Characteristics of 2975 Porton Down veterans exposed to sarin and 2919 non-Porton Down veterans
| Sarin-exposed Porton Down veterans (n=2975) | Non-Porton Down veterans (n=2919) | |
| n (%) | n (%) | |
| Service at enlistment | ||
| Army | 1192 (40.1) | 1165 (39.9) |
| Airforce | 1082 (36.4) | 1074 (36.8) |
| Navy | 701 (23.6) | 680 (23.3) |
| Decade of birth | ||
| <1920 | 19 (0.6) | 41 (1.4) |
| 1920–1929 | 292 (9.8) | 311 (10.7) |
| 1930–1939 | 1993 (67.0) | 1933 (66.2) |
| >1940 | 671 (22.6) | 634 (21.7) |
| Place of birth | ||
| England | 2440 (82.0) | 2338 (80.1) |
| Scotland | 264 (8.9) | 298 (10.2) |
| Wales | 121 (4.1) | 133 (4.6) |
| Northern Ireland | 41 (1.4) | 41 (1.4) |
| Other | 109 (3.7) | 109 (3.7) |
| Age at enlistment (years) | ||
| <16 | 238 (8.0) | 216 (7.4) |
| 16–17 | 930 (31.3) | 825 (28.3) |
| 18–19 | 1353 (45.5) | 1303 (44.6) |
| 20–21 | 336 (11.3) | 378 (12.9) |
| >21 | 118 (4.0) | 197 (6.7) |
| Age at start of follow-up (years) | ||
| 14 to <20 | 1257 (42.3) | 1191 (40.8) |
| 20 to <22 | 835 (28.1) | 794 (27.2) |
| 22 to <25 | 618 (20.8) | 599 (20.5) |
| 25 to <35 | 242 (8.1) | 298 (10.2) |
| 35+ | 23 (0.8) | 37 (1.3) |
| Period of enlistment* | ||
| Before or during World War II | 94 (3.1) | 104 (3.6) |
| After World War II | 2339 (78.6) | 2295 (78.6) |
| Post-National Service | 542 (18.2) | 520 (17.8) |
| Rank at enlistment | ||
| Private | 2952 (99.6) | 2901 (99.6) |
| Other | 13 (0.4) | 12 (0.4) |
| Missing | 10 | 6 |
| Total duration of service (years) | ||
| <2 | 107 (3.6) | 450 (15.4) |
| 2<3 | 831 (28.0) | 950 (32.5) |
| 3<5 | 318 (10.7) | 330 (11.3) |
| 5<10 | 842 (28.4) | 610 (20.9) |
| 10+ | 870 (29.3) | 579 (19.8) |
| Missing | 7 | 0 |
| Previous duration of service before test/start of follow-up (years) | ||
| <1 | 577 (19.4) | 573 (19.6) |
| 1<2 | 995 (33.4) | 982 (33.6) |
| 2<5 | 922 (31.0) | 897 (30.7) |
| 5<10 | 381 (12.8) | 373 (12.8) |
| 10+ | 100 (3.4) | 94 (3.2) |
| Any neoplasm† | ||
| Yes | 1009 (34.8) | 1021 (35.8) |
| No | 1890 (65.2) | 1832 (64.2) |
| Total number of cancers† | ||
| 0 | 1890 (65.2) | 1832 (64.2) |
| 1 | 789 (27.2) | 792 (27.8) |
| 2+ | 220 (7.6) | 229 (8.0) |
| Vital status | ||
| Deceased | 1598 (53.7) | 1583 (54.2) |
| Alive | 1042 (35.0) | 1032 (35.4) |
| Lost to follow-up‡ | 335 (11.3) | 304 (10.4) |
*World War II dates taken as 1 September 1939–30 April 1945; the period when national service was in force was taken as 1 May 1945–31 December 1960, with the sample, including both regulars and National Service personnel.
†Of 2899 Porton Down veterans and 2853 non-Porton Down veterans alive at the start of follow-up for cancer (1 January 1971).
‡Last known date alive in the UK, for example, discharge from the services, emigration or date last traced.