Effects of occupational metallic mercury vapour exposure on suppressor-inducer (CD4+CD45RA+) T lymphocytes and CD57+CD16+ natural killer cells.
OBJECTIVE
To examine the effects of metallic mercury vapour on the cellular and humoral immune system.


METHODS
We measured T lymphocyte and natural killer (NK) cell subpopulations, B lymphocytes, and serum immunoglobulins (i.e. IgG, IgA and IgM) together with total T (CD3 +) lymphocytes and total lymphocytes in blood samples from 20 male, fluorescent-lamp makers (mercury workers) and the same number of gender-, age- and smoking-matched controls. Urinary concentrations of inorganic mercury (UHg) in the 20 workers ranged from 1.8 to 163.5 (mean 44.8) microg/l. They had been exposed to mercury vapour for 4 to 62 (mean 31) months.


RESULTS
Numbers of CD4+CD45RA+ (suppressor-inducer) T lymphocytes and total CD4+ T lymphocytes in the mercury workers were significantly smaller than those in the controls (paired-sample t-test, P < 0.01). The number of CD57+CD16+ NK cells was inversely correlated with UHg.


CONCLUSIONS
It is suggested that numbers of CD4+CD45RA+ T lymphocytes and CD57+CD16+ NK cells are inversely affected by exposure to metallic mercury vapour in workers, with an average urinary inorganic mercury concentration of 45 microg/l being found.
Park
S H
SH
Department of Public Health and Occupational Medicine, Graduate School of Medicine, University of Tokyo, Japan.
Araki
S
S
Nakata
A
A
Kim
Y H
YH
Park
J A
JA
Tanigawa
T
T
Yokoyama
K
K
Sato
H
H
D000328:Adult; D015703:Antigens, CD / Q000187:drug effects*; D015704:CD4 Antigens / Q000187:drug effects; D018959:CD57 Antigens / Q000187:drug effects; D003627:Data Interpretation, Statistical; D005260:Female; D005453:Fluorescence; D006801:Humans; D019570:Inhalation Exposure; D007694:Killer Cells, Natural / Q000187:drug effects*; D017493:Leukocyte Common Antigens / Q000187:drug effects; D008029:Lighting; D008297:Male; D008628:Mercury / Q000009:adverse effects*; D016273:Occupational Exposure; D009790:Occupations; D017452:Receptors, IgG / Q000187:drug effects; D013601:T-Lymphocytes / Q000187:drug effects*
D015703:Antigens, CD; D015704:CD4 Antigens; D018959:CD57 Antigens; D017452:Receptors, IgG; D017493:Leukocyte Common Antigens; D008628:Mercury