Recommendations for research
The guideline committee has prioritised the following gaps in the evidence as recommendations for research.
What factors influence how vegetation and street trees affect urban air quality?
There is limited evidence on how vegetation and trees influence urban air quality and health outcomes. Information is needed because they are often used to address air pollution or for other purposes.
Research is needed on a range of factors including:
impact of different species of vegetation and tree types
impact of trees depending on where they are sited and how they are maintained
impacts across the course of a year
impact on health inequalities
other potential health benefits.
What methods are effective and cost effective at promoting a shift to zero- and low-emission modes of travel, including active travel?
Achieving a shift to zero- and low-emission modes of travel (including active travel) is key to reducing air pollution. We also need to identify approaches that encourage more efficient, less polluting driving behaviour.
Studies based on behaviour change theories are needed to identify the most effective and cost effective approaches and messages for different groups and in different settings. Useful outcomes include: travel mode and driver behaviour.
How do different elements of a clean air zone interact to improve air quality and what is the overall effect on people's health?
At publication of this guideline, clean air zones were being introduced. These zones are likely to vary across the country and it is important to use this opportunity to identify which elements are most effective and cost effective at reducing air pollution and supporting a shift to zero- and low-emission travel. Studies are needed to evaluate:
exposure to air pollution
acute and chronic health outcomes
impact on health inequalities.
Research is also needed to look at travel behaviour in relation to different groups, to inform public awareness and social marketing approaches.
How can information about driving style gathered from telematics devices and other technologies (such as apps or in-car global positioning systems) be used to reduce individual fuel consumption and vehicle emissions?
Evidence suggests that information and training can help drivers change their driving style.
Research is needed to evaluate how telematics devices can be most effectively used with different groups to influence driving style and so, in turn, reduce emissions and improve air quality. Specific gaps in current research include the impact on individual drivers and those driving as part of a fleet including costs, health and other benefits, and value for money.
What is the effectiveness and cost effectiveness of different methods of awareness raising about air pollution (including air pollution alerts) on people's behaviour and on acute and chronic health outcomes?
Activities to raise awareness of air pollution, including air pollution alerts (using traditional, social media and other methods) are becoming increasingly popular as a way of warning of the potential risk from episodes of poor air quality. But little is known about whether these alerts help encourage people to change their behaviour. Research on the absolute and relative effect of different approaches could be used to develop effective and cost effective systems.
Research is needed on the impact of, for example, air pollution alerts on:
different groups (such as those vulnerable to air pollution and the general population)
behaviours related to the production of pollution (such as changes in mode of transport)
acute and chronic health.
Studies are also needed on:
the risk of adverse effects (such as making people worry unnecessarily, or increasing the level of motor vehicle travel after an alert)
the ability of health services to respond to concerns raised by issuing alerts.
How does altering a person's mode of transport and route affect their personal exposure to air pollution?
Mode of transport (such as walking, cycling, using public transport or driving) influences personal exposure to air pollution. Overall, 'active' travel (such as walking or cycling) reduces emissions of air pollutants. But it could potentially increase someone's personal exposure, depending on the route they take. Research is needed to clarify the health impact of making such changes, including on health-related quality of life.