As reported by Radio NZ earlier this week, an Auckland study into backyard fireworks (the crackers we let off in our own suburban gardens, the sparklers we give the kids to scribble messages and magic in the air) has found them to be more toxic than expected.
Air samples taken in suburban Henderson showed particulate matter in the air rose more than 75% over the 12 hours of Guy Fawke’s night. While playing with sparklers for 8 minutes is the equivalent of breathing in a day’s worth of air pollution, the study found. More disturbingly, sparklers, which are marketed for children, emit harmful metals such as arsenic, lead and chlorine, breaching safe air quality guidelines.
BayBuzz contacted Hawke’s Bay Regional Council’s principal scientist air, Dr Kathleen Kozyniak, to ask if there’s any correlated trend in Hawke’s Bay’s urban centres (i.e. whether there’s a perceptible increase in air pollution over Guy Fawke’s night).
Her response: “Air pollution from backyard fireworks depends on the weather and varies from year to year. On average we do see a spike in particulate concentrations on Guy Fawke’s night, typically between about 9-10pm.”
She says, there has been no exceedance of the National Environmental Standard for PM10 (a 24-hour average of 50 µg/m3) in Hawke’s Bay on Guy Fawke’s Day since monitoring began. But points out that with air quality measuring instruments located in public places to monitor the ambient air, it is likely that the concentrations will be higher in backyards where fireworks are being lit.
And, “As the Auckland study notes, it’s not only particulates that people are breathing in but heavy metals as well. It’s excellent that the study is highlighting the health implications behind the good fun of fireworks so that people have that knowledge when choosing whether or not to partake.”
The graph (below) shows the historical average hourly concentration of particulate matter PM10 and PM2.5 on Guy Fawke’s evening (5 November) recorded at Marewa Park, Napier, and St John’s College, Hastings. These are averages over approximately fifteen years of record for PM10 at both sites, but only two and five years for PM2.5 at Marewa Park and St John’s respectively. Note: the longer PM10 record across many years of varying weather conditions results in the lower evening peak compared to PM2.5.