Male reproductive impairment linked to occupational ionizing radiation exposure in radiology workers.

Chronic occupational exposure to ionizing radiation (IR) may affect male reproductive health but the underlying genetic and immunologic mechanisms remain poorly defined. This study aimed to evaluate the effects of IR on semen quality, CD56-positive natural killer (NK) cell concentration and sperm nuclear protein gene expression. In this case-control study a total of 60 men were assessed 30 radiology workers with IR exposure and 30 men in the control group. Semen analysis was performed according to WHO 2021 criteria. NK cells were determined by CD56 immunocytochemical staining and mRNA expression levels of TNP1, TNP2 and CD56 were measured by qPCR. Compared with the control group the IR group had significantly lower sperm concentration and a higher frequency of morphological abnormalities (p < 0.05). NK cell concentration was significantly increased (p < 0.001) whereas TNP1 was significantly decreased (p < 0.001). TNP1 mRNA levels were downregulated in exposed subjects whereas TNP2 expression showed a non-significant reduction. Weak to moderate correlations were observed between gene expression profiles and selected sperm parameters. In conclusion chronic occupational IR exposure is associated with impaired semen quality, heightened NK cell concentration and altered nuclear protein gene expression, potentially compromising male reproductive health. These findings highlight the need for reproductive health monitoring and protective strategies among radiation-exposed healthcare workers.