In order to improve air quality, the European Union introduced the New Air Quality Directive in 2008 and set its Member States strict targets on air pollution concentrations for the most harmful and challenging substances, such as fine particles. The law enforcement relies on a monitoring and reporting system to inform the European Commission and the public, for it is the citizens’ right to be informed about harmful air quality.
With sectoral measures, air quality could be improved in the past 20 years, but some emissions concentrations have stagnated in recent years and emissions temporarily exceed thresholds in nearly half of the Member States. The European Emission Inventory allows the commission to identify the substances, areas, and times of exceedances, and to implement sectoral measures leading to air quality improvements, all of which have to be made available publicly. This manuscript introduces the air quality legislation and reviews the quality of European air for recent years.
air quality ; European Union ; public participation ; standards
Air quality and climate policies can provide mutual benefits: climate change mitigation actions can help to reduce air pollutants, and clean air measures can help to reduce greenhouse gas (GHG) emissions. The improvement of air quality in some areas is often the result of measures that are taken for mitigating GHG emissions such as efficiency measures or fuel standards in fossil fuels burning in electricity generation, transport, industry and households or emission caps in industrial processes. Air pollution damages the environment and worsens the negative impacts of climate change as it causes acidification of sensitive ecosystem areas, eutrophication, and crop damage. In turn, air pollution policies that are required to reduce aerosols can accelerate global warming as the cooling effect of these aerosols on climate is removed. Therefore, air pollution and climate change are interrelated.
Air pollution cause harm not only to ecosystems but also to human health. Since the Industrial Revolution, the air quality in Europe has decreased as a result of human activities. Since the early 1970s, the European Union (EU) has taken measures to improve air quality, e.g., by controlling emissions of harmful substances into the atmosphere, improving the quality of fossil fuels, and integrating environmental protection requirements into the transport and energy sectors. As a result, emissions of many air pollutants, mostly sulphur dioxide (SO2 ), lead (Pb), nitrogen oxides (NOx ), carbon monoxide (CO) and benzene (C6 H6 ), have decreased over the past decades. This has resulted in improved air quality across the continent [ EEA, 2010 ]. During the 1990s, the EU developed and adopted a series of directives on air quality management and assessment, setting the air quality limit and target values, and methods to monitor and assess air quality. These directives have paved the way for the effective data exchange on air quality, station networks extension, and harmonization of measuring and modeling methodologies. The most important factor for improving air quality was the setting of binding targets for the EU Member States and establishing monitoring and reporting systems.
Although emissions have been reduced at their sources, air pollutant concentrations have not sufficiently declined in recent years. A significant proportion of Europe’s population lives in cities where air quality standards are exceeded frequently. The most stringent is summer smog, which originates in potentially harmful ground-level ozone (O3). Fine particulates present a health risk, which is of increasing public concern. Air pollution in Germany as an example has decreased significantly between the 1990s and the early 2010s. However, this decrease has been stagnating since the beginning of the 2010s. Pollution by particulate matter (PM), nitrogen dioxide (NO2 ) and O3 remains stable despite a continuous decline in emissions [ EEA, 2011 ]. Emissions, of course, have impact on pollution of the ambient atmosphere, but reductions do not cause a linear drop of pollution concentrations. The annual mean O3 concentration in Europe did not change significantly although O3 emissions have been cut significantly between 1999 and 2009. O3 concentrations show distinct differences between traffic stations (measuring at infrastructures), urban stations, rural-low stations, and rural-high stations.
This manuscript introduces European air quality legislation and standards and shows how air pollution and exceedance of standards are communicated with the public. It also provides a brief status of the European air in 2011.
