125—13019

WASH Reprint: Field Report No. 436

Environmental Health Assessment:An Integrated Methodology for Rating

Environmental Health Problems

LIB ~A R YlNiF~Nr~TK~~IArPr~—ER~NCECINT~BFOR OOMMUN[TY VVATER SLI~PL’~&N~

NITATI(G~thb~1993

Eugene BrantlyRobert Hetes

Barry LevyClydette PowellLinda Whiteford

Prepared jointly by the. WASH Projecian&the. ERLIECH Projectfor th~1Office ~f F~eaIth,Bure~ufo~~e~earphEand C4evelopment

U~.Agency for Intemati~)aLD~vêJogmp~tunder WASH T~k~Jô.~3’15~d

I ~RlTE~.I-tAssi9rünent..No.HSS-133lR

~ T.I ~O,uj U~-~ ~ ~

i~il /.1019LO: •~

I~~IJ

EnvIronmental Health ProjectContract No. HRN-5994-C-0O-3036-OO, Project No 936-5994

Is sponsored by the Bureau for Global Programs, Field Support and ResearchOffice of Health and Nutrition

U S Agency for International DevelopmentWashIngton, DC 20523

ENVIRONMENTAL HEALTH PROJECT

WASH and EHP

With the launching of the United Nations International Drinking WaterSupply and Sanitation Decade in 1979, the United States Agency forInternational Development (USAID) decided to augment and streamline itstechnical assistance capability in water and sanitation and, in 1980, fundedthe Water and Sanitation for Health Project (WASH). The fundingmechanism was a multiyear, multimillion-dollar contract, secured throughcompetitive bidding. The first WASH contract was awarded to a consortiumof organizations headed by Camp Dresser & McKee International Inc.(CDM), an international consulting firm specializing in environmentalengineering services. Through two other bid proceedings, CDM continuedas the prime contractor through 1994.

Working under the direction of USAIDs Bureau for Global Programs, FieldSupport and Research, Office of Health and Nutrition, the WASH Projectprovided technical assistance to USAID missions and bureaus, other U.S.agencies (such as the Peace Corps), host governments, and nongovernmentalorganizations. WASH technical assistance was multidisciplinary, drawingon experts in environmental health, training, finance, epidemiology,anthropology, institutional development, engineering, communityorganization, environmental management, pollution control, and otherspecialties.

At the end of December 1994, the WASH Project closed its doors. Workformerly carried out by WASH is now subsumed within the broaderEnvironmental Health Project ([HP), inaugurated in April 1994. The newproject provides technical assistance to address a wide range of healthproblems brought about by environmental pollution and the negative effectsof development. These are not restricted to the water-and-sanitation-relateddiseases of concern to WASH but include tropical diseases, respiratorydiseases caused and aggravated by ambient and indoor air pollution, and arange of worsening health problems attributable to industrial and chemicalwastes and pesticide residues.

WASH reports and publications continue to be available through theEnvironmental Health Project. Direct all requests to the EnvironmentalHealth Project, 1611 North Kent Street, Suite 300, Arlington, Virginia22209-2111, U.S.A. Telephone (703) 247-8730. Facsimile (703) 243-9004.Internet EHP@ACCESS.DIGEX.COM.

WASH Field ReportNo. 436PRITECH ReportNo. HSS-1331R

ENVIRONMENTAL HEALTH ASSESSMENT:

An Integrated Methodology for RatingEnvironmental Health Problems

Preparedjointly by the WASH Projectand the PRITECH Projectfor the Office of Health,

Bureaufor Researchand Development,U.S. Agency for InternationalDevelopment

underWASH TaskNo. 315and PRITECH AssignmentNo. HSS-1331R

by(in alphabeticalorder)

EugeneBrantlyRobertHetesBarry Levy

ClydettePowelland

Linda Whiteford

October1993

WaterandSamtation for HealthProjectContract No. 5973-Z-00-8081-0O,ProjectNo. 936-5973

is sponsoredby the Office of Health,Bureaufor Researchand DevelopmentU.S. Agencyfor InternationalDevelopment

Washington,DC 20523

Technologiesfor PrimaryHealthCare(PRITECH) ProjectContractNo. ALDIDPE-5969-Z-00-7064-00,ProjectNo. 936-5969

is supportedby the Office of Health,Bureaufor ResearchandDevelopmentU.S. Agencyfor lnternalionalDevelopment

Washington,DC 20523

This activity was jointly conductedby the WASHProjectand PRITECH (Technologiesfor PrimaryHealth Care).PRITECH Is operatedby ManagementSciencesfor Health, in cooperationwith the Academyfor EducationalDevelopment,Inc.; the DepartmentofInternational Health, School of HygieneandPublicHealth, JohnsHopkins University; the ProgramforAppropriate Technologyin Health; the CentreforDevelopmentand PopulationActivities; andCreativeAssociatesInternational.

