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Health Impact Assessment

HIA is defined as a combination of

procedures,

Methods tools

by which a project may be judged as to its

potential effects on the health of a population,

and the distribution of those effects within thepopulation.

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Why HIA

An attempt to prevent the manifestations

of health impacts that may emanate from a

development project. Not Only help avoid unnecessary

hardships due to negative health

consequences, but also preventing a

health effect is certainly less costly than

treating it.

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Definition of project

type and location

Health hazard

identification

Initial Health

examination

Need

HIANo further

Action

Consult

bank

health

specialist

TOR for

HIA

Health Risk

Assessment

Health Risk

Management

Project benefit

monitoring &

evaluation

Retrieval of

project

experience

OUTPUT

Long list of hazards

Short list of hazardswith potentiallysignificant health

risks

Initial HealthExamination

Scope

Health impact

Statement

Health monitoringdata

Evaluation report

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Screening

The purpose of this first step in the HIA

process is to screen the potential project

for the need to conduct an HIA.

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Scoping

To list the potential health impacts that mayaccrue from a proposed development

project.

The HIA Assessor should begin by listingthe project activities.

The project activities are usually classified

into 4 phases, namely site preparation phase,

project construction phase,

project operational phase

project abandonment phase. (If needed)

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Activity & Potential Health

Impact

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Description of Existing Public

HealthS

tatus Zone of Impact 5-10 km from the radius

of area.

Environmentally related disease cases

should include respiratory, cardiovascular,

waterborne, vectorborne, zoonotic

diseases, and skin diseases, especiallythose due to atopy.

Community Health Survey

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Community Survey

The survey tool would be a health

questionnaire. Assessments that should be

included in the health questionnaire are

Respondents background information

Household demographic information (age

structure)

Sanitation facilities (toilet, solid waste disposaland drinking water source)

Household members morbidity profile of

environment-related diseases

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Health Risk Assessment

Prior to 1980s assumed that pollutants

had a threshold level, below which they

were harmless

Increasing contradictory evidence,

especially with carcinogens

Initial approach was to demand zero levels

Came to understand that zero not possible

Led to development of field of

environmental risk assessment

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Definitions

Risk -- the probability of injury, disease or

death under specific circumstance (EPA)

Health a state of complete physical,mental and social well-being, not merely

the absence of disease or infirmity (WHO)

Hazard the agent or means by which an

adverse effect can occur in a particular

situation

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Definitions

Risk perception what people believe

poses a risk or hazard

Risk assessment quantifying the riskassociated with a hazard

Risk management evaluating whether

real or perceived risks are acceptable, and

if not, addressing them

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Risk Perspectives

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Risk Perspectives

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Risk Perspectives

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Health Risk Assessment

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1.Hazard Identification

First indication that a hazard exists.

Conventionally thought of as toxicological

evidence. Can be more broadly viewed as any

initiator

contaminant levels -- releases health concerns -- public outcry

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2-A Dose-Response

Assessment Also termed toxicity assessment.

Commonly presented as dose-response

curve

Generally produced in animal studies

Assumes response of the population follows

Gaussian statistics (normal distribution)

Capable of detecting risks ~1%

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2-A.Dose-Response Assessment

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Carcinogens

EPA uses linear model risk decreases

with dose but always some risk no matter

how small the dose

Calculates a potency factor orslope factor

(SF) risk per unit dose, e.g. kgday/mg

EPA maintains a data base of slope or

potency factors

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Potency Factor (Lifetime Risk)

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Integrated Risk Information System (EPA)

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Group A - Human carcinogen. This group is used only when there is sufficient evidence from

epidemiologic studies to support a causal association between exposure to the agents and

cancer.

Group B - Probable human carcinogen. This group includes agents for which the weight of

evidence of human carcinogenicity based on epidemiologic studies is "limited" and also includes

agents for which the weight of evidence of carcinogenicity based on animal studies is "sufficient."The group is divided into two subgroups.

Group B1 is reserved for agents for which there is limited evidence of carcinogenicity from

epidemiologic studies.

