Evaluation of arsenical emission from semiconductor and opto-electronics facilities in Hsinchu, Taiwan

Semiconductor and opto-electronics industries use many chemicals including arsenics in manufacturing processes. Thus, the process vent stream contains toxic air pollutants including arsine and other arsenic compounds, and poses a potential source for the atmospheric arsenic. Limited data are published on arsenic risk assessment and work place condition for electronics industries. Moreover, as per our best knowledge there is no report available on arsenic pollution from the exhaust of semiconductor and opto-electronic industries. In this study, the total arsenic (arsenic compounds as arsenic in gaseous and particulate phase) concentration was measured in the flue gas of 20 stacks of different semiconductor and opto-electronics facilities situated in Science Based Industrial Park (SBIP), Hsinchu, Taiwan during August–September 2002. Ambient concentration of particulate arsenic (arsenic compounds as arsenic) was measured at 15 sites of SBIP twice, i.e. in September and October 2002. The concentration of the total arsenic in the flue gas was from 0 to 55.92 μg m−3 with the emission rate from 0 to 0.1427 g h−1 for the facilities. The ambient arsenic concentration was from 0 to 120 ng m−3. The ambient air level goal (AALG) of arsenic compound is 4.6×10−5 μg m−3, if the lifetime cancer probability (LCP) level is 1.0×10−6. Based on simple risk assessment model, we used Industrial Source Complex Short Term 3 (ISCST3) model to calculate the maximum ground level concentration and employed the value of AALG; the emission limit of arsenic compounds from a factory was determined to be less than 1.0×10−5 kg h−1. On comparison, it was concluded that the arsenical emission of 11 out of 20 facilities was higher than the limited value.