Chronic low-dose gamma-radiation exposure and the alteration of the distribution of lymphocyte subpopulations in residents of radioactive buildings.
OBJECTIVE
To elucidate the immunological change incurred in a human population by protracted gamma-radiation exposure at home environment.


METHODS
An examination on the CD3+, CD4+, CD8+ and HLA-DR+ lymphocyte subsets was arranged for 196 exposed subjects with mean excess cumulative dose of 169 mSv during 2-13 years of exposure. Another 55 close relatives of the exposed subjects were recruited as the non-exposed reference population.


RESULTS
The mean percentages of CD4+ T-lymphocytes, HLA-DR+ lymphocytes and the CD4+ /CD8+ ratios in the exposed subjects (35.5, 19.9 and 1.51 respectively) were significantly lower than those of reference individuals (38.0, 22.6 and 1.72; p= 0.02, 0.003, and 0.03 respectively), while the CD8+ in total counts of the exposed was moderately increased above that of the reference populations (p=0.1). By ANOVA analysis, the percentages of CD4+ and HLA-DR+ subsets were significantly associated with radiation dose (p=0.0046, 0.003), while CD4+/CD8+ ratios were moderately associated with dose (p=0.073). HLA-DR+ counts were significantly and positively associated with duration of relocation from radioactive apartments (p = 0.029).


CONCLUSIONS
Significant immunological effects were observed in those who had received chronic low-dose radiation exposure.
Chang
W P
WP
Institute of Environmental Health Sciences, National Yang Ming University Medical School, Department of Family Medicine, Taipei Municipal Jan-Ai Hospital, Taiwan.
Hwang
J S
JS
Hung
M C
MC
Hu
T H
TH
Lee
S D
SD
Hwang
B F
BF
D000293:Adolescent; D000328:Adult; D017252:CD3 Complex / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000528:radiation effects; D018414:CD8-Positive T-Lymphocytes / Q000528:radiation effects; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003037:Cobalt Radioisotopes / Q000009:adverse effects; D003252:Construction Materials / Q000009:adverse effects; D004307:Dose-Response Relationship, Radiation; D004781:Environmental Exposure; D005260:Female; D005720:Gamma Rays / Q000009:adverse effects*; D006684:HLA-DR Antigens / Q000378:metabolism; D006798:Housing; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000276:immunology / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D013624:Taiwan; D013997:Time Factors
D017252:CD3 Complex; D003037:Cobalt Radioisotopes; D006684:HLA-DR Antigens