Next Article in Journal
Applicability of Food Monitoring Data for Assessing Relative Exposure Contributions of Pyrethroids in Retrospective Human Biomonitoring Risk Estimations
Next Article in Special Issue
An In-Field Assessment of the P.ALP Device in Four Different Real Working Conditions: A Performance Evaluation in Particulate Matter Monitoring
Previous Article in Journal
The Distribution Characteristics and Potential Risk Assessment of Lead in the Soil of Tieguanyin Tea Plantations in Anxi County, China
Previous Article in Special Issue
Airborne Pesticides—Deep Diving into Sampling and Analysis
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Toxics
Volume 12
Issue 1
10.3390/toxics12010023
toxics-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Effects of Fireworks Burning on Air Quality during the Chinese Spring Festival—Evidence from Zhengzhou, China

by
Xinzhan Liu
1,2,
Ling Yang
1,2,*,
Yan Wang
1,2,
Pengfei Yan
1,2 and
Yimeng Lu
1,2
1
College of Geography and Environmental Science, Henan University, Kaifeng 475004, China
2
Key Laboratory of Geospatial Technology for Middle and Lower Yellow River Regions, Henan University, Ministry of Education, Kaifeng 475004, China
*
Author to whom correspondence should be addressed.
Toxics 2024, 12(1), 23; https://doi.org/10.3390/toxics12010023
Submission received: 21 November 2023 / Revised: 21 December 2023 / Accepted: 22 December 2023 / Published: 25 December 2023
(This article belongs to the Special Issue Detection of Air Pollutants)
Browse Figures
Versions Notes

Abstract

:
Fireworks burning significantly degrades air quality over a short duration. The prohibition of fireworks burning (POFB) policy of 2016 and the restricted-hours fireworks burning (RHFB) policy of 2023 in Zhengzhou City provide an ideal opportunity to investigate the effects of such policies and of fireworks burning on air quality during the Spring Festival period. Based on air quality ground-based monitoring data and meteorological data for Zhengzhou City, the article analyzes the impact of the POFB policy and the RHFB policy on air quality. The results show that: (1) The ban on fireworks burning significantly affects Spring Festival air quality, with a decrease of 16.0% in the Air Quality Index (AQI) value in 2016 compared to 2015 and a 74.9% increase in 2023 compared to 2022. (2) From 2016 to 2022, the Spring Festival period witnessed a substantial decrease in average concentration of main pollutants, along with a delayed occurrence of peak concentrations, indicating a noticeable “peak-shaving” effect. However, in 2023, there was an increase in pollutant concentrations, volatility, and a significant surge in hourly concentration. (3) The POFB policy and RHFB policy notably impacted PM2.5 and PM10, with a decrease of 16.1% and 23.6% in PM2.5 and PM10 concentrations, respectively, in 2016 compared to 2015, but an increase of 74.5% and 79.2%, respectively, in 2023 compared to 2022. (4) The contribution of fireworks burning to PM2.5 concentrations significantly decreased during the fireworks burning period (FBP) in 2016 after the POFB policy and increased significantly in 2023 during FBP after the implementation of the RHFB policy. Unfavorable meteorological conditions will undoubtedly exacerbate air quality pollution caused by fireworks burning.

