Earlier this week, the House of Lords voted in favour of an amendment to the environment bill that would commit the government to reduce levels of fine particulate matter (PM2.5) to within World Health Organisation (WHO) guidelines by 2030 at the latest.
The amendment, brought by Labour politician Baroness Sue Hayman, was approved by 181 votes to 159.
MPs will have to consider the new amendment after the bill completes its passage through the House of Lords this month and returns to the House of Commons.
Campaigners, scientists and politicians have long urged the government to commit to air pollution limits that are in line with WHO recommendations.
History was made last year when an inquest found that air pollution contributed to the death of nine-year-old Ella Adoo-Kissi-Debrah.
Ella lived close by to the busy South Circular Road in south London and died following a severe asthma attack in 2013.
The inquest found that pollution from traffic made a “material contribution” to her death, and a coroner’s report released in April said the UK must set stricter air quality limits to prevent similar deaths in the future.
Jocelyn Cockburn, the lawyer representing Ella’s family, told The Independent: “Bringing levels of particulate matter down in line with WHO guidelines was one of the key points to come out of Ella’s Inquest, so I am pleased to see this development.
“Without such limits clearly set out in law, people have no way of holding to account those responsible for the toxic air they are breathing, and as Ella’s case proved, which may also be killing them.”
The legal limit for fine particulate matter pollution (PM2.5) in the UK is currently two and a half times as high as that recommended by experts at the WHO.
In an interview with The Independent published in April, Ella’s mother Rosamund Adoo-Kissi-Debrah urged the government to take the coroner’s recommendation for tougher air pollution limits “incredibly seriously”.
“If nothing changes, then there are going to be families that go through what we’ve gone through,” she said.
“Children are continuing to die, it is a very difficult thing to talk about. Should anyone die from asthma in 2021? The answer is no.”
Ms Cockburn added on Friday: “Lives will be saved if we adopt WHO targets and take the necessary steps to meet these targets as soon as possible.
“The government is on notice that any further delay on its part will lead to unnecessary deaths.”
The government is believed to be aiming for the bill to reach Royal Assent before the global climate summit, Cop26, begins in Glasgow in just a few weeks’ time.