Dr Turnbull completed his PhD in solar UV radiation physics at the University of Southern Queensland in 2005. His PhD research has led to the development of appropriate UV minimisation strategies and recommendations for humans in shade environments, which have been forwarded to all skin cancer related groups in Australia. His research has also led to the development of new ways to expose the human body in relation to vitamin D synthesis and cancer prevention. This new vitamin D research was funded by The Cancer Council Queensland. Dr Turnbull currently works for the Department of Defence as the Executive Officer for Non-Ionising Radiation Hazard Management.