Improvements to air quality monitoring, modelling and assessment regimes – including for additional near-real time data reporting – under policy options III-1 to III-5 will provide additional comparable and objective information that allows to regularly monitor and evaluate the development of air quality in the EU. The availability of this data, and more precise requirements for information to be included in air quality plans as per policy option II-1, will also allow to keep the effectiveness of specific (often local) air quality measures under constant review. Clearer specific requirements on public information as put forward by policy options IV-1 and IV-2 will make it easier and faster for citizens to access the outcomes of monitoring and evaluation of air quality data and related policy action.

The existing provisions on reporting as per Commission Decision 2011/850 guided the development of an effective and efficient digital e-reporting system, hosted by the European Environment Agency. The air quality data reported by Member States is made available to the public as a digital service by the European Environment Agency, including via the European Air Quality Index based on near-real time data. This means that reliable, objective and comparable air quality data and information are online available across the EU for all pollutants covered by the Directives. In addition, monitoring of pollutants of emerging concern as per policy option III-4a will make it possible to keep under observation several air pollutants for which to date no harmonised EU-wide air quality monitoring exist.

The current framework established under the Ambient Air Quality Directives already offers high-quality representative monitoring of air quality, as demonstrated in the fitness check of the Directives, and provides key data for environmental monitoring under the Zero Pollution Monitoring and Outlook and the 8th Environment Action Programme , and it will be further enhanced through specific actions that would result from several of the preferred policy options. Across the EU, Member States have established an air quality monitoring network with some 16 000 sampling points for specific pollutants (often grouped at more than 4 000 monitoring stations) based on common criteria defined by the Directives. Overall, the monitoring network by and large adheres to the provisions of the Directives and ensures that reliable and representative air quality data is available.

The proposed merging of the current Ambient Air Quality Directives 2008/50/EC and 2004/107/EC into a single Directive is expected to reduce administrative burden for public authorities, in particular competent authorities in the Member States, by simplifying rules, enhancing consistency and clarity, and rendering implementation more efficient.

The main costs businesses and citizens may incur stem from measures decided by Member State authorities to achieve the air quality standards set in the Directives. Such mitigation/adjustment costs are analysed throughout this impact assessment – see in particular sections 6 and 8.3 above, as well as Annex 3 for a detailed account, including quantifications.

The policy measures analysed in this impact assessment do not generate significant new administrative costs for businesses and citizens, and there is no need to look at potential off-setting measures as part of the Commission’s commitment to the ‘one-in-one-out’ scheme.

This impact assessment has assessed the changes in administrative costs for public authorities, businesses and citizens with a view to minimise/mitigate any increase. Administrative costs for public authorities are assessed for each policy measure analysed, and quantified for the preferred option, using the EU’s Better Regulation Toolbox Standard Cost Model (cf. section 8.3 above and Annex 3).

For authorities: Annualized one-off costs for I3 50k €, no costs for I1 - generally no costs expected unless sampling points are not relocated.

For authorities: Annualized one-off costs for C2 600k € + E1, E2, E4 are expected to have no cost if compliance is assured (but high cost if not)

For consumers/business: Indirect costs only, and only if it accelerates action taken anyway

For consumers/business: Indirect costs only, if the outcome of such review leads to tighter standards

For consumers/business: Indirect costs only, and only if it accelerates action to be taken anyway

For authorities: Limited direct costs in setting up the metric, but one-off costs if this requires new plans

For authorities: Costs for more action to assure exceedance periods are kept as short as possible

Table 18 – Assessment of administrative costs and burden for preferred policy options – based on a central estimate (note: one-off costs have been annualized assuming a period of 20 years and a discount rate of 3%)

It is important to note that the Ambient Air Quality Directives do not impose any direct administrative costs on consumers and businesses (but these sectors do bear important adjustment costs, i.e. due to measures needed to achieve EU air quality standards).

This includes a fixed cost component independent of the level of ambition assumed via policy options I-1, I-2 or I-3, and a cost component linked to the development of air quality plans, which depends on the number of exceedances above EU air quality standards to be expected in the target year 2030 and hence varies by scenario (ranging between 1 and 31 million Euro). Policy options on developing (or, to a lesser extent, updating) air quality plans, air quality assessments and introducing additional sampling points come with important costs, which include both one-off and recurrent costs. All these are costs borne by public authorities.

Administrative costs also need to be analysed in order to assess the potential administrative burden placed on different actors. For this, the EU’s Better Regulation Toolbox Standard Cost Model (SCM) was used to estimate additional costs of the policy options compared to the baseline scenario. Aggregating the costs yields an estimated range of total administrative costs of 75 to 106 million Euro per year – see Table 18 for costs per policy option.,

Adjustment (or mitigation) costs have been estimated to be substantial in absolute terms (annually 5.6 billion Euro in 2030 for the preferred option, and decreasing therafter), but in relative terms remain well below 0.1% of EU GDP, as shown in the previous section.

These steps would accomplish consolidation of air quality legislation, while simplifying rules applying to competent authorities, enhancing overall consistency and clarity, and thus rendering implementation more efficient.

Notably, monitoring and assessment requirements for heavy metals would be aligned with those for other air pollutants in a single, more harmonised air quality assessment regime. Similarly, monitoring and assessment requirements on ozone, thus far largely separate and often different from the ones for other air pollutants, would be more integrated and aligned within a generalised monitoring approach.

After more than a decade of implementing Directive 2008/50/EC and Directive 2004/107/EC in parallel, the revision of the Ambient Air Quality Directives provides an opportunity to incorporate the latest scientific knowledge and the experience gained on their implementation by merging them into a single Directive. In addition to streamlining relevant provisions in one integrated legal text, several updates and revisions aim to further simplify the rules applicable to different air pollutants covered by the previous Directives.

When Directive 2008/50/EC was adopted, it replaced Council Directive 96/62/EC on ambient air quality assessment and management, Council Directive 1999/30/EC relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead in ambient air, Directive 2000/69/EC relating to limit values for benzene and carbon monoxide in ambient air, Directive 2002/3/EC relating to ozone in ambient air and Council Decision 97/101/EC establishing a reciprocal exchange of information and data from networks and individual stations measuring ambient air pollution within the Member States. Their merging into a single Directive was done in the interest of clarity, simplification and administrative efficiency. At the time, the co-legislators also set out that consideration be given to merging Directive 2004/107/EC with Directive 2008/50/EC, once sufficient experience had been gained in relation to the implementation of Directive 2004/107/EC.

In light of the Commission’s better regulation agenda (and REFIT programme), it is proposed to merge Directive 2008/50/EC and Directive 2004/107/EC into one Directive regulating all relevant air pollutants.

Without the border cell adjustment (i.e. in the main set of results of this impact assessment), costs are hence likely to be overestimated (in Figure 16), depending on the policy option, and the extent of the overestimation is most significant for certain Member States (incl. Poland, Lithuania, Hungary, Greece, Croatia and Bulgaria).

In such cases, in order to provide a more realistic representation of the level of effort (and hence costs) needed in the EU, where the proposed air quality standards will apply, an additional analysis has been carried out, excluding border cells with cities on the non-EU side. This can result in a significant cost decrease compared to the central analysis, varying across options: The differences are most pronounced in Option I-3 (PM2.5 at 15 ug/m3), where, by the year 2030, costs drop by 70% (from €3.3 bn to €1.0 bn), while benefits would drop by just over 50%. The differences are smaller for Option I-2 (PM2.5 at 10 ug/m3), where the costs drop by 9% and the benefits by 5%, and in the case of Option I-1 (PM2.5 at 5 ug/m3), the effect disappears, as the stringency of the target requires such enhanced efforts in that the border cities do no longer lead to skewed results.

As the external borders of the EU do not have the shape of squared grid cells, some of the cells analysed cover territory both within and outside the EU. In order to cover the whole EU territory, the model optimisation for reaching air quality standards includes these cells as well – and therefore also the part of them that is located outside the EU. In some of these cross-border cells, where the level of pollution in the neighbouring country is particularly high, this entails a much higher level of effort needed for the whole cell to achieve an air quality standard than what would be needed if the model optimisation were restricted to EU territory only. This is for instance the case for border cells in Lithuania and Poland, at the border with Belarus and Ukraine, as well as for border cells in Bulgaria, Croatia, Hungary and Greece.

The modelling performed for this impact assessment includes two main aspects. First, it assesses in which parts of the EU different (more ambitious or less ambitious) air quality standards can be achieved. Second, it assesses the costs that achieving such standards would entail. Both aspects are assessed for each geographical grid cell of the model. Each cell has a size of 7x7 km².

As with the impacts of air pollution under the preferred policy option, also the adjustment costs (i.e. the air pollution mitigation or adjustment costs required in addition to baseline assumptions) differs across Member States and economic sectors. Figure 16 offers an overview of additional air pollution mitigation or adjustment costs in 2030 for the preferred policy option. These amount to below 0.1% of GDP in total, with up to 0.3% of GDP in some Member States. Costs are expected to be higher (relatively speaking) for those Member States that either see persistent air pollution challenges today, or where specific measures would be required. In particular, for the residential heating sector additional costs would occur, as well as, to a lesser degree for the industry and agriculture sectors. Note that this Figure 16 likely overestimates the costs for some Member States, due to ‘border cell effects’ (see Box 6).