The Directive 2008/50/EC of the European Parliament and of the European Council on ambient air quality and cleaner air for Europe, in brief New Air Quality Directive, entered into force on 11 June 2008 [ CEC, 2008 ]. It is currently among the strictest acts of legislation worldwide concerning PM10 air pollution [ de Leeuw and Ruyssenaars, 2011 ] and includes the following key elements: (1) merging of most of the existing legislation① into a single directive with no change to existing air quality objectives; (2) new air quality objectives for PM2.5 (fine particles) including the limit value and exposure related objectives (exposure concentration obligation and exposure reduction target); (3) the possibility to discount natural sources of pollution when assessing compliance against limit values; (4) the possibility for time extensions up to 2014 (PM10) or up to 2015 (NO2 , C6 H6 ) for complying with limit values, based on conditions and the assessment by the European Commission, i.e., relevant EU legislation is fully implemented and all appropriate abatement measures are being taken.
Table 1 summarizes the air quality standards as set by the directives, commission decisions, and council decisions mentioned above. It shows the substances considered in the assessment and management of ambient air quality. Standards and priorities for initial assessments have been modified over the years with the evolution of the legislation. A limit value is legally binding from the date it enters into force but allows limited short-term exceedances. A target value has to be attained as far as possible by the attainment date and compliance is checked but not legally binding. An international comparison of EU target and limit values, including Chinese standards, can be assessed from the European Topic Centre on Air Pollution and Climate Change Mitigation [ de Leeuw and Ruyssenaars , 2011 ].
|Pollutant||Concentration||Averaging period||Legal nature||Permitted exceedances each year|
|PM2.5||25 μ g m−3||1 year||Target value entered into force 2010-01-01, limit value enters into force 2015-01-01||Not applicable|
|SO2||350 μ g m−3||1 hour||Limit value entered into force 2005-01-01||350 μ g m−3 not to be exceeded 24 hours per year|
|125 μ g m−3||24 hours||Limit value entered into force 2005-01-01||125 μ g m−3 not to be exceeded 3 days per year|
|NO2||200 μ g m−3||1 hour||Limit value entered into force 2010-01-01||200 μ g m−3 not to be exceeded 18 hours per year|
|40 ng m−3||1 year||Limit value entered into force 2010–01–01||Not to exceed an annual average of 40 μ g m−3|
|PM10||50 μ g m−3||24 hours||Limit value entered into force 2005-01-01||50 μ g m−3 not to be exceeded 35 days per year|
|40 μ g m−3||1 year||Limit value entered into force 2005-01-01||Not to exceed an annual average of 40 μ g m−3|
|Pb||0.5 μ g m−3||1 year||Limit value entered into force 2005-01-01 (or 2010-01-01 in the immediate vicinity of specific, notified industrial sources; and a 1.0 μ g m−3 limit value applied from 2005-01-01 to 2009-12-31)||Not to exceed an annual average of 0.5 μ g m−3|
|CO||10 mg m−3||Maximum daily 8-hour mean||Limit value entered into force 2005-01-01||Not to exceed a maximum daily 8-hour mean of 10 mg m−3|
|CaHa||5 μ g m−3||1 year||Limit value entered into force 2010-01-01||Not to exceed an annual average of 5 μ g m−3|
|O3||120 μ g m−3||Maximum daily 8-hour mean||Target value entered into force 2010-01-01||Maximum daily 8-hour mean of 120 μ g m−3 not to be exceeded 25 days averaged over 3 years|
|As||6 μ g m−3||1 year||Target value entered into force 2012-12-31||Not to exceed an annual average of 6 μ g m−3|
|Cd||5 μ g m−3||1 year||Target value entered into force 2012-12-31||Not to exceed an annual average of 5 μ g m−3|
|Ni||20 μ g m−3||1 year||Target value entered into force 2012-12-31||Not to exceed an annual average of 20 μ g m−3|
|PAHs||1 μ g m−3a||1 year||Target value entered into force 2012-12-31||Not to exceed an annual average of 1 μ g m−3|
a. It is expressed as concentration of Benzo (a) pyrene
Under the new directive, the EU Member States are required to reduce exposure of the population to PM2.5 in two stages: to an annual average limit of 25 μ g m−3 by 2015 and 20 μ g m−3 by 2020. These objectives are set at the national level and are based on the average exposure indicator (AEI). The AEI is determined as a 3-year running mean PM2.5 concentration averaged over the selected monitoring stations in agglomerations and larger urban areas, set in urban background locations to best assess the PM2.5 exposure to the general population.
