Occupational Radiation

Some Canadian workers may be exposed to radiation in the course of their daily work activities. Monitoring the exposure of workers in the radiation field is strictly regulated in Canada.

There are two ways, or pathways that people can be exposed to radiation:

• Internal exposure occurs when radioactive dust or gases get inside the body and irradiate it from within. Radioactive particles can be inhaled, ingested or absorbed through the skin.
• External exposure occurs when a person has been physically close to a source of radiation. The penetrating radiation emitted by the source travels through the air and irradiates the person.

Knowing the pathway by which a person was exposed is important for determining the radiation dose received and appropriate monitoring is available for each of these pathways.

What Health Canada programs and services support monitoring workplace radiation exposure?

• The National Calibration Reference Centre for Bioassay and In Vivo Monitoring (NCRC) provides high quality intercomparison programs to validate measurement of internal ionizing radiation exposure of workers.
• The National Dose Registry (NDR) is a centralized radiation dose record system operated by Health Canada which contains dose records of all monitored radiation workers in Canada.
• The National Dosimetry Services (NDS) provides lifelong occupational monitoring for external ionizing radiation.