Relevance and outlook
Just as medicine should be based on evidence, public health action and policy should be grounded in science. Despite many unanswered questions, the evidence is sufficient to advocate sustained improvements of air quality across Europe. Thus, current scientific knowledge must reach policymakers in a comprehensible way. This is particularly urgent in the European Union, where air-quality standards are less stringent than in many individual member states and other areas of the world, and in conflict with research findings and the guidelines proposed by the World Health Organization (WHO). As with tobacco smoke, the voice of health professionals is instrumental in shaping the opinions of the public and policymakers. European research findings make a strong case for sustained improvements in air quality to support public health. In fact, the early tri-national European health impact assessment of air pollution emphasised what several local and trans-European analyses have since confirmed: the public health impact of air pollution is very substantial, thus, the benefits of a reduction in air pollution will be large, in terms of both cost-relevant morbidity and the summary health indicator of life expectancy. As shown in recent assessments on childhood asthma and air pollution, the benefits of clean air have, if anything, been substantially underestimated in the past.