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Health Impact Assessment Toolkit

Health impact assessment (HIA) bring together scientific data, health expertise, and public input to identify the potential—and often overlooked—health effects of proposed new laws, regulations, projects, and programs. HIA is commonly defined as a combination of procedures, methods, and tools by which a policy, program, or project may be judged as to its potential effects on the health of a population, and the distribution of those effects within the population. HIA can provide a structured process to determine a policy or project's impact on health, bring mmediate and long-term health benefits, and ensure policy and project dollars are used efficiently

Environmental Public Health Tracking Network

This toolkit uses the data from the Environmental Public Health Tracking Network to complete a HIA. The Environmental Public Health Tracking Network makes data available from 25 states and one city. These local networks may also display data beyond what is included on the CDC website on their own local websites. Useful sites for data for HIA:

The Environmental Public Health Tracking Network is funded by the Centers for Disease Control as part of the National Tracking Network.

Phase by Phase Guide for Conducting Health Impact Assessments


The Screening phase determines whether an HIA is feasible, timely, and would add value to the decision-making process. The following elements should be evaluated during the Screening phase:

  • Assess the potential for the proposed decision to result in substantial health effects. To determine whether health outcomes will change, establish baseline data about the conditions which may be impacted by the decision, which can be obtained from the tracking network.
  • Assess the potential for unequally distributed impact. For instance, using the tracking data can determine the rates at which persons in each age group have gone to the emergency department due to asthma. This will show if different age groups or races/ethnicities are disproportionately affected.
  • Assessing the availability of sufficient resources to conduct the HIA is also part of the screening process. This includes determining if the data needed to predict health impacts exists, if it is available, and if it is available at the proper scale. Many data are only available at the county level, but in some cases, ZIP code level data is available. The scale varies by indicator, so be sure to check particular the state and the scale available to ensure that necessary data are accessible, or that some other way of getting to that data is designed into the methodology.


Scoping determines what health impacts are going to be studied, which populations will be included in the study and the methods that will be used to conduct an HIA.
  • Determine how the decision or project can impact health. Pathway diagrams, which illustrate the impacts of the decision to short-, medium- and long-term health, are useful in identifying health effects and benefits. Tracking data can be used to assess these effects by providing baseline information about health status in a community or by predicting the effects and benefits from a policy, plan, or project. See examples on the CDC's webpage of how tracking data can be used in three different domains of health impact assessment, pathway diagrams for climate and health, and transportation and land use.
  • Identify the research questions, data sources, and analytic methods that will be used. The Tracking Network can be a source of data. Using the Tracking Network data to look at community health status before beginning the HIA is useful. Looking at specific underlying causes of death and health indicators that fall outside the "normal" range can help identify health impacts that might not have come up in the literature review. Because the tracking data is organized geospatially, the researcher can look at the "heat maps" created to see which areas have disproportionate impacts and underlying conditions which might make them more vulnerable to certain stressors.


Tracking Network data may be used to evaluate the health effects and benefits of a plan, project, program, or policy by:
  • Assessing baseline health conditions
  • Identifying and characterizing vulnerable populations, health disparities, and health inequities
  • Evaluating the direction and magnitude of potential health effects due to changes in exposure or actions to protect health
  • Assessment also includes projections of health impacts to evaluate the direction and magnitude of potential health effects due to changes in exposure or actions to protect health
  • Tracking data may be used in quantitative or qualitative assessments to make informed projections based on trends over time
For example, HIA practitioners and communities may want to know more about asthma in a particular area. The Tracking Network can provide data about asthma hospitalizations and emergency department visits at state and county levels to establish a baseline health estimate and provide information on the region of interest. State and local tracking programs also may have asthma data at enhanced levels of geography, such as ZIP code or census tract.


Recommendations are a way to suggest action that can enhance positive health effects and mitigate potential negative health effects related to the proposed plan, project, and/or policy. Tracking data can be used to demonstrate the establish baseline data which can be used in modeling the impacts of recommendations.

For instance, if an HIA identifies that a transportation project will impact the instance of respiratory disease, tracking data can be used to establish the baseline number of persons with asthma or cardio-pulmonary disease and that data can be used in models to predict the number of persons who would be affected if different alternatives are implemented like planting trees.

