Information for participants
The Small Area Health Statistics Unit (SAHSU) is a long-standing and internationally-recognised centre of excellence assessing the risk of exposure to environmental agents to the health of the population. SAHSU was established in 1987 as a recommendation of the Black enquiry into the incidence of leukaemia and lymphoma in children and young adults near the Windscale/Sellafield nuclear power plant. SAHSU has a particular role nationally in carrying out environmental health surveillance of the population in relation to environmental agents and sources of industrial pollution, based on routinely collected health data. This is a highly specialised area of work requiring excellence in computing, database management, geographical information systems (GIS), statistics, environmental exposure assessment and epidemiology. The set of skills and expertise that has been established and built up in SAHSU is a unique resource both nationally and worldwide.

A public involvement session

Study publications
The primary outputs from our work are publications in peer-reviewed journals. We maintain a regularly updated list of these on our publications page. We have also provided an atlas of interactive maps for a range of health conditions and environmental agents at a neighbourhood scale in England and Wales.

What happens with my data? How is information about me collected for the SAHSU studies?
SAHSU studies access and use data from several national data providers which include NHS England, Office for National Statistics, Welsh Cancer Intelligence and Surveillance Unit, NHS National Services Scotland, Cystic Fibrosis Trust, and the Department of Education. Data are only obtained, held and used with strict information governance and ethical permissions with over-arching permission for the SAHSU database from the Health Research Authority Confidentiality Advisory Group and the National Research Ethics Service. We do not hold names, phone numbers or emails of individuals.

Is the information collected about me secure?

Your data is processed in a secure environment controlled and managed by Imperial College. Access to your identifiable data is limited to a small database team within SAHSU. Researchers only have access to data that have been anonymised. Separation is maintained at all times between the database team who handle identifiable data and researchers.

How long will my data be held?
The SAHSU research database has been established for many years. Individual projects typically require access to data for up to 20 years. Permission for the length of time a dataset will be held are given by each data provider.

What are the potential benefits of the studies
The SAHSU research database enables research on key public health issues associated with environmental agents within small areas. The results of the SAHSU studies are published and made available to the public. Publications provide information to healthcare providers and help to inform national policy.

What if I do not want to be involved in the studies?
If you do not wish your records to be included in the SAHSU research database then please contact us at and we will contact the data provider(s) as we do not hold names of individuals. If you have already contacted the data provider(s) you do not need to contact SAHSU as well.

Contact us our email address is