Radioactive plutonium was found in the air above Bayview-Hunters Point at twice the federal government’s recommended levels, according to a letter from San Francisco’s chief health officer sent to the U.S. Navy on Thursday.
The levels of plutonium detected were approximately double the safe concentration known as “action levels,” according to the letter from Dr. Susan Philip, San Francisco’s health officer. An action level is a threshold that would trigger further investigation.
But the Navy, which measured the high concentration in November 2024, delayed informing the city of its finding for 11 months, the city said in its letter.
In fact, a Navy representative was adamant when he spoke to Mission Local in July, months after the readings, that the area where the plutonium was found posed no risks to residents. The Navy representative did not mention elevated findings of plutonium.
In its letter, the city told the feds it was deeply concerned over the level of plutonium as well as the delay in the notification, and demanded that the federal government notify the city of future radioactivity “without delay.”
“Full transparency with our department and our communities is critical to protecting public health,” reads a statement from the city’s Department of Public Health today.
“In October 2025, the Navy informed the San Francisco Department of Public Health (SFDPH) that an air sample collected in November 2024 at Parcel C of the Shipyard detected airborne plutonium (Pu-239) at a level above the established ‘Action Level,’” reads a separate letter from Philip to Bayview residents and Supervisor Shamann Walton also sent Thursday.
“This has unfortunately been par for the course for the navy to lack transparency and attempt to misguide community,” Walton said in a statement. His office will call for a hearing on “the Navy’s lack of transparency and any safety issues on the Shipyard.”
The city has requested the Navy immediately provide all information relevant to the incident, including any activities that may have led to it and any actions the navy has taken in response to the level of plutonium. It also requested the navy to provide a full year of air monitoring data for independent review.
In its letter to Bayview residents, the city promised that it would share more information as soon as it becomes available and “hold federal and state partners accountable to the highest safety standards.”
The plutonium was measured in the air above Parcel C. That area has been used for industrial purposes since the late 1800s, when the shipyard was used as a drydock to build and repair commercial and military ships.
Since then, the parcel, which covers approximately 78 acres, has been subject to toxic contamination after the Navy used the shipyard for Cold War-era radioactive testing following World War II.
In July, Mission Local spoke to Michael Pound, a representative from the Navy, who said the Hunters Point Shipyard, including Parcel C, posed no credible risk to nearby residents.
Representatives from the Environmental Protection Agency repeated this claim during a monthly meeting for nearby residents held near the shipyard in July.
The cleanup is subject to variable changes, said Pound in July, and a timeline to complete the cleanup is “hard to predict,” if radioactive materials are found while excavating the shipyard’s six plots of contaminated land, divided into parcels.
In 2023, several radioactive objects were found at the shipyard, including a small piece of glass and a deck marker made with radioactive materials, used to guide ships at night. The finding set back a cleanup process that has already been delayed years following the discovery that Tetra Tech, an engineering firm contracted by the Navy, falsified the radiation level of soil samples over the course of four years, from 2008 to 2012.
“Trust has been difficult to build again” with residents living in Hunters Point, some of whom have lived in the area for decades, since the shipyard was used as a Naval base, said Pound in July.