These worries resurfaced on April 7th when TEPCO started to inject nitrogen into one of the plant's six stricken reactors.

ECONOMIST: A spreading cloud of economic and human costs

In the 1980s nitrogen controls were placed on industrial plant and vehicles, This has led to a cut in emissions of 30%, despite an increase in traffic and economic activity.

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

The Paradise plant in Kentucky is the dirtiest for nitrogen oxide pollution.

CNN: Nature - America's most wanted: Power plants urged to clean up their act

The earthworms selectively fed on slow-germinating, nitrogen-rich seeds and seedlings, actively ingesting the plant material, killing the young plant.

BBC: Earth News - Earthworms eat live seeds and plants, scientists find

The 600-megawatt Indiana plant will convert coal into turbine-ready gas while stripping out pollutants nitrogen and sulfur.

FORBES: A Dirty Game

In a conventional fossil-fuel plant that's prohibitively expensive, since the CO2 is mixed in with nitrogen.

FORBES