Powerful New Dataset Reveals Patterns of Global Ozone Pollution
Although ozone pollution is dropping across many parts of the United States, western Europe and Japan, many people living in those countries still experience more than a dozen days every year in which levels of the lung irritant exceed health-based standards.
This story is based on stories from NOAA and the University of Leicester.
Image: Poor air quality in Tokyo, Japan in 2009. Since then ozone levels have improved, according to a new global assessment.