RELATED WASH REPORTS

Environmental Health Assessment: A Case Study Conducted in the City of Quito and theCounty of Pedro Moncayo, Pichincha Province, Ecuador. Field Report No. 401. Prepared byGustavoArcia, EugeneBrantly, RobertHetes,Barry Levy, ClydettePowell,JoséSuárez,andLinda Whlteford. October1993.

Public Participation in Urban Environmental Management: A Model for PromotingCommunity-Based Environmental Management in Pert-Urban Areas. TechnicalReport No.90. Prepared by May Yacoob, EugeneP. Brantly, and Linda Whlteford. October1993.

Guidelines for Improving Wastewaterand Solid Waste Management. Technical Report No. 88.Preparedby Richard N. Andrews, William B. Lord, LaurenceJ. O’Toole, L. FernandoRequena,with assistancefrom EugeneBrantly, Philip Roark, andFredRosensweig.August1993. (Available In Englishand Spanish.)

The Unique Challenges of Improving Pert-Urban Sanitation. Technical Report No. 86.Preparedby William Hogrewe,StevenD. Joyce,andEduardoA. Perez.July 1993.

Constraints in Providing Water and Sanitation Services to the Urban Poor. TechnicalReportNo. 85. Preparedby Tova Maria Solo, EduardoPerez,and StevenJoyce.March 1993.

CONTENTS

ABOUT THE AUTHORS illACRONYMS vEXECLTIIVE SUMMARY vu

1. INTRODUCTION 1

2. COMPONENTSOF AN ENVIRONMENTAL HEALTH ASSESSMENT

2.1 Definition of EnvironmentalHealthAssessment2.2 HealthRisk Assessment

2.2.1 HazardIdentification2.2.2 ExposureAssessment2.2.3 Dose-ResponseAssessment2.2.4 Risk Characterization

2.3 HealthEffects (Outcome)Assessment2.4 CollectIon and Useof EthnographicData

2.4.1 FocusGroup Research2.4.2 In-Depth Key Informant Interviews2.4.3 SemI-StructuredObservations2.4.4 Integrationof EthnographicData2.4.5 Organizingan EthnographicInvestigation

2.5 IntegratingandRating EnvironmentalHealthRisks2.6 InterpretingResults

3. CATEGORIES OF ENVIRONMENTAL HEALTH PROBLEMS 19

191919

202020

212121

2222

3

3445678

101011111212

1417

3.1 WaterSupply3.1.1 Background3.1.2 Typesof Data

3.2 SanitationandWastewaterManagement3.2.1 Background3.2.2 Types of Data

3.3 Solid Waste3.3.1 Background3.3.2 Typesof Data

3.4 Food Hygiene3.4.1 Background

I

3.4.2 Types of Data3.5 OccupationalHealthand SafetyHazards

3.5.1 Background3.5.2 Types of Data

3.6 Traffic Hazards3.6.1 Background3.6.2 Typesof Data

3.7 Air Pollution (Outdoor andIndoor)3.7.1 Background3.7.2 Typesof Data

3.8 HazardousSubstances(Nonoccupatlonalexposures)3.8.1 Background3.8.2 Typesof Data

4. PLANNING AN ENVIRONMENTAL HEALTH ASSESSMENT 29

4.1 Staffing4.2 Schedule

5. CONCLUSIONS

REFERENCES

TABLES

1. Scoringfor Probability of Effect2. Scoringfor Severityof Effect3. Matrix Illustrating Sumof Scoresof Severity

of Effect and Probability of Effect4. SuggestedSchedulefor an EnvironmentalHealth

Assessment5. MethodologicalIssuesIn EnvironmentalHealth

Assessmentfor DevelopingCountries

31

33

1516

17

30

32

222323232525252626272727

.28

2929

II

ABOUT THE AUTHORS

Eugene Brantly, M.S., J.D., is the WASH Project technicalspecialistin EnvironmentalPolicy andManagementand directs the InternationalEnvironmentandNatural ResourcesProgramin theCenterfor InternationalDevelopment,ResearchTriangleInstitute. At WASH,Mr. Brantly is responsiblefor adaptingrisk assessmentprocedures,priority-settingprocesses,andothermethodsusedIn environmentalmanagementin theUnitedStatesfor applicationsin developingcountries.He hasworkedon projectsin theUnited States,Indonesia,Belize,and Central Asia.

