urban population lives in areas where the EU air quality 24–hour
limit value for particulate matter (PM10) was exceeded in 2011,
also between 14% and 65% of the EU urban population was
exposed to ozone (O3) concentrations above the EU target value
for protecting human health in the period 2002–2011 (EEA, 2013a).
On the other hand, Europe's sustained ambient O3 concentrations
continue to cause considerable damage to vegetation growth and
crop yields, with between 21% and 69% of European agricultural
crops exposed to levels above the EU target value for protecting
vegetation from 2002 to 2010, resulting in serious costs to the
Europe's economy and reducing plant uptake of carbon dioxide
(EEA, 2013b).
The long–