The immune status of basically healthy personnel of OAO Uralkalii and OAO Sil'vinit was studied for three years (1998-2000) to assess the effect of the workplace environment on the parameters of the immune system. All probands were divided into groups depending on their exposure to salts or halite waste. Annual examination did not reveal any statistically significant differences between the parameters of immunograms in the groups studied. The parameters of the humoral component of the immune system of potassium-industry workers manifested a stable tendency toward normalization, irrespective of whether or not these persons were exposed to salts, and the annual contents of T and B lymphocytes and phagocytizing cells were stable within the regional standards