In the directives mentioned above, the minimum assessments requirements are described. The assessments have to include information on specific concentration thresholds as well as on the population within each air quality zone or agglomeration. While in specific cases continuous monitoring is mandated, modeling is always encouraged in order to provide better information on spatial distribution of concentrations. The European Commission with the extensive support of the national experts in the Working Group on Implementation has prepared several guidance documents and assessed standard methods to facilitate implementation of these provisions.
Reference methods for assessing concentrations of pollutants are described in Annex VI of the Proposal for a directive of the European Parliament and of the Council on ambient air quality and cleaner air for Europe [ CEC, 2005 ]. An overview is provided in Table 2 .
|SO2||Norm EN 14212, 2005: Ambient air quality — standard method for the measurement of SO2 by ultraviolet fluorescence|
|NO2 and NOx||Norm EN 14211, 2005: Ambient air quality — standard method for the measurement of the concentration of NO2 and NOx by chemiluminescence|
|Pb||Norm EN 14902, 2005: Reference method for determination of Pb/Cd/As/Ni in ambient air|
|PM10||Norm EN 12341, 1999: Air quality — determination of the PM10 fraction of suspended PM — reference method and field test procedure to demonstrate reference equivalence of measurement methods|
|PM2.5||Norm EN 14907, 2005: Standard gravimetric measurement method for the determination of the PM2.5 mass fraction of suspended PM in ambient air|
|C6 H6||Norm EN 14662, 2005: Parts 1, 2 and 3, ambient air quality — reference method for measurement of C6 H6 concentrations|
Data for all stations and pollutants are recorded in AirBase, the public air quality database system of the European Environment Agency (EEA) based on the information from the continuous monitoring of air quality, collected under the Exchange of Information Decision 97/101/EC [ CEC, 1997 ]. In AirBase, stations are categorized in different types: rural background stations, urban background stations, traffic stations and other stations. For each of the stations, distance-to-target graphs compare the local air quality with the EU standard. AirBase provides a review of air quality while the Member States have to monitor and publish air quality data continuously. This task is typically mainstreamed to the local level. Most of the time series started in 2001, when mandatory monitoring of ambient air concentrations of selected pollutants first produced reliable air quality information.
With this legislation in place, standards, targets, and reference methods apply equally in each of the EU Member States. It is the Member States’ obligation to transpose EU legislation into national legislation, to monitor emissions and to report to the European Commission as well as to their citizens.
The United Nations Economic Commission for Europe (UNECE) Convention on Access to Information, Public Participation in Decision-making and Access to Justice in Environmental Matters, usually known as the Aarhus Convention [ UNECE, 1998 ], was adopted in 1998 in the Danish city of Aarhus at the Fourth Ministerial Conference in the Environment for Europe process. It grants Access to Information, Public Participation in Decision-making and Access to Justice in Environmental Matters, thus introducing government accountability in environmental matters. The Aarhus Convention has emerged as a foremost environmental agreement. It entered into force on 30 October 2001. It has been ratified and signed by 41 countries (primarily in Europe and Central Asia) and the EU. The Aarhus Convention links environmental rights and human rights, links government accountability and environmental protection, and focuses on interactions between the public and public authorities. It is therefore extremely relevant for air pollution legislation and the participation of the public.
The European Community has begun applying Aarhus-type principles in its legislation. Notably, the Directive 2000/60/EC or Water Framework Directive [ CEC, 2000b ] and the air directives are following Aarhus-type principles. In order to set the floor in its decision-making, the EU has also drawn up a directive that has a link with communication.
The EU Directive 2003/4/EC Access to Environmental Information of 2003 [ CEC, 2003 ] constitutes that every citizen has to have enough access to environmental information and that public authorities have to make an effort to inform the citizens about the environment. Public information on air pollution is therefore an obligation under the New Air Quality Directive. Requirements contain minimum amount of information that needs to be provided to the public as regards to assessment of concentrations. It also requires the public availability of abatement plans and programs. Specific actions are required when alert thresholds are exceeded, for example, to inform the public on the health hazards and the recommended personal behavior to minimize exposure. On the community level, different measures are foreseen to disseminate public information. The directives require Member States to ensure that up-to-date information on ambient concentrations of the different pollutants is routinely made available to the public as well as to other organizations. This is done by providing information on websites, teletext, in press and also by public displays. The information needs to be updated as appropriate to the averaging periods. Authorities are also obliged to inform the public when information is available in the organization (passive information). The EEA, for instance, manages several important databases on air quality such as AirBase (see above).