Robert Hetes, M.S.P.H., Is a ResearchEnvironmental Scientist with the CenterforEnvironmentalAnalysis, ResearchTriangle Institute, where he conductsresearchin riskassessmentandrisk characterizationof environmentalpollutants.Hehasworkedin thepublicand private sectors in the United StatesIn environmental impact assessment,industrialhygiene,and hazardouswastemanagement.

Barry Levy, M.D., is a Public Health physician who has worked in environmentalandoccupationalhealthfor over 15 years,focusingfor the last6 yearson work in developingcountriesandEasternEurope.Dr. Levy hasco-edited8 books,publishedover60 articles,anddoneextensiveteaching,research,consultation,and programdirection. At the time of thiswork, Dr. Levy was Directorof the Programfor Environmentand Health at ManagementSciencesfor Health.

ClydettePowell, M.D., M.P.H., is currentlySeniorPhysicianConsultantfor TheHarvardCommunityHealthPlanandHarvardMedicalSchoolin Boston. As amedicalepidemiologist,sheconductsresearchin clinical quality managementand healthservicesdelivery. Overthelastseventeenyearsshehaslived andworkedin Asia, Africa, andLatin America/Caribbean,focusingon maternal/childhealth,epidemiology-basedplanning, urbanhealth,andqualityassurance.

LindaWhiteford,Ph.D.,M.P.H., is currentlyanAssociateProfessorofAnthropology attheUniversityof South Florida. Shehasover 15 yearsof experienceIn dealingwith internationalhealth-relatedissues,including medical anthropology,maternal/childhealth, and politicaleconomyof health.Dr. Whiteford haslived andworkedin severalcountriesin Latin Americaandthe Caribbean,induding Mexico and the Dominican Republic.

III

ACRONYMS

A.I.D. U.S. Agencyfor InternationalDevelopment(Washington)

EHA EnvironmentalHealthAssessment

BOD biological oxygendemand

PRITECH Technologiesfor PrimaryHealthCare

TSS total suspendedsolids

R&D/H Bureaufor Researchand Development,Office of Health

USAID U.S. Agencyfor InternationalDevelopment(overseasmission)

WASH Waterand Sanitationfor HealthProject

V

EXECUTIVE SUMMARY

As developingcountriesIndustrializeand their urban populations grow, they confrontanincreasingarrayof environmentallyrelatedpublic healthproblems.Theincidenceof diseasesassociatedwith Inadequatesanitation,contaminatedwatersupplies,andsolid wasteworsen,especiallyIn peil-urbansettlements;growth in Industrial employment,the useof hazardousmaterials, traffic congestion, air pollution, cigarette smoking, and other sources ofenvironmentalpollutants increasethe occurrenceof work-relatedandtraffic-relatedInjuries,respiratorydiseases,heartdisease,and cancer. As a result, policymakersneedbettertoolsfor sethngprioritiesamongtheseproblemsto targettheirresourcesin away that will produce

thegreatestpublic healthbenefits.

Internationaldonor agenciesand professionalsIn the environmentaland health sciencesrecognizetheneedto userisk assessmenttechniquesIn settingenvironmentalhealthpoliciesand priorities. Many organizationsarecurrently working to developanalyticaltools to helpdevelopingcountriesinvestigate,characterize,and prioritize environmentalhealthproblems.The Office of Health of the Bureau for Researchand Development,U.S. Agency forInternationalDevelopment,Is contributing to this effort by supportingthe developmentofmethodsfor conductingEnvironmentalHealthAssessments(EHAs). This effort hasbeenImplementedthrough two Office of Health projects: the Waterand Sanitationfor Health(WASH) Project andthe Technologiesfor Primary HealthCare(PRITECH) Project.

