Recently, Assistant Professor Ying Li’s research group from the Southern University of Science and Technology (SUSTech) published a paper in Environmental Science & Technology, a top journal in the field of environmental science, entitled “Are Environmentally Friendly Fireworks Really ‘Green’ for Air Quality? A Study from the 2019 National Day Fireworks Display in Shenzhen.” This study has been reported widely on the Internet.

This study questioned the benefits of environmentally friendly fireworks in reducing air pollution and reported that environmentally friendly fireworks are not really “green” as they can cause heavy air pollution, even though the particulate (PM) emission can be reduced by 15‒65% when substituting environmentally friendly fireworks for traditional fireworks.

Fireworks are widely used around the world during celebrations due to their special effects. These fireworks can cause severe air pollution as they can rapidly emit large amounts of pollutants into the atmosphere from the chemical reactions in the combustion and bursting processes that shine colorful lights and make a tremendous sound.

Emitted from the fireworks, particulate matter (PM) and SO₂ can reach a very high concentration in a very short period of time. These high-concentration pollutants can usually sustain several hours before diluted, and cause a serious burden on the respiratory system of residents. Besides, toxins such as heavy metals and perchlorates can further harm the health of residents.

A large-scale fireworks display can generate a smoke plume with an even higher concentration of pollutants, though with fewer areas under the influence. To reduce the negative impacts of fireworks, it’s beneficial to substitute environmentally friendly fireworks for traditional fireworks. However, it is unclear what benefits can be achieved by using environmentally friendly fireworks. Therefore, it is necessary to evaluate the benefits of fireworks in real conditions. Additionally, it is important for environments and residents to reliably forecast the impact of firework displays and to warn residents under possible influence.

As an expert of the Shenzhen Air Quality Consultation committee, Ying Li led her team to build and optimize an air-quality forecasting system with a dynamical interaction module to simulate the irregular firework emission. With the data support from the Shenzhen environmental monitoring center station including the number of fireworks and observations from the high-density air quality monitoring network, they successfully forecasted the pollution level, trajectory, influencing areas of the smoke plume, and then comprehensively assessed the benefits of using environmentally friendly fireworks.

Figure 1 Modeled trajectory of the smoke plume, and the PM_2.5 concentrations at the five response stations.

They used the PM_2.5 measurements from the observation network which is managed by the Shenzhen Environmental Protection Bureau to validate the modeled pollution level (PM_2.5 concentration). Based on the results, they modeled the air pollution under the condition of using traditional fireworks.

By comparing the two simulated results, they found that traditional fireworks can approximately double the air pollution level, as well as the influencing areas. From the uncertainty analysis, it is shown that environmentally friendly fireworks can generate anywhere between 15‒65% fewer air pollutants, confirming that substituting environmentally friendly fireworks for traditional fireworks can reduce firework-generated air pollution.

However, the overall pollution level caused by environmentally friendly fireworks is significant. At the Taoyuan station (located in the SUSTech), the hourly PM_2.5 concentration can reach 370 μg/m³ under the influence of the smoke plume.

Figure 2. (a) PM_2.5 concentrations at the five response stations and (b) the influencing areas, caused by traditional (CaseTRAD) and environmentally friendly fireworks (CaseEF).

This study illustrated the estimation of firework emissions, which can be a reference for demonstrating the impact of fireworks and provide the basis for forecasting the firework-generated air pollution from large-scale fireworks displays. Also, the use of environmentally friendly fireworks, “greener” than traditional fireworks, showed less air pollution but still a significant amount in the overall scale. The environmentally friendly fireworks are not truly green for air quality. The researchers concluded that the number of “green” fireworks used at one time should still be restricted. This research can help to provide some guidance to policy-makers.

Shidong Fan, a Ph.D. student of the Department of Ocean Science and Engineering (OSE) at SUSTech, is the first author of this paper. Ying Li, Assistant Professor of OSE at SUSTech, is the second and corresponding author. Chanfang Liu of Shenzhen environmental monitoring center station is the third author.

The authors acknowledge funding from the National Natural Science Foundation of China (NSFC), the Science and Technology Planning Project of Guangdong Province, and the Shenzhen Science and Technology Program.

Original article: https://pubs.acs.org/doi/abs/10.1021/acs.est.0c03521