Elevated levels of fine particulate matter (PM2.5) in Southern Europe are much linked to the occurrence of air pollution due to natural sources, and Sahara dust and sea spray in particular (which the current Ambient Air Quality Directives allow to be deducted from air pollution levels reported). A particular challenge for this region is the handling of elevated ozone concentration levels, which climate change (in particular rising and increasingly longer heat patterns) may further exacerbate, and for which air quality management would require additional measures on ozone precursors (incl. methane).

Figure 15 – Concentrations for PM2.5 in 2020 (left), and for 2030 (right) under the preferred policy option I-2, example border region between Poland, Czechia and Slovakia (for additional maps, please see Annex 5).

Similarly, for much of Eastern Europe (see, for example, Figure 15), residential heating (often reliant on fossil fuel combustion) and industry production facilities today lead to elevated PM2.5 concentration levels. Under the preferred policy option and based on the measures taken to address these emissions, the area exposed to PM2.5 concentration levels above 10 µg/m3 reduces almost to zero by 2030. However, Annex 5 shows that in many areas across this region, elevated levels of benzo(a)pyrene remain to be a concern in a 2030 perspective.

Figure 14 – Concentrations for PM2.5 in 2020 (left), and for 2030 (right) under the preferred policy option I-2, example Northern Italy (for additional maps, please see Annex 5).

For Northern Italy (see Figure 14), specific meteorological and orographic circumstances lead to reduced dispersion, and thus accumulation of air pollution. This is aggravated by elevated emission levels from residential heating (including biomass burning) as well as agricultural emissions across the Po Valley region. While under the preferred policy option the area exposed to PM2.5 concentration levels above 10 µg/m3 reduces significantly by 2030, some hotspots would be expected to remain, and may require additional time to reach this level.

Figure 13 provides an overview of expected changes of fine particulate matter (PM2.5) concentrations between 2020 and 2030 under the preferred policy option I-2. This highlights specific challenges to meet the levels recommended by the World Health Organization Air Quality Guidelines in some parts of the EU, including Northern Italy (see also Figure 14), the border region of Czechia, Poland and Slovakia (see also Figure 15), as well as southern regions along the Mediterranean coast of the EU.

Figure 13 – Concentrations for PM2.5 in 2020 (left), and for 2030 (right) under the preferred policy option I-2, EU overview (for additional maps, including for other pollutants, please see Annex 5).

This translates into an air quality management challenge. On the one hand, air pollution and elevated air pollutant concentration levels affect human physiology and health in a similar manner no matter where it occurs – and require the same level of protection across the EU. On the other hand, which and how much air pollution occurs, and which options are available to manage air quality, will depend much on regional and local circumstances – and, in instances where exceedances persist, will require devising tailor-made national, regional and local approaches and responses in addition to EU policy and measures.

Air pollution is an EU-wide challenge and is considered the biggest environmental health risk in Europe. However, the degree to which air pollution affects individuals, and regions, differs significantly across the EU – and depends on a range of factors from meteorology and orography (which affect air pollution dispersion patterns) to the proximity to air pollution sources and different structural emission patterns.

(c) Based on VOLY (value of a life year), i.e. damage cost calculations based on the potential years of life lost.

(b) If ‘border cell effects’ were excluded in the analysis, mitigation costs (and benefits) would be lower (see section 8.2, Box 6).

(a) This analysis assesses technical feasible reductions only and does not include assumptions on fundamental changes in economic activity, dietary patterns, technological breakthroughs or major shifts in our energy systems.

For all three policy options (i.e. independent of the political choice made) there is a clear case for embracing a staged approach towards setting current and future EU air quality standards: (1) establish clear EU air quality standards for the mid-term, i.e. the year 2030 (with a limited number of temporary exceptions where these are clearly warranted – see also Section 8.2); (2) develop a long-term, post-2030 perspective for a full alignment with the 2021 WHO Air Quality Guidelines, whilst getting on track towards alignment also with future WHO Guidelines to achieve the zero pollution vision by the year 2050; (3) a regular review mechanism to assure that the latest scientific understanding of air quality guides future decisions, and retains flexibility elements given potential (future) geo-political challenges.

Under policy option I-1 (‘full alignment’ with the 2021 WHO Air Quality Guidelines by 2030) the benefit-to-cost ratio remains significantly positive also (between 6:1 and 18:1). However, 71% of sampling points would not be expected to meet the corresponding air quality standards without additional effort at local level (and in many of these instances would not be able to meet these standards at all with technical feasible reductions only). The net benefits amount to more than 38 billion Euro, i.e. 5% more than policy option I-2.

For policy option I-2 (‘closer alignment’ with the 2021 WHO Air Quality Guidelines by 2030) the benefit-to-cost ratio is expected to be slightly lower (between 7.5:1 and 21:1). Some 6% of sampling points would not be expected to meet the corresponding air quality standards without additional effort at local level (or may need time extensions or exceptions). The net benefits amount to more than 36 billion Euro, i.e. 25% more than policy option I-3.

This analysis shows that policy option I-3 (‘partial alignment’ with the 2021 WHO Air Quality Guidelines by 2030) has the highest benefit-to-cost ratio (between 10:1 and 28:1). Most air quality sampling points in the EU might be expected to meet the corresponding air quality standards with little additional effort. The net benefits amount to more than 29 billion Euro.

All three of these options, i.e. ‘full alignment’ (I-1), ‘closer alignment’ (I-2) and ‘partial alignment’ (I-3), would render significant health and environment benefits – albeit to varying degrees. Even under relatively ‘low’ assumptions regarding the value of health benefits (using ‘VOLY’, see section 6.1), the total benefits are assumed to outweigh the implementation costs by 2030 for all three policy options - see Table 17 for details.

Indeed, when considering the degree of alignment with WHO Air Quality Guidelines, it is important to bear in mind that the overall objective of the guidelines is to provide quantitative health-based recommendations for air quality, primarily based on epidemiological evidence. They do not take into account whether it is feasible to reduce air pollution to these recommended levels. Instead, the guidelines recognise that this may not be possible for some time in many locations. Hence the guidelines also provide interim targets to guide reduction efforts towards full alignment with the recommended air quality levels. The guidelines also point out that setting standards may require taking into account additional factors, such as costs and technical feasibility, and that these should be considered during the policy-making process.

The remaining three policy options, namely those contrasting different levels of alignment with the WHO Air Quality Guidelines (I-1, I-2 or I-3), will require a political choice. This outcome of this choice will have environmental, economic, social and health implications.

Meanwhile, Table 16 summarises the policy options that would not be retained to their full extent (these may be still addressed partially, also due to positive spill-over effects from preferred policy options).

Table 15 gives an overview of the preferred policy option(s), based on the comparison of options within each problem area (section 6), and the analysis of synergies and complementarities across problem areas (section 7).

This impact assessment considers a total of 69 potential specific policy measures, combined in 19 potential policy options (and with additional 15 sub-options that might be considered), to address the four problem areas in the existing air quality legislation (see section 2) – and to align more closely with the WHO Air Quality Guidelines. Of the 19 potential policy options assessed, 16 are complementary and somewhat independent from each other, even if there are some co-benefits to consider across options.

Policy option I-6 on the regular review of EU air quality standards ensures that the standards are future-proof with regards to possible future changes in scientific knowledge or technological development.

Policy coherence is also crucial when it comes to various policies that address pollutant emissions at sources such as energy generation, transport, industrial installations, domestic heating and agriculture. This concerns, for instance, the recent proposal for revising the Industrial Emissions Directive , and the proposal for Euro 7 emission standards for road vehicles. These and other existing source policies have been considered in this impact assessment, notably regarding the impacts of policy options I-1 to I-3 on air quality standards.

Coherence with the Zero Pollution Action Plan was assessed with a focus on policy options I‑1 to I-3 to ensure that the preferred policy option is in line with the 2030 goals of the Action Plan to reduce by more than 55% the health impacts (premature deaths) of air pollution, and supports, through a trajectory path, the 2050 vision of the Action Plan to reduce air, water and soil pollution to levels no longer considered harmful to health. Also, the implementation of the Nature Restoration Law can deliver on clean air aspects.

When it comes to coherence with other policies, coherence with climate policy, in particular the European Climate Law , is central due to the many common sources of greenhouse gas and pollutant emissions. In combination with an effective overall legislative framework (policy options under problem areas II, III and IV), an ambitious revision of EU air quality standards by 2030, combined with a trajectory towards a post-2030 perspective to achieve a zero pollution vision for clean air are coherent with the Climate Law and its 2030 and 2050 targets, as measures to achieve clean air will lead to greenhouse gas emission reductions as well.

Policy coherence and future-proofing: The main analysis of policy coherence between different policy options for the revision of the Ambient Air Quality Directives is covered in the considerations on synergies, complementarities and trade-offs presented above.

Proportionality: The proportionality of the policy option to revise the number of pollutants subject to ‘limit values’ (II-2) as the most binding type of standard depends on the strictness of air quality standards (I-1 to I-3, also see the discussion on effectiveness above). All policy options that improve knowledge on the state and development of air quality, notably III-1, III-4 and III-5, support proportionality of clean air measures and air quality plans.

Finally, legal action on air quality monitoring and assessment rules of the current Ambient Air Quality Directives at EU and national level has demonstrated that enforceability (problem area II) is an important safeguard for solid air quality assessment (problem area III).

