Quoting from Air and Space Forces Daily Report 1 Jun 2023:

https://www.airandspaceforces.com/daily-report/20230601/

The Air Force is conducting a detailed investigation of environmental hazards at ICBM bases as part of its broad study of cancer risks at the facilities. There is an improved understanding of the environment and factors that can affect the issue, as well as better technology and “access both to personnel and to the actual silos and launch facilities and launch control centers,” Col. Robert Peltzer, a senior medical official at Air Force Global Strike Command, said.

Quoting from Chris Gordon article  -- bullet points were added for emphasis:

https://www.airandspaceforces.com/icbm-cancer-study-environmental-monitoring/

“Two separate efforts are planned in the future,” Col. Tory W. Woodard, the director of the U.S. Air Force School of Aerospace Medicine (USAFSAM), which designed the study, recently told Air & Space Forces Magazine.  

• The first is an epidemiology study to look at cancer rates in missileer and associated career fields.
• The second, he added, is “dedicated environmental hazard sampling to assess the work areas.”  

Quoting:

“We’re not going to take that the stickers are inaccurate or accurate,” Peltzer said. “We’re going to make sure and validate one way or the other—are there PCBs down there?”

PCBs are not the only hazard. Another major concern for missileers is radon exposure and water contamination. Radon is a radioactive gas that comes from bedrock and soil, and missile facilities are buried underground with personnel living in cramped quarters on 24-48 hour shifts.

“There’ll be looking for air sampling, air intake, water—both above ground and below ground,” Peltzer said.

The U.S. government does not own the land around many missile facilities where some harmful materials may be present. 

“We’re going to test the water and soil at different times for environmental changes,” Peltzer said, noting the schedule for doing agriculture work, as well as temperature changes, could affect the level of risk. 

The team will also keep sampling equipment, which had to get special clearance to be used in ICBM facilities, on the bases to continue monitoring well into the future.