An EHA examinesa broad range of environmentalconditions that have adversehealthconsequencesand determineswhich of the conditions presentsthe greatestrisk to publichealth.By Identifying the mostseriousenvironmentalhealthproblemsin a particularcity orvillage, an EHA providesobjectiveInformationto helpmunicipalities,nationalgovernments,and donor agenciesIdentify new Investments,allocateexisting resources,andmakeotherdecisionsto Improveenvironmentalconditions.

The EHA methodologyIntegratesthreeapproachesto investigating environmentalhealthproblems: healthrisk assessment,healtheffects(outcome)assessment,andtheethnographicInvestigationof health-relatedbehavior. It Is amulti-disciplinaryapproach,usingspecialistsinepidemiology,anthropology,andhealth-relatedbehavior,in additiontospecialistsin exposureassessmentand risk assessment.An EHA examinesthe potential health consequencesofenvironmentalconditions In eight categories:

• potable watersupply

• sanitationand wastewater

• solid waste

• food hygiene

vu

U occupationalhealth

• air pollution (indoor and ambient)

• toxic and hazardousmaterials

• traffic and householdInjuries.

This report describesthe componentsof the El-IA methodology,including anapproachtoratingthe relativesignificanceof environmentalhealthproblems,anddescribesthetypes andsourcesof dataneededto conductan El-IA. The report alsosuggestsa typicalscheduleforconductingan El-IA, describesthe limitations of the methodology,and Identifies the mostImportantaspectsof themethodologythat requirefurtherdevelopment.

TheEHA methodologydescnbedin thisdocumentwasfield-testedin Ecuadorin June1992.Resultsfrom the field test are reported in a companiondocument,Environmental HealthAssessment:A Case Study Conductedin the City of Quito and the County of PedroMoncayp.PichinchaProvince.Ecuador.WASH FieldReportNo. 401; PRITECHReportNo.HSS-133IR;October1993.

viii

1

INTRODUCTION

Developingcountriesthroughoutthe world areexperiencingrapidurbanpopulationgrowthand gradualindustrialization. Thesetrendsgreatly Influence the public healthproblemsthatdeveloping countries confront. The “pre-transition” infectious diseasesassociatedwithinadequatesanitation,contaminatedwatersupplies,poor housing, and overcrowdedlivingconditionscontinueto compromisethe healthof millions of people,especiallyIn pen-urbansettlements.At thesametime, IncreasesIn industrialemployment,useof hazardousmaterials,traffic congestion,air pollution, andcigarettesmoking,amongotherchanges,are increasingthe occurrenceof “post-transition” diseases,suchaswork-relatedandtraffic-relatedinjuries,respiratorydisease,heartdisease,and cancer(Jamison,1991).

Becauseof thesetrends,local andnationalgovernmentsin developingcountriesfacehealthproblemsof Increasingcomplexity that competewith other priorities centralto achievingsustainableeconomicdevelopment.Developingcountry officials needto know how to setprioritiesandmakesoundpolicy decisionsin thehealthand environmentalsectors.Thisneedhasbeenrecognizedby Internationaldonor agenciesandprofessionalsIn the environmentalandhealthsciences.Many organizationsareworking todevelopanalyticaltoolsto investigate,characterize, andprioritize public healthproblems.

A.I.D’s Office of Health of the Bureau for Researchand Development (R&D/H) isparticipatingin this researcheffort by developingproceduresfor conductingEnvironmentalHealthAssessments(El-lAs). This work wasimplementedundertwo contractsmanagedbythe Office of Health: the Water and Sanitation for Health (WASH) Project and theTechnologiesfor Primary Health Care (PRITECH) Project. WASH and PRITECH jointlydevelopedthis methodologyand cooperatedIn everyaspectof the work.

The Environmental HealthAssessmentmethodologydescribedin this documentwas field-testedandrefinedby a joint WASH-PRITECHteamin Ecuadorin June1992. The resultsofthefield trial arereportedin a companiondocument,EnvironmentalHealthAssessment:ACaseStudy Conductedin the City of Quito andthe County of PedroMoncayp.PichinchaProvince. Ecuador.WASH FieldReport No.401;PRITECH Report No.HSS-1331R;October1993.

