Jonathan I. Levy, Sc.D.Professor and Associate Chair, Department of

Environmental HealthBoston University School of Public Health

SRA-New England seminar seriesApril 3, 2013

Statement of taskAn 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.

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)

NRC, 2011

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 outputsCharacterizing impacts more than informing

specific interventions or decisionsRisk assessment omits stakeholder and

community engagement

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

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

• What are the relative health or environmental benefits of the proposed options?

• How are other decision-making factors (technologies, costs) affected by the proposed options?

• What is the decision, and its justification, in light of benefits, costs, and uncertainties in each?

• How should the decision be communicated?

• Is it necessary to evaluate the effectiveness of the decision?

• If so, how should this be done?

Stage 1: Planning

• For the given decision-context, what are the attributes of assessments necessary to characterize risks of existing conditions and the effects on risk of proposed options? What level of uncertainty and variability analysis is appropriate?

Stage 3: Confirmation of Utility

• Does the assessment have the attributes called for in planning?

• Does the assessment provide sufficient information to discriminate among risk management options?

• Has the assessment been satisfactorily peer reviewed?

FORMAL PROVISIONS FOR INTERNAL AND EXTERNAL STAKEHOLDER INVOLVEMENT AT ALL STAGES

• The involvement of decision-makers, technical specialists, and other stakeholders in all phases of the processes leading to decisions should in no way compromise the technical assessment of risk, which is carried out under its own standards and guidelines.

• What problem(s) are associated with existing environmental conditions?

• If existing conditions appear to pose a threat to human or environmental health, what options exist for altering those conditions?

• Under the given decision context, what risk and other technical assessments are necessary to evaluate the possible risk management options?

• Hazard Identification

What adverse health or environmental effects are associated with the agents of concern?

• Dose-Response Assessment

For each determining adverse effect, what is the relationship between dose and the probability of the occurrence of the adverse effects in the range of doses identified in the exposure assessment?

• Risk Characterization

What is the nature andmagnitude of risk associated with existing conditions?

What risk decreases (benefits) are associated with each of the options?

Are any risks increased? What are the significant uncertainties?

• Exposure Assessment

What exposures/doses are incurred by each population of interest under existing conditions?

How does each option affect existing conditions and resulting exposures/doses?

Stage 2: Risk Assessment

NO YES

PHASE I: PROBLEM FORMULATION

AND SCOPING

PHASE II: PLANNING AND CONDUCT

OF RISK ASSESSMENT

PHASE III: RISK MANAGEMENT

But…

NRC, 2009

Key differences from risk assessment (NRC, 2011)

What truly differs?A matter of degree

Amount of quantitative vs. qualitativeExtent of stakeholder participationFocus on impacts vs. intervention/mitigationBreadth vs. depth

Current practice vs. proposed approachesRisk assessment strives to be more holistic and

cumulative but often is still narrowly focusedHIA strives to be more quantitative and decision-

driven but is often still descriptive and informational

Can a blended approach give greater insight?

Case example (MAPC/BUSPH/HSPH) January 2012: MBTA announces proposed rate

increases and service cuts to meet projected $161M budget deficitScenario 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?

Wasted time/wasted fuelStraight 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 commutingAdditional time driving x value of time

(individual and commercial)Fuel economy as function of speed

Air pollutionTraffic 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

Physical activityLiterature 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

AccidentsNational 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

Other dimensionsGreenhouse 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)

Lessons learnedMBTA HIA had 2 key dimensions that attracted

public and policymaker attentionRaising 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

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

ConclusionsBroad scope of HIA coupled with analytical

methods typical to risk assessment can lead to valuable insights for public policyScreening-level risk assessment highly

informative for many HIAsPractitioners in both fields need to recognize

increasing commonalities and find ways to combine effortsHIA session at SRA?Risk assessment session at HIA meetings?