Activities to support individual dosimetry of children in Kawamata Town.

This paper does not necessarily reflect the views of the International Commission on Radiological Protection.Kawamata Town in Date District, Fukushima Prefecture is located more than 30 km north-west of Fukushima Daiichi nuclear power plant, but on 22 April 2011, part of the Yamakiya District of Kawamata Town was designated as a planned evacuation area. The exposure of children was a concern in Kawamata Town. Based on the proposal of Kindai University, Kawamata Town Board of Education took the initiative to measure individual radiation doses with an integrated dosimeter (glass badge) for all kindergarten children, nursery school children, elementary school students, and junior high school students in the town. These measurements were continued for nearly 3 years from June 2011 until the end of March 2014. The total number of measurements was approximately 16,800 across 11-cycle measurement, with 3 months' accumulation taken as one-cycle measurement. Kindai University provided financial support for the glass badge measurement service, and cooperated in the analysis of measured values and the development of advice based on the results. The main body implementing the measurements was Kawamata Town Board of Education, and the data obtained belong to Kawamata Town. When measurements were starting to be taken, schools got involved in the collection and distribution of dosimeters after explanations were provided to principals and school nurses who were in charge of risk communication. Thanks to the efforts of the schools, the recovery rate exceeded 90%, increasing the reliability of the measurements. It was clear who needed the information - the children and their parents. Kawamata Town Board of Education summarised the cumulative dose results for each measurement and notified parents via personal reports. These were sent to parents with advice on measurement results prepared by Kindai University, and care was taken to ensure that people could understand the measured results. Further briefing sessions were held as appropriate. At the briefing sessions, at the request of Kawamata Town Board of Education, the faculty members of Kindai University explained the measurement results from a professional point of view, and a professor from the Faculty of Medicine provided individual health consultations. Kawamata Town took the lead in using specialists to gain peace of mind, and this was key to the project's success. The situation was managed by taking measurements by dosimetry, and asking experts to interpret the data and provide advice to help reassure the residents.

Characterization of an area of reference for inhalable particulate matter (PM2.5) associated with genetic biomonitoring in children.

Humans are exposed to health-impairing air pollutants, especially children who are more sensitive to cancer-causing toxins. This study described an area of reference for inhalable particulates (PM2.5) by chemical (polycyclic aromatic hydrocarbons) and mutagenic characterization associated with the genetic biomonitoring of children (aged 5-11 years). The area studied was in a small town in Brazil, used as reference in previous studies. Organic matter of PM2.5 (extracted with dichloromethane) was evaluated for mutagenesis in a Salmonella/microsome (microsuspension) assay, in strains measuring frameshift error (TA98, YG1021 and YG1024) and base pair substitution (TA100) of DNA, in the presence and absence of rat liver metabolization fraction (S9). Exposure was studied analyzing a sample of 45 children using comet assay (peripheral blood lymphocytes) and micronucleus (exfoliated buccal mucosa cells). PM2.5 concentration for the period was 9% (25.89-64.71 µg/m3) events above WHO limit value (25 µg/m3). Mutagenesis responses (revertants/m3) varied from negative (spring) to 8.3±0.69 (autumn) (-S9) and 5.4±0.36 (winter) (+S9), in strain TA98, and for TA100, in spring, from negative to 14.8±4.23 (-S9) and 17.5±2.72 (+S9). YG strain results show mononitroarenes and aromatic amines. Mean biomonitoring values were established for MN, 0.3±0.41 (‰) and for other cell types a variation from 0.6±0.73 (‰), nuclear buds to 57.5±24.92 (‰), karyorrhexis. Comet assay means were 23.1±12.44; 7.3±11.66 and 0.9±2.30 for tail length, intensity and moment, respectively. There was no difference for sex and age for the different parameters. A significant difference in confounding factors was observed for passive smoking and MN induction. PAHs and mutagenesis in the air may be related to local vehicular emissions. These results challenge the definition of areas of reference for air pollution associated with human biomonitoring including the region studied.