Children’s stunted lungs show recovery in ultra low emission zone

超低排放区内儿童受损肺部显示出恢复迹象

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. 科学家们表示，在居住地实施污染限制措施后，幼儿肺部开始恢复和生长的速度之快令他们感到“震惊”。

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. 研究人员发现，伦敦儿童因污染而受阻的肺部发育在2019年引入超低排放区（Ulez）并减少排放后，表现出了显著的改善。

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. 这项研究追踪了伦敦和卢顿的3400多名小学生，提供了科学家们认为迄今为止最有力的证据，证明地方清洁空气区有助于减少童年时期因污染造成的部分伤害。

But independent researchers caution that other factors must also be considered. 但独立研究人员提醒，必须同时考虑其他因素。

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. Children are also more vulnerable to pollution because their lungs and immune systems are still developing. And when outside, they tend to be closer to the ground and nearer sources of exhaust fumes, for example. 空气污染会阻碍幼儿肺部的发育，使他们面临哮喘、心脏病、糖尿病甚至过早死亡的风险增加。儿童对污染也更为脆弱，因为他们的肺部和免疫系统仍在发育中。此外，当他们在户外时，往往更靠近地面，也更接近废气排放源。

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. 2020年，来自伦敦的9岁女孩埃拉·阿杜-基西-德布拉（Ella Adoo-Kissi-Debrah）成为英国首位被正式认定死因为空气污染的人，她于2013年因哮喘发作去世。

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. Children in the study had annual lung function and capacity tests in the year before Ulez came in and for four years after. 在这项研究中，研究人员招募了伦敦超低排放区内小学就读的6至9岁儿童，并对这些儿童进行了为期五年的追踪，同时将他们与卢顿地区背景相似（社会经济背景、体育活动和种族方面）的儿童进行了对比。研究中的儿童在Ulez实施前一年以及实施后的四年里，每年都接受了肺功能和肺活量测试。

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. At the end of the study the children’s lung capacity reached near identical levels in both groups. 初步结果显示，伦敦儿童的肺活量小于卢顿儿童，卢顿的污染程度低于伦敦，但污染物构成相似。研究结束时，两组儿童的肺活量达到了几乎相同的水平。

“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. “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. “The speed of catch up in lung capacity in the London group was surprising and impressive.” 研究人员表示：“虽然我们预期儿童的肺部会逐年增长，但我们的结果表明，伦敦儿童的肺部生长在四年间加速了，从而‘赶上’了卢顿的对照组，达到了相似的肺活量水平。”伦敦玛丽女王大学的研究资深作者克里斯·格里菲斯（Chris Griffiths）教授告诉BBC：“当我第一次看到结果时，我感到非常震惊。伦敦组肺活量的追赶速度令人惊讶且印象深刻。”

“This shows an ambitious clean air zone can drive pollution levels down, rapidly restoring children’s stunted lung growth.” “这表明，雄心勃勃的清洁空气区可以降低污染水平，迅速恢复儿童受损的肺部发育。”

The main test measured how much air a child could forcibly breathe out in one second after a big breath in. 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. 格里菲斯解释说，主要的测试是测量儿童在深吸气后一秒钟内能用力呼出的空气量。在实际应用中，这种改善意味着伦敦组的儿童可以像卢顿组的儿童一样快速奔跑而不气喘，或者能吹灭同样数量的蜡烛。

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%. In Luton - where some smaller scale measures were put in place to tackle air pollution - the figures were 9% to 7%. 总体而言，伦敦肺活量被认为“临床受损”（暗示肺部损伤导致咳嗽或呼吸困难）的儿童比例从14%下降到9%。在卢顿——那里采取了一些较小规模的措施来治理空气污染——这一比例从9%下降到7%。

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. 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. 研究小组的测量结果还显示，在此期间，伦敦儿童接触到的二氧化氮水平下降速度快于卢顿。研究人员表示，这一点至关重要，因为它很可能证明了他们所观察到的肺部生长改善与Ulez实施后的空气质量提升有关。

London’s Ulez was first introduced in 2019 by Mayor Sadiq Khan in a bid to “clean up London’s air”. London had high levels of the harmful gas nitrogen dioxide which comes from motor vehicles. Older, more polluting vehicles had to pay a daily charge to drive in central London. The measures were later expanded to cover the whole capital. While many supported the policy it provoked political opposition and protests. 伦敦的Ulez最初由市长萨迪克·汗（Sadiq Khan）于2019年引入，旨在“净化伦敦空气”。伦敦当时存在大量来自机动车的有害气体二氧化氮。较旧、污染较重的车辆在伦敦市中心行驶需支付每日费用。这些措施后来扩展到整个首都。尽管许多人支持该政策，但也引发了政治反对和抗议。

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.” 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. 未参与此项研究的莱斯特大学安娜·汉塞尔（Anna Hansell）教授表示，儿童肺功能的改善“很可能对他们的健康产生终身益处”。她补充说，这项研究由“受人尊敬的研究人员”精心开展，伦敦和卢顿之间的地理比较非常重要，因为随着时间的推移，空气污染总体上有所减少。

“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. 她说：“鉴于研究期间包含了新冠疫情，这一点显得尤为重要，它证明了伦敦的研究结果并非源于与疫情相关的变化。”

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”. 伦敦玛丽女王大学的首席作者海伦·伍德（Helen Wood）博士表示，虽然结果非常有希望，但绝不能自满，因为“伦敦和卢顿以及英国其他城市的空气污染水平仍然高于世界卫生组织的指导标准，因此仍有工作要做”。

“We know clean air zones are a complex area and the impact on businesses and individuals must be considered. What we are doing is adding new evidence to inform the debate,” Griffiths said. “There are more than a billion kids living in cities around the world, most of them in polluted environments, getting a really bad start in life. That’s why these are important findings with global relevance.” “我们知道清洁空气区是一个复杂的问题，必须考虑对企业和个人的影响。我们所做的是增加新的证据来为辩论提供参考，”格里菲斯说。“全球有超过十亿儿童生活在城市中，其中大多数处于污染环境中，人生起点非常糟糕。这就是为什么这些发现具有全球意义。”