1. Introduction

Fireworks burning is a traditional Spring Festival custom, which has been part of the celebration for more than 1000 years in China. Throughout ancient times, the widespread practice of fireworks burning emerged within Chinese culture. Fireworks are emblematic of peace and prosperity, not only in China but also in other cultures, such as during Diwali in India [1,2,3,4], the Chaharshanbe-Suri Cultural Festival in Iran [5], New Year in the Netherlands [6], and various New Year’s celebrations observed in numerous countries [7,8,9,10,11].
Fireworks are primarily composed of black powder [12], which includes sulfur powder (S), potassium nitrate (KNO3), charcoal powder (C), and may also contain potassium chlorate (KClO3) and potassium perchlorate (KClO4). To achieve vibrant colors, additional components, such as magnesium powder, iron powder, aluminum powder, antimony powder, and inorganic salts, are incorporated into the manufacturing process. Unfortunately, fireworks burning leads to multiple forms of pollution, including noise pollution [13,14,15], light pollution, and significant amounts of litter. Furthermore, fireworks release substantial quantities of particulate pollutants and gas pollutants, such as SO2 and NOx (nitrogen oxides), which significantly contribute to the deterioration of air quality. This release affects the health and safety of individuals. Even when weather conditions are favorable for dispersion, the act of fireworks burning can still result in rapid and significant short-term rises in levels of air pollutants [16,17,18,19]. These increases can further exacerbate existing pollution levels if weather conditions are unfavorable, thereby presenting risks to both human health and environmental quality [17,18,19,20,21,22,23,24].
The impact of fireworks burning on air quality during the Spring Festival period has garnered significant attention from the academic community. Rindelaub et al. [25] compared PM10 samples before and after fireworks burning and found that setting off fireworks and firecrackers caused an increase in airborne particulate matter concentrations and an increased risk of PM10 exposure for the population. Moreno et al. [26] collected aerosol samples before and after fireworks burning, and comparative analyses revealed significant increases in concentrations of suspended particulate matter and metals. The study also highlighted significant health risks associated with highly concentrated fireworks burning. Scholars analyzed the effect of fireworks burning on air quality and found that fireworks increased the concentration of aerosol, resulting in the deterioration of air quality with elevated concentrations of main pollutants [1,16,27,28,29,30]. By monitoring the changes in particulate matter in Nanning, Li et al. [31] found that fireworks burning was the main source of particulate matter. Kong et al. [32] also discovered that fireworks burning was the primary source of PM2.5, leading to significant increases in heavy metal concentrations and contributing to increased air pollution. Yuan et al. [33] measured the size of aerosols in Chengdu during the Spring Festival period in 2019 and found that fireworks burning leads to enhanced hygroscopicity of aerosols of larger sizes, further exacerbating air pollution in the Sichuan Basin. In their study, Song et al. [34] employed diverse exposure models to compare and analyze the risks associated with PM2.5 exposure among residents at various times throughout the year, aiming to assess their health levels. The findings indicated that air quality is notably polluted by fireworks burning. Hickey et al. [35], through a comparison of the metal content in various types of fireworks and their effects on human health, identified a positive correlation between the rise in cardiovascular disease incidence and fireworks emissions. Their research emphasized the imperative of prohibiting fireworks and offered guidance for the development of more environmentally friendly alternatives. In their comparison of air pollution exposure preceding the onset of different types of cardiovascular diseases, Cecconi et al. [36] demonstrated that short-term exposure to air pollutants emitted from a large number of fireworks-related activities significantly increased the probability of myocardial infarction.
Drawing from an extensive body of research literature, Lin [15] demonstrated the imperative of stringent environmental regulations and holiday restrictions on fireworks burning. Wang et al. [37], through a study on the variations in PM2.5 concentration in the air during holiday celebrations, particularly focusing on changes in the concentration of heavy metal substances, confirmed that the intake of heavy metals through respiration can elevate the burden on blood circulation. These substances can then reach various organs through the bloodstream, leading to disorders and dysfunctions in several systems within the human body. Li et al. [38] integrated long-term PM2.5 ground monitoring data with volunteers’ blood data to investigate the impact of varying environmental health levels on human blood health. The results confirmed a close correlation between various blood parameters and the level of air pollution. The findings consistently demonstrated a strong association between blood data and air pollution levels. Fan et al. [39] precisely modeled changes in air quality levels in economically developed cities in China, utilizing data from a high-density air observation network of sites to quantify the extent of the impacts. Simultaneously, they proposed the production of more environmentally friendly fireworks in future campaigns to counteract the negative impacts on human health caused by fireworks emissions, leading to significant improvements.
To solve the serious problem of air pollution, government departments have formulated a series of policies, namely no-burn, no-setting off, and no-sale. Scholars conducted a comparative assessment of the air quality before and after the enforcement of the POFB policy and found that the concentrations of particulate showed a decreasing trend after the implementation of the POFB policy, indicating a significant improvement in air quality. Liu et al. conducted a comparative analysis of air quality in Zhengzhou before and after the implementation of the POFB policy spanning from 2014 to 2019. The study revealed a significant “peak-shaving” effect, with findings strongly suggesting that the enforcement of the POFB policy played a crucial role in enhancing air quality in Zhengzhou [40]. Zhao et al. analyzed the impact of fireworks burning on air quality in Linyi City from 2021 to 2022 during the implementation of the POFB policy. Their study focused on the Spring Festival period and revealed a significant improvement in air quality due to the POFB policy. The findings underscored the necessity of implementing the POFB policy during the Spring Festival [41]. Yao et al. analyzed the changes in air quality before and after fireworks burning by measuring the concentrations of gaseous pollutants in Shanghai from 2013 to 2017 and found that PM2.5 concentrations showed a decreasing trend after the implementation of the POFB policy [42]. Yang et al. analyzed the changes in PM2.5 concentrations before and after the implementation of the POFB policy based on a random forest model and found that restricting fireworks burning had a significant effect on mitigating air pollution and that the air pollution mitigation effect had significant spatial and temporal heterogeneity [43]. Singh et al. found that a government ban on fireworks burning during the COVID-19 period resulted in effective pollution prevention and control during Diwali [44]. Parra et al. modeled changes in PM2.5 concentration and observed a decrease, with regards to an earlier fireworks display [14].
The above studies are based on the premise of the POFB policy to explore the overall impact of fireworks burning on the region. However, fewer studies conduct pairwise comparisons before and after the implementation of the RHFB policy. Additionally, existing studies often have a relatively short duration, typically limited to one year. Consequently, long-term comparative serial studies are deficient, and there is no comparative analysis of air quality during the three distinct periods of “no ban—ban—restricted hours” for fireworks burning discharge.
In 2014, Zhengzhou City, the capital of Henan Province, experienced poor air quality, leading to its inclusion in the list of cities with poor air quality made by China’s ecological and environmental monitoring agency [45]. Consequently, the POFB policy was introduced in 2016, with the banning area gradually expanding until 2019, when fireworks were banned citywide in Zhengzhou. However, the municipal administration of Zhengzhou announced its intention to permit limited-duration fireworks burning at the end of December 2022. As a result, in 2023, Zhengzhou witnessed not only extensive fireworks organized on a large scale but also numerous fireworks ignited by individual residents. The implementation of the “no ban—ban—restricted hours” policy on fireworks provides us with a different perspective, making it even more crucial to consistently pay attention to and assess the effectiveness of these prohibition and restriction policies.
By analyzing ground-based air quality monitoring data, we studied the effects of the POFB policy and the RHFB policy on air quality during the fireworks burning period (FBP) and non-fireworks burning period (NFBP) from 2015 to 2023. The results of the study will provide scientific guidance for government.

2. Materials and Methods

2.1. Study Area

Zhengzhou City (112°42′ E to 114°14′ E, 34°16′ N to 34°58′ N) is located in the central part of Henan province and is the provincial capital. The study area is depicted in Figure 1.

2.2. Data Sources

China’s Ministry of Ecology and Environment has implemented a ground-level air quality monitoring system that covers a majority of the country’s cities. The monitoring data are released on its official website. The ground-level air quality monitoring data used in this study are sourced from the China Ecological Environment Monitoring Platform (https://www.air.cnemc.cn:18007, accessed on 3 May 2023). The meteorological monitoring data, which includes information on wind speed and relative humidity, were obtained from the World Weather website “https://www.rp5.ru (accessed on 4 May 2023)”. Figure 1 illustrates the distribution of 12 air quality ground monitoring stations and 2 meteorological stations in Zhengzhou City.

2.3. Methods

2.3.1. Data Processing and Analysis

The investigation period spans from the Chinese New Year to six days after the Chinese New Year (from the 1 January to the 7 January in the lunar calendar), comprising a total of 7 days annually from 2015 to 2023.
The following definitions are applied in this study: “daily average” refers to the average of the 24-h concentrations in a day, while “annual Spring Festival average” represents the arithmetical average of the daily concentrations averaged over the entire Chinese Spring Festival period within a calendar year [46]. Following the National Ambient Air Quality Standards, as presented in Table 1, the AQI is divided into six levels, each corresponding to the respective level of air pollution [46,47,48,49].
The pandas package in Python was used for data processing and analysis. The matplotlib package in Python was used for data graph drawing. The air quality monitoring data and meteorological data have passed both the Shapiro–Wilk test and the Levene test. The data meet the necessary criteria for conducting research and analysis.

2.3.2. Correlation Analysis

Pearson’s correlation coefficient is employed to quantify the strength of a linear correlation between two variables. The range of the correlation coefficient is (−1, 1). It is calculated as follows:
P X , Y = c o v ( X , Y ) σ X σ Y = n ∑ i = 1 n x i y i − ∑ i = 1 n x i ∑ i = 1 n y i n ∑ i = 1 n x i 2 − ( ∑ i = 1 n x i ) 2 n ∑ i = 1 n y i 2 − ( ∑ i = 1 n y i ) 2

2.3.3. Relative Ratio Method

To exclude the effects caused by meteorological conditions, CO [41,50,51] was selected as a reference indicator to compare and analyze the contribution of fireworks burning to PM2.5 before and after the POFB policy and RHFB policy, and calculated as follows:
P M 2.5 ( R ) = C O × ( P M 2.5 ¯ / C O ¯ ) P n f
P M 2.5 ( F ) = P M 2.5 ( M ) − P M 2.5 ( R )
P M 2.5 ( C ) = P M 2.5 ( F ) / P M 2.5 × 100 %
The ( P M 2.5 ¯ / C O ¯ ) P n f represents the ratio of hourly average PM2.5 to CO concentrations during NFBP. The PM2.5(R) represents the effect of other emission sources on PM2.5 during FBP. The PM2.5(M) represents the hourly average concentrations of PM2.5 during FBP (ug/m3). The PM2.5(F) the relationship of fireworks burning to ambient PM2.5, with units of μg/m3. The PM2.5(C) represents the contributions rate of ambient PM2.5, with units of %.
According to the traditional Chinese Spring Festival custom [52,53], the NFBP was defined as 19:00 on Lunar 29 December to 12:00 on NewYear’s Eve, and the FBP was defined as 19:00 on NewYear’s Eve to 12:00 on Lunar 1 January.

