Every breath you take — air quality in Europe

Anna is 37 years old and lives in the centre of Brussels. She and her young son Johan are planning a trip outside the busy city. Anna suffers from asthma and her doctor has warned of the dangers of air pollution, especially on hot summer days.

Anna has heard about the London fogs of the 1950s that killed 2 000 people in one week. She has childhood memories of evening news bulletins showing dead fish and dying trees as ' acid rain' first came to popular attention in the 1970s.

Motherhood and a recent asthma attack have quite rightly brought air pollution back to mind. The fact is that emissions of many air pollutants have fallen substantially across Europe since Anna's childhood. The air she and Johan breathe is much improved compared to the past, and air policy is one of the great success stories of the EU's environmental efforts. In particular, EU policy has dramatically cut emissions of sulphur, the main component of 'acid rain'.

In contrast, nitrogen — also a major component of 'acid rain' — has not been dealt with to the same extent and so continues to cause major problems. A significant proportion of Europe's urban population still live in cities where EU air quality limits, protecting human health, are regularly exceeded. Each year, many more people die prematurely from air pollution in Europe than die in traffic accidents.

The European goal of achieving levels of air quality that do not damage people's health or the environment has still not been reached. EEA analysis suggests that 15 of the 27 EU Member States will miss one or more of their legally binding 2010 targets to reduce harmful air pollutants.

Particulate matter and ozone

Two pollutants, fine particulate matter and ground-level ozone, are now generally recognised as the most significant in terms of health impacts. Long-term and peak exposure can lead to a variety of health effects, ranging from minor irritation of the respiratory system to premature death.

Particulate matter, a term used to describe a variety of tiny particles from sources such as vehicle exhausts and domestic stoves, affect the lungs. Exposure can harm people of all ages, but people with existing heart and respiratory problems are particularly at risk.

According to the latest EEA data, since 1997 up to 50 % of Europe's urban population may have been exposed to concentrations of particulate matter above the EU limit set to protect human health. As much as 61 % of the urban population may have been exposed to levels of ozone that exceed the EU target. It has been estimated that PM_2.5 (fine particulate matter) in air has reduced statistical life expectancy in the EU by more than eight months.

The EEA has noted that while emissions of these two key air pollutants have dropped since 1997, measured concentrations in the air we breathe have remained largely the same. As yet, we don't know why there has not been a drop in ambient concentrations but it could be a combination of several factors: increased temperatures caused by climate change could be affecting air quality; perhaps we are on the receiving end of pollution from other continents or natural emissions of ozone forming substances released from trees, for example.

A day in the country

Anna is planning a day in the country with Johan. Before leaving her apartment she logs onto IRCEL, a government web service providing a host of regular information on air quality around Belgium. Using maps, Anna can scan readings and forecasts for particulate matter, ozone, nitrogen dioxide, sulphur dioxide among many others. The data are relayed to the web from monitoring stations around the country.

Improvements in monitoring and availability of information on air pollution are another of the success stories of recent years. For instance, local data on ozone levels are now passed onto the EEA 'Ozone web' (1) service that provides an overview of the situation across Europe.

Anna scrolls across a map of Belgium, zooming in on a monitoring station in the centre of Brussels, less than two kilometres from her home.

The reading, taken minutes earlier, shows high levels of ozone in Brussels. Indeed the website forecasts that levels will exceed EU target values later that day and again the following day ( Figure 1).

Anna leaves her apartment building and makes for the nearest Metro station, a 10 minute walk away. Out on the street, the full impact of the city's traffic problems are easy to see — and smell.

Exhaust emissions from cars in the centre of Brussels, and all major cities, irritate the respiratory tract and eyes and lungs. Anna and Johan turn into their local train station and head for the countryside.

Soon, Anna and Johan are entering a national park just outside Brussels. A sign tells them that they are visiting a Natura 2000 site — one part of a European-wide ecological network, set up to secure natural habitats and to maintain the range of plant and animal life.

Figure 1: The location and levels of ozone at air quality monitoring stations in Brussels on Sunday 27 July 2008

Nitrogen

But what's that smell? A tractor is spraying liquid manure onto a field not far away. This is irritating, Anna thinks, but it's also part of real country life which is shown in a rather more romantic way in Johan's picture books.

The pungent smell is caused by as many as 40 different chemical substances emitted from the manure. Ammonia (NH₃), a volatile nitrogen compound, is one of them. In very high concentrations NH₃ is caustic and can damage the respiratory tract. However, the levels here are not dangerous for human health. Anna can breathe a sigh of relief, albeit a stinky one.
Nitrogen is an essential nutrient in nature. Reactive nitrogen forms are actually used by our bodies to produce proteins. However, excess nitrogen can lead to severe environmental and health problems.

'Acid rain' forms when high levels of sulphur and nitrogen oxides are present in the air. One of the great success stories of air pollution policy over the last decades has been the massive reduction in emissions of sulphur dioxide. The 32 EEA member countries reduced sulphur emissions by 70 % between 1990 and 2006. Nitrogen, on the other hand, has not been dealt with as successfully.

