Air quality monitoring and evaluation of bag filter performance for removal of fine particulates in roadway tunnels

Air quality was monitored in four roadway tunnels located near Seoul metropolitan area from 7:00AM to 9:00AM. PM10 concentrations range 111~268 ㎍/m 3 , which are 2~5 times higher than annual standard 50 ㎍/m 3 , and PM2.5 concentrations range 35~65 ㎍/m 3 , which are 1.5~2.5 times higher than annual standard 25 ㎍/m 3 . Benzene concentrations range 300~500 ppb, which are 200~300 times higher than 1.5 ppb which is air quality standard. Four-month long term air quality monitoring and test results in one of long tunnels show that PM10 range 30~400 ㎍/m 3 and over 97% of them can be removed by bag filter, effectively. Finally, benzene concentrations range 250~350 ppb.