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10.4.1. Inhalation and air pollution

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10.4.1. Inhalation and air pollution






Air Quality Guidelines


Clean Air for Europe Climate Strategies


Environment Action Program


European Commission


European Consortium for Modelling of Air Pollution and


European Environment Agency


Eastern Europe. Caucasus and Central Asia


Environment and Health Information System


EU Limit Value


Statistical Office of the European Communities


Externalities of Energy project for Scenario Assessment


Health and Environment Integrated Methodology and Toolbox


Integrated Assessment of Health Risks of Environmental


International Study of Asthma and Allergies in Childhood


Joint Research Centre


Maximal Technical Feasible Reduction


National Emission Ceilings


Nitrogen Oxide


Nitrogen Dioxide




Particulate Matter


Science, Children, Awareness, Legislation, Awareness Stressors in Europe


United States


Value of Lost Years


Value of Statistical Life


World Health Organisation Introduction



Air pollution is the environmental factor with the greatest impact on health in Europe and is responsible for the largest burden of environment-related diseases. Air pollution, mainly by fine particles and ground-level ozone, continues to pose a significant threat to human health: it shortens average life expectancy in Western and Central Europe by almost one year and threatens the healthy development of children. There are many examples that show that respiratory health and life quality improve when air quality improves.


In Europe, emissions of air pollutants are projected to decline during the next two decades as a result of progressive implementation of current and envisaged emission control legislation and continuing structural changes in the energy system. The main contributor to air pollution in cities is the continuing growth in road transport. Although the EU thematic strategic on air pollution - setting objectives for 2020 – has brought some improvements, it is clear that significant damage from air pollution will still remain in 2020. Meeting air quality targets will require efforts in other policy areas, in particular in the energy, transport and agriculture sectors.


Poor indoor air quality is the source of a number of health problems, including cancer, allergic symptoms, distress, sleeping and concentration problems, and coughing, wheezing and asthma-like symptoms in children. Many indoor problems are related to increased moisture and humidity, part of which is a consequence of energy-saving policies that have led to reduced rates of air exchange in homes, schools and office buildings. Other indoor air quality problems arise from construction materials, paints, household cleaning agents, environmental tobacco smoke and combustion processes.


Despite a substantial body of international and national legislation and significant reductions in the emissions of some common pollutants, poor air quality is still associated with hundreds of thousands of premature deaths in Europe every year. Air pollution by fine particles represents the highest risk to public health in all regions of Europe. The health risks of air pollution by fine particles are at least in an order of magnitude higher than those for other air pollutants (Clean Air for Europe, 2005).


Today, the drivers of the European air pollution problem are different between European regions. However, traffic is the main contributor. In North-West Europe, despite the economic growth, legislation on air quality, together with associated abatement measures and economic instruments, have led to a continuous decrease in emissions of air pollutants since 2000. Emissions in South-Eastern Europe have generally followed a similar trend.


In EECCA, economic recovery and the growth in transport since 2000 have led to increases in the emissions of most air pollutants, because of the poor effectiveness of protection policies. The age of the vehicle fleet, low quality and high sulphur content fuel, poor infrastructure and maintenance, and a declining share of public transport are the main causes of environmental problems in this region. Industrial sources have declined in importance, but remain relevant locally and are difficult to address.


Particulate matter and ozone are the main threats to public health. Of special concern are, therefore, emissions of particulates and particulate precursors, and emissions of the precursors of ground-level ozone.


Small particles, particularly if containing polycyclic aromatic hydrocarbons (PAHs), and nano-particles have been identified as an emerging risk. Interactions between air pollutants and natural particles such as pollen have to be taken into account, and these are likely to be affected by climate change and change of pollen seasons. Data Sources



This chapter is based on the European Environment Agency (EEA) reportEurope’s Environment: the fourth assessment’ (chaptersAir Quality’ and ‘Environment and Health Perspective’)” (EEA, 2007), and the EEA/Joint Research Centre reportEnvironment and Health” (EEA, 2005).

·         Europe’s Environment: the fourth assessment:

·         Environment and Health:


EEA assessments are peer reviewed and quality checked by scientific experts and policymakers at national authorities and the European Commission Services.


