PM2.5 Emissions from Hand-Held Sparklers: Chemical Characterization and Health Risk Assessment

The central goal of this work is to improve our understanding of the distinctive and unusual chemistry of aerosol particles released from firework displays and their potential health risks due to inhalation exposure. The chemical composition of fine particles (PM2.5) released from three commonly used sparklers (low smoke sparklers (LSS), whistling sparklers (WS) and colored sparklers (CS)) was investigated. In particular, total and water soluble elemental fractions (22 elements) and 13 polycyclic aromatic hydrocarbons (PAHs) in PM2.5 were quantified. The particulate emissions from LSS had relatively lower particulate-bound metals and less water-soluble fractions in them compared to those from WS and CS. However, PAHs were found to be relatively higher in LSS compared to those from WS and CS. Health risk due to inhalation of PM2.5 emitted from all the three types of sparklers was estimated for various dilution conditions including the case with little or no dispersion of particles. It was observed that WS had the highest carcinogenic risk (25 x 10(-6) for adults and 75 x 10(-6) for children) followed by CS (2.6 x 10(-6) for adults and 7.9 x 10(-6) for children) and LSS (7.6 x 10(-7) for adults and 2.6 x 10(-6) for children) for the worst case scenario of no dilution of emitted particles during inhalation. This carcinogenic risk is pronounced only when there is no or very low dilution (similar to 10) of emitted particles during inhalation. The health risk estimates for all sparkler types are below acceptable limits for dilution factors above 80 and thus exposure to PM2.5 in sparkler emissions is unlikely to have serious health effects. The water soluble fraction of metals (bioavailable metals) made a major contribution to the carcinogenic health risk due to inhalation of PM2.5 released from WS (similar to 100%) and CS (similar to 96%) while PAHs played a major role in the carcinogenic risk associated with PM2.5 from LSS (similar to 66%).