Citizens in many UK cities fare poorly in exposure to nitrogen dioxide pollution, whereas London is the only UK city where air pollution from particulates is of significant concern.

The new annual survey of air pollution in European cities by the European Environment Agency (EEA) finds that Britain's cities on the whole experience much better quality air than much of the rest of Europe.

For hydrocarbon particulates, London was the only city where exceedences of the daily limit values were recorded in 2010.

Nitrogen dioxide

But on nitrogen dioxide, the United Kingdom fares much worse than other European areas, and pollution limits were exceeded in 11 cities in England and Scotland.

These cities include Aberdeen, Glasgow, Liverpool, Bristol, Manchester, Birmingham, Oxford and London, where daily averages of over 45µg/m3 were recorded.

The limit value of the annual mean NO2 concentration is set at 40 µg/m3. Countries throughout Europe were obliged to meet this target two years ago.

As with particulates, traffic is a prime agent of these emissions.

The EEA notes that real-world emissions from vehicles may exceed their allowed test cycle emissions, especially for light duty diesel vehicles. Vehicle manufacturers and regulators use these to decide whether products meet the regulations.

Although there is good news, that nitrogen dioxide levels are decreasing at 92% of the monitoring stations registering a trend throughout Europe, the EEA report concludes that the worst offender is diesel passenger vehicles: "'real-world emissions' of NOX from these have decreased very little over the last decade and are considered to be the main driver of the exceedances of the NO2 limit value found across the EU," it says.

Health impacts

EU Environment Commissioner Janez Potocnik called the report “a really serious warning about the importance to our quality of life and health" of air pollution.

There are economic costs too. Pollution costs, across Europe, one trillion euros a year in health care and dealing with the wider impacts on ecosystems, said EEA executive director Jacqueline McGrade.

She added that, on average, pollution is still reducing life expectancy by around eight months across European cities. In some areas it is as much as 22 months.

Hydrocarbon particulates

18 to 41% of the EU urban population was exposed to concentrations of PM10 in excess of the EU air quality daily limit value in the period 2001–2010, with no discernible downward trend.

The situation is even worse for ground level ozone, although not in the UK.

Traffic is often the major cause of particulate pollution. The combined urban and local traffic contribution to PM10 concentration values reached a particular high in Glasgow at 61%, whereas in Yorkshire it was as low as 6%.

The transport sector is also the largest contributor to NOX emissions, while the energy production and industry sectors dominate the SOX (sulphur dioxide) emissions.

The legal limits of air pollution from particulates were exceeded most often in 2010 in Poland, Italy, Slovakia, the Balkan region, Turkey and several other urban clusters in the continent.

For regulating PM2.5, a new limit value won't come into force until 2015 under the 2008 Air Quality Directive; it is presently a target value.

Euro 6

Although the Euro 5 legislation has been successful in reducing NOX and PM emissions from vehicles over the last 10 years, under real-world driving, which it does not regulate, emissions from vehicles often exceed those recorded under tests.

The report criticises the high-level uncertainty that these tests therefore imply.

The upcoming Euro 6 standard will focus on real-world emissions, but Europe will have to wait 15 months before it comes into force; then, from 1 January 2014, all newly registered trucks and buses in Europe must fulfil this standard.

Under it, as compared with Euro 5, particle emissions are to be reduced by 66% and nitrogen oxide emissions (NOx) by 80% over the existing exhaust-gas standard. They will be capped at 170 mg/km for all vehicles.

Many manufacturers, like DAF and MAN, are already putting vehicles on the market that comply with this legislation. Euro 6 certification has been possible in the European Union since April 2012.

Vehicles emit pollutants in other ways than from their tailpipes, however: through wear on the tyres and brakes and from road abrasion. These are currently not regulated.

The Agency estimates that they equal about 60% of the exhaust emissions of PM10 and 30% of PM2.5.

Good news

There is good news in the report. On the industrial front, the Large Combustion Plant Directive and the IPPC Directive have been very successful in substantially reducing emissions from large plants.

Britain also comes out well in performance on ozone pollution. Despite the warmer weather there is only one place in the UK, on the Norfolk coast, where a level above 100 µg per cubic metre was recorded in 2010.

The target or threshold value for human health for ground level ozone is 120 µg/m3 in the Air Quality Directive, although the World Health Organisation has reduced their recommended limit to 100µg/m3.

Throughout Europe, 97% of its citizens were exposed to ozone above the WHO reference levels in 2010; 17% above the lower EU target level.

Finally, for the first time in industrial history, no one in towns and cities throughout Europe was exposed to sulphur dioxide above the EU limit level.

Story: David Thorpe, News Editor