Occupational exposure to ionizing radiation has no effect on T- and B-cell total counts or percentages of helper, cytotoxic and activated T-cell subsets in the peripheral circulation of male radiation workers.
OBJECTIVE
To investigate changes in immune cell subsets in the peripheral circulation of a male population occupationally exposed to ionizing radiation.


METHODS
Peripheral blood samples were taken from 194 male workers with cumulative exposures of >200 mSv (mean exposure 331.5 mSv, mean age 51 years) and from a reference population of 131 male workers with cumulative exposures of <27.5 mSv (mean exposure 13.9 mSv, mean age 47 years). Samples were analysed by flow cytometry for T- and B-cell total counts and for the T-cell subset percentages of CD4+ (helper T-cells), CD8+ (cytotoxic T-cells) and CD3+/HLA-DR+ (activated T-cells).


RESULTS
Comparison of the >200 and <27.5 mSv exposure groups using linear regression analysis showed no statistically significant differences between the two groups for T-cell total count, B-cell total count or for percentages of the T-cell subsets CD4+, CD8+ or CD3+/HLA-DR+ and CD4+:CD8+. However, statistically significant increases in both T- and B-cell total counts were observed within the two exposure groups and data pooled from both groups when non-smokers (never and ex-smokers) were compared with current smokers. For pooled data T-cell total count increased in smokers by 35% (p=0.0001) and B-cell total count increased by 37% (p=0.0004).


CONCLUSIONS
No significant immunological effects were observed in male radiation workers with cumulative exposures of >200 mSv when compared with a reference population with cumulative exposures of <27.5 mSv, although highly significant increases in both T- and B-cell total counts were observed in smokers compared with non-smokers.
Rees
G S
GS
Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3JY, UK. gwen.rees@westlakes.ac.uk
Daniel
C P
CP
Morris
S D
SD
Whitehouse
C A
CA
Binks
K
K
MacGregor
D H
DH
Tawn
E J
EJ
D000328:Adult; D001402:B-Lymphocytes / Q000528:radiation effects*; D006801:Humans; D008213:Lymphocyte Activation / Q000528:radiation effects; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D012907:Smoking / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000528:radiation effects; D013601:T-Lymphocytes / Q000528:radiation effects*