Monitoring and Evaluation

The final two phases determine future health impacts resulting from policy changes and assess the HIA process, results and lessons learned. Because the Network data is updated on an ongoing basis, the data is especially useful for monitoring and evaluating actions and decisions over time. Use Tracking data to evaluate progress pre-and post-implementation of the HIA decision or action.

Case Studies

These organizations used tracking data in their HIA, primarily in the scoping phase of the studies.

Florida HIA on Extreme Flooding in Escambia County

This HIA that was conducted by the Florida Department of Health's Environmental Public Health Tracking Program in partnership with the University of West Florida and the Florida Department of Health in Escambia County.

The team used the Health Impact Assessment (HIA) Framework to examine adverse health outcomes that may be related to an extreme flooding event in Pensacola, Florida (Escambia County) during April 30—May 3, 2014. Infrastructure impacts from this extreme event included destroyed bridges and roads, and the failure of many sewage lift stations. To determine if there were associated increases in injury, illness, and death, data on reportable diseases, hospitalizations, emergency department (ED) visits, and deaths that occurred during the impact period were compared to a control period in 2008.

The results of this comparison were mixed, with some Escambia County ZIP Codes showing increased hospitalizations and ED visits, and some ZIP Codes showing a decrease. However, county-wide, there were increases in the proportion of both injury and respiratory-related hospitalizations and ED visits during the impact period. The report also looked at infrastructure impacts and their influence on health including flooding of lift stations and surface water contamination.
Recommendations of the HIA include developing guidance for cleanup activities and a suggestion to raise the electric panels on lift stations above the flood elevation, in order to keep them operational during extreme rainfall events.

Assessing the Health Impacts and Benefits of Regional Climate Action Plan Strategies in Western Massachusetts

This HIA represents a collaborative effort by the Massachusetts Department of Public Health (DPH), the Pioneer Valley Planning Commission (PVPC), and the municipalities of Springfield and Williamsburg.

The climate action strategies are based on the regional Pioneer Valley Climate Action and Clean Energy Plan (PV Climate Action Plan) completed by the PVPC in 2013. The aim of that plan was to promote a greater understanding of the causes and consequences of climate change in PVPC's service region, which includes Springfield and Williamsburg, and to identify a set of actions that local governments and other partners could consider to mitigate and adapt to climate effects.

Data from the Environmental Public Health Tracking Network used include baseline data assembled during the scoping phase such as demographics of the target area and prevalence of diseases including pediatric asthma, lung, and bronchial cancer. Tracking data was also used to inform the identification of vulnerable populations.

Recommendations of this study include the establishing of an emergency plan to fuel regional cooling centers in case of power failure, community-scale mitigation strategies like green infrastructure, and incentives to drive energy efficiency in government buildings.

Gateway Gold Line Bus Rapid Transit: A Closer Look at Health and Land Use

This HIA examined the impacts of Minnesota's first rapid bus transit line with a dedicated traffic lane the Washington County, Minnesota.

The team was made up of staff from the Washington County Department of Public Works, the Washington County Public Health and Environment, and Saint Paul—Ramsey County Public Health. The study looked at connectivity, housing, jobs, and safety along the corridor. They used tracking data to support their baseline assessment of demographics and health conditions.

This is a comprehensive HIA and its recommendations are wide-ranging. Examples include: changing the zoning code to support land use densities that promote transit; strategies that support economic development in the corridor and to make housing more affordable.

Connecting Health to Transportation

Review the PDF report from the HIA with the Minnesota Department of Health (MDH) partnering with the Minnesota Department of Transportation (DOT) in 2015 to ensure that health was being considered in the 2017 revision of the Statewide Multimodal Transportation Plan (SMTP).

The SMTP is the highest-level transportation plan in the state. The MDH and DOT performed a HIA to identify how proposed changes in the SMTP could impact health and offer recommendations that better support health. This HIA used tracking data in the scoping phase in the baseline health assessment to identify trends in demographics and to demonstrate inequities.

Other Data Resources

  • Transportation and Health Tool, CDC and U.S. Department of Transportation | Webpage