In December 2004 and January 2005, the European Commission held a public consultation on air quality and used the results as input for the 2005 thematic strategy on air pollution. As an interactive policy making instrument under the Aarhus convention, two online questionnaires were made available for citizens, consumers and businesses, and answers were collected likewise. More than 11,000 comments and opinions were selected and analyzed. The European Commission, its agencies, Member States, environmental stakeholders, and interest groups announced the questionnaires. The results show that more than 80% of the population that feel somewhat or not enough informed about air pollution, pollution peaks, local emissions, impacts on health and ecosystems. Most respondents are willed to spend substantial funding for the improvement of air quality with actions in the fields of industrial air pollution and traffic. The detailed findings show that the basis and targets of the thematic strategy on air quality are in line with observations and people’s concerns. The full results of the consultation can be obtained from TNO  .
Likewise, the European Commission allows comments during any steps in the legislative processes for air quality, from preparation to implementation and review. Stakeholder expert groups (SEGs) meet on 6-monthly basis and provide input to the implementation of exiting legislation or propose legislative measures. The SEG is made up of the EU Member States, business associations, environmental NGOs and other stakeholders. All presentations and protocols are publicly available from a dedicated website. The SEG meetings are live streamed on the internet and citizens can provide their views through the expert groups. A coalition of stakeholder experts for instance responded to the second stakeholder expert group meeting in January 2012 with a fact that had not been treated appropriately in EU legislation yet concerning PM emissions in the domestic sector.
On 30 June 2011, the Commission launched online questionnaires as part of a broad consultation process on the EU Air Quality Directive with a short questionnaire for the general public and a longer section for experts and practitioners from national administrations, regional or local authorities, researchers, businesses, stakeholders, health, environmental, and other groups involved in the implementation of EU air quality legislation. Results provided important responses that help improve the communication of actors. The full report on the responses to the consultation process on the EU Air Quality Directive can be obtained from TNO  .
Based on the latest Air Quality Report published by the European Environment Agency [ EEA, 2012 ], Figure 1 displays the annual emissions of six main air pollutants in the EU from 2001 to 2010. SOx experienced the sharpest drop in emissions during the past 10 years, followed by NOx , non-methane volatile organic compound (NMVOC), and ammonia (NH3), all of which are O3 precursor gases. At present, PM and O3 are Europe’s most problematic pollutants in terms of harm to health. Air pollution’s most important effects on European ecosystems are eutrophication, acidification and vegetation damage resulting from exposure to O3. As sulphur emissions have decreased, NH3 emitted from agricultural activities and NOx from combustion processes have become the predominant acidifying and eutrophying air pollutants. Several air pollutants are also climate forcers, having a potential impact on the planet’s climate.
Annual emissions of six main air pollutants in the European Union during 2001–2010 [ EEA, 2012 ]
Figure 2 shows the annual concentration of PM2.5 for each Member State in 2010, averaged for all stations. The dashed line shows the target value of 25 μ g m−3 . The diagram indicates the lowest and highest observations, the means and the lower and upper quartiles. The lower quartile splits the lowest 25% of the data and the upper quartile splits the highest 25% of the data. As can be seen, for some Member States such as Estonia, Sweden, and Portugal, the means are below 10 μ g m−3 and succeed the target value for all stations. Some stations in Poland and the Czech Republic exceed the value by far.
Annual concentration of PM2.5 for Member States of the EU in 2010 [ EEA, 2012 ]
A combination of different measures has reduced emissions of SOx by 82% between 1990 and 2010. This success can be attributed to desulphurization technology installed in many industrial sources, and EU directives, which led to sulphur reduction in some liquid fuels. This cut is also partly due to power stations and industry switching from high sulphur-containing solid and liquid fuels to low-sulphur fuels such as natural gas.
