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