(USATODAY) — The thousands of Fourth of July fireworks celebrations across the nation bring a toxic brew of air pollution to our atmosphere, according to a recent study from federal scientists.
The exploding fireworks unleash tiny particles — about 1/30th the diameter of a typical human hair — that can affect health because they travel deep into a person's respiratory tract, entering the lungs.
The tiny particles are known as "particulate matter" and include dust, dirt, soot, smoke and liquid droplets and are measured in micrometers, according to the Environmental Protection Agency. A micrometer is one-millionth of a meter.