Characteristics of fine dust pollution PM₂.₅ in Hanoi in 2021

Fine particulate matter (PM2.5) is one of the most dangerous pollutions in the atmosphere in the Hanoi capital. PM2.5 fine dust pollution characteristics in Hanoi in the duration from 5/2021 to 3/2022 have been studied. The concentration of main chemical elements (such as As, Br, Ca, Cd, Ce, Cl, Cu, Fe, K, Mn, Pb, S, Sr, Ti, Zn, Zr…), main water-soluble ions (such as Na+, NH4+, K+, Mg2+, Ca2+, SO42-, Cl-, NO3-, F-, NO2-) and black carbon (BC) in the PM2.5 sample have been analyzed. The average PM2.5 fine dust concentration was (78.09 ± 51.71) µg/m3 and ranged from 17.55 to 271.39 µg/m3. PM2.5 tends to increase and is about 3.12 times larger than Who Air Quality Guidelines 2005 (25 µg/m3 for PM2.5 24h). The average PM2.5 concentration in the rainy season from 5/2021 to 9/2021 was (51.97 ± 16.40) µg/m3. This value for the dry season from 10/2021 to 3/2022 was (104.70 ± 61.19) µg/m3. It is much higher than that in the rainy season about 2.01 times. The major contributors were the secondary components such as NH4+, SO42-, NO3- and BC... The main pollution contribution sources and the potential pollution areas map have been identified. This research shows a worrying picture of fine dust PM2.5 in Hanoi in the studying duration.