Occupational exposure to anaesthetic gases and urinary excretion of D-glucaric acid

In order to ascertain whether the urinary excretion of D-glucaric acid (DGA) might be a suitable biomarker of effect in monitoring workers exposed to anaesthetic gases, we measured DGA before and after an operating session (and, in some workers, before and after a 2-week vacation) in 229 workers of surgical units and in 229 controls. In the former, we also measured urinary levels of nitrous oxide (N₂O) and isofiurane after at least 4 h of exposure. For all subjects, information on age, smoking habits, daily intake of alcohol, coffee, and drugs, history of liver or kidney disease was collected. Study subjects were ranked according to: exposure (class 0: subjects not exposed; class 1: N₂