Skyrocketing pollution: assessing the environmental fate of July 4th fireworks in New York City.

Background: Pyrotechnic displays often lead to significant increases in poor air quality. The widespread environmental fate-involving air, water, and spatial-temporal analyses-of fireworks-produced pollutants has seldom been investigated.

Objective: This study examined the environmental fate of pollutants from the largest fireworks event in the U.S.: Macy's Fourth of July Fireworks show in New York City (NYC).

Methods: Real-time PM_2.5 and gravimetric PM_2.5 and PM₁₀ were collected at locations along the East River of NYC. Airborne particles were assayed for trace elements (X-ray fluorescence) and organic and elemental carbon (OC/EC). River water samples were evaluated by ICP-MS for heavy-metal water contamination. Spatial-temporal analyses were created using PM_2.5 concentrations reported by both EPA and PurpleAir monitoring networks for NYC and 5 other major metropolitan areas.

Results: The fireworks event resulted in large increases in PM_2.5 mass concentrations at the river-adjacent sampling locations. While background control PM_2.5 was 10-15 µg/m³, peak real-time PM_2.5 levels exceeded 3000 µg/m³ at one site and 1000 µg/m³ at two other locations. The integrated gravimetric PM_2.5 and PM₁₀ concentrations during the fireworks event ranged from 162 to 240 µg/m³ and 252 to 589 µg/m³, respectively. Zn, Pb, Sb, and Cu more than doubled in river water samples taken after the event, while S, K, Ba, Cu, Mg, Fe, Sr, Ti, and Zn increased in airborne PM_2.5 from the fireworks. Data from hyperlocal monitoring networks for NYC and other metropolitan areas yielded similar, but generally smaller, increases in PM_2.5 levels.

Impact: Fireworks shows have been associated with environmental contamination. This comprehensive analysis considers the fate of pollutants from the largest annual U.S. pyrotechnic show through air, water, and hyperlocal temporal characterization.