Cancer incidences among uranium processing workers in an Ontario community were no different than general population, a federal study suggests.

The town of Port Hope, about 100 kilometres east of Toronto, has had a radium and uranium refinery and processing plant since 1932. Projects are underway to remove radioactive soil from the town and to track health outcomes of workers.


A device used for measuring radiation levels is seen in front of a container with spent highly-enriched uranium at a nuclear research facility. Port Hope, Ont. has had a radium and uranium refinery and processing plant. (Gleb Garanich/Reuters)

"Overall, workers had lower mortality and cancer incidence compared with the general Canadian population," the Canadian Nuclear Safety Commission said in a release Thursday.

Researchers looked at cancer cases and deaths among 3,000 refinery workers in the town, 90 per cent of whom were followed for at least 20 years and compared the incidence and mortality with elsewhere in Canada.

 "There was no meaningful evidence of an association between radon decay product exposure and increased risk of any causes of death or cancer incidence," Lydia Zablotska of the University of California, San Francisco's department of epidemiology and biostatistics and her co-authors wrote in the journal BMJ Open. 

The study's authors, including Rachel Lane from the commission, looked at all cancers combined as well as specific cancers that are sensitive to radiation.

Exposures to radium and uranium were analyzed separately.

Mortality and incidence of tobacco-related cancers were similar to the general population.

The length of the study and follow-up were strengths. Given the relatively small size of the group of workers, the authors called for data to be pooled with other groups of radium and uranium processing workers.