WHO EURO, within it’s the ENHIS and ENHIS 2 projects on environment and health information system based on indicators, proposed a list of air pollution indicators. Not fully developed yet, this review is only partly based on these indicators and mainly on scientific knowledge, assessments and case studies in Europe.


The EC SCALE process, the Clean Air for Europe (CAFÉ) process and several assessments made by WHO are also important building blocks of this chapter, as well as several DG Research consortia.


·          European Commission :

·          CAFE CBA: 

·          WHO:  

·          EC4MACS: 

·          ExternE Project: 

·          HEIMTSA: 

·          INTARESE:


Near real time information on ground-level ozone in Europe is available on the EEA website: Data description and analysis


Air pollution research and monitoring has led to a vast amount of data that have been used in European air pollution management. This presentation contains only some glimpses of data, compared to current European guidelines, target values and limit values (Table


Table Guidelines, target values and limit values.


Long-term average exposure to particulate matters (PM10) determines both the risks of chronic effects of pollution on children’s health, such as impaired development of lung function, and the frequency of acute effects, such as the aggravation of asthma or incidence of respiratory symptoms. This indicator is also well correlated to the risk of a wide range of health effects, including increased mortality, in adults. The measure of exposure combines the PM10 concentration and the size of the population subject to the exposure.

Most (89%) people (including children) in European cities, where PM10 is monitored, are exposed to PM10 levels exceeding the WHO air quality guideline level (AQG) (20 μg/m3) (1), giving rise to a substantial risk to health. For 14% of people, the European Union (EU) limit value of 40 μg/m3 is exceeded.

Figure presents the total population distribution of annual PM10 concentrations in 2004 (or the last available year); Figure shows the changes in exposure occurred in cities in the 2002-2004 period. This distribution is an approximation of the distribution of the exposure of children based on the assumption of similarity in the proportion of living children in cities.


Figure Percentage of children living in cities with various PM10 levels, 2004 or last available year

Figure Changes in exposure of children to PM10 in cities, 2002-2004


Air pollution management has today focused on fine particles, generated primarily by traffic and with potential serious health impacts. Table here below describes the estimated health damage due to PM2.5 and the effect of the implementation of the current legislation in 2020.


Table Estimated health damage due to PM2.5 in the EU 2000 and through implementation of current legislation (CL), in 2020


Ambient air pollution and health


There is no doubt that pollutants in outdoor air have an impact on respiratory health, as confirmed by a large number of epidemiological studies on both short and long-term exposure. Many studies show that fine particles (usually measured as PM2.5) have serious effects on health, such as an increase in mortality and emergency hospital admissions for cardiovascular and respiratory symptoms. Modelling results indicate that PM2.5 levels in Europe are now estimated to reduce the statistical life expectancy of the European population by approximately nine months, which is comparable to the impacts of traffic accidents. The highest estimated damage to health occurs in the Benelux area, in Northern Italy and in parts in Poland and Hungary, where the average loss in life expectancy may be more than one year.


While much information is available for short-term acute exposures, there is little data about the effect of long-term exposures. In a study made in the former East Germany, an association was found between air pollution levels in the city of residence, the presence of chronic respiratory (especially bronchial) symptoms and lung function growth in children. A study conducted in Switzerland also found an increased occurrence of symptoms in children with increased air pollution levels. Several studies in the USA and Canada (6-city study, 12-city and 24-city study) also found increased bronchial, but not asthmatic, symptoms in children and lower lung function at higher air pollution levels.


Much of the burden of diseases resulting from air pollutants relates back to childhood. Air pollutants augment acute respiratory infections in children and disturb the normal development of the lung. Scientists and health-care professionals are focusing more and more on events during foetal life and early childhood. There is growing evidence that these periods are critical for the later development of many diseases that present themselves during child and adult life. Children who grow up in polluted areas, or whose parents grew up in polluted areas, are more likely to develop reduced lung function as adults. Estimates show that the risk of reduced lung function is doubled in children who grow up in urban areas. Children with asthma are particularly vulnerable, but it is uncertain whether air pollutants trigger the onset of childhood asthma. Intervention studies clearly show the health benefits of improved air quality. Dublin, Ireland, and towns in former East Germany are typical examples. When considering human health and the quality of life, the most urgent requirement to reduce the environmental burden on health appears to be the improvement of the quality of outdoor and indoor air.


