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Air pollution is a major environmental risk to health. By reducing air pollution levels, countries can reduce the burden of disease from stroke, heart disease, lung cancer, and both chronic and acute respiratory diseases, including asthma.
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Health impact assessment



    Health Impact Assessment (HIA) is a practical approach used to judge the potential health effects of a policy, programme or project on a population, particularly on vulnerable or disadvantaged groups. Recommendations are produced for decision-makers and stakeholders, with the aim of maximising the proposal's positive health effects and minimising its negative health effects. The approach can be applied in diverse economic sectors and uses quantitative, qualitative and participatory techniques.

    HIA provides a way to engage with members of the public affected by a particular proposal. It also helps decision-makers make choices about alternatives and improvements to prevent disease or injury and to actively promote health. It is based on the four interlinked values of democracy (promoting stakeholder participation), equity (considering the impact on the whole population), sustainable development and the ethical use of evidence.

    WHO supports tools and initiatives in health impact assessment to dynamically improve health and well-being across sectors.

    More on  Health impact assessment (HIA) tools and methods


    Economic sectors such as transport, agriculture and housing have profound impacts on health. For instance, transport is a major factor in traffic injuries, air pollution and noise, and healthy transport policies can help reduce these risks, as well as promoting walking and cycling. In agriculture, fertilizers and pesticides may boost crop yields, but wise use is important to protect farm workers and consumers from excessive chemical exposure.

    Health impact assessment can be a valuable tool for helping to develop policy and assisting decision-makers in these and other areas. Because HIA provides a way to engage with members of the public affected by a particular proposal, it can show that an organization or partnership wants to involve a community and is willing to respond constructively to their concerns. The views of the public can be considered alongside expert opinion and scientific data, with each source of information being valued equally within the HIA. The resulting decisions are often more easily accepted by all stakeholders because they are based on the ideals of transparency and active participation.


    Health impact assessments begin by identifying the relevant stakeholders. This usually produces a large number of relevant people and organizations. HIA is a framework to implicate stakeholders in a meaningful way, allowing their messages to be heard. The process draws on all resources in the project and wider community to help guide decision making, including developers and planners, employers and unions, local and national health workers, and those living in the community—particularly the most vulnerable members of the community and those directly impacted by the programme or project. 

    The HIA process begins with screening activities meant to quickly establish the health relevance of the policy, programme or project. It then investigates the key issues and public concerns and creates boundaries and expectations. In the appraisal phase, a rapid or in-depth assessment is completed on the health impacts of the project with a focus on those most affected. Conclusions and recommendations are then prepared on the positive and negative aspects to help guide decision making. When the project is complete or the policy is initiated, HIA begins the monitoring phase, in which the impacts are recorded and analysed to enhance the existing evidence base and better inform later developments.

    Tools for HIA include HEAT for walking and cycling a web-based tool used to estimate the health and economic impacts of increased walking and cycling.

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