Jon has over 15 years' experience in radiation protection including performing radiological assessments, working on the underlying models and tools and developing guidance to protect public health. He has contributed to the development of the Level-3 (off-site consequences) probabilistic safety analysis code PACE, for evaluating the consequences of radiation accidents and is an expert in modelling the transfer of radionuclides through the terrestrial foodchain, in particular using the UKHSA's model FARMLAND. He was a member of UKHSA teams which contributed to WHO and UNSCEAR assessments of the levels of exposure to members of the public following the Fukushima-Daiichi nuclear power plant accident in 2011. Since 2020, he has become more involved in developing guidance for managing recovery following a radiation incident and was a lead author of version 5 of the UK Recovery Handbook for Radiation Incidents, published in 2024.