Air pollution is responsible for the highest burden of environmentally-related diseases in Europe. Recent estimates indicate that 20 million Europeans a day suffer from respiratory problems. Air pollutants with strongly-indicated respiratory health effects are particulate matter (PM), especially fine and ultra-fine particles, which are able to penetrate the lower respiratory tract (PM2.5), ozone (O3), nitrogen oxides (NO - NO2) and sulphur dioxide (SO2). In addition, chemicals such as polyaromatic hydrocarbons (PAH) and benzene from combustion processes contribute to toxicity and potential health effects.


The WHO earlier estimated that particulate matter is considered to be responsible for 100 000 deaths and 750 000 life years lost annually in a selection of European cities (WHO, 2004). The more recent estimates of the air pollution impact made within the European Commission Clean Air For Europe (European Commission, 2005d) programme found that in the EU about 350 000 people died prematurely in 2000 due to outdoor air pollution with fine particulate matter (PM2.5) alone. This corresponds to an average loss of life expectancy of about 9 months for every EU citizen. Exposure to PM is also linked to an increased frequency of chronic bronchitis, respiratory hospital admissions and days with restricted activities for people suffering from respiratory and cardiovascular diseases.


The loss of statistical life expectancy attributed to anthropogenic contributions to PM2.5., 2000 and 2020 is mapped on EEA data service (


In addition, current levels of ozone have severe health implications such as bringing forward the deaths of more than 20 000 people (CAFE web site and the new web site).


The total cost of air pollution related health damage in the EU in 2000 has been estimated by the CAFE programme in the range of Euro 305 billion to 875 billion, depending on the methodology used to assess the value of a statistical life (VSL) and of life years lost (VOLY).

This estimated cost of non-action has to be compared with cost of action focused on different sources of particles: mobile sources (diesel passenger cars and heavy duty vehicles), industrial processes, and domestic heating and cooking systems, including wood or coal stoves.


A new policy to reduce emissions of acid gases, ammonia and fine particles is being developed within an EU Thematic strategy on air pollution. The aim is to halve the health impact due to PM between 2000 and 2020, which would require action at both Community and national level. The cost of action has been calculated at around Euro 10 billion per year for the EU as a whole, if only technical measures are taken. When non-technical measures are also considered the costs may be lower.


There are many examples that show that respiratory health and life quality improves when air quality improves. This is clearly exemplified by intervention studies such as the Dublin case study, the former East Germany and the Atlanta case. There are also several studies which showed a reduction in respiratory health effects associated to reduced air pollution levels over several years in the former East Germany.

One of the best examples is the study carried out during the 1996 summer Olympic games in Atlanta, USA in which the impact of changes in transportation and community behaviour on air quality and childhood asthma was investigated. Implementation of alternative transport strategy resulted in lower traffic emissions and less hospital admissions of children with acute asthma symptoms.


Asthma - indoors and outdoors


A part of the air pollution-related disease burden consists of respiratory problems in children, who are exposed to outdoor and indoor air pollutants in their homes, schools and day-care and during travel. The quality of the indoor environment is particularly important since European children spend more than 90% of their time indoors. Some of the mechanisms through which environmental factors influence children’s respiratory health remain unclear and sometimes controversial. This is especially the case with asthma and allergies.


Prevalence of asthma and allergies among children has become an increasing problem in the last few decades (ISAAC, 2007) Asthma has become the most common chronic disease among children and is one of the major causes of hospitalization among those younger than 15 years of age. As more people are sensitized to allergens, allergic diseases may increase in Europe in the coming years.


