Fireworks generate aerosols which disperse according to wind direction and speed. Little is known about the level and content of exposure to fine particles (PM2.5) among people attending or living in proximity to firework launch sites. To document levels of PM2.5 and their elemental content in proximity to fireworks, a pilot project was carried out during the nine fireworks launches of the 2007 Montreal International Competition.
For each event, the Lagrangian model of the Canadian Meteorological Centre (CMC) was used to predict the location of the firework plume. Then within the predicted plume location (“predicted sites”), PM2.5 was continuously measured with a photometer (Sidepak, TSI) and, integrated samples were collected for about 50 minutes using portable personal samplers (at breathing zone height). Each “predicted” sampling location was situated within 500 to 2000 m of the launch site. To collect a greater amount of PM2.5 mass for more detailed chemical characterization, an additional sampler was located on a roof (“fixed site”, collection at 50 lpm for one hour) in relatively close proximity to the launch site (1100 m). The elemental composition of the collected PM2.5 samples from “predicted sites” was determined using both a non-destructive energy dispersive XRF method and an ICP-MS method with a near-total microwave-assisted acid digestion. The elemental composition of the “fixed site” samples was determined by ICP-MS.
Given wind variation and the challenge of accurate forecasts, both the “fixed” and the “predicted sites” turned out to be in the plume for only four of the nine launches. The highest PM2.5 levels, measured at the closest location to the launch site, reached nearly 10 000 μg/m3, 500 times background. Elements such as sulphur, chlorine, barium, magnesium, antimony, strontium, titanium and copper were higher in plume-exposed filters.
This project showed that 1) the CMC Lagrangian model accurately predicted the location of the plume four times out of nine, notwithstanding the near misses, 2) persons in the plume and in close proximity to the launch site may be exposed to extremely high levels of PM2.5 for about 30 minutes and, 3) the plume contains specific elements for which little is known of their acute cardio-respiratory toxicity. Further consideration is needed to accurately assess the risk of exposure to fireworks plumes and what if any public health measures should be implemented.