Clean air in Europe for all: A call for more ambitious action.

Ambient air pollution is a major global public health risk factor. There is now broad consensus that exposure to air pollution causes an array of adverse health effects based on evidence from a large scientific literature that has grown exponentially since the mid-1990s.1–4 Air pollution damages most organ systems and is linked to many debilitating diseases, such as asthma, cardiovascular diseases, chronic obstructive pulmonary disease, pneumonia, stroke, diabetes, lung cancer, and dementia.5 The Global Burden of Disease study estimated that in 2019 air pollution ranked as the fourth global risk factor for mortality, surpassed only by high blood pressure, tobacco use, and poor diet.6 The European Environment Agency estimated 300,000 premature deaths due to air pollution in the EU-27 in 2020—an unacceptable high air pollution burden.7 Air pollution levels have generally declined over the last several decades in Europe, due largely to successful air quality regulation and subsequent improvements in technology and industry. The current air quality legislation in Europe—the Ambient Air Quality Directive (AAQD) from 2008—set limit values for the annual mean of the air pollutants PM2.5 and NO2 to 25 and 40 μg/m3, respectively.8 These limit values are criticized for being insufficient to protect the health of EU citizens.9,10 The World Health Organization (WHO) released new Air Quality Guidelines (AQG) in September 2021, based on a comprehensive synthesis of the scientific evidence on health effects of air pollution.4 They recommended that annual mean concentrations of PM2.5 and NO2 should not exceed 5 and 10 μg/m3, respectively, demonstrating that serious health effects occur above these values. The health community supports full alignment of EU legislation with the 2021 WHO AQG, indicated by a joint statement which was endorsed by more than 140 medical, public health, and scientific societies and patient organizations.11 The European Commission (EC) published a proposal to revise the AAQD on October 26, 2022.12 The EC also published an accompanying impact assessment, quantifying the expected air pollution concentrations and resulting healthand implementation costs for various policy options.13 The European Parliament and the Council are currently considering the proposal. The proposal includes important steps to achieve cleaner air but falls short of what is ultimately needed to maximize public health benefits, for the reasons explained below.