In 19992004, asthma prevalence in children across the European study centres (ISAAC) varied from less than 5% to over 20%. The societal cost is estimated at 3 billion Euro/year. The well-documented rise in asthma prevalence has coincided with a general increase in the density of road traffic in most of these countries. A number of recent studies confirm that residential proximity to traffic sources is associated with increased asthma occurrence and exacerbations in both children and adults (11). In addition to particles (PM), many studies indicate that ground-level ozone may be a critical air pollutant. But the issue is still controversial. For example a number of studies found allergic disorders (including asthma) to be relatively less frequent in the eastern parts of Europe, although levels of many air pollutants were higher than in Western Europe. Clearly, asthma has a multi-causal background with many factors involved. “Life-style factors’ are important, including the increased level of hygiene in homes and the contribution of nutritional factors. Another important factor is genetic predisposition.


There is a lack of substantial knowledge about the contribution of indoor air quality to respiratory symptoms and whether factors in the indoor environment contribute to the increase in asthma prevalence. Indoor air quality is therefore, receiving more and more attention, which is logical in the light of the total time European children and adults spend indoors. Indoor air pollutants can be classified into chemical, biological or physical agents. Many outdoor air pollutants are found indoors, but there are several specific indoor sources of air pollution, such as building and construction materials, paints and indoor furnishings (furniture, carpets, etc). Some indoor sources are linked to human activities and habits, such as smoking, cooking and the use of cleaning agents, disinfectants and air-cleaners. Open fires (wood, coal or gas) for heating, cooking and leisure are significant sources. The continuing stress on energy-saving policies has led to reduced air exchange in homes, schools and office buildings. This leads to an increase in indoor humidity, which stimulates the development of biological pollutants such as mites, moulds and bacteria. Ventilation-related humidity problems arise in the warmer climatic zones of Southern Europe - because of the increased use of air conditioners - as well as in the ¢coldclimates of central and Northern Europe. Maintenance of ventilation systems is clearly important, particularly regular cleaning or changing of dust filters.

Many acute health problems are connected to the indoor environment, including allergic symptoms, distress, sleeping and concentration problems, and in children, coughing, wheezing and asthma-like symptoms. Damp and humidity are important factors because they provide a suitable environment for the growth of micro-organisms (mould, bacteria) but also increase the release of chemicals from construction materials. Several reviews find respiratory problems, including asthma, in children from homes with visible damp and mould or smell of mould. Several studies also highlight the importance of the combined effects on children with allergic and asthmatic problems of exposure to emissions from moisture and mould in combination with tobacco smoke, emissions from gas stoves, mites and allergens from house animals. Chemicals like formaldehyde and benzene from construction materials, chemicals from treatment of furniture and decorations, fragrances from cleaning agents and other household products add to the combined burden of the indoor environment. Although the importance of the indoor environment is generally recognised, there is far less knowledge about indoor than outdoor air quality. There are several European directives that regulate outdoor air quality but no European guidelines for indoor air quality. In the US, the Dept of Housing & Urban Development has established emission standards for floor underlay to address the issue of formaldehyde levels. Control tools and policies


During the 19992004 period the Framework Directive 96/62/EC on ambient air quality assessment and management was complemented by four daughter directives. The directive sets common objectives and basic principles, while the daughter directives set limit and target values for the listed pollutants (European Commission, 2005a; European Commission 2005b).

The air quality directives require EU Member States to assess air quality throughout their territory. For zones and agglomerations where the levels of one or more pollutants are higher than the limit value, Member States are required to develop plans and programmes aimed at attaining the limit values within the set time frame. In addition to establishing limit or target values and alert thresholds for the identified pollutants, the daughter directives aim at harmonisation of monitoring strategies, measuring methods, calibration and quality assessment methods in order to arrive to comparable measurements throughout the EU and provide effective public information.

In 2001, the European Commission launched the Clean Air for Europe (CAFE) programme. The main tasks of CAFE are to inform and assist the development of a thematic strategy on air pollution towards the long-term objective of the 6th Environment Action Programme (6EAP), which was to achieve levels of air quality that do not give rise to significant negative impacts nor risks to human health or the environment, and to assess the progress towards this objective.


The main objective of the CAFE Programme was to develop long-term advice to protect against significant negative effects of air pollution on human health and the environment (Holland et al, 2007)


The pollutants addressed were Emissions of fine particles (PM2.5), NH3, NOx, SO2 and VOCs and their reaction products (ozone and secondary particles).

