Indicator Assessment

Persistent organic pollutant emissions

Indicator Assessment
Prod-ID: IND-170-en
  Also known as: AIR 002
Published 20 Dec 2013 Last modified 18 Nov 2021
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  • EEA-33 emissions of a number of compounds categorised as persistent organic pollutants (POPs) have decreased between 1990 and 2011, including hexachlorobenzene (HCB) by 96%, hexachlorocyclohexane (HCH) by 95%, polychlorinated biphenyls (PCBs) by 73%, dioxins & furans by 84%, and poly-aromatic hydrocarbons (PAHs) by 58%. While the majority of individual countries report that POP emissions have fallen during this period, a number report that increases in emissions of one or more pollutants have occurred.
  • In 2011, the most significant sources of emissions for these POPs included the sectors 'Commercial, institutional and households' (61% for PAHs, 19% of HCB, 39% of dioxins and furans, 15% of PCB emissions) and 'Industrial processes' (43% of HCB, 75% of HCH, 38% of PCB emissions).
  • Important emission sources of PAH include residential combustion processes (open fires, coal and wood burning for heating purposes etc.), industrial metal production processes, and the road transport sector. Emissions from these sources have all declined since 1990 as a result of decreased residential use of coal, improvements in abatement technologies for metal refining and smelting, and stricter regulations on emissions from the road transport sector.
  • Environmental context: Persistent organic pollutants (POPs) are chemical substances that persist in the environment, have potential for biomagnification through the food web, and pose a risk of causing adverse effects to human health and the environment. This group of substances includes unintentional by-products of industrial processes (such as PAHs, dioxins and furans) pesticides (such as DDT) and industrial chemicals such as polychlorinated biphenyls (PCBs). All share the property of being progressively accumulated higher up the food chain, such that bioaccumulation in lower organisms to relatively low concentrations can expose higher consumer organisms,  including humans, to potentially harmful concentrations. In humans they are also of concern for human health because of their toxicity, their potential to cause cancer and their ability to cause harmful effects at low concentrations. Their relative toxic/carcinogenic potencies are compound specific, but in general the major concerns are centred on their possible role in causing cancer, neurobehavioral, immunological and reproductive disorders. More recently concern has also been expressed over their possible harmful effects on human development.

Changes in hexachlorobenzene emissions, 1990–2011


Change in hexachlorocyclohexane emissions


Change in polychlorinated biphenyl emissions


Change in dioxin and furan emissions


Change in polycyclic aromatic hydrocarbons emissions


In the EEA-33 region, emissions of PAHs have fallen by 58% between 1990 and 2011 (Figure 1). A combination of targeted legislation, details of which are set out in the 'Indicator specification - policy context' section, coupled with improved controls and abatement techniques has led in general to significant progress being made in most countries to reduce PAH emissions (Figure 6).

While the majority of individual countries report decreased PAH emissions since 1990, there are five countries (Denmark, Iceland, Estonia, Italy and Liechtenstein) in which emissions have increased by 10% or more. Of these countries, emissions in Denmark and Iceland have risen by more than 50% since 1990, although in both cases emissions have been falling since 2007. One cause of these increased emissions has been due to the introduction of policy measures that have encouraged the burning of renewable materials (e.g. wood by Danish households). Wood-burning produces emissions of PAHs, and hence in this instance policies that have been implemented to address one environmental issue (climate change) have had unintended consequences in terms of air pollution. In absolute terms, emissions of PAHs from both countries are relatively low compared to other countries, but the effect on local population and environmental quality may nevertheless be notable. Of the EEA-33 group of countries, the most PAH emissions are reported by Spain and Germany, where emissions are more than 12 times greater than in Denmark.

Emissions of HCB have fallen sharply in the EEA-33 since 1990, mostly due to a drop in HCB emissions in the United Kingdom of 4.3 tonnes between 1998 and 1999, accounting for 98% of the EEA-33 emissions decrease in 1999 (Figure 2). This large decrease was due to the introduction of regulations in the UK to control the use of hexachloroethane (HCE) tablets as a degassing agent in secondary aluminium production. 63% of the reduction across all EEA-33 countries since 1990 is due to the fall in HCB emissions in the United Kingdom, from 61% of EEA-33 emissions in 1990, to just 11% in 2011.

