Economic Impacts of Ozone Exposure

Air quality is an important social, economic and environmental driver within the EU and globally. Exposure to poor air quality is attributed to detrimental human health conditions, environmental degradation and associated economic costs for individuals and public services. This study assesses the health and environmental impacts specific to exposure to O3 across the EU and selected Member States using best available data from 2022. The study further qualitatively explores the role of methane (CH4) in the formation of O3, drawing on existing academic literature to understand the extent to which methane mitigation could lead to a reduction in O3 concentrations.

Exposure to air pollutants lead to varying types and magnitude of health and environmental impact due to their distinct chemical properties, sources, and modes of interaction with biological and environmental systems. As understanding of these impacts and interactions improves, international, EU, and national legislation have targeted reductions of air pollutant emissions and air quality concentrations through a series of legislative measures. Notable EU legislation has included the National Emission reduction Commitments Directive focused on reducing air emissions below levels deemed harmful to human health and ecosystems through setting reduction commitments for key pollutants (nitrogen oxides - NOx, non-methane volatile organic compound - NMVOC, fine particulate matter - PM2.5, sulphur dioxide - SO2, ammonia - NH3). The Ambient Air Quality Directive (revised in 2024) has established concentration limit values and a harmonised EU air quality management system. Policies focused on CH4 emissions have typically been included within broader frameworks to address greenhouse gases (GHG), but the 2024 ‘Methane Regulation’ sets requirements for operators to measure, report, and verify methane emissions for fuels.

This study analyses the formation of O3 across the EU in 2022, reviewing geographic locations where concentrations are most (and least) significant. O3 concentration target values are included within the AAQD, and more stringent guidelines are set by the World Health Organisation (WHO). However, O3 concentrations targets have not been met in many areas within the EU. O3 is not directly emitted, but is a secondary pollutant formed by complex photochemical reactions. As such, reducing O3 concentrations to meet these targets requires nuanced policies and measures, including targeting multiple pollutants contributing to its formation, rather than a solitary source. Pollutants which contribute, to varying degrees, to the formation of O3 include NOx, VOCs, and carbon monoxide (CO). Another key pollutant is methane (CH4), which is emitted primarily through the agricultural sector and livestock production in the EU.

The relationship between health and environment and exposure to O3 concentrations is well documented across academic literature and policy assessments, and policymakers have increasingly focused on mitigating these impacts. There is a growing body of evidence detailing the relationship between O3 and respiratory morbidity and mortality and damage to plants and trees leading to substantial losses in agricultural crop yield. The European Environment Agency (EEA) has also explored the impacts to both health and the environment resulting from exposure to O3, finding, most notably, that 94% of the EU’s urban population exposed to harmful levels and that remaining within WHO’s Air Quality Guideline values could potentially prevent 70,000 premature deaths annually in the EU. Based on 2022 O3 concentrations levels, a health and environmental assessment has determined the associated impacts.