Chemical composition and morphology of PM2.5 in a rural valley during Chinese New Year's Eve: Impact of firework/firecracker display

Relaxation of Spring Festival Firework Regulations Leads to a Deterioration in Air Quality

“…Corresponding to the increase in metal tracers during firework displays, a significant rise in the RPA of chlorine was observed, accompanied by a synchronous and noteworthy increase in the EC mass concentration and the EC/PM 2.5 mass ratio (Figure a). Charcoal is the main ingredient in fireworks, and potassium perchlorate (KClO 4 ) or potassium chlorate (KClO 3 ) primarily serve as the oxidizers in fireworks, releasing O 2 and leaving behind KCl through thermal decomposition. − Similar concentration spikes of these chemical components have also been widely documented in other firework events. ,, …”

“…43−45 Similar concentration spikes of these chemical components have also been widely documented in other firework events. 13,14,42 The increased abundance of the aforementioned species associated with fireworks, coupled with a decrease in the RPAs of nitrate and ammonium, as well as a reduction in the OC/EC mass ratio (mean: 2.33; minimum: 0.96) during firework displays, provided compelling evidence that direct emissions from fireworks significantly contributed to the elevated PM 2.5 levels observed on NYE, NYDN, and LFN. The atmospheric particles observed during firework displays, which comprised emissions from fireworks and local sources such as residential coal combustion, vehicle exhaust, road dust, and cooking emissions, exhibited an enrichment in organic compounds, EC, inorganic ions, and metals (Figure S9).…”

“…SO 2 and CO exhibited patterns similar to those of PM 2.5 during the displays on the NYE and LFN, providing additional evidence of the direct impact of fireworks on air quality, given that sulfur and carbon are integral components of pyrotechnics. 2,19,37,38 In contrast, previous years, particularly 2022, witnessed stringent restrictions on fireworks to ensure optimal air quality for the 2022 Winter Olympics and benefited from favorable meteorological conditions, 13,39,40 resulting in the minimal occurrence of high PM 2.5 events during the study period.…”

“…Fireworks, a prevalent feature of celebratory events worldwide, pose a significant threat to air quality and public health due to their widespread usage. − The Chinese Spring Festival (SF), celebrated from New Year’s Eve (NYE) to the 15th day [Lantern Festival (LF)] of the Lunar New Year, is marked by extensive fireworks and firecracker displays, raising environmental pollution and public health concerns. , Both NYE and LF hold cultural significance and are celebrated with nationwide nocturnal firework displays. Firework emissions release substantial amounts of gaseous pollutants and particles, which include organic compounds such as polycyclic aromatic hydrocarbons (PAHs), − elemental carbon (EC), , inorganic salts (i.e., sulfate, nitrate, chloride, potassium, chlorate, and perchlorate), and metals like Al, Cu, Ba, Sr, Mg, and Ti. − These emissions pose a challenge for dispersion within a stable nocturnal boundary layer and tend to accumulate near the ground, thereby deteriorating air quality. ,, Even with the use of environmentally friendly fireworks, their extensive utilization can still have a detrimental impact on air quality, potentially inducing the formation of reactive oxygen species and acute respiratory infections such as coughing, fever, rhinitis, asthma exacerbation, and pneumonia due to inhalation of dense smoke containing toxic chemicals including heavy metals and PAHs. ,, …”

“…Given the prevalence of stagnant meteorological condition and heightened emissions from coal-fired heating during winter, − many cities have progressively implemented policies since 2015 to prohibit or restrict the sale and release of fireworks during the SF in order to mitigate severe pollution. ,− However, considering the arguments for preservation and reverence of traditional folk culture in China, as well as the evident improvement in air quality resulting from a series of stringent clean air actions, certain regions opted to considerably relax these restrictions during the 2023 SF, which thereby led to a substantial challenge in maintaining air quality . Therefore, a comprehensive analysis of the precise impact of fireworks on air quality in China’s current atmospheric environment is imperative to establish scientifically reasonable management measures and strike a balance between cultural conditions and environmental protection.…”