Nearly 1,000 watchmaking buildings and workshops in Switzerland could be contaminated by radium, a radioactive element that was used to add luminescence to watch dials and hands until the 1960s.
The study by the University of Bern, commissioned by the Federal Office of Public Health, shows that radium was used in almost 700 buildings. In addition, there are approximately 300 other buildings where the use of radium is uncertain. The findings double previous estimates of potential radium contamination in Switzerland.
A third of the identified sites are in the canton of Neuchâtel, and another third in the canton of Bern –mainly in the Biel watchmaking region. The remaining third is divided between the canton of Solothurn and the rest of the Jura Arc, which houses the bulk of the country’s watchmaking hubs.
The Federal Office of Public Health examined the premises with the help of the municipalities concerned. Systematic checks have already taken place on 400 of the 700 contaminated buildings. Eighty sites required remediation work that has been completed or is underway in over 50 locations.
According to the health office, buildings must be remediated if the people spending time there are exposed to more than one millisievert (mSv) of radium per year.
For buildings in which the use of radium is uncertain, investigations are under way. Authorities will assess whether systematic monitoring is required.
The University of Bern's research was conducted within the framework of the Radium 2015-2019 action plan launched by the health office. The remediation work already carried out by the health office, the Swiss Accident Insurance Fund (SUVA), and the army consisted in most cases of removing floors or other materials, and soil from gardens. An evaluation report will be submitted to the Federal Council by the end of 2018.
The budget for the clean-up – approved by the Federal Council in 2015 – is CHF5 million ($5.1 million at the time).