Hundreds of heads are piloting bans on school runs in a bid to protect kids from car pollution.
Thousands more are due to follow and campaigners want it introduced nationwide.
Fumes have been linked to soaring asthma cases.
One expert said: “Pollution levels around schools are worrying.”
And in a bid to tackle the dangerous levels of toxic air linked to a rise in young asthma cases, hundreds of heads across the country are piloting bans on vehicles parking near the gates.
Thousands more are expected to trial the schemes, backed by a number of measures including £50 fines and fixed penalties leading to points on licences.
But parents and experts now want the ban rolled out across the country, as figures show one in four cars on the road at peak times are on the school run.
The British Lung Foundation backed the call. Director of policy and communications Alison Cook said: “Toxic air is linked to asthma and chronic chest problems, and damage to the lungs in early age is irreversible.
“That’s why illegal levels of pollution around schools is hugely worrying.”
Rosamund Adoo-Kissi-Debrah’s daughter Ella died at the age of nine from an asthma attack she believes was caused by illegally high levels of air pollution near the youngster’s school in Lewisham, South East London.
She also called for a nationwide ban on school runs to prevent more deaths and “stop Ella from dying in vain”.
Rosamund said: “The UK has the highest rates for asthma deaths in Europe. Pollution levels can soar by as much as 50% by cars left running, commonly occurring at school gates across the country.
“I can’t stress enough how damaging this is to our children’s health. The only way we can really make a difference is for uniform rules across the country.”
The pilot schemes include closing roads, setting up “park and strides”, walk-to-school initiatives and “playing dead” protests.
Police in Solihull,West Mids, hand out £50 fines to those who flout the ban.
While most parents back the bans, there are concerns from those who live in areas with little or no public transport.
But transport charity Sustrans, which is helping pilot some of the schemes, said they “will significantly help reduce children’s exposure to pollution while creating a safer environment for pupils, parents and teachers”.
Experts say kids are particularly at risk from pollution as they absorb and retain toxins for longer.
Permanent bans have been put in place at a primary in Hackney, East London, after an 18-month trial, and in Southampton.
Tragic Ella, 9
Rosamund Adoo-Kissi-Debrah writes:
My daughter Ella was a healthy, happy child winning numerous gymnastics medals.
But that changed a few months before her seventh birthday when she developed a chest infection and was diagnosed with asthma.
Doctors at Great Ormond Street said it was one of the worst cases of child asthma they had seen.
By the time she died in February 2013, she had been in hospital 27 times.
A leading expert in child asthma and air pollution discovered 26 of those times coincided with very high spikes in pollution.
The night she died was one of our area’s highest recorded spikes in nitrogen dioxide and PM10s, the most noxious pollutants.
Police kids give tickets to polluting cars
Pupils at a primary school are patrolling the streets outside as uniformed “junior” police.
They issue fake tickets to parents parked on the pavement or sitting with their car engines running near the school.
Steve Marsland, head of Russell Scott Primary, in Denton, Greater Manchester, came up with the idea after he noticed an increase in children with asthma.
Eighteen months ago even he started to use an inhaler after having trouble breathing polluted air. The school is not far from the M67 and M60.
Last year air nearby was found to be above legal limits of poisonous nitrogen dioxide.