The Mayor of London’s office has issued an air pollution warning linked to air currents and ongoing hot weather.
Analysts from Imperial College London advising Sadiq Khan say there are signs that the capital’s skies will contain ‘high levels of ozone’ on Tuesday.
Although no specific health warnings have been issued, it means people with certain health conditions such as asthma may be at higher risk of adverse effects.
Ozone is a naturally occurring gas formed by reactions of other chemicals in the air.
It is present in at high concentrations in the upper atmosphere, where it absorbs UV radiation, and at low concentrations in the lower atmosphere, where it is normally harmless.
Weather conditions and human activity can cause higher concentrations of ozone near ground level, which is one of the two causes of smog.
This can trigger inflammation of the respiratory tract, eyes, nose and throat, as well as asthma attacks.
Mr Khan called on Londoners to avoid unnecessary car journeys, adding: ‘Pollution and heat can be a dangerous combination, which is why I’m urging Londoners to look after themselves and each other by choosing to walk, cycle or take public transport, avoid unnecessary car journeys, stop their engines idling and refrain from burning wood or garden waste, all of which contribute to high levels of pollution.
‘This is particularly important in order to protect those who are most vulnerable and help us to build a safer and greener London for all.’
The Mayor’s alert stated: ‘Tuesday is forecast to be a hot sunny day with temperatures into the high twenties.
‘A continental air feed from central Europe is likely to contain some precursors for ozone formation.
‘These, combined with London’s emissions and with sunshine and high temperatures, could possibly result in “high” levels of ozone.’
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