Exposure Worry, Ageing, and Cognitive Functioning.

George Collett and Mary Gilhooly

Centre for Health Effects of Radiological and Chemical Agents, Institute of Environment, Health and Societies, Brunel University London

What is the aim of this project?

The aim of this PhD project is to examine factors associated with cognitive functioning. This is an important aspect of healthy ageing and quality of life. There is no current research on the cognitive/mental health effects upon British nuclear test veterans from witnessing nuclear tests, and more research is urgently required. However, this aspect is being explored with increasing priority for people elsewhere, affected by radiation effects from the Chernobyl and Fukushima incidents. A special feature of this veteran study is an examination of radiation ‘exposure worry’ and cognitive functioning in later life.

Specifically, we will be examining whether levels of ‘exposure worry’ predict cognitive functioning. We will also look to explore the mechanisms of ‘exposure worry’ and how it may develop after witnessing a nuclear test. Furthermore, we will examine whether employment history and education are related to levels of ‘exposure worry’ and cognitive functioning.

How will we conduct our research?

The overall project will invite members of the British Nuclear Test Veterans Community to participate and will involve data gathering via in-depth interviews, questionnaires, and cognitive assessments.

We are currently developing a questionnaire to measure ‘exposure worry’ in nuclear test-veterans. Before we can use our questionnaire in our main study, we need to ensure that our questionnaire is appropriate and that our questionnaire “works”. In order to do this, we require around 120 test veterans to complete and return our questionnaire. If you would like to take part, you can contact us using the details below. We will then send you a ‘pack’ containing our questionnaire and information regarding the study. The pack will also include a stamped envelope which you will use to send your completed questionnaire back to us.

Why is this important?

This study would add to the growing body of research on the impact of life events on cognitive functioning in old age. The benefits from this research would be wide, because a deeper understanding of the factors that influence decline in cognitive functioning with age would be of interest to older people across society. The health services would also benefit from a better knowledge of the factors contributing to poorer cognitive functioning and dementia. The present study will also apply to the psychological effects of being exposed to chemicals such as Agent Orange and the Bhopal Gas Tragedy.

What do we already know about radiation exposure, worry, and cognitive functioning?

Recent studies suggest a link between radiation exposure (particularly after relatively high doses) and faster biological ageing, and as a consequence, to age-related diseases which may impact mental processes (known as cognitive functioning). Cognitive functioning includes memory, problem solving, and reasoning. There is evidence following Chernobyl suggesting that higher levels of radiation exposure in adults is associated with reduced cognitive functioning in later life, although the relationship between lower levels of radiation exposure and cognitive functioning is not clear. However, public health studies examining Hiroshima survivors did not find a link between levels of radiation exposure and dementia, nor a link between radiation dose and cognitive decline in later life.

Aside from the physical effects of radiation exposure, the World Health Organisation has argued that mental health impact is one of the biggest consequences following a nuclear incident. For example, widespread anxiety and depression in both contaminated and decontaminated regions surrounding the Chernobyl area have been observed. Even in people who were exposed to very low levels of radiation, the psychological effects can be large and persistent. The term radiation-anxiety is used to describe the worry regarding the possible negative health effects of radiation exposure, as well as any perceived stigma relating to radiation exposure.

Research has suggested a link between poorer cognitive functioning and greater levels of anxiety in older adults. Although anxiety is not the same as stress, the two are closely related and both are associated with raised blood pressure. High blood pressure in mid-life has been associated with poorer cognitive functioning in later-life. Furthermore, anxiety is associated with health-risk behaviours such as smoking and heavy alcohol consumption, both of which contribute to poorer cognitive functioning in later life. It is possible, therefore, that besides any impact of potential exposure to radiation on cognitive functioning in old age, persistent worry about the potential damage to oneself and to one’s children could also impact the cognitive functioning of test veterans.