Exposure to Methyl Methacrylate and its Subjective SymptomsAmong Dental Technicians,Tehran-Iran

Background and aims Methyl Methacrylate (MMA) which is known as a long, skin and eye irritant is the most common form of acrylic plastic used in dental laboratories. The aims of this study were to evaluate dental technicians, exposure to MMAand to assess their health with a focus on respiratory and dermal symptoms. Methods Exposure to MMA, total dust and health symptoms were investigated in 20 dental laboratories located in Tehran, Iran. Time weighted average (TWA) of MMA and peak concentrations were determined , using XAD-2 tubes followed by GC-ID analysis. Total dust were evaluated gravimetrically. Health symptoms were asked using a questionnaire. Results The TWAfor technicians with direct and indirect exposure to MMAwere 327.28 + 79.42 and 282.9 + 41.84 mg/m3, respectively. Peak concentration of MMA for those technicians were 337.0 + 36.81 and 328.88 + 45.40 mg/m3, respectively. There were no significant differences between TWAof MMAand peak concentration in different weakly workdays; low ever, within - day variations were observed (P<0.05). TWAof MMA and peak concentration correlation with the laboratory volume were 0.61- 0.65, Dust exposure of technicians was 2.35 + 2.70 mg/m3. Cough and Skin dryness were the common health symptoms. Smoking and asbestos exposure history were factors influencing cough prevalence (P