1

2

COMPONENTS OF AN ENVIRONMENTAL HEALTH ASSESSMENT

2.1 DefinItion of Environmental Health Assessment

An EHA, as defined and applied in this task, examinesa broad range of environmentalconditions that have adversehealth consequencesand seeksto determinewhich of theconditions presentsthe greatestrisk to public health. By identifying the most seriousenvironmentalhealth problemsin a particular city or village, an El-IA provides objectiveinformation to help municipalities,national governments,anddonor agenciesidentify newinvestments, allocate existing resources, and make other decisions that will improveenvironmentalconditionsthataffectpublic health.An El-IA differs in two Importantwaysfromahealthrisk assessmentasit hasbeenappliedin theUnitedStatesandin developingcountries(e.g., USAID, 1990).

First, anEl-IA integratesthefollowing threeapproachesto investigatingpublic healthproblems:

• Healthrisk assessment,asdevelopedandpracticedunderthesponsorshipof theU.S.Environmental ProtectionAgency, for the study of environmentallyrelatedhealthproblems(USEPA, 1987 and 1993);

• Healtheffects(outcome)assessment,asdevelopedandpracticedby epidemiologists(ATSDR, 1992);

• Ethnographic Investigationof health-related behavior, asdevelopedandpracticedbymedical anthropologists (Scrimshaw and Hurtado, 1987).

An EHA usesexisting (secondary) data on environmental quality and the occurrenceofenvironmentallyrelateddiseases,aswell asoriginal (primary) ethnographic data collectedbya field study team.

Second,consistent with related programs at the World Health Organization and the WorldBank, USAID has defined “environmental health” broadly, to include public health problemsassociatedwith all of the following (USAID, 1991):

Pre-transitlon environmental health problems: Post-transitionhealthproblems:water supply air pollution (ambient and indoor)sanitationand wastewater occupational healthsolid waste toxic and hazardous materialsfood hygiene traffic and household InJUrIeSvector-borne diseases

3

Previouscomparativehealth risk assessmentshavenot addressedsucha diverseand largegroupof environmentallyrelatedhealth problems.

The EHA methodology involves three major innovations vis-a-vis a typical health riskassessment:

• EHA is amulti-disciplinaryapproach,usingspecialistsin epidemiology,anthropology,andhealth-relatedbehavior,in additionto specialistsin exposureassessmentand riskassessment.

• Risk assessmentmethodsdesignedfor use in Industrialized countries have beenmodified to take into accountthe limited quantity andsophisticationof datathataregenerallyavailablein developingcountries.

• Original ethnographic data are collected in focus group discussions,in-depthinterviews, and structuredobservationsto help the assessmentteam understandrelevantenvironmentaland health conditions and to compensatefor the lack ofreliable,quantitativedataon environmentalconditionsandthecausesof morbidity andmortality.

2.2 Health Risk Assessment

Risk assessmentis definedastheoverall procedureby which potential adversehealtheffectsof humanexposureto toxic agentsarecharacterized.TheU.S. NationalAcademyof Sciencesdefined risk assessmentto consist of four components:hazard identification, exposureassessment,dose-responseassessment,andrisk characterization(NationalResearchCouncil,1983). Information and data from a variety of sourcesare requiredfor a completeriskassessment.Eachof the four componentshasits own datademands,and thosewhich aremostcritical in risk assessmentin developingcountriesarein exposureassessmentanddose-responseassessment.

2.2.1 HazardIdentification

Hazardidentification Is a qualitativedeterminationof whetherhumanexposureto anagenthasthepotentialto produceadverseeffects.It involvesanevaluationofall availabletoxicologydata and other relevant biological and/or chemical Information for the agent underconsideration.Usually hazard identification Is conductedprior to an in-country visit andidentifiesthe initial list of environmentalconcerns.ThoseIssuesidentified during the hazardIdentification phasewould then be analyzedin detail during the in-country visit. Data foridentifyingpotentialhazardswould comefrom local representativesandanysecondarysourcesof information that might be available, such asstatisticson environmentalconditions andhealthstatusand major Illnessesand healthconcerns.HazardIdentifIcation in developingcountriesdiffers from that conductedin industrialized nations. In industrializedcountries,hazardIdentification focuseson agent-specificdata:

4

• Physico-chemicalpropertiesrelevantto exposure;

• Sources,routes,and patternsof exposure;

• Structure-activityrelationships;

• Metabolicand pharmacokineticproperties;

• Short-termin vivo and in vitro tests;

• Long-termanImalstudies;

• Humanexposurestudies;

• Humanepidemiologicalstudies.