The effectiveness of air quality standards (problem area I) and of their governance and enforcement (problem area II), as well as public information (problem area IV), also depend on effective assessment of air quality (problem area III): without solid knowledge about the state and development of air quality, the attainment of air quality standards cannot be properly checked in a reliable and comparable manner – and in such circumstances actions to improve air quality risk being insufficiently and/or unsuitably justified and/or not well targeted.

In addition, policy option II-1 supports more targeted, and hence more efficient air quality measures by ensuring that the effect of air quality measures on pollutant concentrations be estimated in air quality plans. Policy options III-1, III-4 and III-5 on air quality assessment, monitoring and modelling quality also support more efficient clean air measures through improved knowledge on the state and development of air quality. By avoiding a double burden on public authorities to develop short-term action plans and air quality plans separately, policy option II-1 improves efficiency.

A key interdependence in this regard is between the level of ambition enshrined in air quality standards (problem area I) and their enforceability (problem area II). The fitness check of the Ambient Air Quality Directives concluded that legally binding and enforceable limit values have been more effective in facilitating downward trends than other types of air quality standards. The level of ambition of revised air quality standards will require corresponding reductions in air pollution and health impacts to meet these standards. On the other hand, enforceable binding standards must be set at levels that remain attainable. A very ambitious standard that is hard to attain but is not enforceable, risks not being effective.

While policy options developed here are largely self-standing (and have been assessed as such), there are some important interdependencies between the policy options aimed at addressing the four problem areas I though IV.

(*) The assessment raises questions as to whether this is attainable at all based on available measures and current knowledge

Table 14 provides a comparison of the environmental, social and economic consequences of each policy option, and an indication of the costs the respective policy options are expected to entail. This allows a comparison of the relative benefit to cost ratio of different options.

Following the comparison of policy options within each of the problem area in section 6, this section analyses synergies, complementarities and trade-offs of different policy options across the problem areas with regards to their effectiveness and efficiency in achieving identified objectives, to their policy coherence and proportionality, as well as to how future-proof they are, given long-term challenges, including in terms of coherence with other policies.

Harmonisation of air quality data saves costs for developing and updating separate indices. Provides clarity for citizens across the EU.

Policy option IV-3 would have an indirect positive impact on the health of citizens, in particular that of more vulnerable populations, because it will enable them to take informed decisions based on the air quality data available to them. Moreover, the costs would be low, as the technology is already developed and being used. The stakeholder survey showed there is very high support for this measure particularly from civil society & NGOs followed by public authorities. However, public authorities also expressed doubts around the effectiveness of the European Air Quality Index on its own (for example, around its ability to represent multi-pollutant effects), and complete harmonization may restrict the ability of Member States to tailor advice and information to the specific situations.

Policy option IV-3 (introduce a requirement to use harmonised air quality index bands- see table 13.3) is assessed as being very beneficial to improve clear communication of air quality information to the public, in line with the overarching objectives of the Ambient Air Quality Directives. This option will strongly enhance the effective implementation of the current Article 27 of Directive 2008/50/EC and Annex XVI to the Directive by introducing a common metric system for indices (i.e. harmonised air quality index bands) or by ensuring that, where alternative metrics are used at national level, clear reference is made to EU agreed air quality index bands (for example, via the online European Air Quality Index).

Potentially impactful measure, will require closer interaction between health practitioners and policy makers to inform a wider public (and vulnerable populations) better. Likely significant initial costs.

Policy option IV-2, would allow EU citizens to take timely action and thereby have significant indirect health and societal benefits. However, there would be initial costs of setting this up. The stakeholder survey showed that views on these policy options are mixed. Public authorities were divided about these policy options, civil society & NGOs were particularly positive and industry & business mostly not supportive. Conversely, there is little added value seen in sub‑option IV‑2a (mandate the use of specific communication channels), as the use of those by the public can vary strongly between regions/population groups and can evolve rapidly.

Up-to-date data provision will allow more for additional societal responsiveness to pollution peaks. Related costs will vary, and include a punctual expansion of the monitoring network.

Policy option IV-1, will indirectly benefit public health, in particular that of the sensitive population. Moreover, most Member States already publish (nearly) real-time data, therefore the costs of this policy option would be low.

Policy option IV-1 (introduce more specific requirements to provide up-to-date data- see table 13.1) and policy option IV-2 (introduce requirements to provide health related air quality data- see table 13.2) are assessed as being useful to enhance the quality and quantity of the air quality information communicated to the public and thereby make the Ambient Air Quality Directives more effective.

Policy options to address air quality information shortcomings should in particular improve access to clear and objective air quality information – and thus make the Directive more effective. For all policy options under this cluster the administrative burden of implementing the corresponding measures would fall upon public authorities (and in some cases would require the more active involvement of health sector authorities also).

This policy option is a prerequisite to an effective implementation of policy option III-1. Important for robust data, but little other direct consequences.

Policy option III- 5 (introduce requirements on modelling quality objectives- see table 12.5) is a prerequisite to an effective implementation of policy option III-1. However, little other direct consequences are identified. Any modelling application used in support of the implementation of the Ambient Air Quality Directives should be of sufficient quality and be fit for purpose (assured via a standardized modelling quality objective metric). This would provide for robust modelling data, and therefore support and increase its use and was largely supported by stakeholders, especially public authorities and research & academia. Cost may vary depending on the starting point on the use of modeling by public authorities.

Additional clarity will enhance reliability and comparability of air quality data – but may also result in significant cost to update existing air quality monitoring and assessment networks.

A majority of stakeholders (regardless of stakeholder group) favoured to define measurement uncertainty in absolute values alongside percentage values, as per sub-option III-4a (revise approach to air quality assessment uncertainty), to assure the reliability of air quality measured at lower concentrations than is commonly monitored today.

Policy option III-4 (revise the criteria for air quality sampling points - see table 12.4) aims to improve the siting of sampling points and their data quality, with significant impact on the accuracy of air quality levels measured. Clarification on the application of the macro-siting criteria for sampling points (and a reduction of flexibilities in this regard) will further increase comparability of air quality data. A majority of stakeholders indicate support to this measure, but especially public authorities point to the need for some flexibility to be able to deal with practical and administrative challenges in establishing a monitoring network. Also related to micro-siting criteria, a number of public authorities argue that current requirements are clear and any change could hamper long-term comparability of air quality data; nevertheless especially civil society & NGOs call for reducing flexibilities afforded. National Air Quality Reference Laboratories stressed that data quality objectives can be updated to secure greater data quality of monitored data.

Clarifies current levels of these air pollutants, as a requisite for verifying health effects and need for taking action. Costs related to the expansion of the monitoring network and adding ‘super-sites’.

Sub-option III-3a (revise and expand list of VOCs to monitor) received strong support by all stakeholders, insofar that VOCs should be monitored based on latest scientific knowledge, especially for their health impacts, but also for their oxidative potential and their role as ozone precursors, as well as their role as particulate matter precursors. However, there was no consensus on which pollutants such an expansion of the list of VOCs should make mandatory (which specific VOCs to monitor in specific circumstances will vary depending on the location and on emission sources in the proximity). Moreover, a relative majority of public authorities have not expressed their views on this sub-option. The cost of continuous VOCs measurements are potentially high and any further monitoring should be accompanied by data quality and siting specifications (see table 12.3).

Policy option III-3 (establish a requirement to expand monitoring to additional pollutants) is assessed as increasing the understanding of current levels of any additional pollutants and their health effects, and a prerequisite for future reviews of the legislation – and to be crucial to better anticipate possible future related health risks. A majority of stakeholders suggested new pollutants should be located at ‘supersites’ to facilitate research on pollutant interactions and trends in both urban and rural locations (with one such ‘supersite’ monitoring station per 5 to 10 million inhabitants). There is general support to include monitoring of ultrafine particles, ammonia, oxidative potential and fine combustion particles but less generalised support for additional heavy metals, hydrogen sulphide, nitro-PAHs and pesticides monitoring. Monitoring of ammonia would benefit from coordination with monitoring efforts under the National Emission reduction Commitments Directive, and a focus on locations where ammonia concentrations could particularly impact ecosystems. Moreover, public authorities have also expressed strong support for this policy option. The burden primarily lies with public authorities at regional and/or national level.

Sub-option III-2a (Introduce obligations to monitor long-term trends- see table 12.2) would result in a more complete long-term data set, improving air quality assessments. Even if long-term trends are seen as important by stakeholders in general, many of them, particularly public authorities and civil society & NGOs, considered that neither indicative measurements nor modelling could fully replace a discontinued fixed monitoring station, as the uncertainty of the results is too high.

Policy option III-2 (introduce requirements to ensure continuity in air quality monitoring) represents a no-regret option that would guarantee an improvement of air quality monitoring and assessment. This would effectively be done by specifying that sampling points with exceedances of limit values for any of the pollutants measured under the Ambient Air Quality Directives should be maintained for a defined number of years, and by developing a protocol to follow should a sampling point have to be re-located due to, for example, infrastructure development or changes in the assessment regimes. A broad majority of stakeholder showed support for long term continuity of sampling points, with public authorities acknowledging that relocation should only be allowed under specific circumstances and civil society & NGOs suggesting relocation should not be allowed at all if and where exceedances persist. The development of a clear protocol for relocation is considered as essential to guide instances in which sampling points are relocated. Costs involved are expected to be low (as it this should be limited to exceptional circumstances). The burden primarily lies with public authorities.