The main outcomes of the CAFE Programme were in the development of:


·          Thematic Strategy on Air Pollution

·          Directive on Ambient Air Quality and Cleaner Air for Europe (the CAFE Directive, COM (2005) 447)

·          Revision of the National Emission Ceilings Directive.


The Health impact Assessment in the CAFE Programme was based on:


·          Development of methods      

-          WHO, EC ExternE Project, other expert groups,


·          Main assumptions


-          Quantification against concentrations of fine particles and ozone

·          Direct SO2 and NO2 effects omitted, less evidence and concern over double counting

-          No threshold for particle effect at whole population level and a 35 ppb cut-off point used for ozone

-          More information on methods available at:


Health effects quantified in CAFE CBA included:


·          Chronic exposure:

o         Mortality (PM) – the dominant effect

o         Development of bronchitis (PM)


·          Acute exposure (daily variations)

o         Mortality (O3)

o         Hospital admissions


·          Respiratory (PM,O3); Cardiovascular (PM)

o         Days of restricted activity; days off work (PM,O3)

o         Days with symptoms (PM, O3)


·          In people with chronic lung disease (sthma, COPD)

·          In the general population


Evidence for effects was achieved through:


·          Consistency of a very large number of time-series studies

-          Acute effects on mortality

-          Acute effects on respiratory hospital admissions


·          Intervention studies

-          Dublin, Hong Kong, etc.


·          Cohort studies

- Pope et al and re-analyses


Table The CAFE analysis and the strategy


The need to revise current air quality protection legislation was revealed by analysis under the CAFE programme that showed that the health risk of pollution by fine particles was of an order of magnitude higher than that of the other pollutants (European Commission, 2005b).

Following the CAFE analysis of the various scenarios, the Commission adopted in September 2005 its thematic strategy on air pollution by establishing interim environmental objectives for 2020 and setting the level of ambition regarding air quality in the EU up to 2020 (between scenario A and B above). Although this means some improvements, it is clear that significant damage from air pollution will still remain in 2020. The Commission also made it clear that meeting air quality targets will require efforts in other policy areas, in particular in the energy, transport and agriculture sectors.


The Commission proposal is for a new directive (EC 2005a) that would mean retaining the current PM10 standard and adding a new standard for PM2.5 – with the so-called concentration cap of 25 µg/m3 as annual mean – to be met by 2010, and the revision (currently under preparation) of the directive on national emission ceilings (NEC), which sets binding requirements for maximum total emissions of sulphur dioxide, nitrogen oxides, volatile organic compounds and ammonia, for each member State. A proposal for a revised directive that will require more far-reaching reductions in the air pollutants that act as precursors to secondary particles is foreseen by mid-2007. The proposal may include national emission ceilings also for primary particles.

Air quality protection policy of South-eastern European countries is driven by the overall goal of joining the EU, and their efforts and cooperation have focused mainly on this process. The countries and territories of the region are at various stages of accession or association and stabilisation. Bulgaria and Rumania became Member States in 2007 and harmonised their air quality protection legislations with the EU within the framework of the accession process.


The most effective policies for controlling air pollution relate to the further reduction of emissions, for example through improving fuels, setting emission limits for industry and efficiency standards for buildings and equipment and reducing demand for polluting activities.

Those policies can be strengthened through the use of air quality standards and national emission ceilings, and also by linking climate and air quality policies.

Most of this action clearly falls outside the health community, so we need to ask what the role of the health community should be in pursuing health improvements via reduced emissions of air pollutants.


In particular, effective pollution control policies can be summarized as:

·          Fuel quality standards

·          Emission limits for industry, vehicles

·          IPPC for major industry

·          Efficiency standards for buildings and appliances

·          Linkage of climate and air quality policies

·          Reduced demand for polluting activities

·          Air quality standards

·          National emission ceilings; and

·          Pricing in energy and fuels.
 Future developments


The issue of air pollution and health is characterised by combined exposures, where also the importance of indoor air has increasingly been recognised.


