The heatwave in June brought summertime smog to most of England. This type of air pollution was once synonymous with Los Angeles and Mexico City but is now a problem globally.
Ozone is one of the main smog pollutants in summer. In the upper atmosphere it protects us from harmful solar UV, but ozone is chemically very reactive; it is used to disinfect swimming pools for example.
When breathed it harms our lungs and creates difficulties for endurance athletes. It rots rubber and damages food crops too.
On 24 and 25 June, ozone across most of England reached concentrations where people may have experienced stinging eyes and breathing problems.
Ozone is not emitted directly into our air. It forms in strong sunlight from chemical reactions between a cocktail of pollutants. This makes it hard to control.
A report from the government’s Air Quality Expert Group highlights how sources of these pollutants have changed over the last two decades.
Organic pollutants in the air were dominated by the petrochemical industry, car exhaust and fuel evaporation. Now they come mainly from things used in our home including solvents, personal care products and paint.
While there are regulations limiting organic pollutants from factories and vehicles, there are no regulations on their use in our homes.