Will significantly improve air quality monitoring and assessment, allowing for more targeted air quality measures, and make better use of avail. methods. Costs related to the expansion of the monitoring network and adding ‘super-sites’.

On the contrary several sub-options have been assessed to only have a limited benefit-to-cost ratio. Sub-option III-1a (revise rules for regular review of air quality assessment) and sub-option III‑1b (simplify the definitions of sampling points types) would bring low additional benefits for a low cost. Stakeholders across groups generally felt the current requirement to review assessment regimes every five years was sufficient. Public authorities support maintaining the current system, while civil society & NGOs in particular would welcome improvements that allow better identification of hotspots (especially those due to household heating – note, however, that this can also be addressed via policy option III-4). Sub-option III-1c (introduce up-to-date data at all sampling points) would allow for increased transparency of digitally available up-to-date pollutant information but at a potential high cost if required at all sampling points (and with limited added value to requiring it a well-defined sub-set of stations).

Regarding the sub options contained under this policy option, sub-option III-1d (introduce the obligation for a spatial representative area), is considered as the most beneficial supporting measure. This would significantly contribute to the overall comparability and harmonization of air quality data and would support the use of monitoring data in the assessment process. Not having spatial representativeness of measuring sites defined in the legislation, in some instances currently hinders in the effectiveness of the monitoring network design and suitability to assess actual population exposure. Stakeholder feedback indicated this measure would generally be useful but would need further guidance to support it.

While there is a broad strong support for the need to clarify and enhance the circumstances where additional tools (indicative measurements and modelling) are to be employed for supplementing fixed monitoring, public authorities, and civil society & NGOs expressed a clear view these should not translate in a decrease of fixed monitoring stations or replace them, and modelling should not be made mandatory to all its possible uses. Stakeholders across all groups, especially those working on air quality monitoring research & academia, generally expressed support for increasing the number of sampling points and reviewing them in specific situations (for example, in highly urban populated areas), decoupling the minimum number of sampling points for measuring fine particulate matter (PM2.5) and particulate matter (PM10), and requiring public authorities to install monitoring stations that measure continuously pollutants of emerging concern. Contrary, public authorities have expressed reservations about the policy measure revising the minimum number of sampling points.

Policy option III-1 (revise the requirements for air quality assessment- see table 12.1) is considered to contain critical policy measures to address monitoring and assessment shortcomings identified. This policy option increases the use of key tools for assessing air quality, including complementary use of indicative measurements or mandatory use of models to support fixed monitoring and air quality planning, as well as expanding monitoring for pollutants already covered by the Directives as well as for pollutants of emerging concern. This option presents a particularly significant opportunity to improve the effectiveness and efficiency of an already well-established air quality monitoring regime in all Member States of the EU (as confirmed by the fitness check in 2019). This will result in an increase of the costs for monitoring air quality (in particular due to additional one-off investments). The highest costs relate to the increase of tools used, and capacity needed, to assess air quality and the requirement to monitor pollutants of emerging concern. However, the exact extent of these costs, will depend on the current practice of Member States as in many cases complementary tools are already being used to augment mandatory monitoring.

Policy options to address air quality monitoring, assessment shortcomings and data quality should in particular improve the efficiency and effectiveness of the assessments performed by public authorities to meet the objectives of the Ambient Air Quality Directives. This cluster of policy options would entail (rather indirect) health and environmental benefits next to costs, mainly related to the additional monitoring and assessment requirements, translating into needs for monitoring equipment, targeted training and expertise development. Improvements in this area constitute however a fundamental pillar for meeting the objectives of the Ambient Air Quality Directives.

Transboundary air pollution is already the focus of the NEC Directive. Further cooperation is desirable but difficult to enforce. Additional guidance helpful.

Policy option II-5 (revise the approach to exceedances due to transboundary air pollution- see table 11.5) is assessed as being useful to potentially enhance the effective implementation of the Ambient Air Quality Directives. This option will indirectly contribute to reducing air pollution concentrations, especially for Member States currently suffering from transboundary air pollution. Stakeholders point out that transboundary air pollution is already the focus of the NEC Directive and that further cooperation would be desirable but difficult to enforce. A stronger role for the Commission to support transboundary cooperation, including via additional technical guidance (e.g., by introducing a common methodology on assessing transboundary air pollution) is supported by all stakeholder groups.

Penalties and damages have not been sufficiently dissuasive. Adding additional clarity will help set priorities and incentives. Note that if there is compliance the related costs do not manifest.

Conversely, a policy option where the potential impact is still uncertain and where stakeholders have raised additional questions is sub-option II-4a (introduce a clean air fund to be fed by penalties paid- see table 11.4). The potential benefits of this sub-option will largely depend on which air quality measures will be eligible for funding and who is going to manage such a fund (the EU or Member States). The political feasibility of this measure seems to be limited as Member States might find that there is a risk of interference with their national funding competencies. Also, on EU level there might be hesitation given that there is a general movement towards mainstreaming EU environmental and climate expenditure, thus moving away from dedicated funding for specific issues. Stakeholder feedback to this policy sub-option has been divided, with a medium to high support from civil society & NGOs, whereas public authorities and industry & businesses were more negative about it.

Policy option II-4 (revise the legal tools available to address breaches of obligations) will strongly enhance the effective public enforcement of the Directives and ensure coherence with other EU measures, international treaty obligations and the case law of the Court of Justice of the EU. The costs for authorities to implement these measures will largely depend on their compliance with the current Ambient Air Quality Directives. If currently compliant, then the additional costs should be zero, whereas environmental and societal benefits will be high in any case. Stakeholder feedback to this policy option has been divided, with civil society & NGOs strongly supporting the measures proposed under this option, whereas public authorities and industry & businesses are more hesitant; there is a consensus however that current financial penalties are not sufficiently effective, proportionate or dissuasive. Moreover, a significant majority of public authorities did not express their views on these policy measures. The burden of implementing this policy option would primarily fall upon public authorities at EU and national levels – and would be zero if all provisions of the Ambient Air Quality Directive(s) are met.

The key added value would be to ensure regular updates of air quality plans. Alert thresholds for particulate matter would address additional health concerns, but likely at a cost.

Meanwhile revising provisions related to alert thresholds and short-term action plans would likely have indirect positive impact on air quality and human health, although the added value might be low given that the framework currently in place has not rendered deficits (and therefore might not need fundamental changes). The burden of implementing these policy options would fall upon public authorities at local level.

Stakeholders indicate that replacing the term “as short as possible” with a specific timeframe might be counterproductive or ineffective which explains the low (to medium) stakeholder support for this measure. Public authorities were also not in favour of this measure.

Policy option II-3 will have an indirect positive impact on air quality and human health, as it will help to limit the exceedance period to a minimum. Regularly reviewing air quality plans will entail costs for authorities, especially for regions where exceedances occur. Stakeholders strongly support this measure and indicate that an update every three years would be considered feasible. Public authorities also expressed their strong support for this measure.

Policy options II-3 (introduce an implementation timeline for measures & revise short-term action plans- see table 11.3) are assessed as being beneficial to enhance the effective implementation of the Ambient Air Quality Directives.

Fitness Check indicates that ‘limit values’ have been more effective than other types of air quality standards. For some pollutants (notably O3), however the concept is unlikely to have benefits.

Policy-option II-2 (revise the number of air pollutants subject to ‘limit values’- see table 11.2) is assessed as being important to enhance the effective enforcement of the Ambient Air Quality Directives. However, it may not be technically feasible to establish limit values for all pollutants (for example, ozone levels depend much on natural factors and transboundary pollution). Stakeholder feedback offered moderate to strong support for this policy option. Public authorities expressed strong support for the policy measure introducing additional short-term standards.

This policy option will update the means by which air quality plans are developed. Costs to change existing approach compensated or even reduced by more effective air quality plans and measures.

Conversely, a potential policy measure not to be retained is the introduction of a requirement for Member States to secure a single air quality plan for each air quality zone – as per measure D2 (introduce a ‘one zone, one plan’ requirement) considered under sub‑options II‑1a. Stakeholder response to this measure has been mixed, with more scepticism (or no opinion) than endorsement across groups. Public authorities have expressed particularly strong reservations about this sub-option. A rethink of the scale of air quality plans (in cases where this measure would require it) could result in a significant administrative burden (as it could require re-zoning. It should also be noted that, under current provisions, Member States that wish to fully align their air quality plans and air quality zones can do so, and several have opted to do so.

This policy option will have an indirect but important positive impact on air quality and human health, as it will help to ensure that exceedances of air quality standards are addressed more effectively. The costs for authorities to implement these measures will depend on their current expertise and practice in the setting up of air quality plans. Given the additional implementation tools presented in this option, authorities might even experience a decrease of their administrative burden, as the implementation becomes more effective. It was pointed out by stakeholders that this would still have to leave room for manoeuvre to Member States, given that the sources of air pollution can vary strongly between countries, regions and cities- warranting more localised solutions (i.e. rather than “one-size-fits-all” measures). The majority of stakeholders agree that there is a benefit in further clarifying current obligations related to exceedances and that the design of effective air quality plans is a core element in ensuring the effectiveness of air quality measures. Also, the notion of refining the minimum information required by an air quality plan saw high support by all stakeholder groups. Public authorities have expressed strong support for the policy measure introducing guidance on how to address exceedances. Contrary, the policy measure on revising obligations for measures triggered by exceedances was largely not supported by public authorities. The burden of implementing this policy option would primarily fall upon public authorities at EU and national levels.

