Health impact assessment and health risk assessment: Common methods and future challenges

1. Health impact assessment and health risk assessment: Common methods and future challenges Jonathan I. Levy, Sc.D. Professor and Associate Chair, Department of Environmental Health Boston University School of Public Health SRA-New England seminar series April 3, 2013

2. Statement of task • An NRC/IOM committee will develop a framework, terminology, and guidance for conducting health impact assessment (HIA) of proposed policies, programs, and projects (for example, transportation, land use, housing, agriculture) at federal, state, tribal, and local levels, including the private sector. The committee will assess the value and potential value of such assessments; the impediments and countervailing factors that have limited the practice of HIA to date; the circumstances and criteria for conducting them; the concepts, tools, and information required; and the types, structure, and content of HIAs. Based on these considerations, the committee will develop a systematic, conceptual framework and approach for improving the assessment of health impacts in the United States.

3. What is HIA? • “HIA is a systematic process that uses an array of data sources and analytic methods and considers input from stakeholders to determine the potential effects of a proposed policy, plan, program, or project on the health of a population and the distribution of those effects within the population. HIA provides recommendations on monitoring and managing those effects.” (NRC, 2011)

4. NRC, 2011

11. Key differences from risk assessment (NRC, 2011) • Risk assessment focuses on: • Individual chemicals, not numerous factors influencing health across various policies, programs, projects, and plans • Adverse health effects rather than beneficial and adverse effects • Quantitative outputs • Characterizing impacts more than informing specific interventions or decisions • Risk assessment omits stakeholder and community engagement

12. But… • EPA 2003: Cumulative risk assessment: An analysis, characterization, and possible quantification of the combined risks to health or the environment from multiple agents or stressors • EPA 1999: Cumulative impact assessment: The cumulative impacts of an action can be viewed as the total effects on a resource, ecosystem, or human community of that action and all other activities affecting that resource no matter what entity (federal, non-federal, or private) is taking the actions

13. But… • Sexton and Linder (2010): Cumulative risk assessment: • involves evaluation of collective health effects of multiple stressors [as opposed to individual effects of a single stressor]; • broadens the spectrum of environmental agents being appraised to include psychological (e.g., residential crowding) and sociological (e.g., racial discrimination) stressors [not just chemicals]; • focuses on population-based or location-based assessments of real-world cumulative exposures experienced by actual people • provides for the possibility of a semi-quantitative or qualitative analysis/result

14. But… NRC, 2009

15. Key differences from risk assessment (NRC, 2011) • Risk assessment focuses on : • Individual chemicals, not numerous factors influencing health across various policies, programs, projects, and plans • Adverse health effects rather than beneficial and adverse effects • Quantitative outputs • Characterizing impacts more than informing specific interventions or decisions • Risk assessment omits stakeholder and community engagement

16. What truly differs? • A matter of degree • Amount of quantitative vs. qualitative • Extent of stakeholder participation • Focus on impacts vs. intervention/mitigation • Breadth vs. depth • Current practice vs. proposed approaches • Risk assessment strives to be more holistic and cumulative but often is still narrowly focused • HIA strives to be more quantitative and decision-driven but is often still descriptive and informational • Can a blended approach give greater insight?

17. Case example (MAPC/BUSPH/HSPH) • January 2012: MBTA announces proposed rate increases and service cuts to meet projected $161M budget deficit • Scenario 1: Fares increase by 43%, service reductions affect between 34–48 million trips each year. • Scenario 2: Fares increase by 35%, service reductions would affect between 53-64 million trips each year • Analysis requested by March 2012 to be timely for fare decision: • What are the health implications of these proposed policies? • How does the economic impact compare with the cost savings?

19. Wasted time/wasted fuel • Straight economic analysis without direct health component (other than broad-based health-wealth argument) • Determined mode shift from transit to driving, resulting changes in average vehicle speeds and time commuting • Additional time driving x value of time (individual and commercial) • Fuel economy as function of speed

20. Air pollution • Traffic volume inputs linked to MOBILE6.2 to estimate emissions of primary PM2.5, SO2, NOx • Source-receptor matrix used to link emissions estimates to county-resolution PM2.5 concentration outputs • Epidemiological evidence and population data used to calculate mortality and morbidity impacts • Value of statistical life used to monetize

21. Physical activity • Literature values: • 8.3 minutes additional walking for those using public transit vs. driving • Relative risk of obesity vs. time spent walking (analysis of National Household Travel Survey data) • WHO HEAT model to estimate mortality and economic impact associated with decreased walking

22. Accidents • National statistics show rate of fatal injury per person-trip 23 times lower for bus vs. car, rate of non-fatal injury per person-trip 5 times lower • Baseline traffic fatality rate per VMT taken from NHTSA estimates for MA • Crash costs derived from AAA study (property damage, lost earnings, lost production, medical costs, emergency services, travel delay, rehab, workplace costs, administrative, legal, pain, quality of life): $0.26 per VMT

23. Other dimensions • Greenhouse gas emissions: Increased CO2 emissions from motor vehicle use linked to social cost of carbon value • Access to healthcare: Number of individuals estimated to lack cars who currently have MBTA access to healthcare facilities but would no longer, based on combination of ArcGIS buffer mapping and census data on car availability (Not monetized) • Noise: Look-up tables from Transportation Noise Model, estimation of additional people exposed to 60 dB (Not monetized)

25. Lessons learned • MBTA HIA had 2 key dimensions that attracted public and policymaker attention • Raising awareness of links between policy and health that were previously not considered (HIA) • Providing quantitative insight (even if simplified) to compare the impact of a policy in relation to its cost (risk assessment/benefit-cost analysis) • http://www.wcvb.com/Study-MBTA-Rail-Cuts-Could-Be-Harmful-To-Health/-/9849586/12198090/-/14aqsmm/-/index.html

26. Promising press (Dec 2012) • Most effective, efficient quantitative analysis. The folks at the Boston Metropolitan Area Planning Council, in their work with the Harvard and Boston University Schools of Public Health, broke the record for the shortest full HIA report with their HIA of the MBTA’s proposed service cuts and fare increases for the T. Twenty pages including references! It is remarkable how they do this while still including a solid, compelling quantitative analysis of the health and economic effects of the public transit proposal. - Human Impact Partners

27. Conclusions • Broad scope of HIA coupled with analytical methods typical to risk assessment can lead to valuable insights for public policy • Screening-level risk assessment highly informative for many HIAs • Practitioners in both fields need to recognize increasing commonalities and find ways to combine efforts • HIA session at SRA? • Risk assessment session at HIA meetings?