PILOT MONITORING OF ULTRAFINE PARTICLE NUMBER CONCENTRATIONS IN SOME HIGH RISE APARTMENTS IN HANOI

Abstract

Epidemiological studies have consistently shown that fine and course airborne particles (PM_2.5 and PM₁₀), as well as ultrafine (UF) particles measured in terms of particle number (PN) concentrations, are toxic to human health. A number of studies on particle concentrations in households were conducted worldwide; however, no such studies have so far been conducted in Vietnam. Using two Nano-Tracers, the authors have simultaneously and continuously measured both indoor and outdoor number concentrations of UF particles at two high rise apartments in Hanoi in order to quantify the concentrations and initially develop an understanding of factors driving them. Daily average indoor and outdoor PN concentrations ranged from 12.9 to 19.8 x 10³ p/cm³ and from 21.3 to 35.5 x 10³ p/cm³, respectively. However, mean concentrations of indoor and outdoor PN during rush-hours were higher and increased up to the maximum of 24.0 and to 57.8 x 10³ p/cm³, respectively. Inspection of time series of particle concentration and subsequent statistic analysis showed that outdoor PN concentrations were strongly influenced by the outdoor vehicle emissions, while indoor PN concentrations were contributed by both indoor and outdoor sources. It is the first time, UF particle number concentrations outside and inside the high rise apartments in Hanoi were quantified.

Keywords: Ultrafine particle; high rise apartment; traffic; indoor activities.

Received: August 22^th, 2016, revised: September 5^th, 2016, accepted: October 13^th, 2016