Policy option II-1 (introduce additional provisions of what to do in case of an exceedance- see table 11.1) is assessed as being fundamental to secure the functioning of the Ambient Air Quality Directives. This option will strongly enhance the effective implementation of current Article 23 of Directive 2008/50/EC by reinforcing and clarifying the obligation of what should be contained in air quality plans, who should be involved in their design and how they should tackle the need for short-term action.

Policy options to address governance and enforcement shortcomings should in particular improve the implementation effectiveness and policy coherence of action taken by public authorities to meet the objectives of the Ambient Air Quality Directives. Costs relate especially to changing the way the Ambient Air Quality Directives are implemented (rather than them resulting from administrative burden of specific policy options suggested here). Having said that, by increasing the stringency of the existing policy framework, costs to those in breach of the provisions of the Directives would increase significantly. At the same time, such increased stringency of the legislative framework would also ensure higher compliance with the set objectives, and thus translate into environmental, social, and economic benefits for the wider public.

Regular review will ensure scientific evidence base of EU policy making, but should be spaced to allow for sufficient scientific progress and regulatory certainty.

Stakeholders were generally supportive of such measures to ensure regular review triggered by scientific progress (especially civil society & NGOs and, to a lesser degree research & academia). A relative majority of public authorities did not support this measure. There was less support to link reviews to technical progress (sub-option I-6a). The establishment of a list of priority substances (sub-option I-6b) to ensure air pollutants of emerging concern are monitored received some stakeholder support, especially from some public authorities. However, the costs can be high to establish mandatory monitoring of an extensive ‘gross list’ of air pollutants. It may instead be more effective to expand further the number of substances of concern monitored at selected monitoring stations, as suggested by policy option III-3.

The scientific understanding of air pollution and its health impacts has evolved significantly over the past decades, and resulted in regular updates of the WHO Air Quality Guidelines. Whilst the 2021 edition of the WHO Air Quality Guidelines provides the basis for this impact assessment, it is to be expected that, over the coming decade(s), the scientific understanding will trigger future updates. Against this backdrop, policy-option I-6 (introduce a mechanism for a regular review of EU air quality standards) is assessed as offering a safety clause to accelerate alignment to scientific developments, whilst securing the involvement of the co-legislators. The burden of implementing this policy option would primarily fall upon public authorities at EU and national levels.

Can build on existing concept and monitoring, but at more appropriate regional resolution, to help assure continuous decrease in background PM2.5.

Introducing an additional average exposure indicator for particulate matter (PM10, sub-option I-5a) in addition to one for PM2.5 is assessed as having low added value. This is because the measures taken to reduce PM10 and PM2.5 concentrations are often the same. The concentration levels of PM10 and PM2.5 correlate strongly, too (as the latter is a sub-set of the former). Conversely, establishing an additional average exposure indicator for nitrogen dioxide (NO2, sub-option I-5b), could help focus measures on reducing background concentration levels affecting larger areas, in addition to reducing pollution in hotspots affecting smaller areas but with higher concentrations and limit value exceedances. For ozone pollution (O3, sub-option I-5c) it is uncertain whether an average exposure indicator would be useful for reducing ozone concentrations. This is because of the specific chemical characteristics of how ozone forms in the atmosphere, and how ozone formation is linked with meteorological conditions (resulting in pronounced local and year-to-year variability).

Meanwhile, already the fitness check of the Ambient Air Quality Directives concluded that limit values for fine particulate matter (PM2.5) have been more effective in facilitating downward trends – especially where this has been done in conjunction with a requirement to reduce average exposure, as per policy option I-5 (revise average exposure reduction obligations). Generally, stakeholders showed some support for this option, especially for introducing an exposure reduction target applicable at regional or local level. This was in particular supported by a majority of industry & businesses respondents, as well as regional or local level public authorities. This is expected to have positive direct effects through better targeting exposure, thereby improving health protection of the general population. Compliance costs have the potential to be significant and depend on the ambition level.

May have benefits, but to date no basis in WHO recommendations to set such air quality standards. Priority should be establishing a monitoring network for these pollutants (see III-1).

A significant number of stakeholders, in particular those representing civil society & NGOs and those representing research & academia, support policy option I-4 (establish air quality objectives for additional air pollutants). However, based on a review of the scientific evidence available, it is suggested not to retain this policy option. While there is a growing body of research suggesting the relevance of various components and precursors of particulate matter, the WHO Air Quality Guidelines concluded in 2021 that, as yet, there is a consensus that the body of epidemiological evidence is not yet sufficient to formulate an guideline exposure levels for additional air pollutants – and thus offer no basis for setting EU air quality standards. Furthermore, to date no harmonised monitoring approach for these pollutants exists in Europe: establishing this, as per policy option III-3 should be considered a priority, to generate more knowledge on current concentrations of these air pollutants. Also, these pollutants should ideally be kept under review as per policy option I-6 via a regular review of EU air quality standards.

Three further policy options look at establishing objectives for other air pollutants, at revising and expanding obligations to ensure reductions in the average exposure to air pollution, and at putting in motion a regular review mechanism for EU air quality standards. This assessment of these policy options is guided by considerations as to whether they make the Ambient Air Quality Directives more effective and future proof.

Current baseline policies will achieve this level in almost all of the EU. Thus setting targets at this level offers only limited added benefit (but where it triggers additional action this is of high benefit).

Even if all effort is made, the related targets cannot be fully achieved everywhere (due to physical geography constraints). But at locations where achieved, they bring major health benefits.

Table 10.1 to table 10.3 summarises this assessment in a simplified manner – for details please also see the detailed assessment of specific potential policy measures in Annex 6.

Stakeholder feedback pointed to a desire to opt for a high level of ambition. In the public consultation, 73% percent of all respondents expressed a clear preference to align with the 2021 WHO Air Quality Guidelines. In particular, a large majority of civil society & NGOs (93%) and EU citizens (79%) confirmed that EU air quality standards should be fully aligned with the latest WHO recommendations (i.e. policy option I-1). This view was only shared by a minority of public authorities (36%), with a majority of them (62%) calling for partial alignment. In a more targeted survey, public authorities expressed almost equal support for policy options I-2 and I-3. Representatives from research & academia largely shared this view. A clear majority of industry & businesses stakeholders favoured keeping EU air quality standards at current levels or only moderate increases in ambition for 2030.

When it comes to social impacts, sensitive population groups (including children, pregnant women, elderly citizens and those suffering from pre-existing conditions) will in most instances benefit the most from reduced air pollution impacts on their health, notably under policy options I-1, I-2 and I-3. This is because the health of members of this group is most affected by air pollution today. The degree of benefits correlates with the different levels of ambition of the three policy options. Whether different population groups (e.g. regarding income or education) will bear higher or lower shares of the costs air pollution abatement can vary substantially depending on what measures are taken. Based on assessment of policy options I-1, I-2 and I-3 it is possible to conclude that they offer three different levels of ambition that translate into both corresponding increasing positive impacts (highest for I-1), as well as corresponding increasing costs (highest for I-1). Nevertheless, all three options point to a high benefit-to-cost ratio. An important caveat, however, is that, based on the assessment, the feasibility to actually reach the EU air quality standards implied by the three policy options differs significantly when only considering technical abatement options. While standards implied by policy option I-3 seem reachable with only technical measures throughout the EU, requiring only some additional emission reduction at the EU level compared to the baseline trajectory, those implied by policy option I-2 may be unattainable with only technical measures in up to 2% of the sampling points by 2030. The standards implied by policy option I-1 appear unattainable in around half of the stations in the EU, if only technical abatement measures are considered (see section 8.2 for further details which regions face particular challenges). Additional measures at local level (such as local restrictions to biomass burning, or promotion of active mobility) or wider societal changes (such as changes in dietary patterns) would be needed to achieve such levels.

Table 9 - Economic outcomes of clean air policy in the EU – expressed as percentage change relative to reference baseline. Note that the first number in a cell represents the effect of gross costs only. The second number (after the vertical line) represents the net effect, i.e. benefits minus costs.

These macroeconomic developments translate into very small (especially in relative terms) employment changes by sector that are consistent across scenarios. Focusing on the net effects, the number of jobs in industry increases in response to increased production of abatement equipment. The agricultural sector experiences job losses compared to the baseline, which relates to output losses (livestock sector) or a transition of workers into industry (crops sector).

This analysis focuses on productivity gains from clean air, leaving aside other ‘market’ benefits, such as reduced healthcare expenditures and increased crop yields, as well as ‘non-market’ benefits (such as reduced premature mortality, improved ecosystem health). The more ambitious the EU air quality standards, the larger the net gains, as reflected by the positive impact on gross domestic product (GDP) and private consumption. Net GDP gains by 2030 are expected for all policy options, in the range of 0.26% to 0.44%. Except for livestock-based agriculture, all sectors displayed in Table 9 raise output compared to the baseline assumptions when productivity gains of clean air are accounted for (second number in Table 9). Zooming in on option I-2, output increases by 0.53% in 2030 compared to the baseline for industry – the sector shown to bear the largest share of costs (Figure 12), by 0.45% for crop production, by 0.44% for the power sector, and by 0.38% for the services sector.

