Investigation of immunoglobulin (IgG, IgA, IgM) levels in the blood serum of uranium miners after higher and lower exposure to ionizing radiation.

The levels of IgG, IgA and IgM were measured in the blood serum of uranium miners in a minin-district, where after a geological disturbance exposure to a high level of ionizing radiation took place. The mean exposure to 222-Rn daughters after first year was 7.35 WLM, after the second year 0.13 WLM only. Serum was sampled before miners started their occupation, for the second time after the first year and for the third time after the second year. The levels of IgG and IgM significantly decreased after one year of exposure, while the IgA changed only slightly. After the second year the levels of IgG and IgM significantly rose. IgG exceeded the initial levels: a regenerative hypercompensation took place. On the other hand IgA at the same time decreased. The IgG levels are only slightly correlated with radiation dose rate; for IgA and IgM the correlation is lacking. Individual Ig levels appear to be very variable. The reduction of IgG reached hypogammaglobulinemic levels in some miners after the first year and was followed by a propensity to infections of the respiratory tract. The significance of these observations is discussed from the immunological, radiological and radiohygienical point of view.