Long-Term Strategies Needed to Battle Particulate Matter Air Pollution

Interview with Michael Krzyzanowski, World Health Organization European Centre for Environment and Health

Germany is at the forefront of environmental friendly lifestyles. That's an assured wisdom for many, if not most Germans. But since the sudden outbreak of public discussions regarding particulate matter (PM), this fact is questioned. Now the European Centre for Environment and Health of the World Health Organisation Regional Office for Europe says that on average PM claims 10.2 month of life for each German, compared to an average of just 8.6 month of life from the life of every person in the EU.

EC Directive 1999/30/EC, which sets limits for PM concentrations, was put into force at the beginning of this year, six years after it was adopted. But the vivid discussion started not until major German cities like Munich and Stuttgart were about to exceed the limits. Obviously, communities were ill prepared to deal with a foreseeable situation.

Telepolis talked with Dr Michal Krzyzanowski about the risks of PM air pollution and the cooperation between the World Health Organization and the European Commission (EC). Michal Krzyzanowski is "Regional Adviser Air Quality and Health" at WHO's European Centre for Environment and Health (ECEH), Bonn Office.

The topic of air pollution due to particulate matter (PM) has hit the general public in Germany quite unprepared. Since then, a variety of experts have shared their views of the situation with the public. What is the role of WHO with regard to air quality in general and PM in particular?

Michal Krzyzanowski: It is the role of WHO to assess health effects of air pollution worldwide, identify health hazards and calculate risks based on scientific findings of exposure to various hazards. We organize systematic reviews of the scientific evidence and organize meetings of experts. PM is one of the main pollutants and its effect was assessed for Europe in the WHO project Systematic Review of Health Aspects of Air Pollution in Europe.

What are your personal responsibilities and tasks?

Michal Krzyzanowski: Within the WHO European Centre of Environment and Health I'm Regional Adviser Air Quality. This function is based in the Bonn office of ECEH. Over the last years I have lead projects on systematic reviews on the health effects of air pollution. It was – and is – our role to organize scientific reviews and prepare reports from these reviews, which are addressed to decision makers as well as the public.

There is no level under which exposure to PM is not harmful

What is the effect of particulate matter to the human body?

Michal Krzyzanowski: PM is often described by two indicators. PM 10 covers particles of all kinds that are smaller than 10 micrometers. PM 2.5 covers particles smaller than 2.5 micrometers. The EC directive on PM, which is in force since January, is based on measurements of PM 10. The smaller a particle, the easier it is for it to enter the human body in a harmful way.

PM has a wide range of documented health effects. It starts with mild effects like aggravating symptoms of respiratory diseases. PM negatively affects the development of lungs in children and increases the severity of respiratory and cardiovascular diseases. This results in increased use of medication, more frequent consultation of physicians and more hospital admissions. In some cases effects are manifested in an increased number of deaths due to pulmonary and respiratory diseases.

It is quite important that those effects are observed at all levels of PM concentrations. There is no level under which exposure to PM is not harmful. Even in clean areas small increases in air pollution are followed by increased symptoms and mortality. Most severe effects has the long-term exposure to air pollution, which is faced for example by residents in urban areas with intense road traffic. According to a large study from the US, people in the highest polluted areas have a 10-15% higher risk of death than people living in clean parts of the country.

How do WHO and the European Commission (EC) collaborate in the area of air quality?

Michal Krzyzanowski: Based on reviews of scientific evidence WHO prepares air quality guidelines that are used by WHO member states to design policies and air quality standards. WHO provides an independent assessment of damage to health by air pollution. The European Union uses this information to set standards, define directives and define limits.

For many German citizens it is an unquestioned wisdom that Germany spearheads in environmental friendly technologies and policies. Why then is the situation here worse than in other countries?

Michal Krzyzanowski: Air pollution with PM claims an average of 8.6 months from the life of every person in the EU, but Germans lose 10.2 months of life in the year 2000. The actual impact of pollution on health depends on the level of exposure to the population. There are a number of complex factors determining this exposure. Emissions are most often correlated with transport intensity and industrial activities, but geographical and climate conditions are also relevant. On the one hand, pollutants from a specific area are transported to other areas. On the other hand that area receives pollutants from the outside. This indicates how important international collaboration is. Germany is densely populated with a high amount of traffic. So health hazards from air pollution are quite high in some areas, but not everywhere.

Any long-term solution must consider different modes of transport

In the current discussion, Diesel combustion and particle filters play a dominant role. But PM 10 is a mixture of quite different constituents from natural and industrial sources, not only from Diesel combustion, but also natural dust and, especially in springtime, pollen. Is it therefore justified to pay so much attention to Diesel combustion and road traffic? Is smoking not even more dangerous?

Michal Krzyzanowski: Road traffic is contributing to 1/3 of particle emissions and has probably a similar share in population exposure. The evidence on hazardous properties of Diesel emissions is relatively well developed and this increases our confidence in attributing a large share of health effects to this fraction of pollution.

Smoking and diesel emissions cannot be compared. The health effects of active smoking are of course severe, since the smoker inhales the cigarette smoke. It is, by the way, WHO's declared policy to eliminate smoking.

City councils are looking for short-term solutions of the problem fostering instalment of particle filters or temporarily closing specific roads for trucks. Is that enough?

Michal Krzyzanowski: Closing specific roads may have a quick effect in certain locations. But if the traffic is just deviated, pollutants are just diluted. The total amount of emissions may even rise due to longer detours, resulting in a larger population being exposed. But since there is, as we have already seen, no level of PM concentration under which the exposure is harmless, the overall health effects stay the same or may even worsen.

Instead, the installation of particle filters is fact contributing to a long-term solution. Currently the penetration of this technology is low and will rise slowly. This will delay its impact on pollution for some years. There is also the risk that, to a certain degree, the positive effect of this technology will be compensated by more traffic. Thus, not only advances in technology like increasing the efficiency of engines are necessary. Any long-term solution must consider different modes of transport as well.

How could the public awareness be kept alive for implementing such a long-term strategy?

Michal Krzyzanowski: The public must be informed in real time about the air quality situation in an area to affect the short-time behaviour of the people. This should be possible, because thanks to the directive, air quality monitoring stations are now widely installed in urban areas. In addition, the long-term effects of the actions taken should be easily retrievable for everybody, from the general public to decision makers. WHO fosters the use of key environment and health indicators, which will help to assess policies. They will also be part of the EC reporting, which is developed by WHO ECEH, Bonn Office.