Nitrous Oxide Exposure Among Dental Personnel and Comparison of Active and Passive Sampling Techniques

The environmental impact of nitrous oxide inhalation sedation appointments and equipment used in dentistry

PURPOSE

This paper reports a life cycle impact assessment (LCIA) to calculate the environmental footprint of a dental appointment using N2O, comparing single-use equipment with reusable equipment. Nitrous oxide (N2O) is used successfully in dentistry to provide sedation and pain relief to anxious patients, most commonly in children. However, N2O is a powerful climate pollutant 298 times more damaging than carbon dioxide over a 100-year estimate.

METHODS

The functional unit chosen for this LCIA was 30 min delivery of N2O to oxygen in a 50:50 ratio at 6 L per minute flow rate as inhalation sedation to one patient. Two types of equipment were compared to deliver the anaesthetic gas: reusable and disposable items.

RESULTS

The use of disposable equipment for N2O sedation produces a significantly larger environmental impact across nearly all of the environmental impact scores, but the overall global warming potential is comparable for both types of equipment due to the vast environmental pollution from N2O itself.

CONCLUSION

N2O sedation is a reliable treatment adjunct but contributes to climate change. Single-use equipment has a further deleterious effect on the environment, though this is small compared to the overall impact of N2O. Dental priorities should be to deliver safe and effective care to patients that protects staff, minimises waste and mitigates impact on the environment alongside promoting research into alternatives.

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.

Operationalizing the Exposome Using Passive Silicone Samplers

The exposome, which is defined as the cumulative effect of environmental exposures and corresponding biological responses, aims to provide a comprehensive measure for evaluating non-genetic causes of disease. Operationalization of the exposome for environmental health and precision medicine has been limited by the lack of a universal approach for characterizing complex exposures, particularly as they vary temporally and geographically. To overcome these challenges, passive sampling devices (PSDs) provide a key measurement strategy for deep exposome phenotyping, which aims to provide comprehensive chemical assessment using untargeted high-resolution mass spectrometry for exposome-wide association studies. To highlight the advantages of silicone PSDs, we review their use in population studies and evaluate the broad range of applications and chemical classes characterized using these samplers. We assess key aspects of incorporating PSDs within observational studies, including the need to preclean samplers prior to use to remove impurities that interfere with compound detection, analytical considerations, and cost. We close with strategies on how to incorporate measures of the external exposome using PSDs, and their advantages for reducing variability in exposure measures and providing a more thorough accounting of the exposome. Continued development and application of silicone PSDs will facilitate greater understanding of how environmental exposures drive disease risk, while providing a feasible strategy for incorporating untargeted, high-resolution characterization of the external exposome in human studies.