And no special camera mode used, Wat?
Nope. Almost all of my photography is done in manual mode shooting.
and one of the things that was mentioned was the toxicity of the metals used that produce those brilliant colors (lead was mentioned, and I believe mercury also?)
There should not be significant amounts of lead or mercury in fireworks (except for those novelty "snakes" which are essentially the mercury thiocyanate chemistry reaction.) Neither lead or mercury produce good colors that cannot be produced by other elements, anyway. For example, strontium is used to make red. Sodium for yellow. Barium for green. Brilliant bright white is from magnesium. And so forth. You can easily look these all up or experiment for yourself with a flame test.
Wherever fireworks are illegal, the main reasons are because of being disturbing to others (especially in more urban settings; respect thy neighbor), and from a safety standpoint of potentially causing injury when misused, or starting fires. Personally I find the latter ridiculous. It is sad that there are too many people who cannot be trusted to use fireworks safely. I'm not much concerned about my health from the smoke, either, as it is very quickly dispersed in the air, especially from shells that explode up high.
That's good to know, Wat. I remember researching emission/absorption lines when I was looking into different light pollution filters and what elements emit what colors of light when burned! Strontium red is very famous, as are sodium yellow and mercury red vapor lamps! Magnesium is highly reactive to water and creates the most brilliant white I've ever seen! Even more fascinating for me are the links between these elements and the colors of stars and nebulae and their chemical makeup.
We had illegal fireworks going on in the city and a 6 yr child who was watching from a window in his apartment got burns on his face because the firework actually came inside the apartment he was watching from. Another case I remember well is a few days ago a woman was throwing fireworks at a group of people who were walking on the sidewalk. She just stopped her car in the middle of the street and got out and tossed lit fireworks at them! She didn't even know them- it was some random thing. On a personal note I was driving during the early evening of July 4th to see a fireworks show and I drove by this store where they had wood piled up in the front and the guy who runs the store was doing his own private fireworks display and as I drove by he (accidentally) dropped the fireworks and they lit up on the ground right next to my car....he apologized, it was an accident. Not very safe though.
Interesting thing about lead, I was watching a report on the Flint crisis and a pediatrician said "no amount is safe." She analyzed the results of the lead crisis there years later and found that 80% of the children who had been exposed to lead in their drinking water suffered from cognitive decline (and only 10% passed a reading test they were given.) There should be some major lawsuits there as the problem was ignored for many years- the officials didn't do anything even when it was shown to them that the water was corroding engine parts! The doctors have developed a highly interesting method for determining exactly when the children ingested the lead and in what amounts- they analyze their teeth. It even works in utero as the fetus has baby teeth when still inside the mother, and lead was even found in these teeth. It was a hockey stick graph! They compared it to tree rings, in how teeth record the history of everything that the child is exposed to. Highly interesting report and well worth the watch!
We also had a lead problem in our region, in Newark. It's taken many years to get a handle on, but we're finally making some headway.
Here's the thing on Flint I watched:
https://www.cbsnews.com/news/flint-wate ... 020-07-05/
and
https://www.cbsnews.com/news/flint-wate ... 020-03-12/
The second link has the quote from the doctor "There are no safe levels of lead because lead is an irreversible neurotoxin."