Specific indoor environmental quality parameters in College computer classrooms

The indoor environmental quality parameters, including temperature, relative humidity, air velocity, particulate matter concentration, illumination level, sound level, carbon dioxide concentration and ventilation rate in two computer classrooms and one general classroom were evaluated. Analytical results reveal average carbon dioxide concentration in the three classrooms during daytime classes was 785"1681 ppm. These values exceeded the exposure limits for indoor air quality suggested by the Environmental Protection Administration of the Republic of China, Taiwan [ROCEPA]. The particulate matter concentration in the general classroom was 0.087 mg/m[3], which exceeded the indoor air quality exposure limit for Type-1 venues recommended by the ROCEPA. Illumination level in the two computer classrooms was 386 and 176 Lux; these values are far lower than the illumination level for school classrooms suggested by Ministry of Education, Taiwan. Indoor sound levels in the three classrooms during non-class [51.4"61.9 dB[A] and class times [61.0"73.6 dBA exceeded the limit recommended by the Ministry of Education, Japan. The ventilation rates for the three classrooms were 0.41"0.65 h[-1]; such low ventilation rates were likely responsible for the very high indoor carbon dioxide concentrations in the three classroom during class periods. These analytical results indicate schools should examine the efficacy of air-conditioning equipment in classrooms, particularly computer classrooms. Schools should also pay attention to ventilation rates and sound levels. Due to the poor ventilation rates in computer classrooms, this study suggests that problems arisen from the accumulation of specific toxicants dispersed by computer equipment, such as polybrominated diphenyl ethers, need further investigations

Airborne polybrominated diphenyl ethers in a computer classroom of college in Taiwan

This study characterized the airborne exposure of students to thirty polybrominated diphenyl ether congeners inside and outside a computer classroom in a southern Taiwan college. Arithmetic mean values of total indoor and outdoor polybrominated diphenyl ether concentrations were 125.0 pg/m3 [89.8 to 203.9 pg/m3] and 110.3 pg/m3 [83.5 to 157.0 pg/m3], respectively. Total indoor polybrominated diphenyl ether concentrations were one order of magnitude lower than those detected in homes in Birmingham, United Kingdom and in Ottawa, Canada but were several times higher than those measured in the ambient air in Ottawa, Canada and from the Bohai Sea to the Arctic. The five highest indoor concentrations of polybrominated diphenyl ether congeners were decabromodiphenyl ether [23.0 pg/m3], 4,4'-dibromodiphenyl ether [15.9 pg/m3], 2,2',3,4,4',5,5',6-octabromodiphenyl ether [10.6 pg/m3], 2,4-dibromodiphenyl ether [10.3 pg/m3] and 2,2',3,4,4',5',6-heptabromodiphenyl ether [10.0 pg/m3]. Although indoor and outdoor total polybrominated diphenyl ether concentrations did not significantly differ, the indoor concentrations of 2,4-dibromodiphenyl ether, 2,2',4-tribromodiphenyl ether, 2,4,4'-tribromodiphenyl ether, 2,2',4,5'-tetrabromodiphenyl ether and 2,3',4',6-tetrabromodiphenyl ether were significantly higher than their outdoor concentrations. This study suggests the following measures: 1] to increase the air exchange rate and open classroom doors and windows for several minutes before classes to reduce indoor PBDE concentrations; 2] to reduce polybrominated diphenyl ether emissions from new devices, it's better to use computer-related products that meet the Restriction of Hazardous Substances Directive adopted by the European Union

Exposure to ethylene glycol monobutyl ether and related workers habits in an ink factory

Forty six workers fram an ink fzctoy were included in this study in with passive badge sampler and questionnaire interview were used to assess the concentrations of airborne exposure to ethylene glycol monobutyl ether during work shifts and to understand the subjects' working habits. The geometric mean value [95% confidence interval] of the airborne ethylene glycol monobutyl ether concentrations was 0.12 [0.08-0.19] ppm, with a range of <0.02-1.82ppm. The exposure group was exposed to statistically significantly higher ethylene glycol monobutyl ether concentrations than the control group [geometric mean value: Q.l4vs. 0.03ppm; P=0.017]. Some chromatograms showed that subjects were co-exposed to m-xylene, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether acetate. According to the completed questionnaires, subjects might also be exposed to 1,2,4,5-tetramethylbenzene, propylene glycol ethers, ethanol, 1,2,4-trimethylbenzene, methanol and diisononyl phthalate. This study also suggests that, the Taiwan occupational time-weighted average level of ethylene glycol monobutyl ether be reconsidered with a view to being lowered