Air pollution has detrimental welfare impacts by affecting health outcomes. In addition, related healthcare expenditures, crop yield losses due to ozone, absence from work due to illness (including of dependent children) and lower productivity at work can imply a drag on the economy. Improving air quality is therefore expected (despite gross cost resulting from costly investments and purchases of abatement equipment) to bring economic gains. Annex 5 provides a detailed macro-economic assessment as to whether air pollution control policies lead to net economic gains or losses, and how these are distributed across economic sectors.

(*) Total administrative costs include costs for all policy options that are not linked to the level of ambition of revised EU air quality standards (i.e. for the preferred policy options (section 8.1), which adds up to about 75 million Euro per year) plus the costs linked to the development of air quality plans which depends on the number of exceedances above EU air quality standards to be expected in the target year 2030 (note: this depends on the level of ambition assumed via policy options I-1, I-2 or I-3, which adds up to between 1 and 31 million Euro per year). For simplicity, no remaining exceedances in the target year 2050 are assumed here (note: this is likely an underestimate).

Table 8 compares the mitigation costs and administrative costs to the expected benefits (from Table 7), showing large net benefits for all policy options.

Consistent with the results for emission reductions associated with the policy options analysed in this work, the additional annual costs (compared to cost under baseline assumptions) of reaching the 15 µg/m3 target for annual mean PM2.5 (policy option I-3) amount to 3.3 billion Euro in 2030 (this would become close to zero by 2050). A 10 µg/m3 target for annual mean PM2.5 (policy-option I-2) amounts to costs of 5.6 billion Euro in 2030 (this would reduce to 4.7 billion Euro by 2050). And a 5 µg/m3 target for annual mean PM2.5 (policy-option I-1) translates into 7.0 billion Euro in 2030 (this would reduce to 6.1 billion Euro in 2050. For the latter a strong caveat remains that, at around half of the stations in the EU, it may not be possible to meet the objectives set at all, at least in a 2030 perspective, even as virtually all technology options are explored without considering other abatement options, such as behavioural change or fuel shift.

The gradient of ambition translates into a gradient of the air pollution mitigation (or adjustments) costs applied in the different policy options. Such costs, which represent additional costs compared to the baseline scenario costs, are shown in Figure 12.

Figure 12 – Air pollution mitigation or adjustment costs (EU total) beyond the baseline, for different policy scenarios (I-1 at 5 µg/m3, I-2 at 10 µg/m3, I-3 at 15 µg/m3).

These health and non-health impacts can be translated into monetised benefits and costs. Table 7 shows the direct benefits that result from better air quality and associated reduced impacts on human and environmental health./ This does not include macro-economic knock-on effects (shown in Table 9).

Also as regards impacts on the environment, and on ecosystem area exceeding critical loads for eutrophication from deposition of nitrogen, the policy options show a gradient. Under baseline assumption, by 2030, 69% of ecosystem area in the EU is subject to such levels above critical loads. By 2030, policy option I-3 reduces this share of ecosystem area suffering from high loads to 61%. Policy-option I-2 reduces it to 58% and policy-option I-1 to 55%. In a post-2030 perspective, policy-option I-1a reduces this to 50%.

Nevertheless, all three policy options translate into significant positive health impacts (due to the reduced exposure to air pollution above WHO Air Quality Guideline levels). Under baseline assumptions, compared to 2020, premature mortality in 2030 due to air pollution in areas in excess of the WHO Air Quality Guidelines reduces by ‑57% linked to PM2.5 (at least 56 100 premature deaths) and by ˗81% linked to NO2 (at least 4 050 premature deaths). Policy option I-1 would by 2030 reduce these figures by a further ˗53% for PM2.5 and ˗20% for NO2, respectively. For policy option I-2 the additional reduction by 2030 would still be ˗49% for PM2.5 and ˗16% for NO2 – and for policy option I-3 the reduction by 2030 would be limited to a further ˗38% for PM2.5 and 12% for NO2. This shows that there is a clear gradient in the positive health impact of the three policy options (with a larger increase from policy option I-3 to I-2, than from I-2 to I-1).

This assessment might change, and further reductions may be possible, if also more fundamental assumptions about changing economic activity, dietary patterns, technological breakthroughs or major shifts in our energy systems were to be considered (but this was beyond the scope of this impact assessment – also because any related assumptions would be at risk to be speculative, especially in a 2030 perspective). Such more fundamental assumptions would also have likely co-benefits for other environmental and climate policies.

None of the three policy options indicate a pathway to meet a target of 5 µg/m3 throughout the EU in either a 2030 or even 2050 perspective if only technical abatement measures are considered in addition to the co-benefits from other existing policy initiatives considered in the baseline. A sensitivity study shows that additional measures resulting from revised IED full implementation lead to only relatively small changes in population weighted exposure to PM2.5 and NO2 of up to 0.2 µg/m3 (see Annex 5.8 for details). Even with this full implementation assumption, this corresponds to a comparatively small number of additional stations (i.e. 35 out of 994 sampling points) that would attain a target of 5 µg/m3 in 2030 under baseline assumptions. This indicates that fully implementing the proposed revisions of the IED will be required to affect the air quality improvements assumed by each of the three policy options (note that these additional improvements can be expected to intensify after 2030, given that the gradual roll-out, including of strengthened BAT, will accelerate post 2030).

Under policy option I-1, the projected emission reductions described above result in that the fraction of sampling points exceeding annual PM2.5 levels of 5 µg/m3 is reduced from 95% in 2020 to 71% (710 out of 994 sampling points) in 2030 (compared to a baseline of 85% in 2030). In other words, even if the EU air quality standards are set in full alignment with the 2021 WHO Air Quality Guidelines, by 2030 more than 225 million people in the EU would continue to be exposed to levels above the target of 5 µg/m3 (if only technical abatement measures are considered). Out of these, 11.5 million people would even continue be exposed to levels above 10 µg/m³ in 2030. In a 2050 perspective, due to reductions in air pollution resulting, inter alia, from co-benefits with EU climate policies the number people exposed above the target of 5 µg/m3 would further reduce to 111 million. For NO2, the fraction of sampling points above the target of annual mean concentrations of 10 µg/m3 reduces from 71% in 2020 to around 31% (more than 821 out of 2 670 sampling points) in 2030 (compared to 968 sampling points above this level under baseline assumptions in 2030).

Under policy option I-2, the projected emission reductions described above result in that the fraction of sampling points exceeding annual PM2.5 levels of 10 µg/m3 is reduced from 52% in 2020 to 6% (60 out of 994 sampling points) in 2030 (compared to a baseline of 15% in 2030); 11.6 million people would continue to be exposed to levels above the target of 10 µg/m3, but only 0.1 million would still be exposed to levels above 15 µg/m³. For NO2, the fraction of sampling points above the target of annual mean concentrations of 20 µg/m3 reduces from 33% in 2020 to around 4% (110 out of 2 670 sampling points) in 2030 (i.e. compared to 144 sampling points under baseline assumptions for 2030).

Under policy option I-3, the projected emission reductions described above result in that the fraction of sampling points exceeding annual PM2.5 levels of 15 µg/m3 is reduced from 16 % in 2020 to 0.8 % (8 out of 994 sampling points in the EU) in 2030 (compared to a baseline of 1.2 % in 2030); some 0.4 million people would continue to be exposed to levels above the target of 15 µg/m3. For NO2, the fraction of sampling points above the target of annual mean concentrations of 30 µg/m3 reduces from 13% in 2020 to around 1% (27 out of 2 670 sampling points) in 2030 (note that this brings no improvement compared to baseline assumptions which also see 27 out of 2 670 sampling points above this level in 2030).

Figure 11 - Number of stations above selected annual mean concentrations in the EU for PM2. and NO2. Note that I-1 is labelled OPT05, I-2 is OPT10, and I-3 is OPT15 – also see Annex 5 for similar estimates for population exposed to different levels of air pollution under the different scenarios.

These reductions in air pollutant emissions translate into a significant reduction in concentrations for all air pollutants across the EU – see Figure 11.

Meanwhile, EU air quality standards that correspond to policy option I-3 and its sub-options (incl. annual mean PM2.5 at 15 µg/m3 by 2030) appear to be feasible with only technical abatement measures (i.e. end-of-pipe measures that do not require a rapid technological shift or behavioural change). They require only some additional emission reduction at the EU level, compared to the baseline trajectory (which, however, already includes ambitious policy developments notably for greenhouse gas emission reductions that support strong reduction of air pollutant emissions associated with reduced fossil fuel use, as explained above). Attaining such targets would thus not require disproportionate reductions in emissions of individual Member States (see Annex 5 and the underpinning support study on the revision of the Ambient Air Quality Directives, which include more disaggregated data).

EU air quality standards that correspond to policy option I-1 (incl. annual mean PM2.5 at 5 µg/m3 by 2030) or policy option I-2 (incl. annual mean PM2.5 at 10 µg/m3by 2030) require significant additional effort. In some locations this would require the implementation of all measures assumed in the MTFR scenario – or, especially for policy option I-1, the standards are likely not even fully attainable based on current technology alone, and would require specific local measures that address specific local emission sources. The main driver of emission reductions (especially for direct emissions of PM2.5) in the cost-optimal scenario to reach the 10 µg/m3 and 5 µg/m3 targets are measures to be taken in industry, residential heating and agriculture. Reduction of industrial emissions are relevant for several pollutants, while PM2.5 emissions from residential heating can be reduced in the model optimisation by addressing biomass burning, since the role of coal is declining and so abatement potential around coal becomes less and less relevant (assuming effective implementation of the climate related targets for reduced reliance on fossil fuels; the recent RePowerEU approach also aims to reduce fossil fuel use).

