Health Impact Assessment

Stage 1: Recognise the need to estimate the impacts of poor air quality on health, and identify data and skills required to quantify health impacts
01 Commit to conducting a Health Impact Assessment
02 Map existing policies and identify key questions
03 Develop staff capacity
04 Conduct outreach to populations and stakeholders
05 Evaluate possible tools to conduct the air pollution health risk assessment
06 Collect data
07 Start the process to quantify the health risk from exposure to ambient air
08 Make the data available
09 Develop a sustainability plan and use the data and analysis for public health messages
10 Allow informed decisions and policy tracking

Stage 1: Recognise the need to estimate the impacts of poor air quality on health, and identify data and skills required to quantify health impacts 

At this initial Stage, you understand that poor air quality poses a burden to human health, but you do not yet know the number of people exposed to air pollution or the resulting number of premature deaths and illnesses. You and your colleagues see the value in describing the burden of poor air quality on health and are familiar with the substantial monetary benefits of reducing air pollution (e.g. UNEP/CCAC, 2026) but have no prior experience in performing such an analysis, you are unfamiliar with the data needed and are unsure of how a health impact assessment (HIA) could inform a policy decision. In Stage 1 you are identifying the data and skill gaps that must be filled before you can begin quantifying effects and supporting policy choices in Stages 2-5.  

Key objectives:

  • Develop a foundational understanding of the types of policy questions that HIAs are best able to address.
  • Identify the key input data and technical expertise needed to perform this analysis.
  • Create a plan for filling the gaps in expertise and data. 

You will find below the Health Impact Assessment Guidance for Stage 1. Stage 2, Stage 3, Stage 4, and Stage 5 are also available. If you are unsure which Stage best applies to your current circumstances, take the Interactive Questionnaire to find out.

01 Commit to conducting a Health Impact Assessment

Make sure you/your department have adequate staffing, resources and authority to carry through with what is required in the Health Impact Assessment guidance (including data collection, quality assurance, and data analysis). Ensure that your management is committed to sustaining your efforts beyond your/their tenure. An overview of information on Health Impact Assessment is available in the resources below.

02 Map existing policies and identify key questions

Identify the relevant policies that need to be assessed across sectors, including household energy, waste, transport, industry, agriculture, energy and buildings, considering WHO’s One Health approach. Identify the key questions you would like to address in your Health Impact Assessment.

03 Develop staff capacity

Organize training and capacity-building for staff in governmental institutions, academics, and experts by cooperating with institutions and specialists that can provide expertise. This basic technical training could include webinars, online courses, or in-person workshops. The goal at this stage is to develop baseline information on the health impacts of air pollution to lay the foundation to conduct a health risk assessment (HRA) in the future.

04 Conduct outreach to populations and stakeholders

Ensure participatory mechanisms to discuss the different steps and scenarios that will be developed.

05 Evaluate possible tools to conduct the air pollution health risk assessment

Modelling criteria may differ among countries because of the different levels and sources of air pollution and availability of data; however, best practices follow similar principles. In several cases there is the need to adapt and apply methodologies as dictated by available data and the information needs of policymakers and stakeholders.

06 Collect data

A key priority is to collect data input for the analysis. Data to be considered first are: 1) population data, 2) air quality data and 3) health data for mortality and morbidity following International Statistical Classification of Diseases and Related Health Problems (ICD) codes. To assess policies or build scenarios (for example reaching WHO Air Quality Guidelines Interim targets) it is important to have access to air quality monitoring representative of ambient conditions across the area, in particular for residential areas. For exposure characterization, it is also important to have data from potential hotspots, for example affected by traffic or industrial activities. Initial data sources can be found in the resources below.

07 Start the process to quantify the health risk from exposure to ambient air

Analyze the data with experts. Aim to provide an idea of the current burden of disease of air pollution and conduct an economic evaluation of the different scenarios evaluated. Be specific on sectors (e.g. transport, waste, etc.) contributions and impacts. Do not hide alternative solutions or potential existing conflicts. Consider also potential co-benefits related for example to reduction in noise levels or road injuries.

08 Make the data available

It is essential to make the data available to the research community and the public by establishing a public data archive that is accessible within a reasonable period and includes all the appropriate information to understand the analysis done. Future HIA and policy tracking cannot be done without publicly accessible data.

09 Develop a sustainability plan and use the data and analysis for public health messages

Developing public messages should be done targeting different audiences. Communication experts should be involved since the first step of the health impact assessment activities and should consulted on the best use of media.

10 Allow informed decisions and policy tracking

The role of policy tracking is to enable policy-makers and stakeholders to identify potential setbacks, delays, and negative impacts of policies and develop corrective measures rapidly, increasing the chance of the policy being successful.

Curated Guidance Developed by

 

WHO_Logo_Small