Fireworks are used in celebrations around the world, including Independence Day in the U.S., the Lantern Festival in China and the Diwali Festival in India. However, the popular pyrotechnic displays emit large amounts of pollutants into the atmosphere, sometimes causing severe air pollution. Now, researchers reporting in ACS' Environmental Science & Technology have estimated that, although so-called environmentally friendly fireworks emit 15-65% less particulate matter than traditional fireworks, they still significantly deteriorate air quality.
source https://phys.org/news/2021-03-green-environmentally-friendly-fireworks.html