The countdown has begun to the launch of one of the world’s boldest attempts to tackle air pollution.

From next Monday, thousands of drivers face paying a new charge to enter central London.

The aim is to deter the dirtiest vehicles in an effort to reduce diseases and premature deaths.

The initiative comes as scientists say the impacts of air pollution are more serious than previously thought.

He added: “One of the things that has troubled me is that because we can’t see the particulate matter, the nitrogen dioxide, the poison, you don’t take it seriously.”

But over the last few decades, research has revealed how gases like nitrogen dioxide and tiny particles, known as particulate matter or PM, can reach deep into the body with the danger of causing lasting damage.

Asthma attack

The most obvious effects are on our breathing – anyone suffering from asthma, for example, is more likely to be at risk, because dirty air can cause chronic problems and also trigger an attack.

“I had to stay up one night because my chest was really bad because [of] all the polluted air,” 10-year-old Alfie told me. “I couldn’t go to sleep and my mum had to stay awake.”

One motivation for the work is that breathing in dirty air at an early age can have implications that last a lifetime.

Research has shown that children growing up in heavily polluted streets have smaller lung capacity than those in cleaner areas – on average by 5% according to a study in London – a limitation that cannot be reversed.

Greater challenges

And air pollution can exacerbate other respiratory conditions too, including emphysema and chronic bronchitis, and lung cancer is thought to be linked as well.

Dr Ben Barrett of King’s College London, who is running the backpack research, says that children born in a more polluted environment face greater challenges in life.

“We know what pollution particles look like when they’re in the cells elsewhere in the body particularly in the lungs, and the black bits that we’re seeing in the placenta are a very similar shape and colour to those what making us think they could be pollution particles.”

Their presence does not prove a link with premature birth or lower birthweight but it does suggest a possible mechanism.

Fifteen young mothers have so far agreed to donate their placentas to the study, and one of them, Rachel Buswell, told me that of all her concerns while pregnant, air pollution was not one of them.

“It’s pretty scary,” she said, “you protect yourself when you find out you’re pregnant in as many ways as you can and that’s going to be something people can’t protect themselves as easily, living in London especially, it is quite frightening.”