Figure 10 – EU emission in 2030 and 2050 for key air pollutants, and by key sector, under baseline assumption and for three policy options (I-1 at 5 µg/m3, I-2 at 10 µg/m3, I-3 at 15 µg/m3), and MTFR scenarios.

Figure 10 shows the projected emissions in the years 2030 and 2050, respectively, for key air pollutants under the different scenarios analysed, both in total and by sector. These projections assume cost-optimal emission reduction measures for each policy option (meaning the most cost-effective technical measures to reduce air pollution and notably PM2.5 concentration levels are taken first, regardless of which economic sector would bear these costs and of where in the EU such would need to occur - see Annex 4 for a description of the optimisation process).

The presented impacts of policy options I-1, I-2 and I-3 allow for comparing the options with each other, and also with both a baseline scenario and a theoretical ‘maximum technically feasible reductions (MTFR or MFR)’ scenario. The MTFR scenario minimises emissions by taking into account all available end-of-pipe technologies irrespective of costs and thus represents the lower limit of emissions reduction achievable with technical measures only).

This assessment places particular focus on emission reductions needed to achieve (revised) EU air quality standards, the number of exceedances above EU air quality standards expected to remain even if all end-of-pipe measures are taken, how many people are expected to be exposed to levels above these standards, and what the resulting health and environmental impacts would be (including whether sensitive populations are disproportionally impacted). Also an economic analysis is undertaken to assess the expected benefits to society (including from reduced health damage) in comparison to the expected costs of taking measures.

Three distinct policy options that reflect three different degrees of alignment with WHO recommendations have been assessed in detail – assuming EU air quality standards are set at ambition levels that correspond to 5 µg/m3, 10 µg/m3, or 15 µg/m3 (see Table 2). The key criteria assessed are to what degree setting standards at the respective levels is expected to result in tangible environmental, social and economic benefits, and at which costs (see Annex 4 for the description of the model and of its optimisation process).

A general assessment of stakeholder views per policy option is also presented below, with a particular focus on views expressed by public authorities, as the burden of implementing the majority of these policy options, and the related administrative costs, would primarily fall upon public authorities at EU and national levels. For a more in-depth analysis of stakeholder views, see Annex 2 (synopsis report of the stakeholder consultation) and Annex 6 (potential policy measures). Impacts on UN sustainable development goals are summarised in Annex 3.

The assessment of the environmental, social and economic consequences alongside the direct costs allows for the construction of a comparative benefit-to-cost ratio. If the expected benefits outweigh the expected costs, this is assessed as ‘Medium’; if they do so significantly they are assessed as ‘High’. Conversely, if the expected benefits do not outweigh the expected costs, the ratio is ‘Low’. In some instances, the expected benefits would potentially justify a ‘High’ benefit-to-cost ratio, but it is questionable whether these expected benefits could be attained with only end-of-pipe measures (i.e. without rapid technological shift and behavioural change) at all: in this case, to remain cautious, the benefit-to-cost ratio is regarded as ‘Uncertain’.

Direct costs include costs both from taking additional measures to curb air pollutant emissions and from administrative action to improve air quality management, in particular related to air quality assessment regimes (including monitoring, modelling, and digital reporting of related data) – i.e. beyond the current established practice resulting from the existing Ambient Air Quality Directives. The administrative cost / burden on public authorities will depend on the degree to which they can rely on existing air quality assessment structures.

Economic consequences of policy options are two-fold. On the one hand, the overall economic implications of air pollution action entail both direct and indirect costs and benefits. The latter include benefits by reducing health-related and healthcare costs, lost working days, crop and animal value loss. On the other hand, taking measures to curb air pollutant emissions to meet EU air quality standards will generate costs (often: direct and short-term ones, including costs for key economic operators in some sectors, and in some cases with clear regional distributional differences across the EU; indirect costs could result from effects such as reduced investments in certain sectors but are unlikely). This assessment of the economic consequences focusses on the net effect on the broader economy – while short-term and implementation costs (including for key economic operators in some sectors) are highlighted separately, below.

Social consequences refer to whether the policy option alleviates the impact of air pollution on sensitive population groups, including children, pregnant women, elderly citizens and those suffering from pre-existing conditions. At the same time, this dimension necessarily also considers whether the related measures increase or decrease social and economic inequalities (i.e. by considering who is most affected, who bears the costs), including as relates to the likely effect of measures to address air pollution on employment.

Environmental consequences refer to the primary objectives of the Ambient Air Quality Directives, namely to protect human health and the environment from the adverse effects of air pollution. Assessment criteria include the impact of the policy option on air pollutant concentrations; the resulting health impact on mortality and morbidity; the impacts on ecosystems including acidification, eutrophication, and ozone damage; and whether or not measures taken are in synergy with climate action and climate change adaptation efforts.

Each policy measure is assessed as regards its expected environmental, social, and economic consequences, as well as the costs and administrative burden it is likely to incur. This is based on a qualitative and, where possible quantitative assessment against a set of 12 more detailed assessment criteria described in Annex 4, and assessed in Annex 6. This more detailed assessment allows a summary assessment of each potential policy option along four dimensions: environmental, social, economic, and costs/administrative burden.

Finally, expanding the scope of the Ambient Air Quality Directives to include indoor air quality was also discarded. Most pollutants affecting indoor air quality originate from sources inside buildings (for more limited pollutants originating outdoors, action on ambient air quality will bring co-benefits), which requires a bespoke policy response. The Commission has agreed to ‘assess pathways and policy options to improve indoor air quality, and propose legislative measure as relevant’ as from 2023 in its Zero Pollution Action Plan .

The latter also includes discarding considerations to designate a formal role to citizen science approaches as part of the air quality monitoring and assessment strategy, for example via low-cost air quality sensors. While these approaches currently offer a useful complement to air quality monitoring carried out to the criteria of the Ambient Air Quality Directives, they do not offer the same level of quality assurance as data collected by public authorities. For these types of measurement devices, further harmonisation and standardisation may be warranted.

The fitness check of Ambient Air Quality Directives also explicitly highlighted that, over the past decades, across the EU, Member States have established an air quality monitoring network with more than 4 000 monitoring stations based on common criteria defined by the Ambient Air Quality Directives. This extensive network can be considered a success in itself, and is the product of continuous investments into an EU-wide air quality monitoring framework to secure objective, comparable and reliable air quality data. Options to fundamentally rethink the monitoring strategy have consequently also been discarded (which does not preclude policy options to improve specific aspects of the monitoring network).

Furthermore, the revision of the Ambient Air Quality Directives only considers air pollutants covered by recent WHO recommendations, or that are known to be major precursors to fine particulate matter (PM2.5). All policy options to include standards for the concentrations of additional air pollutants were discarded at an early stage. This notably concerns pollutants for which the WHO did not consider scientific evidence to be sufficient to establish guideline concentration levels. For some of them, such as ultrafine particles and black carbon/elemental carbon, additional monitoring is considered instead (based on corresponding good practice statements issued in the WHO Air Quality Guidelines). Note that mercury as an environmental pollutant is instead addressed by the Minamata Convention on Mercury and the corresponding EU Mercury Regulation. And while some air pollutants are also climate forcers (such as black carbon), most greenhouse gas emissions, and especially carbon dioxide (CO2), are addressed via EU climate legislation. Similarly, methane (CH4), which contributes to elevated ozone concentrations, requires a comprehensive emission and concentration management strategy, and is not included here – and is instead covered by a bespoke methane emission strategy.

A consequence of retaining this overall framework is also that, while EU legislation to reduce emissions from key air pollution sources will continue to reduce background concentration levels, the responsibility to meet EU air quality standards throughout their territories primarily lies with the Member States and the competent authorities they designate. Guided by the principle of subsidiarity, the Directives leave the choice of appropriate means to achieve air quality standards to the Member States, but explicitly require that exceedance periods are kept as short as possible.

This also includes discarding any consideration to merge EU clean air policy into a single legislative instrument, for example by combining the Ambient Air Quality Directives, the NEC Directive, and relevant source legislation for key emission sources under a single umbrella. The NEC Directive, adopted in 2016, has now entered a key implementation phase, and will benefit from following its own timelines to achieve 2030 targets for emission reductions. At that stage a combined reflection on a post 2030 framework may be warranted, including based on a review of the NEC Directive in 2025. In the meantime, Member States already have to take into account the local air quality situation when preparing and implementing their National Air Pollution Control Programme, to reflect, inter alia, the effects of past and future national-level measures on air quality, if possible at the level of air quality zones.

While this fitness check identified a number of lessons learned and potential for improving the legislation further, it did not point to fundamental flaws in the legislative framework as such. Also, stakeholder feedback to the Inception Impact Assessment and feedback received during the consultation phase did not point to the need for a structural change. All options to drastically alter the scope of the Directives as such were thus discarded at an early stage.

