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The Porton Down Veterans Cohort Study


The study was set up in 2003 by the University of Oxford to explore the long-term health of former servicemen who were exposed to chemical warfare agents as part of the ‘human volunteer programme’ at the UK government research establishment, Porton Down. The study includes 18,276 former servicemen who participated in the programme from 01/04/1941 to 31/12/1989, and a comparison group of 17,600 similar servicemen who did not.

The original, first phase of the study examined whether exposure to chemical agents was associated with excess cancer or mortality up to 2004. The results of the first phase showed no overall difference in cancer rates between the Porton Down and non-Porton down veterans. Mortality rates were slightly (6%) higher in Porton Down veterans compared to non-Porton Down veterans; however, this excess could not be directly attributed to chemical exposures at Porton Down. Publications from the first phase of the study can be found listed below.

A new, second phase of the study, based at KCMHR, is currently underway and will extend follow-up for cancer and mortality data by at least another ten years. The study is also exploring the potential for linkage with further  datasets, so that health outcomes other than cancer and mortality (e.g. hospital admissions) can be included in future analyses.

Who are we?

The study is coordinated by King’s Centre for Military Health Research (KCMHR), King’s College London, which is the leading civilian United Kingdom (hereafter “UK”) centre of excellence for military health research. KCMHR is independent of the UK Ministry of Defence (hereafter “MoD”) and our work has helped shape government policy towards military personnel, veterans and their families. Our research is conducted within the KCL governance framework which ensures that our work is carried out to high scientific and ethical standards.

King’s College London is the sponsor for this study based in the UK. We will be using information from military records and national registry data on deaths and cancers in order to undertake this study, and will act as joint data controllers for this study in collaboration with the University of Lancaster. This means that we are responsible for looking after your information and using it properly.


What information was collected in the original study?

We extracted the names, service numbers, and chemical exposure information (e.g. type of chemical, date of the test) of all service personnel who were in the Porton Down records from 01/04/1941 to 31/12/1989. We then cross-checked names and service numbers against military personnel records to gather other data relevant to health or necessary for data linkage, where that data was recorded in the records (e.g. date of birth, place of birth, military rank, dates of joining and leaving the service, address at enlistment, National Health Service (hereafter “NHS”) number). In order to create a similar comparison group, for every Porton Down veteran we picked another serviceman with a neighbouring service number who had not visited Porton Down, and extracted the same military service details. To link these veterans’ data with information on cancers and mortality, we needed to share some details (e.g. name, date of birth, place of birth, address, military service number, NHS number) with the Office for National Statistics (hereafter “ONS”). If the veteran had died in the period up to 2004, the ONS sent us the date and cause of death and, if the veteran had developed a cancer, the cancer registration details. After we received the data from ONS, we removed all identifiable information, e.g. name and military service number, to create a ‘de-identified’ data file to be used for statistical analyses.


What information are we collecting for the new study?

King’s College London are collecting updated information on mortality and cancer data for the Porton Down Veterans study from NHS Digital, NHS Scotland and the Northern Ireland Statistics and Research Agency. As in the first phase, this information will include cancer type and date of registration, which is regarded as a special category of information. We will use this information to update the original analyses. In future analyses, we plan to link veterans’ data with NHS data on other health outcomes; for example, cardiovascular and respiratory diseases, and mental health problems.   


Why is the study being updated?

Almost nothing is known about whether exposure to a chemical warfare agent might affect a person’s long-term health. But this topic remains of concern, given that rogue states and terrorists continue to use these chemicals. Even though the tests at Porton Down used low exposures, this study is the largest and best-documented in the world on this topic and it is, therefore, a valuable scientific resource, not only for the Porton Down veterans themselves but also for others who might become exposed to these chemicals, e.g. emergency service personnel and civilian populations. The longer we can continue our follow-up, the more informative it is scientifically; for example, we may be able to conduct analyses not possible in the original study (e.g. investigate rarer forms of cancer).


How will we share the findings of the study?

We will publish the findings of the updated statistical analysis in scientific papers and we will publicise them in the veterans’ and armed forces communities, e.g. by making them available for relevant newsletters and websites. If the updated statistical analysis shows that there is an effect on the pattern of deaths or cancers that appears to be caused by the chemicals used in the ‘human volunteer programme’, then we will inform the MoD and the NHS armed forces team so that support can be put in place for veterans and their families. We will also inform organisations responsible for public health, e.g. Public Health England. If there appears to be no effect, then this will reassure veterans and their families.

