Reading Room

U-238 & The Toxic Aftermath of Site 300 Blasts

Lawrence Livermore National Lab’s high explosives testing range, called Site 300, in Tracy, CA performs large-scale test explosions with Uranium-238 (U-238). U-238 is a radioactive metal that the Institute for Energy and Environmental Research (IEER) links to kidney problems, inhibited fetal development, a higher risk of soft tissue cancers, and more. These test explosions put U-238 pollutants ranging from gaseous to particles the size of a softball into our surroundings.

U-238 particles don’t necessarily stay within the boundaries of Site 300, in fact we don’t know how far they have been dispersed and that is dangerous. In a draft work plan for clean-up, Lawrence Livermore National Lab (LLNL) planned to sample soil at the edge of Site 300 to establish a background concentration of U-238 to compare to uranium concentrations in soil samples around the rest of the site. This work plan is only a draft, however it fails to adequately study the full impact U-238 has on our community. There will be no sampling of the area surrounding Site 300 or sampling in the neighboring cities of Tracy and Livermore. It is also establishing a background concentration, which should be clean compared to other samples, at Site 300 where the U-238 tests originate.

Until we have studies done on where U-238 particles settle and on their behavior in our area, we can only assume answers to these questions based on current scientific knowledge. We know that in the summer, in anticipation of fire season, there are control burns through most of Site 300. No one tests these fields for U-238 before they burn them, therefore U-238 particles could be lifted by the smoke and carried away from Site 300. Inhaling U-238 as a result of these control burns is more harmful than being exposed to particles in other ways, according to the IEER, which states that “if inhaled…its radioactivity poses increased risks of lung cancer and bone cancer.” In 1987 the U.S. Environmental Protection Agency required national ambient air quality standards to regulate particulate matter of size “PM10 (particles with a nominal mean aerodynamic diameter ≤ 10 µm)” (National Center for Biotechnology Information (NCBI)). The NCBI goes on to explain that “PM10 delineates a subset of inhalable particles that are thought small enough to penetrate to the thoracic region of the respiratory tract” and that there is “greater particle penetration into the thoracic and respiratory regions of children than adults.”

With no information available about the exact size of U-238 particles originating from Site 300 or of how many there are and how far they have been dispersed, it is possible that people living in proximity of the site are inhaling toxic U-238. Supporters of explosives testing will claim that control burns don’t reach temperatures high enough to turn U-238 particles into a mobile gaseous form or that the fires are too short-lived to lift particles, however we can’t know this until it is actually studied in the field. This isn’t something we can continue to ignore as U-238 will remain in our environment for billions of years (half-life 4.5 billion years). We urge LLNL to clean up U-238 that they are responsible for putting into the environment.