New research estimates that air pollution contributed to the deaths of as many as 9,400 Londoners in 2010; around 3,500 from particle pollution and up to 4,900 from nitrogen dioxide, which has been included in a health impact assessment for the first time.
Unlike road accidents or cancer in smokers, the impacts of air pollution are hard to see as it adds to the health burden from heart and lung problems, stroke and many other causes. This means that the impact cannot be worked out from counting death certificates. Instead, the estimates were made by taking the effect of pollution on survival rates of over 1.5m people living in places with different air pollution around Europe and North America, and combining the results with air pollution exposure data from London.
Scientists prefer to express the health burden as life lost; in this case up to 140,000 years in 2010. This is a whole lot of birthdays but is hard to understand. It is easier to think in terms of loss of life expectancy; the average Londoner exposed to 2010 levels of pollution through their lives could lose around nine months life from particle pollution and up to 16 months from nitrogen dioxide. For each week lived in London this is an hour and a half life loss from particle pollution and nearly three hours from nitrogen dioxide.
Although London is the first to assess air pollution in this way, cities around the UK and Europe have similar pollution. However improvements are slow. Imagine the outcry if poisoned tap water was contributing to the deaths of almost 10,000 Londoners annually.