Exposure assessment to waste anesthetic isoflurane during large-animal surgery: Environmental, personal and biological monitoring.

Isoflurane is a potent greenhouse gas and a significant occupational hazard in veterinary operating rooms (VORs) lacking scavenging systems. This study performed a novel, integrated and complementary exposure assessment during large-animal anesthesia by measuring ambient air concentrations, personal breathing zone levels (badges), and internal biological doses (urinary isoflurane). Additionally, data from small- and large-animal VORs were consolidated to characterize institution-wide indoor pollution within the monitored surgical environments. Ambient concentrations were measured via infrared gas analyzer, while badges and post-shift urine samples were analyzed by GC and GC-MS, respectively. Results revealed high residual concentrations exceeding the NIOSH Recommended Exposure Limit. Large-animal anesthesiologists had mean exposures of 9 ± 1 ppm (badges) and median urinary isoflurane concentrations of 32μg/L, demonstrating that both markers were consistent with high exposure. These findings emphasize the implementation of effective scavenging and ventilation systems in veterinary settings, particularly in resource-limited regions, to safeguard occupational health and mitigate the environmental impact of anesthetic emissions.