Emissions of NOx have almost halved between 1990 and 2010. The 47% reduction of NOx emissions over this period was largely due to the introduction of the three-way catalytic converter in petrol vehicles, as well as reductions from industry as a result of tighter controls on emissions.
Together with NOx , emissions of two other main air pollutants responsible for the formation of harmful ground-level O3 have dropped significantly since 1990. CO fell by 62%; NMVOCs fell by 56%. This drop was also facilitated by installing improved vehicle catalysts in road transport.
The agricultural sector is responsible for the vast majority of NH3 emissions: 94% in 2010. NH3 fell by 28% between 1990 and 2010, although the highest reductions occurred in the early 1990s and emissions have since been rather stable. The largest reductions have been reported by Poland, the Netherlands and Germany. All other countries except Cyprus and Spain also reported decreases. The report attributes reductions in NH3 emissions largely to better animal manure and fertilizer management techniques.
During 1997–2009, 18%–49% of the urban population in the EU was potentially exposed to ambient air concentrations of PM10 in excess of the EU limit value set for the protection of human health (50 μ g m−3 daily mean not to be exceeded more than 35 d a calendar year and to be met by 2005).
In the period 1997–2009, 6%–41% of the urban population in the EU was potentially exposed to ambient air NO2 concentrations above the EU limit value set for the protection of human health (40μ g m−3 annual mean and to be met by 2010).
In the period 1997–2009, 13%–61% of the urban population in the EU was potentially exposed to ambient O3 concentrations exceeding the EU target value set for the protection of human health (120 μ g m−3 daily maximum 8-hour average, not to be exceeded more than 25 d per calendar year by 2010, averaged over three years and to be achieved where possible by 2010). The 61% of the urban population exposed to ambient O3 concentrations over the EU target value was recorded in 2003.
Figure 3 shows average O3 concentrations for each Member State’ stations② . It shows the range of O3 concentrations at all stations and how the concentrations relate to the 120 μ g m−3 target value (marked by the dashed line). The boxplot indicates the lowest and highest observations, the means and the lower and upper quartiles. At the box ends the lower quartile splits the lowest 25% of the data and the upper quartile splits the highest 25% of the data. Member States such as France, Italy and Portugal show large disparities in the highest and lowest observations. Some stations are far below the target value whilst others exceed the target value by nearly 50% (Italy). Other Member States such as the Netherlands, Denmark and Sweden show values that never exceed the target values. In average, the maximum O3 concentration per 8-hour mean is much lower and balanced for the stations in Sweden for instance than in Italy.
Maximum daily 8-hour mean concentration of O3 in 2010 for each Member State [ EEA, 2012 ]
In the period 1997–2009, the proportion of the urban population in the EU that is potentially exposed to ambient air concentrations of SO2 in excess of the EU limit value set for the protection of human health (125 μ g SO2 m−3 daily mean not to be exceeded more than three days a year and to be met by 2005), decreased to less than 1%, and as such the EU limit value is close to being met everywhere in the urban background.
The EEA’s annual European Union Emission Inventory Report 1990–2010 under the UNECE LRTAP Convention presents a summary of the main emissions trends over the past decades. It shows that 11 EU countries exceeded the 2010 ceilings for the four important air pollutants regulated under the Gothenburg Protocol of the Convention on Long-Range Transboundary Air Pollution. Among the 11 EU Member States that exceeded the international emissions ceilings in 2010, Denmark and Spain exceeded three ceilings (for NOx , NMVOCs and NH3 ) while Germany exceeded two ceilings (NOx and NMVOCs). Austria, Belgium, France, Ireland, Luxembourg, the Netherlands, and Sweden exceeded the ceiling for NOx and Finland exceeded the ceiling for NH3 .
