Fireworks on Mall likely to cause hazardous air pollution, documents show (washingtonpost.com) Fireworks on Mall likely to cause hazardous air pollution, documents show By Jake Spring 2026070122220200 Fireworks for this year's July Fourth celebration are expected to cause hazardous levels of pollution around the National Mall and "very unhealthy" conditions in central D.C., according to internal National Park Service documents reviewed by The Washington Post.