“It was really distressing to see her working so hard to breathe. She’s so small.”

It’s a parents’ worst nightmare to see their child being rushed in and out of hospital. Yet Sephie’s parents - Bo and Amii - have all too often seen their daughter confined to a hospital ward, breathing through a toddler-sized breathing machine.

Her body would become limp, she would become unable to eat or get up and was exhausted simply from trying to breathe in and out. Her parents would take her to hospital, go home-then it would happen again. They were terrified.

What’s worse is that, as Bo and Amii waited in the hospital’s emergency department, they noticed it wasn’t just Sephie being rushed into hospital with chest problems – there were lots more children too. Doctors said they thought chest problems were becoming more common in children.

We asked the UK’s leading pediatrician, Dr Jonathan Grigg , what he thought of Sephie and other children being rushed into London hospitals with breathing problems.

“Given the scale of the air pollution problem here in London, it’s sadly predictable that we’re seeing so many children across the capital, like Sephie, suffering from respiratory problems”, Dr Grigg explained.

“We know that air pollution and diesel emissions can greatly impact on children, from childhood lung development to asthma. Drastically reducing diesel emissions would immediately reduce children’s exposure and improve their long – term health.”

Air pollution across the UK is now so bad it’s being called a public health emergency, and has been breaking legal safety limits every year since 2010. A Greenpeace investigation showed that over 1000 nurseries across the UK are in areas close to illegal levels of air pollution. This means thousands of toddlers could be exposed to potentially irreversible impacts of air pollution on their health.

This isn’t just about London, or about Sephie though. Globally, air pollution is ranked as a greater threat to health than ebola and HIV, with it having the biggest impact on vulnerable members of our society – the elderly and children.

We know how to stop this crisis. Diesel vehicles produce at least 80% of the air pollution coming from our streets – that’s why Sephie and her parents have joined Greenpeace’s campaign calling on VW to ditch diesel and go electric.

Amii and Bo worry if Sephie will be able to lead a normal life when she is older. Already she cannot go outside and play with her friends or family as many children would. They want to make things better for Sephie, without leaving the only home the family has ever known.

Take action: Join Greenpeace’s campaign for Clean Air Now.

By India Thorogood, digital campaigner, Greenpeace UK