Although studieson humansprovidethemostdirectevidenceforhazardidentification,in mostinstancesthe majority of Information available on toxic effects comesfrom animal studies.Thus,the Identification of agentshazardousto humanhealthusuallyrequiresassumingthatmammalsusedin toxicity testsarebiologically similar to humansandthat the testconditions(e.g., route of exposure,frequency, level and duration of doses) adequatelyrepresentexposureconditions for humans. In general,unlesshumantoxicity data or comparativemetabolicdataexistthatrefuteanimaltoxicity data,humanhealtheffectsareinferredfromtheresultsof animalstudies.

In developingcountries,however, hazardidentificationfocuseson moregeneralindicatorsofhealthoutcomesandenvironmentalconditionssincedataon specificenvironmentalpollutantsareusually not available.For example,the focusmaybe on evaluatingthe potentialhazardsthataretypically relatedto varioustypesofactivitiesor sources.Pre-visit hazardidentificationshould attemptto Identify the following:

• Incidence/prevalenceof environmentallyrelatedinfectiousdiseases;

• Incidenceof various cancers;

• Mortality rates(infant, disease-specific,etc.);

• Registriesof poisoningsand injuries;

• Distributionsof theabovedataby social, spatial,and/oreconomiccategories.

2.2.2 ExposureAssessment

Exposureassessmentinvolvescharacterizingthenatureandsite of populationsexposedto atoxic agent,andthe quantitativeor qualitativeestimationof the level anddurationof theirexposure.Since assessingexposuremay be difficult in developingcountries,appropriatemethodsmustbe selectedon a case-by-casebasis,dependingon the availabledataandthelevel of sophisticationrequired.Underideal conditions,exposureassessmentshould consistof four steps:

5

• Determining environmental concentrations through source and emissionscharacterization,monitoring, and/or environmentalfate, transport,anddepositionmodeling;

• Estimatingthe magnitude,duration, and frequencyof humanexposurefor relevant

subpopulationsaccordingto geographicdistribution andpopulation estimates;

• Estimatingthe dosereceived,usually expressedasMaximum Daily Dosefor acute,subchronic,or chronicexposuresto noncarcinogens,or as aLifetime AverageDailyDosefor carcinogens;

• Characterizingexposedpopulationsandindividualsandidentifying of subpopulationsat a potentially hIgher risk. The geographicdistribution and other characteristicsofInterest,such as ages,sex, and activity levels of the exposedpopulation should bedetermined.

Becausemany countriesdo not havedetailedenvironmentalmonitoringprogramsanddataon environmentalconcentrationsare not available, it is not alwayspossibleto conductathoroughexposureassessment.Even in countries with monitoringprograms,dataarenotnecessarilyaccurate,sufficiently complete, or representativeof humanexposures.In theabsenceof environmentaldata, investigatorsmustevaluatepollutant sources:definingtheirlocations, type, and emissions;and modeling the dispersion and environmentalfate ofpollutants.Suchmodelingmaybe usedto estimateenvironmentalconcentrationsandhumanexposures.In many instances,ambientconditions and pollutant sourcesmaynot be welldefined in termsof constituentpollutantsor concentrations.As a result, exposuremayneedto be assessedqualitatively by comparingexposedto non-exposedpopulations.

Exposuremay be heavily influenced by patternsof behaviorwhich may vary significantlyamongcountriesor regionsaccordingto culture, education,andclimate. When conductingan exposure assessrnent,time-activity patterns (the time people spend in differentmicroenvironmentsandtheir activItiesin thoseenvironments)mustbe evaluated.Importantpatternstoconsiderincludespatialdistributions(commuting),foodconsumption(e.g.,source,such as street vendors), time spent outdoors/indoors, and specific activities (such asswimming). Specific behaviorsmay alsosignificantly contributeto or minimize exposure:forexample,the way people handlewater,their personalhygiene,andtheir sourcefor water.

2.2.3 Dose-ResponseAssessment

Dose-responseassessmentis a quantitativeprocess.It definesthe relationshipbetweentheadministeredor receiveddoseof asubstance(exposure)andthe prevalenceof an adversehealtheffect in an exposedpopulation.It alsousesamathematicaldose-responsemodeltoestimatethe probabilityof occurrenceof theeffectbasedon humanexposuretothe substance.Althoughbiologically plausiblemodelsarehighly desirable,themechanismsof actionof manytoxic substancesandchemicalmixturesarenot well understood.In suchInstances,statisticalmodelsthatbestrepresentthe availabledataareusedto model dose-responserelationships.

