Environmental monitoring and external exposure to natural radiation in Canada

Thumbnail image

Download files

DOI

https://doi.org/10.1016/j.jenvrad.2022.106811

Language of the publication
English
Date
2022-01-08
Type
Article
Author(s)
  • Liu, Chuanlei
  • Benotto, Mike
  • Ungar, Kurt
  • Chen, Jing
Publisher
ScienceDirect

Abstract

External sources of radiation originate from cosmic rays and natural radioactive elements, principally 40K and decay products in the uranium and thorium decay series occurring in the ground. People are exposed to terrestrial radiation and cosmic rays everywhere and at all times. To assess Canadians' external exposure to natural radiation, five years (2016–2020) of real-time environment monitoring data recorded by Health Canada's Fixed Point Surveillance (FPS) network were analysed for 36 monitoring stations across Canada. Absorbed dose rates in air from terrestrial radiation vary geographically and seasonally. Absorbed dose rates due to cosmic rays depend strongly on the elevation and vary with solar activities. The population-weighted annual outdoor ambient dose equivalent rates are 20 nSv/h for terrestrial radiation and 52 nSv/h for cosmic rays. Considering that, on average, Canadians spend 89% of their time indoors and 11% of the time outdoors, the population-weighted annual effective doses were calculated as 443 μSv (54 μSv outdoors and 389 μSv indoors), with 20.6% (91 μSv) from terrestrial radiation and 79.4% (352 μSv) from cosmic rays.

Plain language summary

External sources of radiation originate from cosmic rays and natural radioactive elements, principally 40K and decay products in the uranium and thorium decay series occurring in the ground. People are exposed to terrestrial radiation and cosmic rays everywhere and at all times. To assess Canadians’ external exposure to natural radiation, five years (2016-2020) of real-time environment monitoring data recorded by Health Canada’s Fixed Point Surveillance (FPS) network were analysed for 36 monitoring stations across Canada. Absorbed dose rates in air from terrestrial radiation vary geographically and seasonally. Absorbed dose rate due to cosmic rays depend strongly on the elevation and vary with solar activities. The population-weighted annual outdoor ambient dose equivalent rates are 20 nSv/h for terrestrial radiation and 52 nSv/h for cosmic rays. Considering that, on average, Canadians spend 89% of their time indoors and 11% of the time outdoors, the population-weighted annual effective doses were calculated as 486 μSv (53 μSv outdoors and 433 μSv indoors), with 20.6% (100 μSv) from terrestrial radiation and 79.4% (386 μSv) from cosmic rays.

Subject

  • Health,
  • Health and safety

Download(s)

URI

Collection(s)

Healthy environments, consumer safety and consumer products

Full item page

Full item page

Page details

Date modified: