Emissions of a number of compounds categorised as persistent organic pollutants (POPs) - e.g. hexachlorobenzene (HCB, by 92%), hexachlorocyclohexane (HCH, by 85%), polychlorinated biphenyls (PCBs, by 75%), dioxins & furans (by 83%), and poly-aromatic hydrocarbons (PAHs, by 61%) - decreased between 1990 and 2012 in the EEA-33 countries. While the majority of countries report that POPs emissions fell during this period, a number report that increased emissions occurred.
In 2012, the most significant sources of emissions for these POPs included ‘Commercial, institutional and households’ (10% of HCB, 32% of dioxins and furans, 16% of PCBs) and ‘Industrial processes’ (70% of HCB, 32% of HCH, 27% of PCBs) sectors.
Anthropogenic emissions of the main air pollutants decreased significantly in most EEA-33 member countries between 1990 and 2012:
Nitrogen oxides (NO X ) emissions decreased by 46% (51% in the EU-28);
Sulphur oxides (SO X ) emissions decreased by 75% (84% in the EU-28);
Non-methane volatile organic compounds (NMVOC) emissions decreased by 56% (60% in the EU-28);
Ammonia (NH 3 ) emissions decreased by 24% (28% in the EU-28); and
Fine particulate matter (PM 2.5 ) emissions decreased by 35% (35% in the EU-28).
The EU-28 as a whole did not meet its 2010 target to reduce emissions of NO X . A further reduction of 2.2% from the 2010 emissions level is required to meet the interim environmental objectives set in the European Union’s 2001 National Emission Ceiling Directive (NECD).
The EU-28 met its continuing obligation to maintain emissions of SO X , NH 3 and NMVOC below legally binding targets as specified by the NECD. A number of EU Member States reported emissions above their NECD emission ceilings: nine for NO X , three for NH 3 , and one for NMVOCs. There are no emission ceilings for primary PM 2.5 .
Three additional EEA member countries have emission ceilings for 2010 set in the Gothenburg Protocol under the 1979 UNECE Convention on Long-range Transboundary Air Pollution (Liechtenstein, Norway and Switzerland). All three countries met the SOx ceiling. Switzerland also met the ceilings for the other three pollutants. Liechtenstein exceeded the NMVOC ceiling. Norway breached two ceilings, for NH 3 and for NOx.
Across the EEA-33 countries, emissions of lead decreased by 89%, mercury by 66% and cadmium by 64% between 1990 and 2012.
Emissions from the road transport sector have decreased by nearly 98%. Nevertheless, the road transport sector still remains an important source of lead, contributing around 12% of total lead emissions in the EEA-33 region. However, since 2004, little progress has been made in reducing emissions further; 97.9% of the total reduction from 1990 emissions of lead had been achieved by 2004.
Acidification and eutrophication
Acidification: In the EU-28, the ecosystem area where acidification critical loads were exceeded decreased from 43% in 1980 to 7% in 2010 (7% for all EEA member countries). There remain some areas where the interim objective for reducing acidification, as defined in the National Emission Ceiling Directive 2001/81/EC, has not been met.
Eutrophication: The EU-28 ecosystem area, where the critical loads for eutrophication were exceeded, peaked at 84% in 1990 and decreased to 63% in 2010 (55% in EEA member countries). This percentage is projected to decrease to 54% in 2020, assuming implementation of current legislation (48% in EEA member countries). The magnitude of the exceedances is projected to reduce considerably in most areas, except for a few 'hot spot' areas in western France and the border areas between the Netherlands, Belgium and Germany, as well as in northern Italy.
Outlook: Only 4% of the EU-28 ecosystem area is still projected to be in exceedance of acidification critical loads in 2020 if current legislation is fully implemented (3% in EEA member countries). The eutrophication reduction target set in the updated EU air pollution strategy proposed by the European Commission in late 2013, will be met by 2030 if it is assumed that all maximum technically feasible reduction measures are implemented, but will not be met by current legislation.
Most of the vegetation and agricultural crops are exposed to ozone levels exceeding the long term objective given in the EU Air Quality Directive 2008/50/EC. A significant fraction is also exposed to levels above the target value threshold defined in the directive. For the past three years, however, the agricultural area exposed to concentrations above the target value threshold is well below 25%.
Accumulated concentrations of crop exposure to ozone over summer months show large year-to-year variations. There is a tendency to decreasing levels after 2006, although this is not statistically significant.
With regard to forest ozone exposure, during the period 2004 to 2011, 60% or more of the forest area has been exposed to concentrations above the critical level set by the Convention on Long-range Transboundary Air Pollution.
The latest year’s available data show a continuation of the general trend for decreases in air pollutant emissions from transport: all transport-derived pollutants decreased between 2011 and 2012 (by 6 % in the case of NO x , 7 % for SO x , and by 6 % and 7 % in the case of PM 10 and PM 2.5 , respectively). The latest data show that non-exhaust emissions are 46 % of the exhaust emissions of primary PM 10 in 2012, and 31 % of the exhaust emissions of primary PM 2.5 .
Aviation is the only subsector where emissions have increased in the last year available, by 7 % for NH 3 and by 9 % for SO x emissions. Aviation and shipping are the two sectors where increases in activity since 1990 have offset reductions elsewhere, in particular for SO x but also for NO x and PM. Road transport and aviation have also increased NH 3 emissions significantly over the last two decades, but while road transport has recently reduced its emissions, aviation has not yet been able to do so.
In general terms, the transport sector achieved important reductions in the period 1990 through 2012: reductions in CO and non-methane volatile organic compounds (NMVOCs) (both 81 %), but also in NO x (33 %), SO x (26 %) and particulates (by 23 % in the case of PM 2.5 and by 18 % for PM 10 ).
In the period 2000-2012, a significant proportion of the urban population in the EU-28 was exposed to ambient concentrations of pollutants above the EU limit (LV) or target (TV) values for the protection of human health. The numbers of people exposed was even higher in relation to the more stringent World Health Organization (WHO) guidelines. The figures (minimum-maximum in the period) are:
For PM 2.5 , 4-14 % for EU LV and 87-98 % for WHO guideline (for the period 2006-2012 only).
For PM 10 , 21-41 % and 64-92 %,.
For ozone, 14-65 % and 93-99 %.
For NO 2 , 8-27 % in both cases.
For B(a)P, 20-28 % and 85-88 % (for the period 2008-2012 only).
Air quality has slowly improved over past years. Following the decreasing tendencies, in 2012 fewer people (urban population) were exposed to concentrations above the PM 10 EU LV and WHO guideline; the O 3 EU TV; the NO 2 EU LV and WHO guideline; and the SO 2 EU LV and WHO guideline values.
Total emissions of primary sub-10µm particulate matter (PM 10 ) have reduced by 24% across the EEA-33 region between 1990 and 2011, driven by a 35% reduction in emissions of the fine particulate matter (PM 2.5 ) fraction. Emissions of particulates between 2.5 and 10 µm have reduced by 12% over the same period; the difference of this trend to that of PM 2.5 is due to significantly increased emissions in the 2.5 to 10 µm fraction from 'Road transport' and 'Agriculture' (of 20% and 6% respectively) since 1990.
Of this reduction in PM 10 emissions, % has taken place in the 'Energy Production and Distribution' sector due to factors including the fuel-switching from coal to natural gas for electricity generation and improvements in the performance of pollution abatement equipment installed at industrial facilities.
Emissions of the main ground-level ozone precursor pollutants have decreased across the EEA-33 region between 1990 and 2011; nitrogen oxides (NO X ) by 44%, non-methane volatile organic compounds (NMVOC) by 57%, carbon monoxide (CO) by 61%, and methane (CH 4 ) by 29%.
