All over the world, since the mid-20th Century, sediments have become measurably enriched in 'reactive' nitrogen - nitrogen oxides and ammonium compounds.

BBC: Leaving our mark: Fossils of the future

These creatures, now called anammox bacteria, transform caustic and hazardous ammonium into dinitrogen, the harmless nitrogen gas that makes up 78% of the air we breathe.

FORBES: Magazine Article

Ammonium nitrate, a solid fertilizer composed of ammonia and nitrogen, is also a component of explosives widely used in mining.

CNN: 12 bodies recovered, 60 unaccounted for after Texas blast

One of the worst disasters in U.S. history involving a form of ammonia occurred in April 1947 when a ship loaded with ammonium nitrate -- a solid fertlizer composed of ammonia and nitrogen -- caught fire while docked in Texas City, Texas, in April 1947.

CNN: What is anhydrous ammonia?