6

If available,dose-responseestimatesbasedon adequatehumandataarepreferableto thosederivedfrom anImal data.In the absenceof appropriatehumanstudIes,datafrom studiesofanimal speciesthat respondmost like humansshould be used.When several studiesareavailablefor agiven agent,all bIologically andstatisticallyacceptableadequatesetsshould bepresented.TheU.S.EPARisk AssessmentGuidelines(1987)recommendplacingthegreatestemphasison datasetsfrom long-term animalstudiesshowingthe greatestsensitivity in orderto accountfor sensitivehumansubpopulations.Someanalysts,however,might stressusingdatarepresentingbiological similarity to humansoverdatathatindicatethegreatestsensitivity.

The use of animaldatato estimaterisksfrom humanexposurerequiresat leasttwo majorextrapolations:(1) Interspeclesdoseextrapolationsto adjustfor differencesbetweenhumansandlaboratoryanimalsthatmayaffect the responseto the toxic agentand (2) extrapolationof the dose-responserelationship observedat the relative high dosesused in animalexperimentsto the much lower dosesto which humansarelikely to be exposed.

Many of the hazardscommonin developingcountriesarenot conduciveto dose-responseassessment.Dose-responseassessmenthasfocusedon singlechemicaleffectsthroughtheuseof experimentalanimal studies.In developingcountries,many environmentalhazardshaveabiological componentthatmayconfuseor not be amenableto dose-responseassessment.Dose-responserelationshipshavenot beenwell definedfor biological contaminantsfrom anymedia.In manycasesof exposureto biological agents,the incidenceof diseaseis definedin

relation to exposurenot to degree of exposure. The development of immunity tobiocontaminantsmay also occur through repeatedexposures,confusing a defined dose-responserelationship,reducingthe anticipatedImpactsfrom exposure.The susceptibilityofan individual may also influence the dose-responserelationshipandmake a quantitativeestimationof Incidencedifficult. FactorsthatmayaffectsusceptibilityindudepreexistingIllness,exposureto other stressors,andnutritional status. In addition, simultaneousexposuretomultiple toxic agentsmayconfuseestimateddose-responserelationships.

2.2.4 RIsk Characterization

Characterizingrisk meansestimatingthe incidence of an adverseeffect on a population.Having assessedthe nature of the hazard, evaluated the appropriate dose-responsecoefficients,andestimatedthelevel andmagnitudeof exposure,therlskto humanhealthfroman agentcanbe estimated.Dependingon dataquality or the levelof sophisticationrequired,risk characterizationcango from highly detailedaccountsof dose-responserelationshipsandwell documentedexposurelevelsfor agiven population,to aqualitativedescriptionbasedonbestguessesaboutexposure.Under ideal circumstances,risk characterizationproducesthefollowing:

• An estimateof the probabilitiesof anadverseeffectoccurringin the averageindividualin apopulation,basedon estimatedexposureanddose-responsefactors;

• An estimateof the numberof casesof the adverseeffectthatarelikely in the exposedpopulation;

7

• A discussionof assumptionsanduncertaintiesin the risk estimate.

Risk characterizationis highly dependenton data for both exposureassessmentanddose-responseassessment.Quantitativemethodscanbe appliedwheretherearedataavailableonenvironmentalconcentrationsin variousmediaandon activity patternsandbehaviorrelatedto exposure.Likewise, dose-responsedata would be required either through the use ofexperimentalanimal data or, to a lesser degree, human epidemiological evidence. Indevelopingcountries, thesedata are often not available. As a result, therewill be somevariability amongcountries as to whetherquantitativeor qualitative risk characterizationispossible.

2.3 Health Effects (Outcome) Assessment

An investigatorcanuseseveralsourcesof secondary(alreadyexisting) information for dataon health outcomes.Morbidity andmortality datamaybe availablethroughpublic sources,such as aministry of health.Individuals within private institutions,suchasuniversities,mayalso be sourcesif they conduct researchgermaneto the subject. The investigatormayinterview thoseindividuals or simply refer to their works. In someinstances,whendataarenot In the requiredform, manualor computermanipulation of the datamaybe necessary.This is mostlikely to happenwhenthe Investigatorneedsdataon adifferentsubgroupof thepopulation (denominatordata)than in the original dataset. In someInstances,focus groupsor site visits maybe appropriatesupplementsto the investigation.