3. Results

3.1. Air Quality Index(AQI) Characteristics

3.1.1. Variation of Annual Spring Festival AQI Average

As shown in Figure 2, the annual Spring Festival AQI average exhibited a fluctuating pattern, wherein it first decreased sharply and subsequently fluctuated downwards and then saw a sharp rise. The lowest annual Spring Festival AQI average occurred in 2022 (AQI = 64.1), falling under Grade II (Moderate), while the highest was recorded in 2015 (AQI = 181.3), classified as Grade IV (Very unhealthy). This is primarily attributed to Zhengzhou’s initiation of the POFB policy in 2016, resulting in a substantial decrease in fireworks burning. As a result, the annual Spring Festival AQI average in 2016 decreased by 16.0% compared to 2015.
There was a small increase in AQI values in 2017–2018, compared with the same period in 2015. This was largely attributed to the exemption from the RHFB policy for certain areas during the 2017–2018 Spring Festival period. This situation was further exacerbated by a significant number of firework thefts and subsequent illegal discharges [17].
The expansion of the ban on fireworks burning in 2019 led to a significant drop in the AQI average compared to 2018, and the air quality improved overall. From 2019 to 2022, the annual Spring Festival AQI average continued to decrease, due to the POFB policy. The implementation of the RHFB policy in 2023 (AQI = 112.2) resulted in a significant increase in the annual Spring Festival AQI average, rising by 74.9% compared to 2022 (AQI = 64.1), with air quality once again reaching Grade III (Unhealthy for sensitive people) pollution levels.

3.1.2. Variation of Daily AQI Average

In 2023, the daily AQI average in Zhengzhou exhibited fluctuations during the Spring Festival period, as revealed in Figure 3. Specifically, the daily average AQI value was 112.2, with the highest values recorded on 1 January and the lowest on 3 January, with values of 237.5 and 51.5, respectively. Notably, the AQI average increased and decreased significantly from 1 January to 3 January, reaching its peak on 1 January.
Such observations can be attributed to the temporary deterioration of air quality resulting from widespread fireworks burning during the Spring Festival period, followed by a continued decrease in existing pollutants leading to an overall improvement in air quality. Essentially, the AQI average displayed noteworthy fluctuations throughout the Chinese Spring Festival period, characterized by single peaks, with the worst air quality recorded on January 1st, followed by a rapid improvement in air quality post-festival.
Figure 4 presents the daily average AQI and corresponding air quality classes for the Chinese Spring Festival period from 2015 to 2023. From 2017 to 2022, the air quality improved, indicating the effectiveness of the POFB policy in maintaining stable air quality. The peak AQI average on 2 January 2019 was mainly due to elevated humidity and the proximity of Zhengzhou City to the Beijing–Tianjin–Hebei region. The regional transport and diffusion of pollutants from New Year’s Eve fireworks burning also played a contributing role, aligning with the findings of Fu et al. [20].
Conversely, the implementation of the RHFB policy in 2023 resulted in a pronounced degradation of air quality, marked by a notable increase in the AQI average. This can primarily be attributed to residents participating in fireworks activities more frequently due to the policy, resulting in a decline in air quality.

3.2. Variation of Concentrations in Main Pollutants

The burning of fireworks has an impact on the levels of different pollutants in the air. Figure 5, Figure 6 and Figure 7 display the changes in average concentrations of the main pollutants from 2015 to 2023, both annually and daily. The concentrations of the main pollutants were discussed in two time periods: first, from 2015 to 2016, which included the period before and after the POFB policy in 2016; second, from 2022 to 2023, which included the period before and after the implementation of the RHFB policy in 2023.

3.2.1. Variation before and after Implementation of POFB Policy (2015–2016)

Based on the graphs in Figure 5, Figure 6 and Figure 7, it is observed that there are changes in the average concentrations of main pollutants. The concentrations of PM2.5, PM10, SO2, NO2, O3, and CO recorded in 2015 were 136.8, 206.2, 39.5, 34.4, 35.7 μg/m3, and 1.6 mg/m3, respectively. In 2016, these concentrations were 114.7, 157.4, 49.3, 37.7, 57.9 μg/m3, and 2.2 mg/m3. Notably, PM2.5 and PM10 levels significantly declined, while O3 concentrations showed a minor increase. Other pollutants remained relatively unchanged during the Spring Festival period from 2015 to 2016.
According to Figure 7, daily average concentrations of PM2.5, PM10, and O3 decreased from 1 January to 2 January 2015. On 2 January, the daily average concentrations of PM10, SO2, and CO reached their lows at 106.5, 25.5 μg/m3, and 1.3 mg/m3, respectively. In contrast, PM2.5, NO2, and O3 showed a marked decrease. The daily average concentrations of PM2.5 and NO2 reached their respective troughs of 95.7 and 21.7 μg/m3 on 4 January. Following the implementation of the POFB policy, the daily average concentrations of all pollutants, except O3, reached their maximum from 4 January to 5 January 2016. However, there was no notable rise in pollutant concentrations on 1 January 2016.
In conclusion, there was a significantly higher concentration of main pollutants on 1 January before the implementation of the POFB policy. After the introduction of the POFB policy, the daily average concentrations of main pollutants peaked and then rapidly minimized, indicating a significant improvement in air quality due to the POFB policy. The POFB policy has been identified as having the most notable impact on the concentrations of PM2.5 and PM10, as indicated in previous studies [54,55].

3.2.2. Variation of before and after Implementation of RHFB Policy (2022–2023)

The annual Spring Festival average concentrations of PM2.5, PM10, SO2, NO2, O3, and CO in 2022 were 42.5, 71.8, 8.0, 16.4, 76.8 μg/m3 and 0.5 mg/m3, respectively. In 2023, these concentrations were 76.2, 128.6, 11.1, 17.1, and 60.0 μg/m3, 0.8 mg/m3, respectively.
Compared to 2022, PM2.5, PM10, SO2, and CO exhibited an increase in average concentrations by 79.2%, 79.2%, 37.7%, and 41.5%, respectively. This rise is mainly attributed to the implementation of the RHFB policy, causing an increase in residents’ fireworks activities and subsequently causing a significant decline in air quality.
From 2 January to 4 January 2022, the daily average concentrations of PM2.5, PM10, SO2, and O3 and CO peaked at 60.1, 96.6, 9.2, 84.7 μg/m3, 0.6 mg/m3, respectively. On 1 January, the daily average concentrations of NO2, and PM2.5 reached a minimum of 11.4, 27.3 μg/m3, respectively, while PM10 reached a sub-minimum of 61.9 μg/m3. This improvement is attributed to the implementation of the POFB policy, contributing to better air quality.
In 2023, the daily average concentrations of PM2.5, PM10, SO2, NO2 and CO peaked at 195.0, 264.3, 26.7, 28.1 μg/m3, and 1.2 mg/m3, respectively, on 1 January. From 1 January to the 3rd, the daily average concentrations of PM2.5, PM10, SO2, NO2, CO exhibited a decreasing trend. Furthermore, on 3 January, the daily average concentrations of PM2.5, SO2, NO2, and CO reached their respective trough levels of 15.2, 5.4, 6.1 μg/m3, and 0.4 mg/m3, with the second trough for PM10 recorded at 59.6 μg/m3 on the same day in 2023. Following the implementation of the RHFB policy in 2023, the annual Spring Festival average concentrations of main pollutants increased in 2023 compared to 2022.
Additionally, the peak daily average concentration increased, and it occurred significantly earlier, peaking on 1 January. These findings further support the idea that fireworks burning can significantly deteriorate air quality over a brief period.

