Since we posted about our radiation monitoring on the island of Hawaii, we have been getting a lot of emails from people wondering if it is safe to come to Hawaii for a vacation. The proximity of Hawaii to Japan has many people concerned that Hawaii has been contaminated by radiation from Fukushima and other nuclear power plant emissions in Japan and the questions we are getting are detailed and specific about their concerns.
Our detector measures milliREM per hour. A reading of .014 milliREM/hour, usually considered background radiation, translates to approximately 14 Counts Per Minute (CPM). Our radiation monitoring on Hawaii Island before March 2011 showed readings between .004 and .006 milliREM/hour (4-6 CPM), substantially below background radiation. Hawaii Island is blessed with protected air flow and isolated from most radiation sources so the levels have typically been low.
Just to keep radiation measurements in perspective, a reading of 100 CPM is still less than 1 REM a year and a worker standard (used for pilots and nuclear workers) is a max of 5 REM a year. These readings are for airborne radiation and not to be confused with ingesting radiation from food or water.
Since the Fukushima explosion in March 2011, our radiation readings reached levels of .016 microREM/hour (16 CPM). The levels settled to twice their previous levels in the .008 to .012 microREM/hour range in late March and April. In early May 2011 we did a video showing ranges of .010 to .014 microREM/hour in the areas around our condo with no signs of high level concentrations in drainage areas, as compared to videos posted on Youtube from areas around Tokyo.
In the past couple of weeks we have been suddenly seeing increased levels with spikes up to .024 microREM/hour (24 CPM). We took readings around our condo in the same areas as the May 9, 2011 video and the readings were slightly higher.
We were concerned that it might be due to air blowing from the ocean, but a trip down to the beach showed low rates on the sand and near the water, so the increased levels do not seem to be related to anything showing up in the ocean.
We have assumed all along that the higher levels of radiation being reported on the mainland and continued leakage of material from Japan would eventually get into our protected Hawaii air supply. The increase in airborne radiation may be the result of the slow build up of radiation around the globe. It may, however, be related to the recent increase in activity of our volcano and earthquake activity. Either way, the background radiation readings we are getting are still at levels that would be considered normal background on the mainland.
To compare our readings, check out Radiation Network a collection of real-time independent radiation readings (CPM) from around the country displayed on a US map.
Our personal view is that radiation contamination is a modern problem due to aging nuclear power plants around the world with questionable safety and unreported accidents and leaks. No place on the Earth is now excluded from radiation contamination. Our approach is to monitor the air borne levels for safety, have protection and a plan in case the numbers spike, live healthy, and take supplements to minimize cell damage from radiation.