This decrease has been achieved mainly as a result of the introduction of catalytic converters for vehicles, which has significantly reduced emissions of NO X and CO from the road transport sector, the main source of ozone precursor emissions.
The EU-28 as a whole reported 2011 emissions at 4% below the 2010 NECD ceiling for NO X , one of the two ozone precursors (NO X and NMVOC) for which emission limits exist under the EU's NEC Directive (NECD). Total NMVOC emissions in the EU-28 were 22% below the 2010 NECD limit in 2011, however, seven of individual Member States did not meet their ceilings for one or both of these two pollutants.
Of the three non-EU countries having emission ceilings for 2010 set under the UNECE/CLRTAP Gothenburg protocol (Liechtenstein, Norway and Switzerland), all reported NMVOC emissions in 2011 that were lower than their respective ceilings, however Liechtenstein and Norway reported 2011 NO X emissions higher than their ceiling for 2010.
Emissions of the acidifying pollutants, nitrogen oxides (NO X ), sulphur oxides (SO X ) and ammonia (NH 3 ), have decreased significantly in most of the individual EEA member countries between 1990 and 2011. Emissions of SO X have decreased by 74%, NO X by 44% and NH 3 by 25% since 1990 within the EEA-33.
Data reported under the NECD indicates that in 2011 the EU-28 as a whole met its continuing obligation to maintain emissions of NO X , SO X and NH 3 below 2010 target as specified by the EU’s National Emissions Ceiling Directive (NECD). However, the EU-15 as a whole and seven individual Member States, all of which are in the EU-15 group, reported emissions in 2011 above their NECD emission ceilings for NO X . Four EU member states reported 2011 NH 3 emissions above the levels of their NECD ceilings, three of which are in the group of fifteen pre-2004 EU member states.
Three additional countries which are current EEA Member States have emission ceilings for 2010 under the UNECE/CLRTAP Gothenburg protocol (Liechtenstein, Norway and Switzerland). Both Liechtenstein and Norway reported NO X and NH 3 emissions in 2011 that were higher than their respective 2010 ceilings.
EEA-33 emissions of non-methane volatile organic compounds (NMVOCs) have decreased by 57% since 1990. In 2011, the most significant sources of NMVOC emissions were 'Solvent and product use' (43%), comprising activities such as paint application, dry-cleaning and other use of solvents, followed by 'Commercial, institutional and households' (17%).
The decline in emissions since 1990 has primarily been due to reductions achieved in the road transport sector due to the introduction of vehicle catalytic converters to reduce exhaust emissions, and carbon canisters on petrol cars for evaporative emission control. These reductions have been driven by tighter vehicle emission standards, combined with limits on the maximum volatility of petrol that can be sold in EU Member States, as specified in fuel quality directives. The reductions in NMVOC emissions have been enhanced by the switching from petrol to diesel cars in some EU countries. Reductions have also occurred in the 'Solvents and product use' sector as a result of the introduction of legislative measures limiting the use and emissions of solvents.
The majority of EU-28 Member States have reduced emissions since 1990 in line with their obligations under the National Emission Ceilings Directive (NECD), however 2 Member states have not met their ceilings (3.4%)  . Emissions in 2011 for the three non-EU countries which have emission ceilings for 2010 set under the UNECE/CLRTAP Gothenburg protocol (Liechtenstein, Norway and Switzerland) were all well below their respective ceilings.
Environmental context: Non-methane volatile organic compounds (NMVOCs) are a collection of organic compounds that differ widely in their chemical composition but display similar behaviour in the atmosphere. NMVOCs are emitted into the atmosphere from a large number of sources including combustion activities, solvent use and production processes. Biogenic NMVOC are emitted by vegetation, with amounts dependent on the species and on temperature. NMVOCs contribute to the formation of ground-level (tropospheric) ozone, and certain species such as benzene and 1,3 butadiene are directly hazardous to human health. Quantifying the emissions of total NMVOC provides an indicator of the emissions of the most hazardous NMVOCs.
