<qa>  What is the relationship between the degree of oxidative stress and psychological stress?The purpose of this study is investigate to the effects of chronic occupational exposure to N20 and volatile anesthetics on the extent of oxidative stress DNA damage and the generation of the biochemical markers in operating room staff, with different levels of exposure to halogenated hydrocarbons, in comparison to unexposed controls Intensive Care Staff, and to determine the relationship between the degree of oxidative stress and psychological stress, as assessed by validated psychometric measures. 