3.3. Variation of Hourly Concentrations of Main Pollutants

Figure 8 illustrates the variation in hourly concentrations of main pollutants from New Year’s Eve to Lunar 1 January, spanning from 2015 to 2023. As depicted in Figure 8, in 2015, the hourly concentrations of the main pollutant increased from 12:00 on New Year’s Eve, reaching their respective peaks between 0:00–4:00 on 1 January, and then declined afterward. In comparison to 2015, the highest concentration levels of main pollutants were significantly reduced from New Year’s Eve to Lunar 1 January from 2016 to 2022, aligning with the findings of Zhang et al. [56]. These positive outcomes can be attributed to the inhibitory impact of the POFB policy on the elevated pollutant concentration phase.
There was minimal variation in the concentrations of O3 from New Year’s Eve to Lunar 1 January from 2015 to 2023. Except for 2017, which displayed a bimodal change, O3 concentration increased on the morning of Lunar 1 January in all other years. This phenomenon is closely related to photochemical reactions [57].
Compared to 2022, there has been an increase in the peak hourly concentrations of main pollutants (excluding O3) in 2023. This trend can be attributed to the implementation of the RHFB policy, along with a rise in anthropogenic firework activities. Notably, there are similarities between the hourly pollutant concentration trends observed in 2015 and 2023.

3.4. Contributions of Fireworks Burning to PM2.5 Concentrations during the FBP

Figure 9 presents the hourly changes in PM2.5(R), PM2.5(M), and PM2.5(F) concentrations during FBP from 2015 to 2016 and from 2022 to 2023. Figure 10 presents the hourly changes in the contributions of fireworks burning to ambient PM2.5 during FBP from 2015 to 2016 and 2022 to 2023.
As illustrated in Figure 9, air quality in Zhengzhou during the Fireworks Burning Period (FBP) in 2016 exhibited improvement compared to 2015, attributed to a reduction in fireworks burning. The average PM2.5 concentration during the FBP in 2016 showed a significant decrease, dropping from 97.3 ± 39.3 μg/m3 to 72.6 ± 32.3 μg/m3, representing a notable decrease of 63.1%. There was a notable decrease in the contribution concentration of fireworks burning to PM2.5 during FBP from 2015 to 2016, declining from 94.8 ± 33.5 μg/m3 in 2015 to 40.1 ± 29.5 μg/m3 in 2016, indicating a decrease of 57.7%.
As illustrated in Figure 10a, compared to 2015, the average contribution rate of firework activities to PM2.5 concentrations during FBP in 2016 did not change significantly. However, the contribution rate of firework activities to PM2.5 concentration during the period from New Year’s Eve 19:00 to 1 January 3:00 still showed a significant decrease.
As shown in Figure 9, a substantial increase in the concentration of fireworks burning to PM2.5 was observed during FBP from 2022 to 2023, rising from 5.9 ± 3.9 μg/m3 in 2022 to 118.4 ± 84.3 μg/m3 in 2023, indicating an increase of 1884%. Compared to 2022, the average PM2.5 concentration during FBP in 2023 significantly increased, from 24.1 ± 5.9 μg/m3 to 220.1 ± 81.7 μg/m3, reflecting an increase of 810%.
As illustrated in Figure 10b, in comparison to 2022, the average contribution rate of fireworks burning to ambient PM2.5 concentrations in 2023 increased significantly, rising from 22.7% ± 9.4% in 2022 to 46.6% ± 20.8% in 2023, indicating an increase of 105%. In 2023, the contribution rate of firework activities to PM2.5 exhibited a continuous upward trend (19.4%) from 19:00 on New Year’s Eve, reaching its peak level (73.2%) at 2:00 on Lunar 1 January, remaining at a high level (55.2–73.2%) until 6:00, and then sharply decreasing to 61.2% within 4 h. This observation aligns with the results reported by Kong et al. [32].
Overall, compared to 2015, the contribution of fireworks burning to PM2.5 concentrations significantly decreased during FBP in 2016 after the implementation of the POFB policy. Compared to 2022, the contribution of fireworks burning to PM2.5 concentrations and the contribution rate of fireworks burning to PM2.5 increased significantly during the FBP in 2023 after the implementation of the RHFB policy. This serves as another confirmation of the necessity of administrative prohibitions, which make a crucial contribution to the improvement of air quality.

4. Discussion

Variations in meteorological parameters can influence air pollution. To further investigate the sudden rise in pollutant levels, the relationship between air pollution and various meteorological factors, including relative humidity (RH) and wind speed (WS), was examined. The meteorological data collected from 2015 to 2023 were analyzed to evaluate the fluctuation pattern, and the association between meteorological factors and the concentrations of main pollutants was assessed. Figure 11 illustrates the correlation coefficients between the hourly average concentrations of main pollutants and meteorological factors. Figure 12 illustrates the variation in the daily average of PM2.5, CO, RH, and WS from 2019 to 2020.
As shown in Figure 11, the results depicted reveal a positive correlation between relative humidity and PM2.5, PM10, NO2, CO, and AQI, with correlation coefficients of 0.42, 0.25, 0.42, 0.29, and 0.4, respectively. Increased humidity in winter enhances the moisture absorption capacity of particulate matter, and higher air humidity facilitates the conversion of gaseous pollutants into particulate matter, while also increasing pollutant concentrations [45,51,58]. The wind speed was inversely correlated with AQI, PM2.5, PM10, and NO2.
Fireworks burning activities in 2020 were significantly reduced due to the COVID-19 pandemic. However, the change in average AQI values in 2020 is minimal compared to 2019. Several studies have been conducted to demonstrate that variations in meteorological parameters can influence air pollution [59,60,61].
As shown in Figure 12, compared to 2019, the average PM2.5 concentration and the average CO concentration in 2020 did not change significantly. However, compared to 2019, the annual Spring Festival average wind speed decreased significantly by 42.65% and the annual Spring Festival average humidity increased significantly by 9.8% in 2020. The change in wind speed and relative humidity caused a smaller change in the annual Spring Festival AQI average in 2020 compared to 2019. The local air quality is influenced by the transmission and diffusion of air pollutants from neighboring areas, an aspect that will be further explored in future studies.

