley said. “And there’s been a lot of reasons for why this process takes so long. But, from a radiological perspective, the actual residual radioactivity at the site is pretty modest.”

In November 2024, a Navy contractor was grinding asphalt on the site — a construction project that, while unrelated to the site’s historical contamination, triggered the Navy to monitor for any air quality issues. One of its air samplers, in Parcel C — collected 8.16 times 10‐15 picocuries per milliliter of Plutonium-239 — twice the established action level — according to a Navy spokesperson.

Navy officials sent the sample to a lab for analysis, and the initial results came back in March 2025, showing high radiation levels. In April, they ordered the lab to reanalyze the sample. In the follow-up analysis, radiation levels of Plutonium-239 were below action levels.

Between May and September, the Navy “further investigated the test results and conducted a methodical review of the laboratory’s procedures and practices to ensure they complied with standards,” according to the Navy spokesperson. “A third party also conducted an analysis of the lab’s performance.”

Later that September, the Navy told the U.S. Environmental Protection Agency and several California state agencies about the elevated airborne radiation from Plutonium-239, in preparation for an upcoming community meeting. That information later trickled down to the San Francisco health department.

At some point, the Navy published some air quality data for Parcel C gathered between October and December 2024 on a website where it curates several environmental monitoring reports. That report only showed the lower Plutonium-239 radiation levels from the reanalysis were below the action level.

A Navy spokesperson told The Times that it was “mistakenly uploaded.”

“As soon as the Navy realized an incomplete report was uploaded, it was removed from the website,” the spokesperson said, while the Navy worked to verify the results.

All that has contributed to the confusion and concern among locals and advocates alike. Navy officials are expected to attend a Hunters Point Shipyard Citizens Advisory Committee Meeting on Nov. 17.

When fieldwork is occurring at the shipyard, the Navy monitors for Plutonium-239 and several other radioactive elements that may have resulted from historic fallout from atomic weapons testing.

Acquired by the Navy in 1940, Hunters Point was initially a base where ships were built, repaired and maintained during World War II. After the war ended, it became home to the Navy Radiological Defense Laboratory, a military research facility dedicated to investigating the effects of nuclear weapons and radiological safety.

The Navy bombarded a fleet of U.S. warships with nuclear weapons as a part of atomic testing in the Marshall Islands. The irradiated vessels were towed to Hunters Point, and used as the material and hardware upon which scientists tested decontamination methods.

In 1974, the shipyard was deactivated. Hazardous chemicals and low-level radiological contamination were identified, prompting the U.S. EPA to place the site on its Superfund list in 1989.

The Navy has led cleanup efforts, excavating contaminated soil and demolishing buildings. A largely residential parcel of the base, Parcel A, was turned over to San Francisco and has been redeveloped with new town houses and condos. A collective of 300 artists live and work in former naval buildings.

But dangers continue to emerge during ongoing remediation work.

In recent years, the Navy has recovered radioactive objects, including dials and deck markers coated with paint containing Radium isotopes to provide a glow-in-the-dark effect. Sumchai, medical director of the biomonitoring foundation, said she has observed large stockpiles of contaminated soil held in areas without any protective fencing to prevent contaminants from spreading off site.

“I view this as a local public health emergency,” Sumchai said. “I think that everything should be done to contain it and to remove people safely, if necessary, from documented areas of exposure.”

But to the casual observer the site looks unremarkable.

Hunters Point juts out into the San Francisco Bay just north of where Candlestick Park, the former home of the San Francisco Giants and 49ers, used to stand. Beyond the abandoned barracks and drydocks, the site is now mostly an empty expanse of grass and reeds, with an unobstructed view of the bay.

The cleanup sites, including Parcel C, are still fenced off, and only those with authorized credentials are allowed onto the property.

On a recent weekday afternoon, ravens flew and cawed over the long-vacant shipyard buildings, while construction crews and trucks ferried building equipment up and down Hill Drive — a steep road leading to brand new homes standing sentinel over the former shipyard.

And beyond waiting for a new batch of Navy reports, there was no way of knowing what’s in the air.

Los Angeles County officials are set to pull kratom and its synthetic extract, sometimes called 7-OH, from shelves immediately.

Inspectors will be sent to retailers next week to begin red-tagging illegal products containing the compounds, the L.A. County Department of Public Health said in a news release Friday morning. Shops that don’t comply could be hit with fines or other penalties.

Kratom is an herbal extract from the leaves of Mitragyna speciosa, a tree native to Southeast Asia. It is sold in shops and online in a variety of forms, including powders, pills and liquid extracts. Brands selling kratom often make claims that it can address pain, anxiety and mood disorders.

Matthew Lowe, executive director of the Global Kratom Coalition, said natural kratom has been used in the U.S. for more than 50 years and according to a 2020 Johns Hopkins Survey, people have been using it to alleviate anxiety and treat chronic pain.

