Chemical Characteristics of PM2.5 during 2015 Spring Festival in Beijing, China

Abstract

Air pollution especially of PM 2.5 pollution is a serious problem in Beijing. In order to quantify the effect of a festival in which pollution was expected to be reduced, we collected and analyzed PM 2.5 samples in urban Beijing during the 2015 Spring Festival (from February 9 th to March 6 th 2015). We divided the sampling period into three phases: non-haze, haze and firework days. The average concentration of PM 2.5 was highest on firework days at 248.9 µg m -3 , followed by haze days (199.9 µg m -3 ) and non-haze days (90.8 µg m -3 ). The air quality of non-haze days during the holiday was better than that during non-holiday periods. 2-/K + and Cl -/K + effectively distinguished the characteristics of PM 2.5 between firework events and haze days. Ion balance calculations indicated that the acidity of PM 2.5 from firework days was higher than that from haze and non-haze days. A method using enrichment factors (EF) found that crustal elements (EF < 10 on all three types of days) included Ca, Al, Fe, Na, Co, Ni, P, Ti, and V; firework elements (EF > 10 on firework days, significantly higher than haze days) were made up of Ba, Cr, Cu, Mg, Pb, S, Si, and Zn; common anthropogenic pollution elements (EF > 10 in all three types of days) were As, Cd, Cu, Pb, S, Sb, Zn. Differences in chemical characteristics indicated that holidays such as the Spring Festival can affect air pollution patterns in two ways: a decrease in the population and vehicles but an increase in activities such as firework displays.

Impact Assessment of COVID-19 on Variations of SO2, NO2, CO and AOD over East China

“…However, after the country adopted strict restrictive measures to control COVID-19, which led to the suspension of many plants and enterprises, emissions of SO 2 , NO 2 and CO throughout the country were significantly reduced, leading to improved air quality. Another reason for the reduction in emissions may be due to the Lunar New Year holiday (from February 5 to 20 in 2019 and from January 24 to February 8 in 2020), which was consistent with the results of previous studies (Lai and Brimblecombe, 2017;Zhang et al, 2017;Safarian et al, 2020). The reduced use of coal and crude oil led to a reduction in CO emissions of about 20% compared to the same two-week period after the Lunar New Year in 2019.…”

Chemical characteristics of water-soluble ions and metal elements in ambient particles of Saitama, Japan during the spring asian dust event, 2017

“…The main ionic contents in coarse particles were Na + , Ca 2+ , Cl − and NO 3 − . Especially, Ca 2+ , usually originated from crustal particles and construction industry [12], was mainly located in the coarse particles and high to 0.37 μg/m 3 in roadside and 0.41 μg/m 3 in 10F sampling site resulting about two times higher value than those in other periods. Na + was also mainly enriched in the coarse particles, which was also considered as the main component of sea salt.…”

“…Ion balance is commonly used to study the acid-base balance of aerosol particles. The ions' mass concentrations into micro-equivalents were calculated to evaluate the cation/anion balance of PM 1.1 and the coarse particles [12]. Ion balance was calculated as in follows eqns.…”

Air quality during and after festivals: Aerosol concentrations, composition and health effects

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