Dr Heather Walton
Policy Group, King's College London
The project, commissioned by the Greater London Authority and Transport for London , estimates,
for the first time, the mortality burden of long-term exposure to nitrogen dioxide
(NO2) in London, as well as providing a new mortality burden estimate for fine
particulate matter (PM2.5). The
final report was published on 15th July 2015.
The mortality burden is expressed as life-years lost across the population as a result of deaths
This result is also expressed as ‘equivalent deaths at typical ages’, the deaths that would
account for the loss of life years if PM2.5 or NO2 were the sole cause.
Generally, many different factors contribute to the development of disease and consequent
The report extends previous work on the mortality burden of PM2.5 in London (Miller,
2010) to cover effects of short-term exposure to PM2.5 and NO2 as well as
the economic valuation of short and long-term effects of both pollutants.
- The total mortality burden of anthropogenic PM2.5 for the year 2010 is estimated
to be 52,630 life-years lost, equivalent to 3,537 deaths at typical ages. The estimate
for PM2.5 attributable deaths has decreased from the previous estimate (4,267
deaths in 2008 based on 2006 concentrations) (Miller, 2010) partly due to a decrease in
concentrations, to which policy interventions will have contributed, as well as some
adjustments to the previous methods and inputs, such as using anthropogenic rather than
- Whilst much less certain than for PM2.5, the total mortality burden of long-term
exposure to NO2 is estimated to be up to 88,113 life-years lost, equivalent to
5,879 deaths at typical ages (assuming the WHO value of up to a 30% overlap between the
effects of PM2.5and NO2. Some of this effect may be due to other
- If added together, the total mortality burden in 2010 from PM2.5 and
NO2 is estimated to be as much as 140,743 life-years lost, equivalent to 9,416
deaths at typical ages.
- In 2010, PM2.5 and NO2 were associated with approximately 1990 and 420
respiratory hospital admissions respectively, with an additional 740 cardiovascular
admissions associated with PM2.5.
- The estimated economic costs of the above health impacts ranged from £1.4 billion to £3.7
Outputs from the health report were also included in the progress report on the delivery of the
of London’s Air Quality Strategy.