The report says government efforts to control emissions of reactive nitrogen from combustion sources have been more successful.

BBC: Nitrogen pollution 'costs EU up to ?280bn a year'

The subsequent industrial production of billions of tonnes of synthetic nitrogen fertilisers - particular after the 1950s - have flooded terrestrial and aquatic ecosystems with reactive nitrogen, and supported the century's human population explosion.

BBC: Leaving our mark: Fossils of the future

But the traffic increase has slowed progress in reducing emissions further, and people in many areas still suffer from nitrogen-related air pollution, including small particulates that get sucked deep into the lungs, and ground-level ozone - a strongly irritant gas formed by the action of sunlight on reactive nitrogen.

BBC: Nitrogen pollution 'costs EU up to ?280bn a year'

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