Porcine Skin Damage Thresholds and Histological Damage Characteristics from 1319-nm Laser Radiation

The study investigated the skin damage thresholds and histological damage characteristics in Guizhou miniature pigs exposed to 1319-nm laser radiation, with exposure durations of 0.4, 1.0, and 3.0 seconds and beam diameters of 0.98 and 1.96 cm. The ED50 damage thresholds were determined using Bliss probit analysis, revealing that at 1 hour post-exposure, the thresholds were 35.5, 36.1, and 37.1 J/cm² for the smaller beam and 28.6 J/cm² for the larger beam at 3.0 seconds. Histopathological analysis showed that near-threshold damage included nuclear chromatin gathering and cell vacuolation, while above-threshold damage involved more severe changes such as chromatin stretching, capillary lumen closure, collagen fiber alteration, and hair follicle cell necrosis. These findings contributed to understanding laser-induced skin damage mechanisms and refining safety standards for lasers in the 1300 to 1400 nm range.