The impacts of firework burning at the Chinese Spring Festival on air quality: insights of tracers, source evolution and aging processes

Abstract

Abstract. To understand the impact of firework-burning (FW) particles on air quality and human health during the winter haze period, 39 elements, 10 water-soluble ions and 8 fractions of carbonaceous species in atmospheric PM2.5 in Nanjing were investigated during the 2014 Chinese Spring Festival (SF). Serious regional haze pollution persisted throughout the entire sampling period, with PM2.5 averaging at 113 ± 69 μg m−3 and visibility at 4.8 ± 3.2 km. The holiday effect led to almost all the chemical species decreasing during the SF, except for Al, K, Ba and Sr which were related to FW. The source contributions of coal combustion, vehicle emission and road dust decreased dramatically, whereas FW contributed to about half of the PM2.5 during the SF period. The intensive emission of FW particles on New Year's Eve accounted for 60.1% of the PM2.5. Fireworks also obviously modified the chemical compositions of PM2.5, with 39.3% contributed by increased organic matter, followed by steadily increased loadings of secondary inorganic ions. The aging processes of the FW particles lasted for about 4 days reflected by the variations of Ba, Sr, NH4+, NO3−, SO42− and K+, characterized by heterogeneous reactions of SO2 and NOx on crustal materials directly from FW, the replacement of Cl− by NO3− and SO42−, coating of NO3− and SO42− on soot, formation of secondary organic aerosols and metal-catalyzed formation of NO3− and SO42− at higher relative humidity. During aging, the main contributors to the extinction coefficient shifted from elemental carbon and organic matter to ammonium sulfate. The particles raised higher cancer risk of 1.62 × 10−6 by heavy metals (especially for Cd and As). This study provided detailed composition data and first comprehensive analysis of the aging processes of FW particles during the serious haze pollution period and their potential impact on human health.

Elemental composition of ambient aerosols measured with high temporal resolution using an online XRF spectrometer

“…Absolute K and S concentrations are in good agreement with the values in Drewnick et al (2006). K likely originated from KNO 3 , a basic constituent of black powder (Drewnick et al, 2006;Kong et al, 2015).…”

“…6 and 7), which are important constituents of fireworks along with Sr as fireworks tracer (Kong et al, 2015;Moreno et al, 2007). Examination of a few raw spectra from the fireworks and non-fireworks periods indeed identified an enhancement of Sr during the fireworks duration, while the peak was definitively absent during the non-fireworks period.…”

Characteristics of air quality in Tianjin during the Spring Festival period of 2015

“…Therefore, the Cl − /Na + and OC/EC ratio of atmospheric fine particles can be used as an indicator of FD. Fireworks contain charcoal (Tsai, Chien, and Yuan 2012) and organic materials are used as adhesives, such as polyvinyl alcohol, polyoxyethylene, phenol formaldehyde resin, and shell-lac (Kong et al 2015). They are responsible for elevated OC and EC concentrations during such events (Tsai, Chien, and Yuan 2012 , respectively.…”

“…Numerous migrant residents leave the metropolises and return to their home towns to celebrate the traditional Chinese Spring Festival with their families. The decline in emissions from industrial facilities and vehicles during the Spring Festival improves air quality in the metropolises, while fireworks discharge (FD), which is the people's favorite traditional custom and practice, causes degradation in air quality (Kong et al 2015) and health hazards (Wang et al 2007). As a result, the long holiday during the Spring Festival provides us with a unique opportunity to evaluate the effects of such variation in anthropogenic emissions.…”

Fine particles from Independence Day fireworks events: chemical characterization and source apportionment

“…The stable 15 component ratio indicates relatively constant PM1 sources in and near Albany, suggesting a stable aerosol evolution process during these two time periods. A higher ratio of organics after FW events may be the result of the primary emissions of organics during the FW events, or the formation of new secondary organic aerosol (Li et al, 2013;Kong et al, 2015, Wang et al, 2007.…”