In the last few years, a more potent, synthetic version of kratom refined into its psychoactive compound 7-Hydroxymitragynine, or 7-OH, hit shelves across the U.S.

7-OH products are often marketed as “plant alkaloids,” drawing criticism from some, including Lowe, who argue the labeling is misleading, confusing consumers into thinking it’s the same as natural kratom.

When mixed with alcohol, medications or illicit drugs, the county health department warns, 7-OH products can “cause severe respiratory depression and death. Importantly, these products are unregulated and may contain unknown concentrations of 7-OH, increasing the risk of unintentional overdose.”

There have been six reported kratom-related deaths in Los Angeles County in just the past few months.

“Given that this is new and emerging substance, this is also since the medical examiner started tracking 7-OH data,” the Los Angeles County Department of Public Health told The Times via email. Since the county began tracking 7-OH in deaths only in April of this year, it is unclear how many other overdoses could have occurred previously.

After publication of this article, the county medical examiner released the death reports to The Times. Each of the deceased had kratom and 7-OH in their bodies, according to the reports, but it was not immediately clear what role they played in the deaths, as compared with other substances — including alcohol, prescription sedatives and muscle relaxants, and illicit drugs like cocaine — that were also found in the six bodies. The Times first requested the coroner’s report for the kratom-related deaths on Oct. 24.

“Kratom and 7-OH products are sold as natural remedies, but they are illegal and unsafe,” Dr. Muntu Davis, the county health officer said in the release. “They are sold in gas stations, smoke shops, online, and other retailers. People should avoid using these products, and store owners/operators must remove them immediately to prevent harm.”

Right now, consumers have no clarity on kratom, 7-OH or any other metabolites, said Yaël Ossowski, deputy director of Consumer Choice Center, a nonprofit consumer advocacy group.

“At any gas station or smoke shop, there’s the powder, the liquid extracts, and pills all offered at different doses, with different brands,” Ossowski said. “This obviously leads to consumer confusion and uninformed choices, incorrect dosing and likely bad experiences that smart regulation would avoid.”

The kratom and 7-OH market has grown largely because people want targeted pain relief and remedies for their ailments, “but don’t necessarily want to have the full effects of more powerful opioids that have a fuller effect on the body,” he said.

“Kratom has been successfully used for generations in other countries as an opioid alternative,” Ossowski said. But highly concentrated 7-OH products are a different beast altogether.

According to the U.S. Food and Drug Administration, kratom and 7-OH are not lawfully marketed in the U.S. as a drug product, a dietary supplement or an approved food additive.

California adopts federal law concerning food and dietary supplements, the California Department of Public Health told The Times via email.

“Until kratom and its pharmacologically active key ingredients mitragynine and 7-OH are approved for use, they will remain classified as adulterants in drugs, dietary supplements and foods,” a department spokesperson said.

The spokesperson added that the department has been conducting investigative work associated with kratom for the last two years and “continues to take appropriate action to protect the public against adulterated products containing kratom or 7-OH.”

“CDPH embargoes or destroys foods and dietary supplements within the state that are adulterated with kratom or 7-OH once they are identified during investigations; however, we do not comment on the specifics of ongoing investigations,” the spokesperson said.

7-OH producers have publicly defended their products in the face of lawsuits and FDA crackdowns, arguing it is a safer alternative to illicit opioids like fentanyl and has saved lives, not taken them.

Vince Sanders, founder and CEO of CBD American Shaman who helped develop an early 7-OH product, has said the attack on 7-OH is being led by companies selling natural kratom, who have had their market share overtaken by what he says is “a vastly superior product.”

The Kansas City businessman said a ban anywhere in the country would hurt people who have used 7-OH to treat substance abuse disorders or chronic pain and now rely on the product as an alternative to costly prescription medication.

“People that have changed their life using it are extremely concerned,” Sanders said. “They’re scared to death. I mean, there are people that … plan to pull money out of their 401K, or load up their credit cards, or whatever they’ve got to do to buy years and years of supply.”

He acknowledged that both kratom and 7-OH are frequently taken in higher doses than he recommends, but argued manufacturers and retailers should not be held accountable for those decisions. He compared it to alcohol: “You buy a 750-milliliter bottle, and if you go home and drink that entire bottle, and you do that every single night, is that your fault, or is that Jim Beams’ fault?”

Communities across the state have taken it upon themselves to act in the absence of state and federal regulation. Orange County and the cities of Newport Beach, San Diego and Oceanside have all prohibited the sale, distribution or possession of kratom. Riverside County is looking to deter the sale and marketing of kratom and 7-OH products to people under the age of 21.

Los Angeles County does not have its own regulatory ordinance for the products.