 Emissions data reported by EU member states under NECD is used for comparison with NECD ceilings, and data reported under CLRTAP is used for all other calculations unless otherwise stated.
EEA-33 emissions of NH 3 have declined by 25% between the years 1990 and 2011. Agriculture was responsible for 94% of NH 3 emissions in 2011.
The reduction in emissions within the agricultural sector is primarily due to a reduction in livestock numbers (especially cattle) since 1990, changes in the handling and management of organic manures and from the decreased use of nitrogenous fertilisers. The reductions achieved in the agricultural sector have been marginally offset by the increase in annual emissions over this period in the road-transport sector, and to a lesser extent, the 'Solvent and product use' and 'Non-road transport' sectors.
All but three of the EU-28 Member States reported 2011 national NH 3 emissions that meet the continuing obligation to stay below the 2010 emission ceilings set in the National Emission Ceilings Directive (NECD)  . Emissions in 2011 for one of the three non-EU countries having emission ceilings set under the UNECE/CLRTAP Gothenburg protocol (Liechtenstein, Norway and Switzerland) were also below the level of the respective 2010 ceilings. In 2010 emissions of NH 3 in Denmark and Germany were slightly (less than 1%) above their ceiling; in Denmark these have now reduced below their ceiling, however, in Germany they have risen a further 2%.
Environmental context: NH 3 contributes to acid deposition and eutrophication. The subsequent impacts of acid deposition can be significant, including adverse effects on aquatic ecosystems in rivers and lakes, and damage to forests, crops and other vegetation. Eutrophication can lead to severe reductions in water quality with subsequent impacts including decreased biodiversity, changes in species composition and dominance, and toxicity effects. NH 3 also contributes to the formation of secondary particulate aerosols, an important air pollutant due to its adverse impacts on human health.
 Emissions data reported by EU Member States under NECD is used for comparison with NECD ceilings, and data reported under CLRTAP is used for all other calculations unless otherwise stated.
EEA-33 emissions of nitrogen oxides (NO X ) decreased by 44% between 1990 and 2011. In 2011, the most significant sources of NO X emissions were 'Road transport' (41%), 'Energy production and distribution' (23%) and the 'Commercial, institutional and households' (13%) sectors.
The largest reduction of emissions in absolute terms since 1990 has occurred in the road transport sector, from which emissions in the EEA-33 have fallen 48% since 1990; in all years since 1990, emissions in this sector have fallen compared with the previous year, by an average of 3% per year. This reduction has been achieved despite the general increase in activity within this sector since the early 1990s and has primarily been achieved as a result of fitting three-way catalysts to petrol fuelled vehicles. However, ambient urban concentrations of NO 2 in EU-28 countries in recent years have not fallen by as much as reported emissions and a number of Member States' NO X emissions could therefore be systematically higher than currently calculated.
In the electricity/energy production sector, reductions have occurred as a result of measures such as the introduction of combustion modification technologies (e.g. the use of low NO X burners, which reduce formation of NO X in combustion), the implementation of flue-gas abatement techniques (e.g. NO X scrubbers and selective catalytic and non-catalytic reduction techniques - SCR and SNCR) and fuel-switching from coal to gas (which has significantly lower NO X emissions per unit energy).
The National Emission Ceilings Directive (NECD) specifies NO X emission ceilings for Member States that must have been met by 2010. In general, the newer EU Member States have made substantially better progress against their respective NO X ceilings than the older Member States of the EU-15. Twelve of the EU-13 Member States had reduced their emissions beyond what is required under the NECD  by 2010, and by 2011 all had met their targets. In contrast, only five EU-15 Member States reported 2010 emissions within their respective national ceilings and by 2011 this had increased to just eight. Of the three non-EU countries having emission ceilings set under the UNECE/CLRTAP Gothenburg protocol, only Switzerland reported 2011 emissions below the level of their 2010 ceiling.