5. Conclusions

This study comprehensively analyzed the effects of fireworks burning on the concentrations of main pollutants. The primary objective was to assess the impact of both the POFB and RHFB policies on air quality. The key conclusions drawn from the study are as follows.
Firstly, the POFB policy had a significant positive impact on air quality in Zhengzhou.
In 2016, the first year of the ban, AQI values notably improved (AQI = 152.2) compared to 2015 (AQI = 181.3), reflecting a 16.0% decrease. Continued implementation of the POFB policy led to remarkable air quality improvements in 2022, with an AQI average of 64.1. However, air quality deteriorated significantly after the implementation of the RHFB policy. In 2023, the first year of the RHFB policy, the situation worsened considerably (AQI = 112.2) compared to 2022 (AQI = 64.1), with a 74.9% increase in AQI values.
Secondly, the ban effectively mitigated the abrupt increase in pollutant concentration and delayed the occurrence of peak values, demonstrating a noticeable “peak shaving” effect. Throughout the introduction of the POFB policy, there was a consistent decrease in the annual Spring Festival average concentration of pollutants, a decline in the peak value of daily average concentration, and a reduction in the rate of change. Conversely, after the introduction of the RHFB policy, the annual Spring Festival average concentration and daily average concentration of pollutants increased significantly, with a more evident increase in amplitude and enhanced fluctuation.
Thirdly, the implementation of the POFB policy had the most noticeable impact on the concentration of PM2.5 and PM10. In 2016, when burning was prohibited, the concentrations of PM2.5 and PM10 decreased by 16.14% and 23.64% respectively, compared to 2015. In contrast, in 2023, when burning was not forbidden, the was an increase of 79.7% and 79.2%, respectively, compared to 2022. Compared to 2015, the contribution of fireworks burning to PM2.5 concentrations significantly decreased during FBP in 2016 after the POFB policy. Compared to 2022, the contribution of fireworks burning to PM2.5 concentrations and the average contribution rate of fireworks burning to PM2.5 increased significantly during the FBP in 2023 after the implementation of the RHFB policy.
Lastly, unfavorable meteorological conditions will undoubtedly exacerbate air quality pollution caused by fireworks burning, impeding the dilution and diffusion of pollutants, and contributing to significantly worse air quality.

Author Contributions

X.L.: Investigation, Investigation, Writing—Original Draft, Writing—Review & Editing. L.Y. and Y.W.: Formal analysis, Data Curation. P.Y., and Y.L.: Conceptualization, Supervision, Resources, Writing—Review & Editing. All authors have read and agreed to the published version of the manuscript.

