Evaluation of isoflurane in air by thermal desorption-gas chromatography

Occupational Exposure to Halogenated Anaesthetic Gases in Hospitals: A Systematic Review of Methods and Techniques to Assess Air Concentration Levels

Objective During the induction of gaseous anaesthesia, waste anaesthetic gases (WAGs) can be released into workplace air. Occupational exposure to high levels of halogenated WAGs may lead to adverse health effects; hence, it is important to measure WAGs concentration levels to perform risk assessment and for health protection purposes. Methods A systematic review of the scientific literature was conducted on two different scientific databases (Scopus and PubMed). A total of 101 studies, focused on sevoflurane, desflurane and isoflurane exposures in hospitals, were included in this review. Key information was extracted to provide (1) a description of the study designs (e.g., monitoring methods, investigated occupational settings, anaesthetic gases in use); (2) an evaluation of time trends in the measured concentrations of considered WAGs; (3) a critical evaluation of the sampling strategies, monitoring methods and instruments used. Results Environmental monitoring was prevalent (68%) and mainly used for occupational exposure assessment during adult anaesthesia (84% of cases). Real-time techniques such as photoacoustic spectroscopy and infrared spectrophotometry were used in 58% of the studies, while off-line approaches such as active or passive sampling followed by GC-MS analysis were used less frequently (39%). Conclusions The combination of different instrumental techniques allowing the collection of data with different time resolutions was quite scarce (3%) despite the fact that this would give the opportunity to obtain reliable data for testing the compliance with 8 h occupational exposure limit values and at the same time to evaluate short-term exposures.

A new approach for diffusive sampling based on SPME for occupational exposure assessment

Passive sampling is a well-established methodology for the evaluation of exposures to environmental volatile organic compounds (VOCs). The solid-phase microextraction (SPME) technique is a reliable means of sampling VOCs in air. SPME is also being applied as a passive sampler to determine time-weighted average exposure. The use of SPME as a diffusive sampler was evaluated. The passive sampler is based on the use of a cylindrical diffusion cell (porous hydrophobic polyethylene) with an 80 μm carboxen/polydimethylsiloxane fiber to obtain radial diffusion of the analytes to the sorbent. Standard atmospheres of organic vapors in air were used to determine the experimental uptake rates for toluene and chlorobenzene. Toluene concentrations between 2 and 38 mg/m(3) with sampling times between 15 and 60 min were evaluated, as well as chlorobenzene concentrations between 2 and 47 mg/m(3) with sampling times between 30 and 60 min. The mean diffusive uptake rate was 2.14 mL/min for toluene and 2.57 mL/min for chlorobenzene, and no statistical significant effects of concentration and sampling time were observed under the studied conditions for the two compounds. Relative standard deviation ranged from 2.6 to 6.5%. The performance of the sampler under varying concentrations of toluene was also tested, showing that the sampler reflects the average exposure concentration. Effects of temperature, relative humidity, velocity of the air, back diffusion, competitive adsorption, and the stability of chlorobenzene in the sampler were also studied. Sampler behavior was tested in gas stations, and the results were successfully compared with a 3M-3500 diffusive sampler. The results are promising for using this new SPME device for diffusive monitoring for occupational exposure assessment.