HCH emissions in EEA-33 countries have fallen overall by 95% from 1990 to 2011 (Figure 1); only Belgium has reported increases in emissions (Figure 3). Of the overall decrease in emissions, 47% may be accounted for by decreased emissions from the 'Agriculture' sector, 32% from 'Industrial processes', and 22% from 'Solvent and product use'. In 2011, 23% of emissions of HCH were from 'Agriculture' sources (Figure 7).

Emissions of PCBs in the EEA-33 have fallen by 73% between 1990 and 2011, due mainly to reductions in 'Industrial processes' emissions, which accounted for 68% of the decrease over this period (Figure 7). Within the EEA-33, the only countries in which PCB emissions have risen from 1990 levels are Portugal and Malta (Figure 4). 21 countries reported lower emissions in 2011 than 1990, and the remaining 10 countries either did not report data, or reported zero emissions for 1990.

EEA-33 countries' reported emissions of dioxins & furans show a decrease of 84% by 2011 when compared with 1990 levels. Of the 31 countries which reported non-zero emissions, only Bulgaria, Latvia and Liechtenstein reported an increase in emissions from 1990 to 2011 (Figure 5). The overall decrease in emissions across all EEA-33 countries was due to significantly reduced emissions from the 'Energy production and distribution' sector (30% of overall decrease), 'Waste' (22%) and 'Commercial, institutional and households' (21%) (Figure 7). In 2011, 39% of dioxin and furan emissions were from sources in the 'Commercial, institutional and households' sector, 18.9% from 'Energy use in industry' and 15.2% from 'Waste' (Figure 8).

Contribution to total change in emissions of persistent organic pollutants per sector


Share of emissions of selected persistent organic pollutants by sector


Important emission sources of POPs typically include residential combustion processes (open fires, coal and wood burning for heating purposes etc.), industrial metal production processes, and the road transport sector (Figure 8).

Emissions from each of these sources have in general declined since 1990 as a result of decreased residential use of coal, improvements in abatement technologies for metal refining and smelting, and stricter regulations on emissions from the road transport sector (Figure 4). In particular, the majority of the PAH emission reduction observed in Europe since 1990 has been due to reduced emissions from within the industrial processes sector (Figure 7). This reflects various initiatives designed to reduce the formation and emission of (unintended) POPs through improved process design, control and pollution abatement technology.

Supporting information

Indicator definition

  • This indicator tracks trends in anthropogenic emissions of POPs since 1990. At the moment, emissions of PAHs are described, but emissions of other POP compounds will be added in the future.
  • The indicator also provides information on emissions by sector: Energy production and distribution; Energy use in industry; Industrial processes; Road transport; Non-road transport; Commercial, institutional and households; Solvent and product use; Agriculture; Waste; and Other.
  • Geographically, the indicator covers the EEA-33. The EEA-33 country grouping includes countries of the EU-28 (Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden and the United Kingdom), European Free Trade Association (EFTA) countries (Iceland, Liechtenstein, Norway and Switzerland) and Turkey.
  • Temporally, the indicator covers the same time coverage of the last version of the LRTAP Report.


The units used in this indicator are the tonne (metric ton).


Policy context and targets

Context description

Targeted European Commission legislation (directives and regulations), coupled with improved control and abatement techniques, have led to good progress being made by the EEA-33 countries towards reducing air emissions of POPs, including the PAH group of chemicals. Such legislation is described below.

