Neurobehavioral functions in paramedical operating theatre personnel were assessed in a cross-sectional survey. Sixty-two subjects (40 males and 22 females) occupationally exposed to anesthetic gases were examined and compared to 46 unexposed hospital workers (18 males and 28 females). The Simple Reaction Time (SRT) test was selected from the MANS battery (Milan Automated Neurobehavioural System). In order to evaluate acute and subacute types of effects on performance, the test was administered before and after the work shift, at the beginning and at the end of the working week. In addition, the complete battery was administered during one working day without exposure to anesthetic gases. On the last day of the working week, atmospheric nitrous oxide (N2Oa) ranged from 7 to 553 ppm (geometric mean 62.6), atmospheric ethrane (ETHa) ranged from 0.1 to 18.8 ppm (geometric mean 1.3), and urinary N2O (N2Ou) ranged from 4 to 297 μg/l (geometric mean 26.8). An impairment of performance on the SRT test was observed at the end of the working week in subjects exposed to anesthetic gases compared to controls. This alteration was observed also considering only the subjects exposed to less than 55 μg/l (which is the Italian exposure limit for N2Ou, equivalent to 100 ppm for N2Oa). No significant differences were observed for the other psychometric tests. No dose-effect relationships where found between SRT tests score and the indicators of exposure (N2Oa, ETHa, N2Ou). These findings suggest that short-term, reversible impairments of vigilance and response speed can occur in operating theatre personnel at levels of exposure to anesthetic gases below the TLVs currently adopted in Italy (100 ppm for N2O in old operating theatres, 2 ppm for ETH). Nonetheless, in these exposure conditions, other factors such as stress and work organization seem to be involved in the impairment of performance.
