Air dose rates and cesium-137 in urban areas—deposition, migration, and time dependencies after nuclear power plant accidents

ABSTRACT

The dynamics of radionuclides in terrestrial environments is a crucial consideration for environmental remediation and radiation protection after a severe nuclear disaster. Although the dynamics of radionuclides, especially ¹³⁷Cs, have been intensively studied in diverse environments and reviewed in-depth, studies in urban areas are limited and have not been reviewed so far despite the fact that urban areas have large impacts on public exposure. Our goal is to review and synthesize knowledge obtained after the Fukushima Dai-ichi and Chernobyl Nuclear Power Plant accidents to provide important information to better understand environmental radiation in urban areas. As was reported in Europe, the ¹³⁷Cs inventory (Bq m⁻²) was high on soil grounds but relatively low on impermeable surfaces such as roads and roofs because of the high initial runoff and wash-off of ¹³⁷Cs from surfaces. The air dose rate in urban areas decreased faster than that in other land uses owing to large ¹³⁷Cs wash-off on pavements and anthropogenic effects, such as decontamination. Thus, environmental recovery in urban area was thought to be facilitated by human activities and ¹³⁷Cs wash-off, reducing radiation risk of local residents comparing to the other land uses.

KEYWORDS:

• Fukushima Daiichi Nuclear Power Plant
• Cesium-137
• air dose
• deposition
• migration
• time dependency
• urban

Acknowledgments

The author would like to thank Y. Urabe and F. Yoshimura for their valuable contributions to create illustrates. This study was partially supported by Research project on the Health Effects of Radiation organized by Ministry of the Environment, Japan.

Disclosure statement

No potential conflict of interest was reported by the author(s).