Determination of perchlorate in soil and air samples during fireworks displays in Taiwan and USA

Abstract

Perchlorate is considered an emerging persistent inorganic environmental contaminant. Perchlorate has been suspected of disrupting the thyroid uptake of iodide and subsequently causing the malfunction of metabolic processes. Firework displays are commonly referred to as a source of perchlorate in the environment. There are two types of fireworks displays: Near-ground fireworks or firecrackers and sky fireworks. During the explosion process, fireworks generate large amounts of smoke that is dispersed into the atmosphere, and the residuals of firecrackers or fireworks would further deposit on the ground or in the water. In this study, sample analysis from the near-ground fireworks and firecracker events demonstrate that during the high time of the fireworks event, the concentration of perchlorate increased dramatically in the air. The outdoor air quality was more deteriorate than the indoor air quality during the fireworks events. However, when the events ended after 12 hours, both the anions and cations concentration in the air recovered to the original level. Unlike air samples, the cations and anions concentrations in the soil increased after the fireworks events. Sample analysis from the sky fireworks display also showed the concentration of perchlorate in the air and soil. However, the concentration of perchlorate during the sky fireworks was smaller than during the near-ground fireworks. In addition, the concentration of cations, such as Ba(II), K(I), Na(I), Mg(II) and Sr(II) in the air and soil samples all increased as the concentration of perchlorate increased. The risk of exposure to perchlorate during the near-ground fireworks/firecrackers events is higher than that during the sky fireworks event. It is found that all the age groups, adults, child age of 6-12 and child age of 2-6 were shown to have high hazard index when exposed to perchlorate during the near-ground fireworks events.