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Health Impact Assessment

Health Impact Assessment (HIA) is 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.”[109] This tool is used to systematically identify how new projects or policies might affect public health. HIAs consider determinants of human health stemming from all of the three pillars of sustainability – social, environmental, or economic.[110] For example, HIA takes into consideration factors such as employment, education, and climate change.

The two main objectives of HIA are: (1) to predict the human health impacts of program- or project-related actions, and (2) to provide stakeholders and decision-makers with information to consider when assessing and prioritizing strategies for addressing health risk and preventing adverse health outcomes over the life of a program or project.[111] HIA is designed to address negative and positive, intended and unintended, and single and cumulative health impacts across entire populations, taking into account the fact that not all subgroups will be affected equally.[110]

Health Impact Assessment

How can Health Impact Assessment contribute to sustainability?

HIA can contribute to sustainability efforts by providing decision-makers with information that enables them to better consider trade-offs and identify synergies across the three pillars.[112]  HIA also contributes to a decision-maker’s understanding of the health issues that may influence a specific program or policy’s overall sustainability objectives.[111] If an HIA is not conducted properly decision-makers may pursue an action that has unintended environmental or economic consequences. Furthermore, maintaining and improving human health is an essential condition for enabling current and future generations to meet their social, economic, and environmental needs.[110, 112]

What are the main steps in an Health Impact Assessment?

Although HIA is a relatively new tool, its use in decision-making settings is rapidly increasing.[113] Specific methodologies for the implementation of HIA are still under development and there are currently no specific well-defined guidelines for practitioners.[112] Various strategies have been set forth by different institutions, however, and these generally include the following elements:[113]

  • Step 1—a preliminary screening evaluation is conducted to determine whether a proposed program or project may contribute to significant health effects on surrounding communities;
  • Step 2—the range and types of positive and negative impacts are scoped, and the appropriate questions to be addressed are determined; input from key stakeholders and relevant authorities are critical, so that the HIA will address the key concerns of the community, provided the analysis can be realistically undertaken;
  • Step 3—an assessment of potential health impacts is then performed to investigate and rank the possible impacts of the project or policy on the health of local communities. This step determines the spectrum and relative importance of potential impacts;
  • Step 4—based on the results of the assessment, feasible and enforceable mitigation strategies, modifications to the project or policy, or other alternatives are presented to decision-makers and publicly reported to the affected community;
  • Step 5—once the alternatives have been implemented, they are tracked to ensure that the project or policy is being implemented as designed, and to provide an early warning of any unintended impacts, as well as a structure for addressing those impacts; and,
  • Step 6—while a formal evaluation is not always a necessary step of the HIA process, evaluation can provide valuable insight into the legitimacy and accuracy of the HIA for future reference.

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What are the strengths and limits of Health Impact Assessment in a sustainability context?

HIAs consider a broad range of health factors, or determinants, and assess how proposed projects or policies might impact those determinants. As a result, HIAs take into account the environmental, social, and economic conditions that affect community health.[113] HIAs provide data and recommendations to decision-makers in order to help them develop projects and policies that will minimize or eliminate unintended adverse health effects, particularly for vulnerable or disproportionally affected subpopulations: in this way, HIAs complement environmental justice analyses (see discussion on page 36).[111, 114, 115]

HIA often involves examining correlations among data and population effects. Practitioners should be mindful that without more definitive data,  information from an HIA should be applied cautiously as one component of a broader sustainability analysis. When sufficient data are available, risk assessments may add a valuable dimension to an HIA.

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How are Health Impact Assessments used to support EPA decision-making?

Application of HIA has been expanding rapidly in recent years and is used by various governmental agencies and private organizations in the United States.[115-117] In 2010, EPA Region 9 scoped an HIA for expansion projects at the ports of Los Angeles and Long Beach, in order to better evaluate the health impacts of expected increases to the size and capacity of those ports.[118] In this case, Port expansion would be expected to result in increased ship, rail, and truck traffic carrying goods to and from the port.[119] The HIA helped decision-makers better understand how changes in air pollution emissions and concentrations resulting from the increased traffic translate into health impacts in nearby communities.

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Where to Find More Information about Health Impact Assessments

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Illustrative Approach Applying Health Impact Assessment

  • Scoping a Health Impact Assessment for the Ports of Los Angeles and Long Beach

    Source: EPA Region 9[119]
    Suite of sustainability tools: health impact assessment

    As the US economy has become increasingly more global, trade through the Ports of Los Angeles and Long Beach has grown. Both globalization and trade through the Ports are expected to increase. In order to meet future demand, the Ports plan to increase their capacity. Over the past decade, several port capacity-building projects have gone through the approval process, including the public review of Environmental Impact Statements/Environmental Impact Reports (EIS/EIR). It is expected that additional capacity-building projects will be proposed at the Ports over the coming years.

    The Ports of Los Angeles and Long Beach are making concerted efforts to address health-related concerns regarding their operations and they are leading ports across the nation in their attention to such concerns. Despite these efforts, there remain several reasons to explore the use of a HIA to address health related concerns associated with port operations, such as the continued existence of health inequities in communities impacted by port operations, the benefits that the HIA process offers the Ports, and the opportunity HIA presents to collaboratively understand project benefits and develop mitigations for adverse health impacts.

    In discussions with, and comment letters to the Ports regarding recent EISs, EPA asked the Ports to include HIA to comprehensively analyze potential health impacts and inform mitigation options. With the goals of increasing understanding of and support for the concept of conducting HIA as part of the EIS process, the EPA offered to develop a model of a HIA Scope (PDF) (111 pp, 2.2MB) with public input.

    On February 10, 2010, US EPA Region 9, with support from Human Impact Partners and an independent facilitator (both EPA contractors), convened a meeting to begin the process of identifying the need for, benefits of, and scope of work for a Ports-wide HIA.

    The Los Angeles and Long Beach Maritime Port HIA Scope

    The Los Angeles and Long Beach Maritime Port HIA Scope is intended for use as a model scope for future HIAs on proposed projects at the Ports. Once the decision to conduct a HIA on a specific project is made and project alternatives are selected for HIA analysis, the pathways, research questions, and definitions put forth in this [HIA Scope] should be refined and narrowed to reflect the most relevant and important potential impacts of the proposed project. This process should be conducted with robust public involvement from a wide variety of stakeholders.

    Specifically, this Scope contains information on the general parameters, questions, and data sources that need to be gathered to begin a HIA, including project alternatives to analyze, geographic and temporal limits of the analysis (i.e., ‘defined geographies’ and ‘defined time period’), sensitive uses and vulnerable populations to consider, and existing population and community vulnerabilities. Questions relevant for this process: What are the demographic characteristics of the populations living and/or working in the impacted areas? What is the prevalence of relevant health issues in the impacted areas?

    The Scope then contains information on each of eight health determinants: air pollution, noise, water pollution, traffic and rail, displacement, economics, neighborhood livability, and Port revenue and funding. For each of these, the Scope provides a brief review of literature linking the determinant to health, research questions for evaluating existing conditions and potential impacts (some of which may already be answered in an EIS/EIR and some of which build on data collected for an EIS/EIR), and examples of methods and potential mitigations.

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