Clean Air Zones Can Affect Children’s Development in New York, London

Clean air zones and areas of congestion pricing may help children within the borders of these zones, especially when it comes to childhood asthma and the development of lung function, which can both be affected by particulate matter in the air. A panel held during the American Thoracic Society 2026 International Conference saw experts from New York, New York, and London, UK, speaking about how congestion and clean air laws, respectively, could have a long-lasting effect on mitigating these potential outcomes.

New York’s Congestion Pricing Laws Are a First for the US

Andrea Titus, PhD, an assistant research professor at New York University Grossman School of Medicine, discussed how the recent congestion pricing implemented in parts of Manhattan could be a blueprint for the US to follow in other cities, as research continues into how it will affect children living within the affected zone.

Congestion pricing began in January 2025 and primarily affects all streets south of and including 60th St in Manhattan. Congestion pricing laws drive up toll prices during peak hours in an effort to dissuade individuals in the area from driving in the city during those hours. Traffic congestion is a major issue in the area, said Titus, with an average traffic speed of only 7 miles per hour prior to the pandemic. The primary reasoning behind congestion pricing was this traffic problem rather than any effect on long-term health. However, health may end up benefiting as a result.

“Our hypothesis is that, by changing the traffic patterns, congestion pricing also has the potential to impact local and regional air quality,” explained Titus.

Thus far, traffic volumes have seen steady decreases, and it is estimated that 21 million fewer vehicles entered Manhattan between January and October 2025, corresponding to an increased use of buses in the area. Pollutant trends are also being continuously monitored throughout all 5 boroughs. Air pollution, in general, had been decreasing in southern Manhattan between 2009 and 2019. However, it is still estimated to cause at least 2000 deaths in the area annually, as well as 1400 hospital admissions for lung and heart conditions and about 4000 emergency department admissions for asthma.¹ With fewer vehicles, it is possible that the air pollution could further decrease and benefit individuals in the area.

Early results have been more mixed. Early results from spring of 2025 showed particulate matter 2.5 (PM_2.5) levels similar to those in the spring of 2023 within the congestion pricing zone. Levels of PM_2.5 were also similar outside of the congestion pricing zone, and levels of nitrogen dioxide in spring 2025 were also similar to the levels in 2023.

However, said Titus, other analyses have been more positive, with a study published in 2025 estimating that average daily maximum PM concentrations were reduced 22% in the congestion pricing zone in the first 6 months of the policy being in place.² Another factor to consider, said Titus, is the distributional impacts that could happen across the city should diversion routes be implemented across all 5 boroughs. Especially in areas with a high burden of pediatric asthma, such as the Bronx, this could end up being detrimental to areas outside of the congestion pricing zone.

“Looking forward, our team is focused on evaluating the impact of the policy on health outcomes,” said Titus. She and her team are currently conducting an evaluation on the effects of the policy in New York using administrative data. “Our goal is to evaluate the impacts of the policy on short- and medium-term respiratory and cardiovascular outcomes, examine longer-term changes in air pollutants as well as the potential mediating role of air quality on health outcomes, and evaluate the policy’s impact on health equity in the New York City region.”

Overall, she said, evidence on the impact of the policy is inconsistent, which should prompt more study into the effects in the future to get a better picture of these impacts, including evaluating the time of day. “Longer-term monitoring of air quality and health outcomes will be essential to understanding the policy’s impact on environmental health equity and can help inform the design of future road pricing interventions in the US,” Titus concluded.

Returns on London Clean Air Initiative Have Been Predominantly Positive

Helen E. Wood, PhD, a research fellow in mixed methods in the Center for Primary Care at Queen Mary University of London, shifted the conversation abroad as she spoke about an initiative to make London a low-emission zone following data in 2008 that showed that parts of the city had dangerous levels of air pollution. The phased introduction, starting in 2008 and 2012, primarily targeted large diesel-powered vehicles and became progressively more strict as the years went on. Unlike the New York congestion pricing, this initiative was primarily done to increase the health of the people of London, said Wood.

Nitrogen dioxide has previously been associated with the stunting of lung growth in children, with children exposed to 35 µm/m³ experiencing 5.5% lost lung volume and those with annual exposure of 55 µm/m³ experiencing 8.7% lost volume.³ These children were primarily living in the low-emission zones in London between 2009 and 2014, which indicated that the original form of the low-emission zone was not working. Because of this, London gradually introduced the low-emission zone to include all parts of London rather than just the central area.

With the new expanded low-emission zone, Wood and her team have monitored the children in the area for potential effects on their health. Although the results are yet to be published, the overall results have been positive when it comes to how children have responded to the reduction of nitrogen dioxide in the air. Previous studies have also found perceptions of cleaner air among the children of London as well as reductions in health care use.⁴ Increased physical activity outside of the house was also observed in children.

“What we can imply from that is that effectively implemented clean air zones can impact on a critical component of children’s development with the potential to prevent long-term adverse health impacts in adulthood, including premature death,” said Wood. “Cities across the world with significant traffic-related air pollution could benefit from implementing effective clean air zones.”

References

1. New York City Community Air Survey. NYC Health. Accessed May 18, 2026. https://www.nyc.gov/site/doh/data/data-sets/air-quality-nyc-community-air-survey.page
2. Fraser T, Park YG, Lu D, Tayarani M, Deng H, Gao HO. A first look into congestion pricing in the United States: PM_2.5 impacts after six months of New York City cordon pricing. NPJ Clean Air. 2025;1:39. doi:10.1038/s44407-025-00037-2
3. Mudway IS, Dundas I, Wood HE, et al. Impact of London’s low emission zone on air quality and children’s respiratory health: a sequential annual cross-sectional study. Lancet Public Health. 2018;4(1):e28-e40. doi:10.1016/s2468-2667(18)30202-0
4. Alliott O, van Sluijs E, Dove R, et al. London’s Ultra Low Emission Zone and active travel to school: a qualitative study exploring the experiences of children, families and teachers. BMJ Open. 2025;15(3):e091929. doi:10.1136/bmjopen-2024-091929