Funding

This research is supported by the Henan Province Science and Technology Research Planning Project (NO. 232102110288).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data are available upon request to the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Nasir, U.P.; Brahmaiah, D. Impact of fireworks on ambient air quality: A case study. Int. J. Environ. Sci. Technol. 2014, 4, 1379–1386. [Google Scholar] [CrossRef]
  2. Moreno, T.; Querol, X.; Alastuey, A.; Amato, F.; Pey, J.; Pandolfi, M.; Kuenzli, N.; Bouso, L.; Rivera, M.; Gibbons, W. Effect of fireworks events on urban background trace metal aerosol concentrations: Is the cocktail worth the show? J. Hazard. Mater. 2010, 183, 945–949. [Google Scholar] [CrossRef] [PubMed]
  3. Tiwari, S.; Chate, D.M.; Srivastava, M.K.; Safai, P.D.; Srivastava, A.K.; Bisht, D.S.; Padmanabhamurty, B. Statistical evaluation of PM10 and distribution of PM1, PM2.5, and PM10 in ambient air due to extreme fireworks episodes (Deepawali festivals) in megacity Delhi. Nat. Hazards 2011, 61, 521–531. [Google Scholar] [CrossRef]
  4. Beig, G.; Chate, D.M.; Ghuade, S.D.; Ali, K.; Satpute, T.; Sahu, S.K.; Parkhi, N.; Trimbake, H.K. Evaluating population exposure to environmental pollutants during Deepavali fireworks displays using air quality measurements of the SAFAR network. Chemosphere 2013, 92, 116–124. [Google Scholar] [CrossRef] [PubMed]
  5. Hamad, S.; Green, D.; Heo, J. Evaluation of health risk associated with fireworks activity at Central London. Air Qual. Atmos. Health 2015, 9, 735–741. [Google Scholar] [CrossRef]
  6. Greven, F.E.; Vonk, J.M.; Fischer, P.; Duijm, F.; Vink, N.M.; Brunekreef, B. Air pollution during New Year’s fireworks and daily mortality in the Netherlands. Sci. Rep. 2019, 9, 5735. [Google Scholar] [CrossRef]
  7. Seidel, D.J.; Birnbaum, A.N. Effects of Independence Day fireworks on atmospheric concentrations of fine particulate matter in the United States. Atmos. Environ. 2015, 115, 192–198. [Google Scholar] [CrossRef]
  8. Godri, K.J.; Green, D.C.; Fuller, G.W.; Dall’Osto, M.; Beddows, D.C.; Kelly, F.J.; Harrison, R.M.; Mudway, I.S. Particulate oxidative burden associated with firework activity. Particulate Oxidative Burden Associated with Firework Activity. Environ. Sci. Technol. 2010, 44, 8295–8301. [Google Scholar] [CrossRef]
  9. Drewnick, F.; Hings, S.S.; Curtius, J.; Eerdekens, G.; Williams, J. Measurement of fine particulate and gas-phase species during the New Year’s fireworks 2005 in Mainz, Germany. Atmos. Environ. 2006, 40, 4316–4327. [Google Scholar] [CrossRef]
  10. Wehner, B.; Wiedensohler, A.; Heintzenberg, J. Submicrometer aerosol size distributions and mass concentration of the Millennium fireworks 2000 in Leipzig, Germany. J. Aerosol Sci. 2000, 12, 1489–1493. [Google Scholar] [CrossRef]
  11. Vecchi, R.; Bernardoni, V.; Cricchio, D.; D’Alessandro, A.; Fermo, P.; Lucarelli, F.; Nava, S.; Piazzalunga, A.; Valli, G. The impact of fireworks on airborne particles. Atmos. Environ. 2008, 42, 1121–1132. [Google Scholar] [CrossRef]
  12. Wang, X.; Wei, W.; Cheng, S.; Wang, R.; Zhu, J. Evaluation of continuous emission reduction effect on PM2.5 pollution improvement through 2013-2018 in Beijing. Atmos. Pollut. Res. 2021, 12, 101055. [Google Scholar] [CrossRef]
  13. Cecconi, A.; Navarrete, G.; Garcia-Guimaraes, M.; Vera, A.; Blanco-Dominguez, R.; Sanz-Garcia, A.; Lozano-Prieto, M.; Lopez-Melgar, B.; Rivero, F.; Martin, P.; et al. Influence of air pollutants on circulating inflammatory cells and microRNA expression in acute myocardial infarction. Sci. Rep. 2022, 12, 5350. [Google Scholar] [CrossRef] [PubMed]
  14. Parra, R.; Saud, C.; Espinoza, C. Simulating PM2.5 Concentrations during New Year in Cuenca, Ecuador: Effects of Advancing the Time of Burning Activities. Toxics 2022, 10, 264. [Google Scholar] [CrossRef] [PubMed]
  15. Lin, C.C. A Review of the Impact of Fireworks on Particulate Matter in Ambient Air. J. Air Waste Manag. Assoc. 2016, 66, 1171–1182. [Google Scholar] [CrossRef]
  16. Kumar, M.; Singh, R.K.; Murari, V.; Singh, A.K.; Singh, R.S.; Banerjee, T. Fireworks induced particle pollution: A Spatio-temporal analysis. Atmos. Res. 2016, 180, 78–91. [Google Scholar] [CrossRef]
  17. Zhang, Y.; Wei, J.; Tang, A.; Zheng, A.; Shao, Z.; Liu, X. Chemical Characteristics of PM2.5 during 2015 Spring Festival in Beijing, China. Aerosol Air Qual. Res. 2017, 17, 1169–1180. [Google Scholar] [CrossRef]
  18. Feng, J.; Yu, H.; Su, X.; Liu, S.; Li, Y.; Pan, Y.; Sun, J.H. Chemical composition and source apportionment of PM2.5 during Chinese Spring Festival at Xinxiang, a heavily polluted city in North China: Fireworks and health risks. Atmos. Res. 2016, 182, 176–188. [Google Scholar] [CrossRef]
  19. Wang, S.; Yu, R.; Shen, H.; Wang, S.; Hu, Q.; Cui, J.; Yan, Y.; Huang, H.; Hu, G. Chemical characteristics, sources, and formation mechanisms of PM2.5 before and during the Spring Festival in a coastal city in Southeast China. Environ. Pollut. 2019, 251, 442–452. [Google Scholar] [CrossRef]
  20. Fu, H.; Yang, Z.; Liu, Y.; Shao, P. Ecological and human health risk assessment of heavy metals in dust affected by fireworks during the Spring Festival in Beijing. Air Qual. Atmos. Health 2020, 14, 139–148. [Google Scholar] [CrossRef]
  21. Ji, D.; Cui, Y.; Li, L.; He, J.; Wang, L.; Zhang, H.; Wang, W.; Zhou, L.; Maenhaut, W.; Wen, T.; et al. Characterization and source identification of fine particulate matter in urban Beijing during the 2015 Spring Festival. Sci. Total Environ. 2018, 628–629, 430–440. [Google Scholar] [CrossRef] [PubMed]
  22. Singh, A.; Pant, P.; Pope, F.D. Air quality during and after festivals: Aerosol concentrations, composition and health effects. Atmos. Res. 2019, 227, 220–232. [Google Scholar] [CrossRef]
  23. Loomis, D.; Grosse, Y.; Lauby-Secretan, B.; Ghissassi, F.E.; Bouvard, V.; Benbrahim-Talla, L.; Guha, N.; Baan, R.; Mattock, H.; Straif, K. The Carcinogenicity of Outdoor Air Pollution. Lancet Oncol. 2013, 14, 1262–1263. [Google Scholar] [CrossRef] [PubMed]
  24. Peeples, L. News Feature: How Air Pollution Threatens Brain Heath. Proc. Natl. Acad. Sci. USA 2020, 117, 13856–13860. [Google Scholar] [CrossRef] [PubMed]
  25. Rindelaub, J.D.; Davy, P.K.; Talbot, N.; Pattinson, W.; Miskelly, G.M. The contribution of commercial fireworks to both local and personal air quality in Auckland, New Zealand. Environ. Sci. Pollut. Res. 2021, 28, 21650–21660. [Google Scholar] [CrossRef] [PubMed]
  26. Moreno, T.; Querol, X.; Alastuey, A.; Minguillón, M.C.; Pey, J.; Rodriguez, S.; Miró, J.V.; Felis, C.; Gibbons, W. Recreational atmospheric pollution episodes: Inhalable metalliferous particles from firework displays. Atmos. Environ. 2007, 41, 913–922. [Google Scholar] [CrossRef]
