It’s that time of year again, when people start complaining about their dogs being terrorised by fireworks. But there’s actually another reason everyone should be upset about fireworks: They are terrible for air quality- full of metals and carcinogens, creating hazardous air pollution that contributes to lifelong health problems. And yes, they can contain lead too.
A 2020 New Zealand study on the matter has some concerning results. Of the tested fireworks, a pack labeled as safer for kids actually created some alarming levels of airborne lead and arsenic, with sparklers singled out as having the highest lead content. Another 2020 study from the US found one kind of firework with 40,000 ppm lead in the collected air fraction. Even our local GNS air quality monitoring data show a spike on their graphs of airborne lead from Guy Fawkes celebrations every year. The thing is- not every firework has lead, but it is common, and there’s no way to know which ones do or don’t have it.
So, should we avoid fireworks altogether and shut ourselves inside our homes with air purifiers on for the whole first part of November? Well, maybe… 
but let’s try to be reasonable. My recommendations would be:
1) AVOID SPARKLERS, full stop. If that’s not possible, limit it to ONE per child, and only outdoors with lots of air flow, not in a garage or under a canopy. Wash hands afterward and before eating.
2) Let the adults light off the fireworks and keep kids at a distance, up wind.
3) Dispose of all fireworks waste in a bin, away from kids, pets and your soil.
4) Limit children’s time outdoors after fireworks.
5) If you have an air purifier, use it on max power through the weekend.
6) Consider supporting community efforts to ban personal fireworks use in NZ, which is more consistent with other countries/ laws. Exposure to individuals through personal fireworks is far more concerning than through professional fireworks shows. Plus there’s the poor dogs and horses to think of too.
I’ll post some links below.
https://www.wired.com/story/your-firework-smoke-could-be-tainted-with-lead/
https://link.springer.com/article/10.1007/s11356-020-11889-4