- Published
Scientists say they have been "stunned" by how quickly young children's lungs began to recover and grow after pollution restrictions were brought in where they lived.
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they → publish → ?
Researchers found that children in London whose lung growth had been stunted by pollution showed impressive improvements after the introduction of an Ultra Low Emission Zone (Ulez) in 2019 reduced emissions.
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introduction → find → emissions
The study followed more than 3,400 primary school children in London and Luton and provides what scientists believe is the strongest evidence yet that local clean air zones could help reduce some of the harm caused by pollution during childhood.
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zones → follow → childhood
But independent researchers caution that other factors must also be considered.
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factors → caution → ?
Air pollution can stunt the growth of young children's lungs leaving them at an increased risk of asthma, heart disease, diabetes and even premature death.
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pollution → stunt → asthma
Children are also more vulnerable to pollution because their lungs and immune systems are still developing.
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lungs → develop → pollution
And when outside, they tend to be closer to the ground and nearer sources of exhaust fumes, for example.
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they → tend → example
In 2020 Ella Adoo-Kissi-Debrah, a nine-year-old girl from London who died following an asthma attack in 2013, became the first person in the UK to have air pollution listed as a cause of death.
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pollution → die → death
In the study, researchers recruited six to nine-year-olds attending primary schools in London's ultra low emission zone and followed the same children for five years, comparing them to similar children (in terms of socio-economic background, physical activity and ethnicity) in Luton.
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researchers → recruit → Luton
Children in the study had annual lung function and capacity tests in the year before Ulez came in and for four years after.
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Ulez → have → years
Initial results showed children's lungs in London were smaller in capacity than those in Luton, which is less polluted than London but has a similar mix of pollutants.
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which → show → pollutants
At the end of the study the children's lung capacity reached near identical levels in both groups.
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capacity → reach → groups
"While we would expect children's lungs to grow year on year, our results indicate that the London children's lung growth had accelerated during the four years to 'catch up' with the control group in Luton to reach similar levels of lung capacity," researchers say.
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researchers → expect → capacity
"I was absolutely stunned when I first saw the results," Prof Chris Griffiths, a senior author on the study, at Queen Mary University of London, told the BBC.
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Griffiths → stun → BBC
"This shows an ambitious clean air zone can drive pollution levels down, rapidly restoring children's stunted lung growth.
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zone → show → growth
"
The main test measured how much air a child could forcibly breathe out in one second after a big breath in.
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child → measure → breath
In practical terms the improvements could mean children in the London group could run as fast as the Luton group without getting out of breath or blow out the same number of candles for example, Griffiths explained.
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Griffiths → mean → example
Another way of testing for lung capacity used in the study showed significant improvements too, though not to the same extent - implying there are still gains to be made.
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way → test → extent
Overall the proportion of children in London whose lung capacity was deemed "clinically impaired" (suggesting lung damage resulting in coughs or breathlessness) fell from 14% to 9%.
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capacity → deem → %
In Luton - where some smaller scale measures were put in place to tackle air pollution - the figures were 9% to 7%.
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figures → put → pollution
The team's measurements also showed the level of nitrogen dioxide children were exposed to fell faster in London than in Luton over this time.
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children → show → time
Researchers say this is key as it likely demonstrates that the improved lung growth they saw was related to air quality improvements following the implementation of Ulez.
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they → say → Ulez
London's Ulez was first introduced in 2019 by Mayor Sadiq Khan in a bid to "clean up London's air".
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Ulez → introduce → air
London had high levels of the harmful gas nitrogen dioxide which comes from motor vehicles.
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which → have → vehicles
Older, more polluting vehicles had to pay a daily charge to drive in central London.
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vehicles → pollute → London
The measures were later expanded to cover the whole capital.
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measures → expand → capital
While many supported the policy it provoked political opposition and protests.
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it → support → opposition
Prof Anna Hansell, at the University of Leicester, who was not involved in the study said the improved lung function in children was "likely to have lifelong benefits for their health."
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function → involve → health
She added the study was "carefully conducted by "well-respected researchers" and that the geographical comparisons between London and Luton were important as there had been general reductions in air pollution over time.
"This proved particularly useful, given that the study period included the Covid-19 pandemic – and demonstrates the findings in London are not due to changes related to the pandemic," she said.
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she → add → pandemic
Another aspect to consider was that the London group may have been more likely to walk or cycle to school once Ulez came in.
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Ulez → consider → school
Meanwhile, Kevin McConway, emeritus professor at the Open University, said it was important to take the full impact of Covid into account and argued that studying other cities could help tease out whether some improvements were due to unmeasured differences between London and Luton.
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improvements → say → London
Lead author, Dr Helen Wood, at Queen Mary University of London said while the results were very promising there was no room for complacency as "air pollution in both London and Luton – as well as other cities across the UK – remains above WHO guideline levels, so there is still work to be done".
"
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pollution → say → levels
We know clean air zones are a complex area and the impact on businesses and individuals must be considered.
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impact → know → businesses
What we are doing is adding new evidence to inform the debate," Griffiths said.
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Griffiths → do → debate
The work involved researchers from the Universities of Bedfordshire, Oxford, Cambridge, Edinburgh and Southern California and is published in the Lancet Public Health.
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work → involve → Health