Damage to health is caused primarily by two types of air pollutants, namely fine particles and ozone. Concentrations of fine particles have a much more important effect than ozone with respect to mortality. Special attention should be given to those particles that, in laboratory trials, show the highest toxicity and often occur in hotspots. These include fine and ultrafine particles from combustion processes, and particularly exhaust fumes from diesel engines. A large, but unregulated source is domestic wood stoves. In urban areas, up to 10 per cent of the population may be living in such “hot spots”. It is important that abatement programmes do not focus solely on meeting the relevant limit values for PM10, as this could mean that too great an emphasis is placed on the largest particles. These admittedly represent the largest fraction by weight, but are not likely to have the biggest effect on health. It is also important to avoid focusing solely on local hotspots where limit values are exceeded, such as areas with heavy road traffic. It is at least desirable to achieve reduction in the background levels, since long-term exposure accounts for the majority of the most serious health effects.


Small particles and nano-particles have been identified as an emerging risk. Interactions between air pollutants and natural particles such as pollen have to be taken into account, and these are likely to be affected by climate change and change of pollen seasons.



In relation to a possible role of the Health Community, according to Holland at al (2007), it is important that health professionals quite generally recognise the links between health and what historically would be considered as low levels of air pollution. This may not be obvious, given that air pollution is ubiquitous and that it may well act in combination with other stresses. Recognising the problem has two important benefits; first, it makes it possible to raise awareness amongst sensitive groups; second, it increases the interest for research in the area, whether it be on new epidemiological and toxicological studies or on the development of integrated frameworks for health assessment, as under projects such as EC4MACS, ExternE, HEIMTSA and INTARESE.


Most important, however, the health community should become more involved in the debate on air quality. Whilst specific actions to reduce emissions need to be taken by other groups, it is after all the health community that will have to experience the impacts. References


AirBase – the European air quality database. Copenhagen, European Environment Agency, 2006 (, accessed 7 March 2007).


European Environment Agency (EEA) (2007). Europe’s environment — The fourth assessment. European Environment Agency, Copenhagen


European Environment Agency (EEA) & Joint Research Centre (2005): Environment and health, NO 10/2005. ISSN 1725-9177.


Clean Air for Europe (CAFÉ) (2005): Second Position Paper on Particulate Matter. CAFE Working Group on Particulate Matter. 20 December 2004. and the new


European Commission (2005a): Proposed Directive on Ambient Air Quality and Cleaner Air for Europe. COM(2005) 447. (, accessed August 2007)


European Commission (2005b): Commission staff working paperImpact assessmentAnnex to the Communication on the thematic strategy on air pollution and the directive on “Ambient air quality and cleaner air for Europe” ({COM(2005)446 final}, {COM(2005)447 final}. Brussels SEC (2005) 1133, 21 9.2005). Available at:



European Commission, Clean Air for Europe (CAFÉ) (2005c): (Access April 2005)


European Commission (2005d): Science for Environment Policy. DG Environment News Alert. 5 December 2005.


Holland, M.,Hurley, F., Pye S., Watkiss P. and Hunt A. (2007) improving air quality: the Clean Air for europe (CAFE) Programme. 10th European Health Forum Gastain.


International Study of Asthma and Allergies in childhood (ISAAC) (2007): Auckland, The University of Auckland, 1998 (, accessed 9 March 2007).


WHO (2004): Health Aspects of Air Pollutionanswers to follow-up questions from CAFE, Report on a WHO working group meeting, Bonn, Germany 15-16 January 2004. Available at


WHO (2004): Health Aspects of Air Pollution. Results from the WHO ProjectSystematic Review of Health Aspects of Air Pollution in Europe”, June 2004.


WHO (2005a): Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulphur dioxide. Global update 2005. Summary of risk assessment. Geneva, World Health Organization, 2006 ( , accessed 6 March 2007).


WHO (2005): Particulate matter air pollution: how it harms health. Fact sheet EURO/04/05. Berlin, Copenhagen, Rome, 14 April 2005.


WHO (2005): WHO air quality guidelines global update 2005. Report on a Working Group meeting, Bonn, Germany 18-20 October 2005. Available at


WHO (2007). Children’s Health and the Environment in Europe: a Baseline Assessment. WHO Europe, June 2007.