Further tests would measure levels of nitric oxide in the breath (higher in people with asthma).
Toxic nitric oxide and nitrogen oxide levels stand at 252 microgrammes per cubic metre (mcg/m3) more than three times the safe limit of 80 mcg/m3.
By far the largest was HM Factory Gretna in southern Scotland, which produced cordite – a complex system involving nitric and sulphuric acids, nitroglycerine, gun cotton, mineral jelly, alcohol and ether.
To do so they took a beaker made of PVC, filled it with a mixture of nitric and sulphuric acids, and left it for six hours.
Fossil-fuel combustion produces nitrogen oxides, which rise into the atmosphere and come down in rainfall as nitric acid.
However, it is not just penile blood vessels that nitric oxide relaxes.
If nitric oxide is what is needed, it can be added to banked blood just before transfusion.
He found that old blood replenished with nitric oxide is as good as fresh blood at relaxing blood vessels.
But for the benefit of journalists who might not have been quite up to speed on the physiological details, the press release announcing the winners helpfully pointed out the connection between this discovery and the invention of Viagra.That nitric oxide a gas better known as a poisonous air pollutant is an important biological signalling molecule came as quite a shock.
Nor do they leak.In this section Dotting the eyes Don't slag it off A slim chance Sun down ReprintsTo check that, Dr Andrés and her team ground their bricks into powder and soaked them in water, shook them in special machines for days at a time, and even tried to dissolve them in nitric acid.
These include nitric oxide, which helps to dilate blood vessels and increase blood flow, reducing the risk of clot formation.
