Effect of simultaneous exposure to inhalational anesthetics and radiation on the adaptive response in operating room personnel

Some operating room personnel, such as orthopedic surgeons, are exposed simultaneously to inhalational anesthetics (IAs) and radiation that both can cause DNA damage. Some studies have shown that low doses of radiation reduce DNA damage when the cells are followed by a higher dose of the same or related agent. This study, therefore, set out to compare DNA damage in the anesthesiologists, radiologists, orthopedic surgeons, and healthcare staff (non-exposed group). In this crosssectional study, breathing zone concentrations of anesthetic gas nitrous oxide (N2O) were measured in the studied groups using standard method. Additionally, DNA damage was measured by micronucleus (MN) assay. The mean concentrations of N2O in the anesthesiologists and orthopedic surgeons were 450.27 +/- 327.44 ppm and 313.64 +/- 216.14 ppm, respectively. The mean annual exposure to X-rays radiation in radiologists and orthopedic surgeons was 15.65 +/- 8.46 mSy/year and 3.56 +/- 1.32 mSy/year, respectively. MN frequencies were significantly higher in anesthesiologists and radiologists exposed to IAs and X-rays radiation respectively than in the non-exposed healthcare staff. While, there were no statistically significant differences between MN frequencies of orthopedic surgeons exposed to both IAs and radiation and healthcare staff. These findings suggest that an earlier exposure of orthopedic surgeons to a small dose of ionizing radiation can increase their resistance to genotoxicity caused by high doses of N2O, a phenomenon that is called adaptive response.