  27. Yerramsetti, V.S.; Sharma, A.R.; Navlur, N.G.; Rapolu, V.; Dhulipala, N.S.K.C.; Sinha, P.R. The impact assessment of Diwali fireworks emissions on the air quality of a tropical urban site, Hyderabad, India, during three consecutive years. Environ. Monit. Assess. 2013, 185, 7309–7325. [Google Scholar] [CrossRef]
  28. Subhashini, R.; Samhitha, B.K.; Mana, S.C.; Jose, J. Data Analytics to Find Out the Effect of Firework Emissions on Quality of Air: A case study. Second International Conference on Material Science. AIP Conf. Proc. 2019, 2201, 020008. [Google Scholar]
  29. Shivani; Gadi, R.; Saxena, M.; Sharma, S.K.; Mandal, T.K. Short-term degradation of air quality during major firework events in Delhi, India. Meteorol. Atmos. Phys. 2018, 131, 753–764. [Google Scholar] [CrossRef]
  30. Lorenzo, G.R.; Bañaga, P.A.; Cambaliza, M.O.; Cruz, M.T.; AzadiAghdam, M.; Arellano, A.; Betito, G.; Braun, R.; Corral, A.F.; Dadashazar, H.; et al. Measurement report: Firework impacts on air quality in Metro Manila, Philippines, during the 2019 New Year revelry. Atmos. Chem. Phys. 2021, 21, 6155–6173. [Google Scholar] [CrossRef]
  31. Li, J.; Xu, T.; Lu, X.; Chen, H.; Nizkorodov, S.A.; Chen, J.; Yang, X.; Mo, Z.; Chen, Z.; Liu, H.; et al. Online single particle measurement of fireworks pollution during Chinese New Year in Nanning. J. Environ. Sci. 2017, 53, 184–195. [Google Scholar] [CrossRef] [PubMed]
  32. Kong, S.F.; Li, L.; Li, X.X.; Yin, Y.; Chen, K.; Liu, D.T.; Yuan, L.; Zhang, Y.J.; Shan, Y.P.; Ji, Y.Q. The impacts of firework burning at the Chinese Spring Festival on air quality: Insights of tracers, source evolution and aging processes. Atmos. Chem. Phys. 2015, 15, 2167–2184. [Google Scholar] [CrossRef]
  33. Yuan, L.; Zhang, X.; Feng, M.; Liu, X.; Che, Y.; Xu, H.; Schaefer, K.; Wang, S.; Zhou, Y. Size-resolved hygroscopic behaviour and mixing state of submicron aerosols in a megacity of the Sichuan Basin during pollution and fireworks episodes. Atmos. Environ. 2020, 226, 117393. [Google Scholar] [CrossRef]
  34. Song, Y.; Huang, B.; He, Q.; Chen, B.; Wei, J.; Mahmood, R. Dynamic Assessment of PM2.5 exposure and health risk using remote sensing and geo-spatial big Data. Environ. Pollut. 2019, 253, 288–296. [Google Scholar] [CrossRef] [PubMed]
  35. Hickey, C.; Gordon, C.; Galdanes, K.; Blaustein, M.; Horton, L.; Chillrud, S.; Ross, J.; Yinon, L.; Chen, L.C.; Gordon, T. Toxicity of particles emitted by fireworks. Part. Fibre Toxicol. 2020, 17, 28. [Google Scholar] [CrossRef] [PubMed]
  36. Cecconi, A.; Franco, E.; Agustín, J.A.; Vilchez, J.P.; Palacios-Rubio, J.; Sánchez-Enrique, C.; Fernández-Ortiz, A.; Macaya, C.; Fernández-Jiménez, R. Hyponatremia-induced stress cardiomyopathy due to psychogenic polydipsia. Int J Cardiol. 2016, 202, 618–620. [Google Scholar] [CrossRef] [PubMed]
  37. Wang, L.; Luo, D.; Liu, X.; Zhu, J.; Wang, F.; Li, B.; Li, L. Effects of PM2.5 Exposure on Reproductive System and Its Mechanisms. Chemosphere 2021, 264, 128436. [Google Scholar] [CrossRef]
  38. Li, Z.; Li, X.; Song, H.; Tao, B.; Qiu, B.; Tian, D.; Zhan, M.; Wu, Z.; Zhang, Q.; Wang, J. Effects of short-term ambient PM2.5 exposure on the blood cell count and hemoglobin concentration among 82, 431 people in eastern China. Sci. Total Environ. 2021, 776, 146046. [Google Scholar] [CrossRef]
  39. Fan, S.; Li, Y.; Liu, C. Are Environmentally Friendly Fireworks Really “Green” for Air Quality? A Study from the 2019 National Day Fireworks Display in Shenzhen. Environ. Sci. Technol. 2021, 55, 3520–3529. [Google Scholar] [CrossRef]
  40. Liu, D.; Li, W.; Peng, J.; Ma, Q. The Effect of Banning Fireworks on Air Quality in a Heavily Polluted City in Northern China During Chinese Spring Festival. Front. Environ. Sci. 2022, 10, 872226. [Google Scholar] [CrossRef]
  41. Zhao, N.; Wang, G.; Zhu, Z.; Liu, Z.; Tian, G.; Liu, Y.; Gao, W.; Lang, J. Impact of fireworks burning on air quality during the Spring Festival in 2021–2022 in Linyi, a central city in the North China Plain. Environ. Sci. Pollut. Res. 2022, 30, 17915–17925. [Google Scholar] [CrossRef] [PubMed]
  42. Yao, L.; Wang, D.; Fu, Q.; Qiao, L.; Wang, H.; Li, L.; Sun, W.; Li, Q.; Wang, L.; Yang, X.; et al. The effects of firework regulation on air quality and public health during the Chinese Spring Festival from 2013 to 2017 in a Chinese megacity. Environ. Int. 2019, 126, 96–106. [Google Scholar] [CrossRef] [PubMed]
  43. Yang, M.; Fan, H.; Zhao, K. Fine-Grained Spatiotemporal Analysis of the Impact of Restricting Factories, Motor Vehicles, and Fireworks on Air Pollution. Int. J. Environ. Res. Public Health 2020, 17, 4828. [Google Scholar] [CrossRef] [PubMed]
  44. Singh, B.; Nagda, C.; Kumar, K.; Kain, T.; Jhala, L.S.; Rathore, D.S. COVID-19 Implicated ban on Diwali fireworks: A case study on the air quality of Rajasthan, India. EQA-Int. J. Environ. Qual. 2022, 47, 22–30. [Google Scholar]
  45. Liu, X.; Yang, L. Spatiotemporal Distribution Characteristics of PM2.5 Pollution and the Influential Meteorological Factors in the Henan Province, China, 2021. Pol. J. Environ. Stud. 2023, 6, 5211–5225. [Google Scholar] [CrossRef] [PubMed]
  46. Xie, Z.; Li, Y.; Qin, Y.; Zheng, Z. Optimal Allocation of Control Targets for PM2.5 Pollution in China’s Beijing-Tianjin-Hebei Regions. Pol. J. Environ. Stud. 2019, 28, 3941–3949. [Google Scholar] [CrossRef] [PubMed]
  47. Ye, C.; Chen, R.; Chen, M. The impacts of Chinese Nian culture on air pollution. J. Clean. Prod. 2016, 112, 1740–1745. [Google Scholar] [CrossRef]
  48. Zhou, X.; Jiménez, Y.S.; Rodríguez, J.V.P.; Hernández, J.M. Air pollution and tourism demand: A case study of Beijing, China. Int. J. Tour. Res. 2019, 21, 747–757. [Google Scholar] [CrossRef]
  49. Li, J.; Wang, B.; Li, H. Research on Computer Forecast Model Using BP Neural Network and Pearson Correlation Coefficient. J. Phys. Conf. Ser. 2021, 2033, 012091. [Google Scholar] [CrossRef]
  50. Pang, N.; Gao, J.; Zhao, P.; Wang, Y.; Xu, Z.; Chai, F. Impact of fireworks control on air quality in four Northern Chinese cities during the Spring Festival. Atmos. Environ. 2021, 244, 117958. [Google Scholar] [CrossRef]
  51. Qian, Y.; Yuan, X.; Dou, W.; Hu, J.; Xia, J.; Li, D.; Zheng, Q.; Zhang, P.; Quan, Q.; Li, Y. Effects of fireworks on air quality in the main urban area of Nanchong City during the spring festival of 2014–2019. Environ. Eng. Res. 2022, 28, 220038. [Google Scholar] [CrossRef]
  52. Wang, Y.; Zhuang, G.; Xu, C.; An, Z. The air pollution caused by the burning of fireworks during lantern festival in Beijing. Atmos. Environ. 2007, 41, 417–431. [Google Scholar] [CrossRef]
  53. Tang, M.; Ji, D.S.; Gao, W.K.; Yu, Z.W.; Chen, K.; Cao, W. Characteristics of air quality in Tianjin during the Spring Festival period of 2015. Atmos. Ocean. Sci. Lett. 2016, 9, 15–21. [Google Scholar] [CrossRef]