Environmental context: NO X contributes to acid deposition and eutrophication of soil and water. The subsequent impacts of acid deposition can be significant, including adverse effects on aquatic ecosystems in rivers and lakes and damage to forests, crops and other vegetation. Eutrophication can lead to severe reductions in water quality with subsequent impacts including decreased biodiversity, changes in species composition and dominance, and toxicity effects. NO 2 is associated with adverse effects on human health, as at high concentrations it can cause inflammation of the airways and reduced lung function, increasing susceptibility to respiratory infection. It also contributes to the formation of secondary particulate aerosols and tropospheric ozone in the atmosphere, both of which are important air pollutants due to their adverse impacts on human health and other climate effects.
 Emissions data reported by EU member states under NECD is used for comparison with NECD ceilings, while data reported under CLRTAP is used for all other calculations unless otherwise stated.
EEA-33 emissions of sulphur oxides (SO X ) have decreased by 74% between 1990 and 2011. In 2011, the most significant sectoral source of SO X emissions was 'Energy production and distribution' (58% of total emissions), followed by emissions occurring from 'Energy use in industry' (20%) and in the 'Commercial, institutional and households' (15%) sector.
The reduction in emissions since 1990 has been achieved as a result of a combination of measures, including fuel-switching in energy-related sectors away from high-sulphur solid and liquid fuels to low-sulphur fuels such as natural gas, the fitting of flue gas desulphurisation abatement technology in industrial facilities and the impact of European Union directives relating to the sulphur content of certain liquid fuels.
All of the EU-28 Member States have reduced their national SO X emissions below the level of the 2010 emission ceilings set in the National Emission Ceilings Directive (NECD)  . Emissions in 2011 for the three EEA countries having emission ceilings set under the UNECE/CLRTAP Gothenburg protocol (Liechtenstein, Norway and Switzerland) were also below the level of their respective 2010 ceilings.
Environmental context: Typically, sulphur dioxide is emitted when fuels or other materials containing sulphur are combusted or oxidised. It is a pollutant that contributes to acid deposition, which, in turn, can lead to changes in soil and water quality. The subsequent impacts of acid deposition can be significant, including adverse effects on aquatic ecosystems in rivers and lakes and damage to forests, crops and other vegetation. SO 2 emissions also aggravate asthma conditions and can reduce lung function and inflame the respiratory tract. They also contribute, as a secondary particulate pollutant, to the formation of particulate matter in the atmosphere, an important air pollutant in terms of its adverse impact on human health. Furthermore, the formation of sulphate particles in the atmosphere following the release of SO 2 results in reflection of solar radiation, which leads to net cooling of the atmosphere.
 Emissions data reported by EU Member States under NECD is used for comparison with NECD ceilings, and data reported under CLRTAP is used for all other calculations unless otherwise stated.
Ozone is both an important air pollutant and a GHG. Excessive exposure to ground-level ozone is estimated to cause about 20000 premature deaths per year in Europe.
Attribution of observed ozone exceedances, or changes therein, to individual causes, such as climate change, is difficult.
Future climate change is expected to increase ozone concentrations but this effect will most likely be outweighed by reduction in ozone levels due to expected future emission reductions.
The data analysed from selected stations in major urban agglomerations indicate that during the period 1999-2008 mean values of NO 2 concentrations at road traffic stations remain relatively stable (trend is smaller than the statistical uncertainty on estimate). An increase is observed after 2003 in the maximum observed concentrations and although a slight reduction is observed in 2007, a further increase is noted in 2008. The background concentrations remain relatively stable throughout the period 1999-2008. For PM10, a slight increase was observed in 2003 in the maximum background concentrations, but these have followed a downward trend since. The trend in the maximum PM10 concentration at traffic stations varies during the period 2002-2008, with a downward trend observed between 2002-2004, an increase in 2006 and a downward trend thereafter. Throughout the period 2002-2007 mean traffic and mean background concentrations remain relatively stable, with a slight downward trend observed in recent years.