Mayor of London Sadiq Khan visited a Bethnal Green nursery school to mark the launch of a new air quality report.
He met pupils and staff at Columbia Market Nursery School, one of 20 nurseries to receive an air quality audit and grant from City Hall.
The Columbia Road nursery is also one of six selected to trial an indoor air filtration system as part of Mr Khan's plans to improve air quality across the capital.
It will be inside the expanded ultra-low emission zone (Ulez) when it extends to the North and South Circular roads next year - with the report revealing that those zones, along with other policies such as low emission bus zones, could prevent up to 300,000 Londoners from contracting diseases attributable to air pollution.
Mr Khan said: "Air pollution is a national health crisis that is contributing to thousands of premature deaths in London alone. Toxic air causes long-lasting harm and could devastate lives for generations.
"I've moved fast in London to implement the most ambitious plans to tackle air pollution of any major city in the world - showing what we can achieve if we are brave enough to take bold action."
The report, released on Wednesday, February 26, reveals that the policies could save the NHS around £5 billion over the next 30 years, and prevent more than a million hospital admissions.
Columbia Market's executive headteacher, Lynn Cottle, said: "I'm really proud that our nursery, with such a long history, is helping to innovate and protect children's health to give them the best start in life.
"Following our air quality audit, we are especially pleased to be awarded funding from the Mayor and Tower Hamlets to install a green screen that will reduce pollution in the playground and to improve the ambience of our outdoor space."
Susannah Kerr, head of public affairs at the British Heart Foundation, added: "This new report shows the transformational impact that measures to curb air pollution can have in improving the capital's health and reducing strain on the NHS.
"It's clear that ambitious action to tackle the sources of air pollution are necessary to protect the nation's health."
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