Escalation of fireworks in Malta : environmental forensic evidence from perchlorate in dust fall

Abstract

Summer in Malta is accompanied by fireworks as part of the numerous (about 85) religious festivals (festa) that occur throughout the period. We attempted to establish whether firework activity is truly following official trade statistics, which imply a decreasing trend, or otherwise. Firework manufacture critically depends on the availability of oxidising agents, two of which (KNO3, KClO3) being controlled by permits but not potassium perchlorate (KClO4) which is freely available. Recent changes in legislation have slightly decreased the quantity of KClO3 and increased that of KNO3 and according to official trade statistics, consumption of KClO4 has decreased from 17 t/a in 2010 to ≈ 2.5 t/a during 2011--2014. However, from levels of perchlorate in dust fall and rate of total deposition we calculated the quantity of KClO4 used during 2012 and obtained ≥ 90 t/a, 36 times the official figure. This situation is serious since the danger of accidental explosion during manufacture escalates as production intensifies. Also, contamination of the environment by firework-waste appears destined to remain high with possible consequent effects on human health.