Daily roadside BTEX concentrations in East Asia measured by the Lanwatsu, Radiello and Ultra I SKS passive samplers

A new home-made diffusive bag-type passive sampler called Lanwatsu was developed for benzene, toluene, ethylbenzene and xylene monitoring in roadside air. The passive samplers were outdoor validated and deployed together with two commercial passive samplers, Ultra I SKC Inc. and Radiello, for daily roadside air monitoring in East Asian cities including HoChiMinh, Hanoi, Cantho, Danang, Vungtau, Hue (Vietnam), Kuala Lumpur (Malaysia), Kyoto, Osaka (Japan), Nanjing (China) and Singapore in 2011. High daily benzene concentrations of 87, 52, 32, 23, 13, 12 and 48µg/m3 were observed in HoChiMinh, Hanoi, Cantho, Danang, Hue, Vung Tau (Vietnam), and Kuala Lumpur (Malaysia), respectively. Kyoto and Osaka (Japan) were clean with daily benzene concentrations below 2.3μg/m3. The daily benzene concentrations in Nanjing (China) and Singapore were 5.6 and 6.9μg/m3, respectively. The three passive samplers were equivalent. Passive sampling by the Lanwatsu passive sampler is acceptable for daily outdoor benzene monitoring. ► Daily benzene in Kyoto, Osaka, Nanjing, and Singapore is lower 6.9μg/m3. ► Daily benzene in small- and medium-size cities in Vietnam is 12–32μg/m3. ► Daily benzene in HoChiMinh, Hanoi, Kuala Lampur is 87, 52 and 48μg/m3. ► Motorcycles badly affect air quality by benzene pollution. ► Lanwatsu, Radiello and SKC passive samplers are alternative to active sampling.