It is with heavy hearts that we announce that Dan Hirsch has passed away. He passed away peacefully, though in significant pain, at his home in Ben Lomond. An official announcement with further details, including an obituary and information about a memorial, will be coming in the next weeks.

On July 27th, CBG posted a press release about Dan’s passing.

Dan was the Founder of CBG, as well as Director, Program on Environmental and Nuclear Policy, at the University of California, Santa Cruz.

See interviews with Dan Hirsch, posted at the UCLA Library’s Center for Oral History Research.

As reflected on CBG’s homepage, if it was about Santa Susana Field Lab, Hunters Point Naval Shipyard, Diablo Canyon Nuclear Power Plant, or San Onofre Nuclear Power Plant, Dan was on it.

Dan just testified at educational sessions intended to push back against the U.S. Nuclear Regulatory Commission’s attempt to do away with the Linear, No Threshold theory of ionizing radiation’s hazards to human health. (See the link to Dan’s slideshow he presented as public comment to NRC on July 16, 2025, posted at NIRS’s website, here.) He had worked at the cutting edge of protecting human health against the nuclear industry’s artificial radioactive pollution, for many decades, including at the National Academy of Science.

As documented in the MSNBC documentary film In the Shadow of the Valley, which also features interviews with Dan, at Santa Susana, his graduate students unearthed the 1959 meltdown, which had been covered up for 20 years.

He testified repeatedly about the seismic, and other risks, at Diablo Canyon, including before U.S. Senator Barbara Boxer’s (Democrat-California) Environment and Public Works Committee, more than a decade ago, as well as at grassroots sessions, such as those of San Luis Obispo Mothers for Peace, a few years ago.

Around two decades ago, Dan stopped a nuclear power industry spokesman dead in his tracks — not for the first time. On an NPR interview about energy and environment, focused on nuclear power, the industry spokesman kept bringing up climate protection. At one point, Dan said “I actually care about the climate,” which stopped the industry spokesman from disingenuously bringing it up again.

See articles authored or co-authored by Dan, posted at The Bulletin of the Atomic Scientists.

CBG’s website also posts many of Dan’s Publications, as well as those of its colleagues.

As anti-nuclear attorney Terry Lodge of Toledo, Ohio shared with the Ohio Nuclear-Free Network about the devastating news: