CAMP ZAMA, Japan (July 15, 2020) – After testing 677 housing units for radon, U.S. Army Garrison Japan found only two occupied units with results slightly over the Environmental Protection Agency’s recommended action level.The EPA’s recommended action level for radon concentration in homes is 4 picocuries per liter of air, and one occupied unit at Sagamihara Family Housing Area had a level of 4.4 pCi/L, and one occupied unit at Camp Kure Pier Six had a level of 8.9 pCi/L, said Phil Gust, chief of the USAG Japan’s Environmental Division at the Directorate of Public Works.“Our results did not identify any housing units for which the EPA recommends completing corrective actions within six months or the removal of any residents due to an acute hazard,” Gust said.Although the results also found five unoccupied units with elevated levels, the results overall show that radon is not a pervasive problem for USAG Japan residents throughout the island of Honshu, Gust said. In addition, they indicate that the housing units are properly ventilated.Vacant units that are not periodically opened up are more likely to have higher concentrations of radon gas, Gust said.For the two occupied homes with elevated levels, the recommended timeframe for corrective actions for results between 4 and 8 pCi/L is within five years, Gust said, and the recommended timeframe for results between 8 and 20 pCi/L is one to four years.USAG Japan officials plan to ensure the ventilation systems in all the units with elevated radon levels are working properly and then evaluate to see if personnel need to take further action, Gust said.Corrective actions could include the inspection and repair of cracks in the foundation or concrete slab of the home, since that is typically where radon enters the home, Gust said.In some cases, personnel install special ventilation systems below the foundation to circulate air and remove radon gas before it enters the home, Gust said.Radon, a naturally occurring gas, is everywhere, and it increases the risk of lung cancer for those exposed to elevated amounts over many years. Gust said.“It is generated through natural radioactive decay in soils and rocks throughout the world,” Gust said. “Certain areas of the world, depending on their geological constituents, have higher levels of naturally occurring radon than other areas.”Gust said the garrison conducted the testing to meet Army guidelines for radon control in housing units. Personnel tested ground-level family housing units and a sample of ground-level unaccompanied housing units.Radon is tasteless, colorless and odorless. Testing for the gas is important because it is everywhere there is no known safe level of exposure to radon, Gust said.“I would compare it to ultraviolet radiation,” Gust said. “It is something we are all exposed to every day and it is best to take basic precautions.”Contractors began installing the monitors in July 2019, and retrieved the last monitors at the end of January, Gust said.Personnel were able to retrieve and analyze a vast majority of the monitors, Gust said, and officials are considering ways to retest units with monitors occupants tainted or they could not retrieve.The garrison contracted out the work because a member of the American Association of Radon Scientists and Technologists who is certified under the National Radon Proficiency Program had to supervise the work, Gust said.There is no established standard for frequency of testing, Gust said, but the EPA recommends retesting remodeled homes and homes with installed radon reduction systems every two years.Radon testing is just one of several types of environmental tests USAG Japan officials conduct.Other efforts include testing for drinking water contaminants, sampling materials suspected of containing asbestos and lead-based paint, monitoring of air emissions for hazardous air pollutants and examining various materials to determine if personnel should handle and dispose of them as hazardous waste, Gust said.Gust said he recommends that anyone with questions about radon or other environmental issues visit the EPA website at“There are a lot of great resources to use in order to better understand environmental hazards and what each individual can do to protect themselves and understand [the] environment, because ultimately everyone has a responsibility to be vigilant when it comes to environmental hazards,” Gust said.