  54. Brink, H.; Otjes, R.; Weijers, E. Extreme levels and chemistry of PM from the consumer fireworks in the Netherlands. Atmos. Environ. 2019, 212, 36–40. [Google Scholar] [CrossRef]
  55. Tian, Y.Z.; Wang, J.; Peng, X.; Shi, G.L.; Feng, Y.C. Estimation of the direct and indirect impacts of fireworks on the physicochemical characteristics of atmospheric PM10 and PM2.5. Atmos. Chem. Phys. 2014, 14, 9469–9479. [Google Scholar] [CrossRef]
  56. Zhang, X.; Shen, H.; Li, T.; Zhang, L. The Effects of Fireworks Discharge on Atmospheric PM2.5 Concentration in the Chinese Lunar New Year. Int. J. Environ. Res. Public Health 2020, 17, 9333. [Google Scholar] [CrossRef] [PubMed]
  57. Zhang, S.; Tan, L.; Xu, K.; Wang, D.; Zhu, X. Characteristics of Atmospheric Volatile Organic Compounds and Photochemical Changes During an O3 Event in a County-Level City of Shaanxi Province, China. Water Air Soil Pollut. 2023, 234, 58. [Google Scholar] [CrossRef]
  58. Singh, B.P.; Singh, D.; Kumar, K.; Jain, V.K. Study of seasonal variation of PM2.5 concentration associated with meteorological parameters at residential sites in Delhi, India. J. Atmos. Chem. 2021, 78, 161–176. [Google Scholar] [CrossRef]
  59. Liu, Y.; Liu, J.; Tao, S. Interannual variability of summertime aerosol optical depth over East Asia during 2000–2011: A potential influence from El Niño Southern Oscillation. Environ. Res. Lett. 2013, 8, 044034. [Google Scholar] [CrossRef]
  60. Chen, Z.; Chen, D.; Zhao, C.; Kwan, M.; Cai, J.; Zhuang, Y.; Zhao, B.; Wang, X.; Chen, B.; Yang, J.; et al. Influence of meteorological conditions on PM2.5 concentrations across China: A review of methodology and mechanism. Environ. Int. 2020, 139, 105558. [Google Scholar] [CrossRef]
  61. Juráň, S.; Grace, J.; Urban, O. Temporal Changes in Ozone Concentrations and Their Impact on Vegetation. Atmosphere 2021, 12, 82. [Google Scholar] [CrossRef]
Toxics 12 00023 g001
Figure 1. Study area and monitoring stations in Zhengzhou City.
Figure 1. Study area and monitoring stations in Zhengzhou City.
Toxics 12 00023 g001
Toxics 12 00023 g002
Figure 2. Variation of annual Spring Festival AQI average in Zhengzhou from 2015 to 2023.
Figure 2. Variation of annual Spring Festival AQI average in Zhengzhou from 2015 to 2023.
Toxics 12 00023 g002
Toxics 12 00023 g003
Figure 3. Variation of daily average AQI during the Spring Festival period in 2023.
Figure 3. Variation of daily average AQI during the Spring Festival period in 2023.
Toxics 12 00023 g003
Toxics 12 00023 g004
Figure 4. The daily average AQI and corresponding air quality classes for the Chinese Spring Festival period from 2015 to 2023.
Figure 4. The daily average AQI and corresponding air quality classes for the Chinese Spring Festival period from 2015 to 2023.
Toxics 12 00023 g004
Toxics 12 00023 g005
Figure 5. Variation in annual Spring Festival average concentration of main pollutants from 2015 to 2023.
Figure 5. Variation in annual Spring Festival average concentration of main pollutants from 2015 to 2023.
Toxics 12 00023 g005
Toxics 12 00023 g006
Figure 6. The annual average Spring Festival average of main pollutants showing year−to−year variations from 2016 to 2023.
Figure 6. The annual average Spring Festival average of main pollutants showing year−to−year variations from 2016 to 2023.
Toxics 12 00023 g006
Toxics 12 00023 g007
Figure 7. Daily changes in concentrations of main pollutants from 2015 to 2023.
Figure 7. Daily changes in concentrations of main pollutants from 2015 to 2023.
Toxics 12 00023 g007
Toxics 12 00023 g008
Figure 8. Hourly changes in concentrations of main pollutants from New Year’s Eve to 1 January from 2015 to 2023.
Figure 8. Hourly changes in concentrations of main pollutants from New Year’s Eve to 1 January from 2015 to 2023.
Toxics 12 00023 g008
Toxics 12 00023 g009
Figure 9. Variation of hourly average contributions of fireworks burning to ambient PM2.5 during FBP from 2015 to 2016 and 2022 to 2023.
Figure 9. Variation of hourly average contributions of fireworks burning to ambient PM2.5 during FBP from 2015 to 2016 and 2022 to 2023.
Toxics 12 00023 g009
Toxics 12 00023 g010
Figure 10. Variation of hourly average contributions rate of fireworks burning to ambient PM2.5 in Zhengzhou during FBP from 2015 to 2016 and 2022 to 2023. The average contribution rate of firework activities to PM2.5 concentrations during FBP from 2015 to 2016 (a); The average contribution rate of firework activities to PM2.5 concentrations during FBP from 2022 to 2023 (b).
Figure 10. Variation of hourly average contributions rate of fireworks burning to ambient PM2.5 in Zhengzhou during FBP from 2015 to 2016 and 2022 to 2023. The average contribution rate of firework activities to PM2.5 concentrations during FBP from 2015 to 2016 (a); The average contribution rate of firework activities to PM2.5 concentrations during FBP from 2022 to 2023 (b).
Toxics 12 00023 g010
Toxics 12 00023 g011
Figure 11. Correlation coefficients between concentrations of main pollutants and meteorological factors. * represent p < 0.05, ** represent p < 0.01, *** represent p < 0.001.
Figure 11. Correlation coefficients between concentrations of main pollutants and meteorological factors. * represent p < 0.05, ** represent p < 0.01, *** represent p < 0.001.
Toxics 12 00023 g011
Toxics 12 00023 g012
Figure 12. Variation of the daily average of PM2.5, CO, relative humidity, and windspeed during the Spring Festival period from 2019 to 2020.
Figure 12. Variation of the daily average of PM2.5, CO, relative humidity, and windspeed during the Spring Festival period from 2019 to 2020.
Toxics 12 00023 g012
Table 1. AQI values, Grade, and Air Quality.
Table 1. AQI values, Grade, and Air Quality.
Air QualityAQI ValueGrade
Good0–50I
Moderate51–100II
Unhealthy for sensitive people101–150III
Unhealthy151–200IV
Very healthy201–300V
Hazardous301–500VI
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Liu, X.; Yang, L.; Wang, Y.; Yan, P.; Lu, Y. Effects of Fireworks Burning on Air Quality during the Chinese Spring Festival—Evidence from Zhengzhou, China. Toxics 2024, 12, 23. https://doi.org/10.3390/toxics12010023

AMA Style

Liu X, Yang L, Wang Y, Yan P, Lu Y. Effects of Fireworks Burning on Air Quality during the Chinese Spring Festival—Evidence from Zhengzhou, China. Toxics. 2024; 12(1):23. https://doi.org/10.3390/toxics12010023

Chicago/Turabian Style

Liu, Xinzhan, Ling Yang, Yan Wang, Pengfei Yan, and Yimeng Lu. 2024. "Effects of Fireworks Burning on Air Quality during the Chinese Spring Festival—Evidence from Zhengzhou, China" Toxics 12, no. 1: 23. https://doi.org/10.3390/toxics12010023

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop