Working night shifts does not appear to increase the risk of developing cancer, a study has shown.
Research conducted in Sweden on records of all people who were on the population census in 1960 and 1970 and who worked at least 20 hours a week in 1970.
Researchers collected information on the 3.2m people included in the study between 1971 and 1989 or until a worker was diagnosed with cancer or died.
This included details of their jobs and looked for those who were exposed to working night shifts.
Final results show no relationship between shift work and prostate, colon or breast cancers or any other type of cancer, regardless of how much the occupation depended on shift work.