Scientific papers will contain only anonymous, aggregated data (e.g. percentages and averages) presented as tables and figures. The scientific papers will not contain any data on individual veterans.

How long will we hold the data?

KCMHR, King’s College London will keep identifiable information about you for 20 years after the study has finished, to enable us to carry out this update and likely future analyses. If, in 20 years no future analyses are planned, all the data we hold will be securely destroyed.

How do we keep your information safe and secure?

The original study data has been transferred from secure storage at Oxford University to KCMHR, King’s College London. Where this information could identify you, the information will be held securely with strict arrangements about who can access the information. At KCMHR, all paper-based documents will be held in a locked filing cabinet in an alarmed office, and a secure off-site archive. All electronic information will be held securely on encrypted external hard-drives. Access to all information will be strictly limited to authorised members of the KCMHR study team. The data file used for analyses by the study team will be de-identified, meaning we remove all names, and other identifiable information (e.g. military service number, NHS number). This information will be stored separately from the analyses file, and password protected and encrypted.

The information will only be used for the purpose of health and care research. It will not be used to make decisions about future services available to you, such as insurance. Where there is a risk that you can be identified your data will only be used in research that has been independently reviewed by an ethics committee.

What is the legal basis for holding these data?

The lawful basis for processing this information is:

Article 6(1.e) of the General Data Protection Regulation (GDPR): processing is necessary for the performance of a task carried out in the public interest or in the exercise of official authority vested in the controller.

The special condition category is article 9(2)(j) of the General Data Protection Regulation (GDPR): processing is necessary for archiving purposes in the public interest, scientific or historical research purposes or statistical purposes in accordance with Article 89(1) based on Union or Member State law which shall be proportionate to the aim pursued, respect the essence of the right to data protection and provide for suitable and specific measures to safeguard the fundamental rights and the interests of the data subject.

How can you access your own data?

We do not have permission to access source records (except for the specific information supplied to us for the original study and this study). Individual veterans can apply to access the same original sources that we used:

Contact the Porton Down Help Line for a detailed report on the tests you took part in:

For a copy of your military service records, see the website:

To order a copy of a death certificate, see the website:

To obtain details about a cancer registration, see the website of the National Cancer Registration and Analysis Service:

The Veterans health team is the team that responds to concerns raised by Porton Down veterans. Details are on

Rights of access

You have the right to see the information we hold about you. If you would like to access your information please contact the KCL Data Protection Officer: Mr Albert Chan (Assistant Director of Business Assurance) Information Compliance team,
King's College London, Waterloo Campus Room 5.20, James Clerk Maxwell Building,
57 Waterloo Road, London, SE1 8WA; or by email:

How can I object to my data being used?

Article 21 of the GDPR gives individuals the right to object to the processing of their personal data.

If you wish to object to your personal data being processed please email your reason(s) to the KCL Data Protection Officer: Mr Albert Chan (Assistant Director of Business Assurance) Information Compliance team, King's College London, Waterloo Campus Room 5.20, James Clerk Maxwell Building, 57 Waterloo Road, London, SE1 8WA; or by email: Objections will be responded to without undue delay and within one month of receipt.


If you wish to raise a complaint on how we have handled your personal data, you can contact our Data Protection Officer who will investigate the matter. If you are not satisfied with our response or believe we are processing your personal data in a way that is not lawful you can complain to the Information Commissioner’s Office (ICO).

Our Data Protection Officer is Mr Albert Chan and you can contact them at Information Compliance team, King's College London, Waterloo Campus Room 5.20, James Clerk Maxwell Building, 57 Waterloo Road, London, SE1 8WA; or email:

Information for researchers

We will not make any record-level data publicly accessible because we need to protect the confidentiality and security of the individual cohort members. You are welcome to contact us with proposals for collaborative research, which the investigators will consider on a case-by-case basis, and which will only occur as part of a legal collaborative agreement and after the collaborator has put in place the relevant research ethics, data protection, and data access approvals. Please contact Professor Fear:

Project status: Ongoing

Principal Investigator

Contact us

For general enquiries relating to the study, or to find out more about how we use your information, please contact us: