Examples of different air quality indexes in use across the WHO European Region.
Air quality advice differs across Europe
A recent WHO report found tremendous variations in the way that air quality is communicated to citizens. Most countries in the WHO European Region use their own country-specific air quality index (AQI) instead of the uniform index provided by the European Environmental Agency (EEA). There was also a large variation in the accompanying health messages of the AQI. There are benefits to a uniform AQI, but generalisation of an AQI could cause problems in countries at both ends of the spectrum of air pollution. Countries with lower levels might have experienced documented health effects even on days when the AQI is reported as good. Countries with high levels might experience many days with fair or poor air quality. They may want a reasonable number of days, when they call on residents to take specific actions, such as change timing or location of outdoor exercise, turn on air filtration without extra energy expenditure, or modify commuting or leisure behaviour. From a health perspective the bands of the AQI should represent WHO recommendations, but some are instead based on limit values, and few have not yet updated their bands to the new WHO (2021) recommendations.
To be able to make informed decisions a forecast model of air pollutants might be more relevant for planning activities. Several countries had forecast models that could predict high-pollution episodes if these are normally triggered by meteorological factors.
Source: WHO report, Risk communication of ambient air pollution in the WHO European Region: review of air quality indexes and lessons learned, https://apps.who.int/iris/handle/10665/365787