  • The ultimate objective of the 1998 UNECE Aarhus Protocol on POPs (to the 1979 Convention on Long-range Transboundary Air Pollution (LRTAP)) is to eliminate any discharges, emissions and losses of POPs. The original protocol bans the production and use of some products outright (aldrin, chlordane, chlordecone, dieldrin, endrin, hexabromobiphenyl, mirex and toxaphene), while others are scheduled for elimination at a later date (DDT, heptachlor, hexachlorobenzene and PCBs). In 2009, the protocol was updated to list commercial pentabromodiphenyl (Penta-BDE) and commercial octabromodiphenyl (Octa-BDE) as POP substances, and the POPs task force concluded that hexabromocyclododecane (HBCD) also met the criteria to be considered a POP, and therefore potential risk management options are currently being considered for it. Finally, the protocol severely restricts the use of DDT, hexachlorocyclohexane (HCH), including lindane, and PCBs, and includes provisions for dealing with the wastes of products that will be banned. It also obliges parties to reduce their emissions of dioxins, furans, PAHs and HCB to below their 1990 levels (or an alternative year between 1985 and 1995). It also lays down specific limit values for the incineration of municipal, hazardous and medical waste.
  • The 2001 UNEP Stockholm Convention on POPs aims to reduce and ultimately cease the manufacture, use, storage and emission of POPs, as well as to destroy existing stocks. It provides for measures to reduce or eliminate emissions resulting from intentional and unintentional production and use. It also plans to meet the obligations on technical and financial assistance for developing countries and countries with economies in transition, and to cooperate and exchange information. Twelve POPs were covered under the original scope of the Stockholm Convention:
    • pesticides: aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene, mirex and toxaphene;
    • industrial chemicals: HCB and PCBs;
    • by-products: HCB; polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF), and PCBs.

 In May 2009, additional chemicals were added to the Stockholm Convention:

    • pesticides: chlordecone, alpha hexachlorocyclohexane, beta hexachlorocyclohexane, lindane and pentachlorobenzene;
    • industrial chemicals: hexabromobiphenyl, hexabromodiphenyl ether and heptabromodiphenyl ether, pentachlorobenzene, perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride, tetrabromodiphenyl ether and pentabromodiphenyl ether;
    • by-products: alpha-HCH, beta-HCH and pentachlorobenzene.

The EC Communication on a Community Strategy for Dioxins, Furans and PCBs (COM (2001) 593 final) aims to assess the current state of the environment and to reduce human exposure and long-term environmental effects. This communication does not propose legislative measures, but could be the basis for a Community action plan.

The Directive on the Limitation of Emissions of Certain Pollutants into the Air from Large Combustion Plants (2001/80/EC) has had the effect of reducing heavy metal and PAH emissions via dust control and absorption.

Regulation (EC) No 850/2004 on Persistent Organic Pollutants entered into force on 20 May 2004. The main purpose of this regulation is to enable the European Community to ratify the Stockholm Convention and the Aarhus Protocol. The regulation also deals with stockpiles of redundant substances.

Emissions of a number of heavy metals released from certain industrial facilities are also estimated and reported under the requirements of the European Pollutant Release and Transfer Register Regulation (E-PRTR) (166/2006/EC).

The EU Directive on Ambient Air Quality and Cleaner Air for Europe (2008/50/EC) and Directive 2004/107/EC relating to heavy metals and polycyclic aromatic hydrocarbons in ambient air contain provisions, and target and limit values for the further control of air pollutants in ambient air.

There are also a number of specific EU environmental quality and emission standards for heavy metals and POPs in coastal and inland waters, drinking waters, etc. These have only indirect relevance to air emissions as they do not directly specify emission or precipitation quality requirements, but rather specify the required quality of receiving waters. Such measures include Directive 84/491/EEC on HCH discharges; Directives 76/464/EC and 86/280/EC on dangerous substances; and the Water Framework Directive (2000/60/EC).


As noted above, the Aarhus Protocol on POPs to the UNECE LRTAP Convention obliges parties to reduce their emissions of dioxins, furans, PAHs and HCB to below their 1990 levels (or an alternative year between 1985 and 1995 inclusive).

Related policy documents



Methodology for indicator calculation

This indicator is based on the national total and sectoral emissions officially reported to the EEA and UNECE/EMEP (United Nations Economic Commission for Europe/Co-operative programme for monitoring and evaluation of the long-range transmission of air pollutants in Europe) LRTAP Convention. For the EU-28 Member States, the data used are consistent with the emissions data reported by the EU in its annual submission to the LRTAP Convention.

