A major step toward cleaner air in the EU

By tightening limits on harmful pollutants like PM2.5 and NO2 the revised Air Qulaity Directive will significantly improve public health and align closer with WHO guidelines.

The revision of two EU ambient air quality directives (AAQD), dating from 2004 and 2008, was put forward by the European Commission in October 2022. The European Council, and the European Parliament, developed their positions during 2023 and after hard negotiations a common position between the three parties was agreed during spring 2024 [1].

Air pollution is the largest environmental killer in Europe with several hundreds of thousands premature deaths attributed to fine particles (particulate matter with a diameter <2.5 µm, known as PM2.5). Air pollution is also responsible for millions of new cases of illnesses and aggravations of these diseases in already ill persons each year [2-4].

The new and old limit values are presented in table 1 and are put in perspective by including the WHO recommendation (see Table 1). For instance, the annual limit values for the pollutants with the highest documented impact on human health, PM2.5 and nitrogen dioxide (NO2), are reduced from 25 µg/m³ to 10 µg/m³ and from 40 µg/m³ to 20 µg/m³ respectively. Carbon monoxide (CO), PM2.5 and NO2 now have short-time (24 hour) limit values that were lacking in the previous directive.

Table 1, The pollutants, and their values in WHO guidelines, previous and new directive.

Benzene has been reduced from 5 µg/m3 in the old directive to 3.4 µg/m3 in the new directive. For arsenic, cadmium, nickel, and benzo(a)pyrene the levels remain as in the old directive, but they have been upgraded from target values to limit values. For arsenic, the levels correspond to a cancer risk according to WHO of one in 100,000 people, which is quite a high risk [5]. Ozone remains a target level with an 8-hour mean of 120 µg/m3. Target values are less enforceable than the limit values.
Possibility for postponements and other flexibilities.

The limit and target values are to be met before 1 January 2030 by the member states and they are allowed to deduct emissions from natural sources and winter-sanding and -salting. Furthermore, the directive also provides member states with the possibility to request a postponement of the 2030 deadline:

• until no later than 1 January 2040 for areas where compliance with the directive by the deadline would prove unachievable due to specific climatic and orographic conditions or where the necessary reductions can only be achieved with significant impact on existing domestic heating systems
• until no later than 1 January 2035 (with possibility to extend it by two more years) if modelling projections show that the limit values cannot be achieved by the attainment deadline.

For these postponements, member states must demonstrate through road maps and reports that the exceedance will be kept as short as possible and that the limit value will be met by the end of the postponement period at the latest.

All member states that risk exceeding the limit or target values in 2030 shall establish air quality road maps ahead of the deadline, which is a new feature. After the deadline, the member states shall establish air quality plans when a limit value has been exceeded, as in the old directive. New to this directive is the establishment of short-term action plans when the alert threshold has been exceeded and there is potential to reduce the pollutants. These are emergency measures, such as suspending construction work or circulation of vehicles, to reduce the immediate health risks.

Under the new AAQD, member states would have to ensure that citizens are entitled to claim and obtain compensation where damage to their health has occurred because of an intentional or negligent violation of certain provisions of the directive.

In all, we see some clear improvement in the new directive, although a clear path to levels on par with WHO recommendations is missing.

1 Council, E., Air quality: Council and Parliament strike deal to strengthen standards in the EU. 2024.
2 Malmqvist, E., et al., Urgent Call to Ensure Clean Air For All in Europe, Fight Health Inequalities and Oppose Delays in Action. International Journal of Public Health, 2024. 69.
3 Turner, M.C. et al., Clean air in Europe for all! Taking stock of the proposed revision to the ambient air quality directives: a joint ERS, HEI and ISEE workshop report. European Respiratory Journal, 2023. 62(4): p. 2301380.
4 Boogaard, H., et al., Clean air in Europe for all: A call for more ambitious action. Environmental Epidemiology, 2023. 7(2): p. e245.
5 World Health Organization, Air quality guidelines for Europe. 2000: World Health Organization. Regional Office for Europe.