Air quality expert group - Fine particulate matter (PM2.5) in ... - Defra

PM2.5 in the UK
Table 1.2: National exposure reduction targets for PM2.5.
Exposure reduction target relative to the AEI
(average exposure indicator) 1 in 2010 2
12
Initial concentration, µg m -3 Reduction target, %
less than or equal to 8.5 0 2020
more than 8.5 but less than 13 10
13 to less than 18 15
18 to less than 22 20
22 or more
All appropriate measures to
achieve 18 µg m -3
Year by which the exposure
reduction target shouldbe met
1 The AEI is derived from three-year average urban background measurements (i.e. 2009, 2010, 2011 for 2010) as defined in the EU
Ambient Air Quality Directive (2008/50/EC).
2 Where the AEI in the reference year is 8.5 µg m -3 or less, the exposure reduction target is zero. The reduction target is also zero in cases
where the AEI reaches the level of 8.5 µg m -3 at any point of time during the period 2010 to 2020 and is maintained at or below that level.
1.3 Effects of PM2.5 and links to climate change
9. Airborne particulate matter has consequences for human health, the
environment and climate change. An overview of the impacts is offered here
to demonstrate the importance of reducing levels of PM2.5 and the linkages
between different impact areas; further review of effects is beyond the scope of
this current report.
1.3.1 Health effects of PM2.5
10. The Committee on the Medical Effects of Air Pollutants (COMEAP) reports Long-
Term Exposure to Air Pollution: Effect on Mortality (COMEAP, 2009) and The
Mortality Effects of Long-Term Exposure to Particulate Air Pollution in the United
Kingdom (COMEAP, 2010) provide an excellent synthesis of the current evidence
on the impact of particulate matter on mortality. There is clear evidence
that particulate matter has a significant contributory role in human all-cause
mortality and in particular in cardiopulmonary mortality.
11. PM2.5 penetrates deeply into the human respiratory system. The acute effects of
particle exposure include increases in hospital admissions and premature death of
the old and sick due to diseases of the respiratory and cardiovascular systems. The
evidence is that both PM2.5 and PM10 cause additional hospital admissions and
deaths on high pollution days. Less severe effects of short-term particle exposure
also occur during pollution episodes, including worsening of asthma symptoms
and even a general feeling of being unwell leading to a lower level of activity.
12. Long-term exposure to particles is associated with increased levels of fatal
cardiovascular and respiratory diseases, including lung cancer, which reveal
themselves as increased rates of death in cities with higher concentrations of
airborne particles. COMEAP (2009) expressed the view that the best estimate
of the chronic health impacts of particulate matter exposure was a 6% increase
in death rates per 10 µg m -3 PM2.5 concentration. As with the acute effects of
particle exposure no wholly safe level has been identified.