With sulphur emissions declining, nitrogen is now the principal acidifying component in our air. Agriculture and transport are the main sources of nitrogen pollution. Agriculture is responsible for more than 90 % of ammonia (NH₃) emissions alone.

Suddenly Johan, who has been walking unsteadily loses his balance and falls into a clump of stinging nettles. Having picked him up and brushed him off, Anna notices nettles everywhere. She has vivid memories of them as a child in a neighbour's garden. Then the nettles grew around a compost heap that was also used as a dump for poultry dung. That was no coincidence — the stinging plant is an indicator of high nitrogen concentrations in soils.

'Eutrophication' is the most likely cause of this explosion of stinging nettles surrounding Johan. It occurs when too many chemical nutrients (such as N) are available to an ecosystem either on land or in water. In water, excessive plant growth and subsequent decay occur, which in turn leads to further effects including oxygen depletion. Fish and other animals and plants ultimately suffocate as the oxygen supply is used up.

The abundance of the nettles here suggests that despite being a protected habitat, the Natura 2000 site is not immune from airborne nitrogen deposits. The fence protecting the area offers no defence — in fact building a greenhouse around the area would be the only way to protect it totally from airborne substances.

Looking ahead

Because air pollution pays no regard to national boundaries the problem needs to be tackled internationally. The United Nations Convention on Long-range Transboundary Air Pollution (LRTAP Convention) agreed in 1979, has been signed by 51 countries and forms the basis of the international fight to tackle air pollution.

In parallel, the EU has developed polices limiting the total emissions of each Member State, setting legally binding limits. The ' National Emissions Ceiling Directive' (NECD) is a key EU policy. It sets 'ceilings' or limits for four pollutants: sulphur dioxide (SO₂), nitrogen oxides (NO_x), non-methane volatile organic compounds (NMVOCs), and ammonia (NH₃). Member States should meet these ceilings by 2010.

The EEA considers that further emission cuts are still needed in order to properly protect environment and health. An EEA analysis of the most recent NECD data (2) indicates that 15 Member States expect to miss at least one of their four ceilings; with 13 anticipating missing ceilings for the 2 nitrogen-containing pollutants NO_X and NH₃ (3).

In 2009 the European Commission plans to publish a proposal to revise the current NECD, including stricter ceilings for the year 2020. National limits are likely to be proposed for fine particulate matter (PM_2.5) for the first time.

The NECD is mirrored by air quality directives setting limit and target values for major air pollutants. A new one called the Cleaner Air For Europe (CAFE) Directive was adopted in April 2008. For the first time it sets legally binding limit values for PM_2.5 concentrations (fine particulate matter), to be attained in 2015. The European Commission is also taking countries to task for having missed earlier limits and, where sufficient measures have not been outlined to improve performance, has begun infringement proceedings.

Later that evening Anna, while watching the evening news, sees that an air quality warning has been issued by the government in response to high ozone levels beyond the EU threshold. The warning advises people with breathing problems to take precautions such as avoiding strenuous exercise while the ozone levels remain high.

Sources

Coordination Centre for Effects, Data Centre of the International Cooperative Programme on Modelling and Mapping of Critical Levels and Loads and Air Pollution Effects, Risks and Trends (ICP Modelling and Mapping, ICP M&M)

Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008 on ambient air quality and cleaner air for Europe.

EEA, 2006. Air quality and ancillary benefits of climate change policies, EEA Technical report No 4/2006.

EEA, 2008a. The NEC Directive status report. EEA Technical report No 9/2008.

EEA, 2008b. Annual European Community LRTAP Convention emission inventory report 2008. EEA Technical report No 7/2008.

EEA, 2009. Assessment of ground-level ozone within the EEA member countries with focus on long-term trends (in preparation).

EEA. Core set indicator CSI-04: Exceedance of air quality limit values in urban areas.

EEA Ozone web. Ozone pollution across Europe.

European Commission, 2002. The Sixth Environment Action Programme of the European Community 2002–2012 (1600/2002/EC).

European Commission, 2005a. Directorate General for Energy and Transport .

European Commission Thematic Strategy on Air Pollution (2005). Communication from the Commission to the Council and the European Parliament. COM(2005)446 final and press release.

European Commission, 2005b. Thematic Strategy on Air Pollution (2005). Communication from the Commission to the Council and the European Parliament. COM(2005)446 final.

IIASA, 2008. 'National Emission Ceilings for 2020 based on the 2008 Climate & Energy Package'. NEC Scenario Analysis Report Nr. 6. International Institute for Applied Systems Analysis, July 2008.

Task Force on Reactive Nitrogen (TFNr), Convention on Long-range Transboundary Air Pollution.

Footnotes

(1) Ozone pollution across Europe. A similar service, providing local information on particulate matter levels across Europe is being developed.

(2) The NEC Directive status report (EEA Technical report No 9/2008) documents the data officially reported by Member States at the end of 2007.

(3) Belgium, France, Germany and the Netherlands believe that new policies and measures, not yet enacted, will help them reach their 2010 emissions ceilings. In addition, several other Member States believe they will over achieve their original ceilings.