Letters | How much do firework displays really affect Hong Kong’s air quality?

We analysed the 24-hour time series of four major air pollutants: sulphur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter (PM10 and PM 2.5) recorded at seven air quality monitoring stations near Victoria Harbour. We also considered the weather conditions using the records at three nearby weather stations. The dominant wind direction was found to be easterly during nearly all the performances.

For NO2, the typical diurnal pattern was observed, where the peak was recorded during daytime and the concentration gradually decreased at night. Some stations recorded an increase in NO2 after the performances, but considering their locations relative to the firework shooting sites and the dominant wind direction, the increase should not be attributed to the shows.

However, PM2.5 and PM10 levels spiked during the New Year and Chinese New Year fireworks, with peaks reaching nearly four times higher than pre-event levels. The impact was most pronounced at the Central and Western station located in the downwind region of the firework shooting sites. However, the effect was transient as the particulate matter levels quickly dropped back to pre-event levels in three hours. Moreover, no significant increase in particulate matter was recorded after the pyrotechnics. Our studies suggested that while fireworks were a major contributor to particulate pollution, the impact was short-term.

We hope our research has shed light on the impact of pyrotechnics on air quality in Hong Kong. These events contributed to short-term air pollution but still met AQO standards. The proposed monthly firework displays can strike a balance between economic gains and environmental concerns. Still, as the air quality stations are somewhat far away from the firework sites, we recommend conducting on-site measurements to further study the dispersion characteristics in detail.