Part III - Historical Survey of the Porton Down Service Volunteer ...

the study was carried out in 1973. If a National Serviceman had left the Services in, for
example, 1955, only his medical history to that date was considered in this follow-up study.
Indeed, the average length of Service after the volunteers had visited Porton was about 4
years, and varied between 4 months and 10 years.
The points made were as follows [113]:
• no significant difference was found in the instances of illness experienced by the
men exposed to GB and those not exposed, after they had been to Porton;
• there was no significant difference in the sicknesses experienced by men
exposed to GB before and after their visit to Porton;
• no incidents of psychiatric illness were recorded among the 37 men who had
been exposed to GB. One man was invalided for psychiatric reasons from the
group who had not been exposed.
The conclusion drawn was that there was no evidence that exposure to GB at Porton had any
adverse effect upon health, psychiatric or otherwise, of the volunteers exposed to GB
considered by this follow-up study.
A third follow-up study was conducted which analysed medical records of volunteers who
attended Porton between March 1975 and Feb 1980 [114]. Sixty volunteers were chosen for
the study: 30 who had not been exposed to GB during their stay and 30 who had (some of
these took part in studies of nerve agent treatments during which they were exposed to GB,
and some were partially protected when they were exposed). Medical records for three of the
men could not be traced from Service sources and therefore 57 volunteers' medical records
were analysed (29 had been exposed to GB). Service medical records were used, covering
the period up to the end of October 1988, when the study was conducted, or up to the
volunteer's discharge from service. The average length of service since a volunteer had
attended Porton was around 80 months; 24 of the 57 volunteers considered were still serving
at the time of the study.
The medical incidences (measured per 1000 man months) for the two groups were compared
and the observations are summarised in Table 9.3.
Medical Incident Group exposed to GB Group not exposed to GB
Pre-Porton Post-Porton Pre-Porton Post-Porton
Admission to hospital, sick
bay, station sick quarters
17.4 9.5 9.1 8.2
Out patient referrals for
specialist consultation
8.7 4.7 7.3 6.1
Days lost through sickness
133.3 109.6 147.7 73.5
Table 9.3. Medical incidences in third follow-up study
The incidences were not significantly different between groups, nor within groups before or
after the men had attended Porton. The causes of illness were also analysed and no
significant differences were found. There were no cases, in the records used in this study, of
psychiatric invaliding. The conclusion made was that there was "no evidence from this study
that the exposure of volunteers to low doses of nerve agents results in any adverse medical
sequelae" [114].
9.6.3. Detachment of the retina
In January 1982 [99] the Institute of Aviation Medicine (IAM) suggested Porton should adopt
more stringent standards for volunteers used in miosis studies. IAM was concerned that
short-sighted people (myopes) might suffer a detachment of the retina if they were exposed
to GB. GB could induce spasms in the ciliary muscles of the eye (the ciliary muscles form a
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