The invisible risks to public health

Air pollution poses significant health risks. More than 9 out of 10 people living in EU cities breathe in dangerous levels of fine particulate matter. Ambient (outdoor) air pollution is responsible for about 5 .7 million deaths globally each year. Sources that can cause significant pollution include traffic, burning fuel in homes, industrial activities, and natural events such as wildfires and volcanic eruptions.

Ground-based sensors monitor local air quality dynamics but do not have global coverage. While satellites in low-Earth orbit provide global, daily data, they do not capture variabilities in shorter time scales.

The Copernicus Sentinel-4 mission addresses these time gaps by providing hourly air quality observations on atmospheric pollutants over Europe with a high spatial and spectral resolution. This continuous monitoring is crucial for assessing exposure risks and public health warnings.

Moreover, the data support compliance with environmental regulations and form a scientific basis for strategies to reduce emissions, thereby protecting ecosystems and human health. With targeted policy action, the number of people exposed to dangerously high levels of fine particulate matter (PM2.5) air pollution could be reduced by 50% by 2040.