Air quality continues to be a very important issue for public health, the economy and the environment. Europe has significantly cut emissions of several air pollutants in recent decades, greatly reducing emissions and exposure to substances such as sulphur dioxide (SO2), carbon monoxide (CO), benzene (C6H6) and lead (Pb). Despite improvements over several decades, air pollution continues to damage human health and the environment. Particulate matter (PM), ozone (O3), reactive nitrogen substances and some organic compounds still pose a significant threat. This leads to ill health, premature deaths, and damage to ecosystems, crops, and buildings. These constitute real losses for the European economy, the productivity of its workforce, and the health of its natural systems (EC, 2011a). The effects of poor air quality have been felt the most strongly in two areas:
- in urban areas, where the majority of the European population lives, leading to adverse effects on public health;
- in ecosystems, where the pressures of air pollution impairs vegetation growth and harms biodiversity.
Emissions of air pollutants derive from almost all economic and societal activities. Policies implemented at the European, national and sectoral level have over time resulted in decreased emissions of many air pollutants and have led to acceptable air quality levels across Europe for some pollutants, e.g. CO and Pb. Nevertheless, road transport, industry, power plants, households and agricultural activities continue to emit significant amounts of air pollution. Combustion of biomass by households — burning fuels such as wood and coal — is an important source of directly emitted PM and polycyclic aromatic hydrocarbons (PAHs: a type of carcinogenic substances). Agriculture is mainly responsible for the ammonia (NH3) emissions which exert pressure on both human health and the ecosystems. Such emissions, as well as PM from the combustion of fuels to produce energy for domestic needs, have either decreased very little (the case of agriculture), or not decreased (in the case of domestic fuel combustion) in the last decade. In fact, biomass combustion has become a more important source of air pollution. This is because wood burning is often relatively cheap, and is considered as an environmentally friendly source of energy since it is renewable and carbon-neutral.
Cross border, or trans-boundary pollution is also a challenge in Europe. For many European countries, less than 50 % of the observed fine particulate matter (PM2.5) concentrations derive from their own emissions (EU, 2013). Many air pollutants are transported over long distances. Countries and continents are both emitters and receivers of trans‑boundary pollution. For example, contributions from intercontinental transport influence the O3 and PM concentrations in Europe.
Air pollution in Europe, as well as being a cross border issue, can also be viewed as a local and regional problem caused by the emission of specific pollutants, which either directly or through chemical reactions lead to negative impacts. Each pollutant produces a range of effects from mild to severe as concentration or exposure increases. The main effects of air pollution are:
- damage to human health caused by exposure to air pollutants, or by intake of pollutants transported through the air, deposited and then accumulated in the food chain;
- acidification of ecosystems (both terrestrial and aquatic), which leads to loss of flora and fauna;
- eutrophication in ecosystems on land and in water, which can lead to changes in species diversity;
- damage and yield losses affecting agricultural crops, forests and other plants due to exposure to ground-level O3;
- impacts of heavy metals or toxic metalloids and persistent organic pollutants on ecosystems, due to their environmental toxicity and due to bioaccumulation;
- contribution to climate forcing and indirect effects on climate;
- reduction of atmospheric visibility;
- damage to materials and buildings due to soiling and exposure to acidifying pollutants and O3.
Purpose and scope of this report
This report presents an overview and analysis of air quality in Europe from 2002 (or later, pending data availability) to 2011. It reviews progress towards meeting the requirements of the air quality directives (EU, 2004b; EU, 2008c) and gives an overview of policies and measures introduced at European level to improve air quality and minimise air pollution impacts on public health and ecosystems. An overview of the latest findings and estimates of the effects of air pollution on health and its impacts on ecosystems is also given. The evaluation of the status and trends of air quality is based on ambient air measurements, in conjunction with data on anthropogenic emissions and their trends. The analysis covers up to 38 European countries (1), including EU Member States and other EEA member countries as of 2011, i.e. EU-27 and EEA-32 respectively.
The report analyses each regulated pollutant at a time, following the single-pollutant approach currently adopted by EU air quality legislation and the World Health Organization (WHO) in its air quality guidelines. In reality, air pollution constitutes a complex mixture of pollutants, which may interact in terms of their impacts on human health and vegetation. Exposure to air pollution is largely a multi-pollutant process.
Existing air quality legislation made simple
The Air Quality Directives 2008/50/EC and 2004/107/ EC set legally binding limits for ground-level concentrations of outdoor air pollutants.
Key elements of EU air quality legislation are:
- EU limit values are legally binding concentration thresholds that must not be exceeded. Limit values are set for individual pollutants and are made up of a concentration limit, an averaging time over which a pollutant is to be measured or estimated, the number of exceedances allowed per year (if any), and a date by which the limit value must be achieved. Some pollutants have more than one limit value covering different endpoints or averaging times. Limit values are legally binding on EU Member States.
- Target values — are to be attained where possible by taking all necessary measures not entailing disproportionate costs. Target values are not legally binding.
- Exposure reduction obligation — concentrations are to be reduced by a given per cent depending on the mean triennial PM2.5 urban background concentrations from 2008–2010 to 2018–2020.
This report also refers to WHO Air Quality Guidelines (AQG), which are often more stringent than EU limit and target values.
The most problematic pollutants
At present, PM and O3 are Europe's most problematic pollutants in terms of harm to human health. European anthropogenic emissions are the most important contributors to O3 and PM concentrations levels over Europe, but intercontinental transport of pollution also contributes to increased impacts on health, ecosystems and our economy (particularly crop productivity).