study of volatile organic materials concentrations (btex) and electromagnetic fields in printing and copying centers in hamadan

printing and copying centers have been implicated as an emission source of pollution, and affecting air quality in closed environments. the aim of this study was to measure the btex compound (benzene, toluene, ethyl benzene, and xylenes), and the intensity of electromagnetic fields and the uva ray in photocopy centers in the hamadan city. this descriptive study was done on 45 printing and copying centers during 2011 to 2012. in order to measure the intensity of electromagnetic fields and uva intensity, the hi-3603 and 3604 vlf and elf survey meter and a radiometer (hanger eci-uv-a) were used, respectively. for sampling btex compounds in the air, using osha and niosh guidelines, activated carbon tubes manufactured by skc was used. air in taking was performed by a personnel pump (skc, 224-44ex). according to niosh method and skc sorbent instructions, the sampling time of 8 hours and air flow passing of ml/min200 was chosen. after sampling, two-end of the glass tube adsorbent was completely closed by a plastic cap and they were maintained at a temperature of zero degrees celsius prior to extraction and analysis. after extracting, the samples were measured using a gas chromatography (varian cp-3800) equipped with a fid detector. data were managed using spss version 16 and the relation between electromagnetic field intensity values ​​and measuring distances (30, 50 and 60cm) was analyzed by pearson statistic test. the results of the analyses showed that maximum concentrations of benzene, toluene and xylene were 9.3, 11.3 and 9 mg/m3, respectively and ethyl benzene was not observed in any of the samples. the results of magnetic fields intensity measurements were 4.33 ± 3.07 and 0.25 ± 0.095 v/m for elf and vlf, respectively and electrical field was 0.292 ± 0.108 ma/m. the mean value obtained for uva was 0.0281 ± 0.02 mw/cm2. the statistical tests showed significant correlation between the electromagnetic field intensity values and measuring distances (p≥0.05). the results of the study showed that btex compound concentrations, intensity electromagnetic fields and uva ray levels were below the accepted occupational standards and guidelines.