Wednesday, 18 July 2018


No, I thought not! Everyone supports clean air, but exactly what is defined as clean and how much does it cost to get it cleaner? Here is a good article on the subject. The graph below from the article shows just how much cleaner our air is today compared with the 1970's . In particular nitrogen oxides down from 100 in 1990 to around 40 today and still falling slowly. The linked article looks at the oft quoted figure of 40,000 deaths a year caused by pollution of air and explains just how it was calculated. [figure 1 does not display properly below, to see the full graph look at it on the link]

Another comparison from the article is to say that breathing typical UK roadside air is the equivalent of spending an extra hour in front of the TV. Of course that may be very bad for you, depending on how active you are the rest of the time. None of us live perfect lives and breathing air containing micro particles and a few parts per billion of NO2 is one small risk among the many we face. The question is, how much is it worth paying to slightly reduce this small risk?

Trends in air-pollution in the UK — from DEFRA 2016

So, if pollution levels have decreased so much, why is there more clamour than ever to reduce them still further? Obviously we are much more aware of the potential harm from certain pollutants and we can now measure them down to levels where they were previously undetectable. There is also the point that measures to reduce things like NO2 and very small particles will also reduce CO2 emissions and the public are much more ready to accept a move to clean our air from pollution than to reduce CO2, a harmless gas that sustains nearly all plant life.

What are the measures to reduce pollution and what implications do they have for us? More tomorrow.

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