Body Burden of Nitrous Oxide
The purpose of this study was to determine the relationships between nitrous oxide concentration in ambient air, worker urine, and exhaled breath in dental operatories. The study also evaluated the effectiveness of a ventilation intervention in decreasing occupational exposure levels to nitrous oxide. There was a significant correlation between adjusted change in breath and urine concentrations, adjusted change in breath and ambient air concentrations, and change in urine and ambient air concentrations. The ventilation intervention did not result in a significant decrease in nitrous oxide exposures.
Pediatric Dental Clinic Nitrous Oxide Exposure and Control Characterization Study
A university dental school requested an assessment of dental personnel exposures to nitrous oxide in its pediatric dental clinic. Six dentists and seven dental assistants were sampled on several occasions with a total of 97 personal air samples collected. During the first phase of the study, 29%-49% of the samples exceeded the WISHA permissible exposure limit. Two interventions to reduce exposure were tested. In the first intervention, a new nose mask with scavenging cone was not effective in reducing exposures because the mask did not conform well to the patient’s face. The personal fan used in the second intervention did not noticeably reduce the mean procedure concentration of nitrous oxide. Recommendations were made regarding staff training, engineering controls, nitrous oxide cart testing and maintenance, and air monitoring protocols.