EU heatwave exposed 298 million to harmful ozone, NGO says

A Global Witness report said nearly 298 million people in the European Union may have been exposed to ozone above the bloc's recommended daily limit during a late-June heatwave.

The NGO said the total included about 100 million children and elderly people. It estimated that around 87 percent of the EU's 450 million people faced levels above the World Health Organization guideline, and that 72 million people faced what it called the most dangerous threshold of 150 micrograms per cubic metre.

The report covered June 21 to 28 and combined data from 162 air quality monitoring stations, atmosphere modelling and census information. It said two thirds of the monitoring stations recorded readings in the top one percent of June days since 2013. The highest was 233.7 micrograms per cubic metre in North Rhine-Westphalia, Germany, on June 27.

Ground-level ozone is different from the ozone layer high in the atmosphere. It is a main component of smog and can cause breathing problems, damage lung tissue and trigger asthma attacks. The European Environment Agency attributed more than 63,000 deaths and billions of euros in crop damage to ozone pollution in 2023.

The report was published after the EU climate monitor Copernicus said Western Europe had its hottest June on record. Laurence Rouil, director of the Copernicus Atmosphere Monitoring Service, said the latest ozone episode was “really remarkable and worrying” because it came so early in the summer.

Global Witness senior campaigner Flossie Boyd said the findings showed an “invisible threat” linked to fossil fuel dependence. James Weber, a University of Reading climate scientist who was not involved in the report, said people should avoid being outside, especially exercising, during the hottest parts of days with high ozone pollution.