Comparison of Ambient Real-Time PM2.5 Concentrations at Major Roadside with on those at Adjacent Residential Sites in Seoul Metropolitan City

In 2013, International Agency for Research on Cancer (IARC) concluded that outdoor air pollution is carcinogenic to humans, with the particulate matter component of air pollution most closely associated with sufficient evidence of increased cancer incidence by exposure to particulate matter component of air pollution. Motor vehicles are one of a major emission sources of fine particle ($PM_{2.5}$) in urban areas. A large number of epidemiological studies have reported a positive association of morbidity or mortality with distance from the roadside. We conducted this study to assess the association of $PM_{2.5}$ concentrations measured at roadside hotspots with those at adjacent residential sites using real-time $PM_{2.5}$ monitors. We conducted real-time $PM_{2.5}$ measurements for rush hour periods (08:00~10:00 and 18:00~20:00) at 9 roadside air monitoring Hotspot sites in metropolitan Seoul over 3 weeks from October 1 to 21, 2013. Simultaneous measurements were conducted in residential sites within a 100 m radius from each roadside air monitoring site. A SidePak AM510 was used for the real-time $PM_{2.5}$ measurements. Medians of roadside $PM_{2.5}$ concentrations ranged from $9.8{\mu}g/m^3$ to $38.3{\mu}g/m^3$, while corresponding median values at adjacent residential sites ranged from $4.4{\mu}g/m^3$ to $37.3{\mu}g/m^3$. $PM_{2.5}$ concentrations of residential sites were 0.97 times of hotspot roadside sites. Distributions of $PM_{2.5}$ concentrations in roadside and residential areas were also very similar. Real-time $PM_{2.5}$ concentrations at residential sites, (100 m adjacent), showed similar levels to those at roadside sites. Increasing the distance between roadside and residential sites, if needed, should be considered to protect urban resident populations from $PM_{2.5}$ emitted by traffic related sources.

서울시 도로변지역과 인근 주거 밀집지역의 실시간 대기 중 PM2.5농도 비교