title: Exposure to methyl methacrylate and its subjective symptoms among dental technicians, Tehran, Iran.
abstract: Exposure to methyl methacrylate (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-FID analysis. Total dusts were evaluated gravimetrically. Health symptoms were asked using a questionnaire. TWA for technicians with direct and indirect exposure to MMA were 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 TWA of MMA and peak concentration in different weekly workdays; however, within-day variations were observed (P < .05). TWA of 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 < .05). It is concluded that the current Short-Term Exposure Limit (STEL) is not low enough to protect technicians against the adverse effects caused by MMA.
authors.affiliation: School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, IR Iran. gol128@sphtums.com
authors.forename: Farideh
authors.initials: F
authors.lastname: Golbabaei
authors.forename: Maryam
authors.initials: M
authors.lastname: Mamdouh
authors.forename: Keramat Nouri
authors.initials: KN
authors.lastname: Jelyani
authors.forename: Seyed Jamaleddin
authors.initials: SJ
authors.lastname: Shahtaheri
mesh_terms: D000328:Adult; D003800:Dental Technicians; D005260:Female; D006801:Humans; D007492:Iran; D008297:Male; D020366:Methylmethacrylate / Q000009:adverse effects* / Q000302:isolation & purification; D008875:Middle Aged; D016273:Occupational Exposure; D011795:Surveys and Questionnaires
chemical_list: D020366:Methylmethacrylate