Regarding changes in the frequency of measurement of radiation dose in the city air

In response to the Great East Japan Earthquake, the city began measuring air radiation levels at 5 cm and 100 cm from the ground at elementary and junior high schools, nursery schools, kindergartens, etc. in June 2011, and in 2016, measurements were taken at 40 locations per month. Conducted once.
In addition, since February 2012, we have selected locations where rainwater, dust, and dirt tend to accumulate, such as under the rain gutters and rainwater basins of public facilities, and have been conducting local measurements of the air radiation level at 1 cm above the ground once a year. Measurements were taken at 729 facilities.
Under such circumstances, the current measurement results since 2011 show that the values ​​are stable and are below the standard value (0.23 microsievert per hour) indicated by the Ministry of the Environment, and that the values ​​in Tokyo have been stable since before the Great East Japan Earthquake. Due to reasons such as the numbers at radiation monitoring posts installed in Shinjuku Ward dropping to pre-earthquake numbers, we will suspend measurements of air radiation levels in the city from 2021 onwards. However, if any concerns arise, measurements will be resumed immediately.