Europe has set itself strict air quality objectives. It can be regarded as a success that targets for many air pollutants have been ratified. On the way to achieving the targets, the continuous measurement is a powerful framework. These measurements show that meeting PM10 limit values is proving challenging for 25 of the 27 EU Member States which are exceeding these limits in at least one part of their territory. The European status shows that emissions are being reduced, but additional measures need to be applied in order to achieve the long-term target. With the agreement on the target thresholds it is possible now for policy makers to identify socio-economic areas where more improvement has to be done with regard to air pollution. This recalls the cooperation of different sector policies. NH3 emissions, which are recorded under the New Air Quality Directive, are mainly a product of agricultural activities. The benefit of the New Air Quality Directive is that European citizens can claim their right to clean air and the agricultural sector has to support the targets under the directive.
The agreement on substances and their target concentrations in ambient air and the stepwise enforcement provides the national governments the opportunity to assess their situations, to test methodologies and their effects, and to identify sectoral strategies that contribute to the air quality targets of the EU. China, at present, is in a similar situation. In 1989, the National People’s Congress [ NPC, 1989 ] ratified the Environmental Protection Law that established a legal framework including specific instruments for environmental management and the protection of public health [ Remais and Zhang, 2011 ]. Since then, the NPC has passed more specific laws on pollution abatement. Recent progress can be traced back to the extensive transformation of China’s environmental regulatory institutions over the past 20 years.
In 2012, China’s State Council approved its first national environmental standard for PM2.5 in ambient air. With this standard, the implementation of the World Health Organization’s recommended interim target of an annual average of 35 μ g m−3 for such particles by the end of 2015 became a requirement in China [ Zhang et al., 2012 ]. This target is being exceeded threefold in many Chinese cities every year. Air pollution levels in many Chinese cities far exceed health-based standards [ HEI, 2004 ]. However, China has the same vision as Europe. Standards have been identified and agreed on and it will take some time until sectoral measures take effect on air quality in China.
It is undoubted that the improvement of air quality has exclusively positive effects on human health. A reduction in pollutant emissions that produce O3 would not only improve public health but also provide climate benefits. Changing environmental conditions, including rising temperatures caused by GHG, are expected to increase concentrations of ground-level O3. Although reducing PM has clear health benefits, understanding the impact of this reduction on climate change is essential if mutual benefits for climate and health are to be delivered. PM is made up of many different chemical components with different physical properties, some of which lead to temperature rising (e.g., black carbon) by absorbing heat from the sun, whilst others (e.g., sulfates) bring about cooling effects by reflecting sunlight. Some studies point out that reducing air pollution could worsen climate change in the short-term by contributing to an increase in global temperatures. This is still an area of active research with many uncertainties. Worldwide, there is a massive ongoing urbanization (from about 70% rural population in 1950 to about 70% urban in 2050), which can influence policy decisions to reduce the multiple detrimental effects of short- and medium-lived pollutants such as O3 , black carbon, sulphate, CH4 . Although there is a long history of research focusing on a local, city-scale basis, there are two aspects of the bigger picture that need far more attention. This also includes trans-boundary policy aiming at air quality improvement, which would also support climate change policy measures.
This manuscript contains extracts from the Comparative Policy and Practice Study of the EU-China Environmental Governance Programme’s core theme Public Access to Environmental Information with funding from the European Union (www.ecegp.com ). This research cannot be taken to reflect either a European Union or any other official view.
Received: 23 August 2012
①. Council Directive 96/62/EC or Air Quality Framework Directive [ CEC, 1996 ], Council Directive 1999/30/EC or First Daughter Directive [ CEC, 1999 ], Directive 2000/69/EC or Second Daughter Directive [ CEC, 2000a ], Directive 2002/3/EC or Third Daughter Directive [ CEC, 2002 ], Directive 2004/107/EC or Fourth Daughter Directive [ CEC, 2004a ], Council Decision 97/101/EC or exchange of information (EoI) decision [ CEC, 1997 ], Commission Decision 2004/461/EC [ CEC, 2004b ]
②. The graphs are based on the 93.2 percentile of maximum daily 8-hour mean concentration values. This corresponds to the 26th highest daily maximum of the running 8-hour mean as the maximum daily 8-hour mean of 120 μ g m−3 can be exceeded by 25 d