From the outset the notion to fundamentally change the scope of the Ambient Air Quality Directives was discarded. The fitness check of the Ambient Air Quality Directives concluded, based on 10 years of experience in implementation of these Directives in their current form, that they have been partially effective in achieving their overall objectives of reducing air pollution and curbing its adverse effects.

The Commission and the European Environment Agency have introduced a European Air Quality Index in 2017, which is regularly maintained and builds on available up-to-date data. Also Member States maintain air quality indices, but the absence of a common metric used for publicised indices often means that the same data is evaluated, and presented, in different ways in different locations. This policy option would require Member States to use harmonised air quality index bands, or make clear reference to EU agreed bands if alternative metrics are used at local or national scale.

A sub-option is considered to mandate specific communication channels with citizens, including user-friendly tools for public access to air quality and health risks information and monitoring (for example, smartphone apps and/or dedicated social media pages).

This policy option is to require that public authorities in Member States provide specific health and health protection information to the public as soon as exceedances occur. Such information would necessarily need to be developed jointly between environmental and public health authorities, and build on scientific advice and WHO recommendations. Furthermore, additional mechanism to inform a wider public of the health risk triggered by air pollution are to be considered.

This policy option looks at introducing additional and more specific requirements to ensure regular digital reporting of up–to–date data / information (instead of allowing Member States to report data as available). This would include a mandatory provision of up-to-date information for certain air pollutants for all sampling points, or for a minimum number of sampling points, per air quality zone to a wider public, and via bespoke communication channels.

Note that the below policy options IV-1 to IV-3 are complementary, and somewhat independent from each other. This means that any of these policy options could be assessed as viable, or any combination of these. Possible synergies and trade-offs are analysed below.

Policy options in this cluster seek to improve access to clear and objective air quality information – see Table 6. They aim to facilitate that the information that is disseminated by Member State competent authorities to the public is the same in all Member States in relation to potential impacts on health. For all policy options under this cluster the administrative burden of implementing the corresponding measures would fall upon public authorities (and in some cases would require the more active involvement as well of health sector authorities).

This policy option considers making air quality modelling a mandatory part of all air quality assessment. Modelling techniques can provide valuable information to supplement fixed measurements. Possibilities under which circumstances should air quality modelling be mandatory include: underpinning of air quality plans, forecasting of air pollution events, air quality mapping, evaluation of monitoring network design, estimation of population exposure, and others. To assure the reliability and comparability of air quality data derived from modelling standardized ‘modelling quality objective’ as a quality control mechanism to assess whether a modelling based assessment is fit for purpose would need to be introduced.

A sub-option to consider is to modify the definition of measurement uncertainty by defining it in absolute values and not in percentage values (or a combination of both) (III-4a).

The placement and measurement quality of sampling points is critical to assure a reliable and comparable air quality monitoring network in all Member States. This policy option further clarifies (and reduces flexibilities related to) the macro-siting criteria for sampling points. It also further clarifies (and reduces flexibilities related to) the micro-siting criteria for sampling points. This would necessarily be coupled with further defined data quality requirements for sampling points / measurements used for air quality assessments.

For the pollutants covered by the Ambient Air Quality Directives an extensive monitoring network of more than 4 000 monitoring stations that report data to the Commission today includes at least 600 sampling points for each of the pollutants. The monitoring of additional air pollutants, including those of emerging concern, is less well established and not necessarily harmonised or always reported to the EU level. This policy option would require sampling points to measure continuously certain air pollutants of emerging concern (including at so-called “supersites” across the Member States), at a minimum number of stations and to agreed measurement standards.

A sub-option is to include the requirement to monitor long-term trends if fixed monitoring stations are discontinued via indicative measurements or air quality modelling (III-2a).

Except for particulate matter, the Ambient Air Quality Directives do not include a requirement to maintain sampling points that have reported exceedances for a minimum time period, which would always allow verifying whether an exceedance has ended. This policy option would specify that sampling points with exceedances of limit values for any of the pollutants measured under the Ambient Air Quality Directives should be maintained for at least three years after the last exceedances was reported. If and when such sampling points need to be relocated due to exceptional circumstances this should be based on a protocol to ensure any air quality exceedance continues to stay under observation.

Sub-options would address the need for regular review of the air quality assessment networks in Member States (III-1a), simplify the typology of sampling points to assure background and pollution hotspots are clearly identified (III-1b), and add requirements to provide up-to-date monitoring data at a fixed number of locations per air quality zone (III-1c). An additional sub-option could be considered to include a provision to estimate and report an area of representativeness for every sampling point (III-1d).

In some instances also air quality modelling and additional indicative measurements would be made mandatory, so that results from modelling and indicative measurements can better support optimal air quality monitoring. Furthermore further improved satellite observation data as provided via the Copernicus Atmosphere Monitoring Service (CAMS) could provide complementary data for all the locations where in-situ instrumentation is lacking. This would be especially relevant on the topic of transboundary air pollution where air pollutants can move long distances and across continents (including aerosols, dust, and precursors to secondary particulate matter and/or ozone. Such additional measurements and data would however not replace in-situ fixed monitoring but complement it.

This policy option looks at ways to further improve (and where necessary expand) air quality monitoring and assessment. This includes changing the minimum number of sampling points that are required per air quality zone to align with the latest scientific understanding of air pollution (and, as part of this, de-couple the minimum number of sampling points for PM2.5 and PM10 from each other). In several instances this will likely lead to a need for additional air quality monitoring sampling points. This would usefully be coupled with requiring a minimum number of monitoring stations that have sampling points to measure a wider spectrum of air pollutants (at so called “supersites” across the Member States).

Note that the below policy options III-1 to III-5 are complementary, and somewhat independent from each other. This means that any of these policy options could be assessed as viable, or any combination of these. Possible synergies and trade-offs are analysed below.

The Ambient Air Quality Directives spell out clear criteria for determining minimum numbers of sampling points, for data quality and acceptable uncertainty in monitoring and modelling, as well as for macroscale and microscale siting of sampling points. These criteria set limits to the flexibility that Member States have in setting up their respective air quality monitoring regimes, but within these limits leave the design, establishment and maintenance of the network to national, regional or local authorities. This flexibility ensures that siting of sampling points is based on local expertise and/or local circumstances. Policy options in this cluster seek to enhance the reliability and comparability of air quality data measured and/or modelled by competent authorities.

Policy options in this cluster seek to ensure more reliable and comparable air quality assessment and would require Member States to make further improvements in the monitoring of air quality and greater use of refined air quality models when assessing ambient air quality – see Table 5.

This policy option would establish the use of an agreed methodology when assessing transboundary air pollution/contributions to local/regional air pollution. Based on this, transboundary cooperation and joint action on air quality would be seen as mandatory if assessments of transboundary air pollution indicate that contributions exceed certain thresholds. In practice this would require the establishment and implementation of joint air quality plans, possibly developed in close interaction with, and facilitated by the Commission. This should also be considered in instances of cross-border pollution and air pollution concerns shared with neighbouring countries that are not part of the European Union (including the Western Balkans).

A sub-option would require setting up a fund based on penalties when rules established by the Directives are infringed, and to be used to compensate damage caused (II-4a).

Penalties, damages and access to justice provisions related to air quality exceedances have been insufficient. This policy option would further define the type of measures that competent authorities must take to ensure that exceedance periods can be kept as short as possible – and expand the current provisions on penalties to specify the magnitude of the financial penalties to be paid in case of breaches of air quality standards by establishing a minimum level for such and better linking breaches to EU source legislation to breaches to the Ambient Air Quality Directives. In addition, it would introduce the right to a compensation for damage to health caused by breaches to the Ambient Air Quality Directives (as well as making a clearer a priori link between air pollution and health damage it causes) – coupled with an explicit provision on ‘access to justice’ in the Directives.

This policy option would add clarification of how quickly any air quality exceedance situation would need to be resolved. Currently the term ‘as short as possible’ leaves room for interpretation. It could be clarified by adding ‘and by no later than (2 to 5) years’., To prevent exceedances, an air quality plan and corresponding measures could be required several years before new air quality standards enter into force, to ensure that they will be met when they become binding. Coupled to this, an obligation might be introduced to evaluate and update any air quality plan that has not succeeded to resolve exceedance situations within this timeframe. This option would also look to expand the concept of alert thresholds to also include particulate matter, including an obligation to adopt effective short-term action plans to prevent and/or tackle pollution events.

The fitness check of the Ambient Air Quality Directives concluded that limit values have been more effective in facilitating downward trends than other types of air quality standards, such as target values. This policy option would establish limit values for air pollutants currently subject to target values, in particular for air pollutants that tend to correspond to specific point source emissions (for example, most heavy metals), air pollutants that tend to correspond to emissions from specific widespread practices (for example, most poly-aromatic hydrocarbons). Furthermore, it would set short-term limit values standards (daily or hourly mean) also for all relevant pollutants for which currently only long-term standards (annual mean) exist and for which latest scientific and technological guidance recommends short-term standards (for example, fine particulate matter).

A sub-option looks at how to clarify the requirements for drawing up air quality plans so that each air quality zone only features one plan, and vice-versa (II-1a).

This policy option seeks to add provisions on what kind of action is to be taken in case of exceedance of different types of standards, including which policy areas are to be considered when drawing up an air quality plan. This will require an update also of minimum information to be included in an air quality plan, including explicit requirements to inter alia estimate the effect of concentration reduction of planned air qual