Environmentally friendly fireworks emit 15-65 per cent less particulate matter (PM) as compared to traditional fireworks, however, they still significantly deteriorate air quality, say researchers.
Fireworks are used in celebrations around the world, including Independence Day in the US, the Lantern Festival in China and the Diwali Festival in India. However, the popular pyrotechnic displays emit large amounts of pollutants into the atmosphere, sometimes causing severe air pollution.
Fireworks displays can cause health problems, such as respiratory ailments, because they release high levels of air pollutants, including particulate matter (PM), sulfur dioxide, heavy metals and perchlorates, said the researchers, including Ying Li from Southern University of Science and Technology in Shenzhen.
As a result, some cities have banned their use. But because the displays are an important aspect of many traditional celebrations, researchers and manufacturers have tried to develop more environmentally friendly pyrotechnics, including those with smokeless charges and sulfur-free propellants.
Although research suggests that these fireworks emit less pollutants, their impact on air quality has not been evaluated.
For the study, published in the journal Environmental Science & Technology, the team used data from a large fireworks display held in Shenzhen on Chinese National Day on October 1, 2019, to assess how “green” these fireworks really are.
The researchers estimated emissions of PM2.5, which is PM with a diameter of 2.5 µm and smaller, from the 160,000 environmentally friendly fireworks set off during the display, as well as emissions from traditional fireworks.
They used information on the wind direction, wind speed, temperature and chemical composition of the fireworks to simulate the size, trajectory and peak PM2.5 values for the smoke plume resulting from the event.
Then they compared their simulated values with actual data on PM2.5 concentrations measured at 75 monitoring stations throughout the city following the fireworks display.
In agreement with the team’s predictions, the data showed that the fireworks smoke plume began as a narrow band that travelled northward before being fully dispersed, with peak PM2.5 levels similar to the predictions.
The researchers used their validated simulation to estimate that the use of environmentally friendly fireworks produces a much smaller, shorter-lasting plume, with 15-65 per cent of the PM2.5 emissions of a display using traditional fireworks. However, the peak concentration of PM2.5 still greatly exceeds World Health Organization guidelines.