On January 19, the Mayor of Nihonmatsu City announced that concrete used by the contractor for the recently discovered contaminated apartment building (article here) has also been used in a recently built home, and new recent reports indicate that the gravel from the quarry has been used in at least 50 homes and apartment buildings, and over 1000 different construction projects throughout the prefecture. A further 7 tons of gravel were shipped to Tokyo.
A home builder measured the radiation levels within a newly built home and found internal air readings of 0.8 ~ 0.85 microsieverts/hour and reported this to the city. The house is already occupied. Following the Fukushima Daiichi nuclear disaster, air readings at the Nihonmatsu City Hall averaged 0.7 microsieverts/hour in 2011. As a comparison, outdoor air levels in Tokyo city are 0.05 ~ 0.10 microsieverts/hour.
Further measurements found radiation levels from the surface of the house’s concrete foundations ranging between 1.5 ~ 1.9 microsieverts/hour.
The concrete foundations for the home were poured in April, 2011. The home builder has also reported the findings to the prefecture.
Jiji Press, January 19, 2012.
NHK, January 21, 2012.
The Tokyo Shimbun, January 21, 2012.