Recommended methodologies for emission inventory estimation are compiled in the EMEP/EEA Air Pollutant Emission Inventory Guidebook (EMEP/EEA, 2016). Base data are available from the EEA Data Service and the EMEP web site. If necessary, gaps in reported data are filled by the European Topic Centre for Air and Climate Change using simple interpolation techniques (see below). The final gap-filled data used in this indicator are available from the EEA Data Service .

Indicator specification and metadata

Base data, reported in the UNECE/EMEP nomenclature for reporting (NFR14) sector format, are aggregated into the following EEA sector codes to obtain a consistent reporting format across all countries and pollutants:

  • Energy production and distribution: emissions from public heat and electricity generation, oil refining, production of solid fuels, extraction and distribution of solid fossil fuels and geothermal energy;
  • Energy use in industry: emissions from combustion processes used in the manufacturing industry including boilers, gas turbines and stationary engines;
  • Industrial processes: emissions derived from non-combustion-related processes such as the production of minerals, chemicals and metals;
  • Road transport: light and heavy duty vehicles, passenger cars and motorcycles;
  • Non-road transport: railways, domestic shipping, certain aircraft movements and non-road mobile machinery used in agriculture and forestry;
  • Commercial, institutional and households: emissions principally occurring from fuel combustion in the services and household sectors;
  • Solvent and product use: non-combustion-related emissions mainly in the services and households sectors including activities such as paint application, dry-cleaning and other use of solvents;
  • Agriculture: manure management, fertiliser application and field-burning of agricultural wastes;
  • Waste: incineration and waste water management;
  • Other: emissions included in national totals for the entire territory that are not allocated to any other sector.


The following table shows the conversion of NFR sector codes used for reporting by countries into EEA sector codes:

EEA classification

Non-greenhouse gases (GHGs) (NFR)

National totals

National total

Energy production and distribution

1A1, 1A3e, 1B

Energy use in industry


Road transport


Non-road transport (non-road mobile machinery)

1A3 (excl. 1A3b)

Industrial processes and product use








Commercial, institutional and households

1A4ai, 1A4aii, 1A4bi, 1A4bii, 1A4ci, 1A4cii 1A5a, 1A5b




Methodology for gap filling

An improved gap-filling methodology was implemented in 2010 that enables a complete time-series trend for the main air pollutants (nitrogen oxides (NOx), sulphur oxides (SOx), non-methane volatile organic compounds (NMVOCs), ammonia (NH3) and carbon monoxide (CO)) to be compiled. In cases in which countries did not report emissions for any year, it meant that gap filling could not be applied. For these pollutants, therefore, the aggregated data are not yet complete and are likely to underestimate true emissions. Further methodological details of the gap-filling procedure are provided in section 'Data gaps and gap-filling' of the European Union emission inventory report 1990–2017 under the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP).

Methodology references



Methodology uncertainty

The use of gap filling for countries that have not reported emissions for one of more years can potentially lead to artificial trends, but it is considered unavoidable if a comprehensive and comparable set of emission data for European countries is required for policy analysis purposes.

Data sets uncertainty

Uncertainties in the emission estimates of PAHs reported by countries are considered to be higher than for other more 'traditional' air pollutants, such as NOx and SO2, because of the relatively high uncertainties that exist with regard to both activity data and emission factors for this group of pollutants. Emission estimates for the other POPs are also considered to have a high degree of uncertainty.

Rationale uncertainty

This indicator is regularly updated by the EEA and is used in state of the environment assessments. The uncertainties related to methodology and data sets are therefore important. Any uncertainties involved in the calculation and the data sets must be accurately communicated in the assessment, in order to prevent erroneous messages from influencing policy actions or processes.

Data sources

Other info

DPSIR: Pressure
Typology: Performance indicator (Type B - Does it matter?)
Indicator codes
  • AIR 002
Frequency of updates
Updates are scheduled once per year
EEA Contact Info


Geographic coverage

Temporal coverage