“I think that the local action is signaling intent. It’s saying to the state and [federal authorities], you need to do something about this,” Lowe said in regard to synthetic 7-OH.

But outright prohibition bans that include natural kratom could bring another host of issues including whether local enforcement of the ban will even happen, and the possibility that a black market for the products may arise, he said.

“You leave people without any options, so they either find alternative options or they just drive across city lines or county lines and and go get it themselves,” Lowe said. Indeed, kratom and 7-OH are widely available on online marketplaces.

Southern California air officials voted overwhelmingly Friday to give themselves the power to levy fines on the ports of Los Angeles and Long Beach if they don’t fulfill their promises to transition to cleaner equipment.

The ports remain the largest source of smog-forming pollution in Southern California — releasing more emissions than the region’s 6 million cars each day.

The South Coast Air Quality Management District’s governing board voted 9-1 in favor of an agreement that commits the ports to installing zero-emission equipment, such as electric truck chargers or hydrogen fuel pumps, to curb air pollution from the heaviest polluters. The plans will be submitted in three phases: heavy-duty trucks and most cargo-moving equipment by 2028; smaller locomotives and harbor crafts by 2029; and cargo ships and other large vessels by 2030.

If the ports don’t meet their deadlines, they would be fined $50,000 to $200,000, which would go into a clean-air fund to aid communities affected by port pollution. The AQMD, for its part, forgoes imposing new rules on the ports for five years.

Many environmental advocates voiced disappointment, saying the agreement doesn’t contain specific pollution reduction requirements.

“I urge you not to sign away the opportunity to do more to help address the region’s air pollution crisis in exchange for a pinky promise,” said Kathy Ramirez, one of dozens of speakers at Friday’s board meeting. “This is about our lives. I would encourage you to think about why you joined the AQMD board. If not for clean air, then for what?”

Port officials and shipping industry officials lauded the decision as a pragmatic way to transition to a zero-emissions economy.

“The give and take of ideas and compromises in this process — it mirrors exactly what a real-world transition to zero emissions looks like,” said William Bartelson, an executive at the Pacific Maritime Assn. “It’s practical, it’s inclusive and it’s grounded in shared goals.”

The vote answers a long-standing question over how the AQMD intends to reduce pollution from the sprawling trade complex, a focus of environmental justice efforts for decades.

The twin ports of Los Angeles and Long Beach, known as the San Pedro Port Complex, is the largest container port in the Western Hemisphere, handling 40% of all container cargo entering the United States. Despite years of efforts at reducing pollution, the vast majority of heavy machinery, big rigs, trains and ships that serve the region’s bustling goods movement still are powered by diesel engines that emit toxic particles and nitrogen oxides, a precursor to smog.

For nearly a decade the AQMD has vacillated between strict regulation and a pact with the ports with more flexibility. Several negotiations over a memorandum of understanding failed between 2017 and 2022. The board was prepared to require the ports to offset smog-forming pollution from trucks, trains and ships through clean air projects, like solar panels or electric vehicle chargers. Instead, the ports presented the AQMD with a proposed cooperative agreement, prompting the agency to pause its rulemaking.

The AQMD doubled the penalties in that proposal and agreed not to make new rules for five years, not the 10 the industry wanted.

Perhaps the most important details of the agreement — the types of energy or fuel used; the appropriate number of chargers or fueling stations — won’t be published for years. The lack of specifics prompted skepticism from many environmental advocates.

“It’s just a stall tactic to make a plan for a plan in the hope that emission reductions will come sometime in the future,” said Fernando Gaytan, a senior attorney with environmental nonprofit Earthjustice.

The contract also includes a clause that the AQMD or ports could terminate the agreement “for any reason” with a 45-day written notice. Wayne Nastri, the AQMD’s executive officer, said this gives the agency the option to switch back to requiring zero-emission infrastructure at the ports.

“If we report back to you and you’re not seeing the progress being made, you can be confident knowing that you can pivot and release that [rulemaking] package,” Nastri said to the board.

At the end of public comment, opponents of the agreement broke into loud chants. The AQMD cleared the gallery as the board discussed the proposal.

Board member Veronica Padilla-Campos, the lone “no” vote, said the agreement lacked the necessary emission reductions and offered “no clear accountability” to local communities.

Fellow board member Nithya Raman acknowledged many criticisms of the agreement but ultimately voted for it.

“I really have come to believe that the choice before us is this cooperative agreement or no action at all on this issue — continuing a decade of inaction,” Raman said.

“I will be voting to support it today, because I do think that it is our only pathway to take any steps forward toward cleaner air at the single largest source of air pollution in the region.”

The plan still must be approved by commissioners at the Port of Los Angeles and the Port of Long Beach Harbor Commission at meetings this year.