Level of ozone pollution in the Nantes agglomeration

This table contains the annual average levels of ozone pollution recorded on measuring stations in the Nantes agglomeration since 2005. OZONE Origins: the lower atmosphere naturally contains little ozone. However, in a polluted atmosphere this gas can be formed by chemical reaction between precursor gases (nitrogen dioxide, volatile organic compounds, etc.). These reactions are amplified by ultraviolet solar rays. Temporal evolutions: the highest ozone concentrations are generally measured in summer. They are minimal in the early morning and maximum in the middle of the afternoon. Geographical distribution: ozone concentrations remain low near traffic axes where some exhaust gases destroy ozone. On the other hand, ozone may have high levels in urban areas far from roads, in peri-urban areas below winds and in rural areas. For more information: www.airpl.org