The study, published today in the International Journal of Behavioral Nutrition and Physical Activity, looked at how the introduction of London's Ultra-Low Emission Zone (ULEZ) impacted on the methods used by children to travel to school. Data from almost 2000 children aged between six to nine in London and in Luton were compared for a period before the introduction of ULEZ and then afterwards.
42% of the London children studied changed from car journeys to either walking or cycling after ULEZ was introduced. This contrasted with just 20% of Luton children who made the same change. The research also found that the impact of ULEZ on the switch to active methods of travel was strongest for children living more than 0.78km (half a mile) from their school.
Joint senior author Professor Chris Griffiths from Queen Mary's Wolfson Institute of Population Health said: "Establishing healthy habits early is critical to healthy adulthood and the prevention of disabling long term illness, especially obesity and the crippling diseases associated with it. The robust design of our study, with Luton as a comparator area, strongly suggests the ULEZ is driving this switch to active travel. This is evidence that Clean Air Zone intervention programmes aimed at reducing air pollution have the potential to also improve overall public health by addressing key factors that contribute to illness."
Dr Christina Xiao from the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge and first author said: "The introduction of the ULEZ was associated with positive changes in how children travelled to school, with a much larger number of children moving from inactive to active modes of transport in London than in Luton. Given children's heightened vulnerability to air pollution and the critical role of physical activity for their health and development, financial disincentives for car use could encourage healthier travel habits among this young population, even if they do not necessarily target them."
Due to the introduction of COVID-19 restrictions in late March 2020, the study was paused in 2020/2021 and results are only reported for the first year of follow-up. The study has restarted following up with the children to examine the longer-term impacts of the ULEZ.
The study was conducted in collaboration with Imperial College, University of Bedfordshire, University of Edinburgh, University of Oxford, and the University of Southern California.
