Air pollution indices are tools that can be used to compare air quality in different geographical regions.

In a new study, researchers evaluated the 'BC indices', primarily designed to assess health risks from particular pollutants over a given time and space, to compare air quality in Italy, Germany and Poland. The indices could be useful for policy makers developing pollution control strategies.

The European Community's Environment Action Plan for 2002-2012 highlights the need for greater efforts to reduce air pollution and associated risks to the environment and human health1. EU legislation on air quality assessment requires each member state to have a system in place to monitor air quality, in order to maintain the status of air quality where it is already good, or requires improvement.

However, it is difficult to compare air quality across the EU because there are differences in the way monitoring networks are set up and distributed in different countries. It has been suggested that a common air quality index could help solve this problem. Several national and international3 indices have been developed in recent years, specifically intended to supply information to the public. In 2002, Italian researchers (Bruno and Cocchi) proposed a strategy for monitoring air pollution based on a set of indices they termed the BC indices.

A second group of researchers have now used BC indices to compare air quality in Italy, Germany and Poland, assessing the indices as tools for air pollution monitoring. The researchers found that the indices are useful for comparing regional trends in air pollution on a day-to-day and seasonal basis, and could be employed to assess the effectiveness of pollution control strategies. The researchers compared air quality in three very different areas: a largely urban region of Northern Italy encompassing Milan and Turin, an area of Eastern Germany surrounding Berlin and the Masovian Province in Poland, which includes the capital Warsaw.

Using air pollution data obtained daily from monitoring stations in each region, they calculated indices to describe levels of several important pollutants, including sulfur dioxide, carbon monoxide, particulate matter and ground-level ozone. Although the density of monitoring stations varied between the regions, the research demonstrates that the BC index methodology is able to accurately capture seasonal variations in pollution unique to each area. As the method includes an index that can provide information about pollutant concentrations at critical individual monitoring stations, the most severe pollutant on any given day in each of the regions can be pinpointed. This information could eventually be used to develop pollution control strategies.

The study identified key pollutants for each of the regions. Particulate matter was the most dangerous pollutant in all three, with ground-level ozone more important in the Italian region.