Group B2 is used for Agents for which there is "sufficient: evidence from animal studies and

for which there is "inadequate evidence" or "no data" from epidemiologic studies. Group C -

Possible human carcinogen. This group is used for agents with limited evidence of

carcinogenicity in animals in the absence of human data. Group D - Not classifiables as to human carcinogenicity. This group is generally used for

agents with inadequate human and animal evidence of carcinogenicity or for which no data are

available.

Group E - Evidence of non-carcinogenicity for humans.This group is used for agents that

show no evidence for carcinogenicity in at least two adequate animal tests in different species or

in both adequate epidemiologic and animal studies.

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2-B Exposure Assessment: Calculation of

Chemical Intake

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2-B Exposure Assessment

1. Identify significant pathways

2. Determine concentrations in

environmental media that are contacted3. Assign exposure factors

4. Calculate chemical intake OR Chronic

Daily Intake (CDI)

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Identification of Significant Exposure

Pathways

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Example Human Exposure Factors

Male Female

Lifespan (yr) 70 78

Body weight (kg) 70 60Residential exposure period (hr/d, d/yr) 24, 365 24, 365

Occupational exposure period (hr/d, d/yr) 8, 250 8, 250

Food intake (wet g/day) 1500 1500

Water intake (mL/day) 2000 2000

Air intake (m3/day) 20 20

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Chronic Daily Intake-CDI

(kg)tbody weightheis

(L/day)rateingestiontheis

(mg/L)in waterchemicalofionconcentrattheis

1

1

11

B

B

W

R

C

where

W

RCCDI !

Exampl : I sti f ri i at r

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3.0 Risk Characterization

Last step in the risk assessment process

Integrates first three steps

hazard identification

toxicity assessment exposure assessment

determines probability of an adverse impact to

individuals or to a defined population

provides the basis for risk communication to

stakeholders, determination of risk

acceptability, and evaluation of risk

management strategies

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3.0 Characterizing Risk for

Carcinogens Incremental Lifetime cancer Risk =

Chronic Daily Intake (mg/kg-day) v slope

factor Example Aldrin

slope factor = 17 (mg/kg/day)-1

suppose CDI = 0.002 mg/kg-day Risk = (17)(0.002) = 0.034

= one in 29

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3.0 Characterizing Risk for

Carcinogens Example - What dose would give a risk of

one in a million?

CDI = Risk/slope factor

= 10-6/17 (mg/kg/day)-1

= 6 x 10-8

mg/kg/day

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Non-carcinogens

EPA approach is to calculate a reference

dose, RfD

Estimates the dose at which noappreciable risk is expected

Obtained by dividing the no observed

adverse effects level (NOAEL) by several

safety factors

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Hazard Index For Non

CarcinogensHazard Index = Sum of Hazard quotients

Hazard quotient = Average daily dose (mg/kg.day)/RfD

Hazard Index>1 , significant toxicity,

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Oral RfDs

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4.0 Risk Management

Technological Solutions

elimination

treatment

isolation

Behavioral Solutions

exposure avoidance

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Mitigation Measures/Emergency

Response Plan

Health specific measures will have to be proposed for occupationaldiseases like noise-induced hearing loss and work accidents.

As mentioned earlier, even with mitigation measures properly in place,

something may still run amiss. An example would be an unexpected

breakdown of the air pollution control equipment resulting in excessive

release of air pollutants into the atmosphere. This calls for an

emergency reaction to minimize the magnitude and severity of thehealth impacts. To assure that this will indeed happen, the Project

Initiator needs to properly draft out an emergency response plan. The

emergency response plan should have the following features :

A detailed information on potential health hazards, health effects and

their control (e.g. a material safety data sheet or MSDS). A plan to engage emergency stakeholders like the Department of

Environment, Ministry of Health, District Office, local Village

Development and Security Committee and others.

A plan to engage security and emergency authorities like the private

security firm, police, fire and rescue, District Hospital, District HealthOffice and others