Use of Direct Reading and Short Term Sampling of Indoor Air Quality in a Veterans Affairs Dental Clinic Laboratory for Select Air Contaminants

This screening survey was conducted to assess the concentrations of select airborne contaminants in a Veterans Affairs Medical Center Dental Laboratory. Airborne concentrations were measured for the following contaminants: ni- trous oxide (N2O), carbon dioxide (CO2), sulfur dioxide (SO2), and airborne particles or particulate matter (PM). The PM was measured and classified by the aerodynamic diameter of the particulates; specifically as PM0.3, PM0.5, PM1.0, PM2.0, PM5.0 and PM10.0.The gases were measured with a Miran Sapphire, portable infrared analyzer. The particulates were measured using the Fluke 983 Particle Counter. Using these instruments, area monitoring was conducted for concentra- tions of gases and aerosols as a result of releases from dental activities such as waxing and grinding of dental models. All area monitoring samples were collected within approximately one foot of the breathing zone of dental workers. The re- sults of this survey found the air quality in the dental laboratory was within the regulatory limits for these agents. How- ever, the concentration of SO2 was found to exceed the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLV) on more than one occasion. This was potentially due to room ventilation inade- quacies. It is recommended that the dental laboratory's ventilation system be modified and operated to assure more effec- tive dilution and removal of air contaminants.