Low-level X-ray exposures on rat skin. Hyperkeratinization and concomitant changes in biometal concentration.

Integumentary structures naturally are more exposed to solar radiation than other body tissues, so there is a big question regarding the biological threshold of skin in respect to low-dose ionizing radiation. In this study, adult male albino rats were exposed chronically to low-dose (0.015 cGy/sec) X-rays for 9 and 18 mo, with total X-ray dose of 2.025 and 4.050 cGy, respectively. In both the dose groups, hyperkeratinization was noted in skin by transmission electron microscopic (TEM) study. Atomic absorption spectrometric (AAS) study revealed decreased zinc concentration (p < 0.01), increased iron concentration (p < 0.001), and status quo cadmium concentration. Moreover, the ratio between zinc and iron became highly depleted in both the irradiated groups. Hence it may be stated that chronic low-level X-rays induce redistribution of biometals in the skin. Nevertheless, specific concentrations of biometals indicate the risk-prone status of irradiated skin.