When an investigatorexaminessecondarydata, it is importantto know how thedatahavebeengathered.The following five Issuesshould be considered:

1. Havedatabeengeneratedthroughan activeor passivesurveillancesystem?A passivesurveillancesystemreceivesincoming data and, therefore,generally suffersfromsubstantialunderreportingof cases.

2. Doestheinvestigatorhavesomesenseof the timelinessof thedata?For example,aretherelagsin reporting suchthat thedatado not reflect recenttrends?

3. Do differential reportingratesexist?Do someareas,districts,or provincesreportmorecompletely than others?Are there any factors, such as cost, staffing, or vestedinterests,which causesuch circumstancesto exist?

4. Are cleardefinitions usedconsistentlyamongall reportingunits?

5. What meansof caseconfirmationexistsfor thosereportedcases?Are somecasesmisclassifiedas non-cases,or vice versa?

In assessingoutcomes,the investigatormust Incorporateinto the analysisseveralbasicprinciples regardingthe relationshipbetweencauseandeffect: consistencyof association,strengthof association,dose-responserelationships,temporalassociation(andlackoftemporal

8

ambiguity), and biologic plausibility. Such considerationswill avoid confusion betweenassociationsandatrue cause-and-effectrelationship.

Parts of the environmental health assessmentare based on a priori knowledge. Theinvestigator may conclude through previous studies or well acceptedfacts that anenvironmentalor occupationalriskleadsto aspecificoutcome.Prior researchmayshowthata particular outcomeis dearly and consistentlyassociatedwith an exposureandthat therelationship Is also biologically plausible. However, past researchhas not always beenconductedmethodically.Someoutcomeshavenotbeenfully explainedscientifically, the laycommunitymayperceivethatotheretiologiesplay amajorrole (for example,toxic dumpsorhigh-voltagepower lines), or at times competentresearchershavereacheddifferent andconflicting conclusions.Theinvestigatormustkeepan openmind, especiallywhenrelying onsecondarydata.

Anotherchallengeoccurswhenthe exposureandoutcomerelationshipis not aone-to-onerelationship.Onetypeof exposuremayleadto severaloutcomes.For example,exposuretolead may causea variety of neurologic, hematologic, and renal disorders. Variability inoutcomemaybe in part a function of the routeof entry, the chemicalform of the agent,orthe ageof the personexposed.In addition, the samehealth outcomemay haveseveraldiscretely different etiologies. For example, acute respiratory illness may be causedbyinfectiousagents,irritating chemicals,particulatessuchascottondust,or allergens.Moreover,theremaybe anexacerbationof anunderlyingdisorder,suchaschronicbronchitisor asthma.Thesedisorderscould just aseasily be environmentalor occupational.

Dose-responserelationshipsalsomust be considered.This will be especiallydifficult wherepeopleareexposedtomanydifferentagentsfor varyingdurations.The investigatormayneedto obtain recordson workers’ jobs andassociatedexposuresfrom workplacesor researchgroupsclosely affiliated with an industry or factory.

Missing datashould be addressedIn any Investigation.Identifying the reasonsfor the lack ofdatais agoodprotectionagainstmakingunfoundedconduslonsabouthealthoutcomes.It Isimportantfor the investigatorto statehis or her assumptionsabout the missing dataandpotential impacton the analysis.

Appropriate determinationof denominatorsis essentialin any dataanalysis.Correctchoiceof denominatorsallowsthe Investigatorto calculateratesandto makecomparisonsbetweenpopulationgroups.Asmentionedpreviously,secondarydatamaynot beIn theform requiredforthisassessment.Theinvestigatorshouldreferto censusdata,carefullynotingthesubgroupstherein.

Whenusing hospital-baseddata,the investigatormustconsiderthe estimatedproportion ofthe population afflicted with an Illness or adverseoutcomethatmayneverseekhealthcareor thathaslimited accessto dinics andhospitals.In addition,somebehaviorsor exposurescould leadto minor ifiness,which maynot requiremedicalattention.Therecould be a largenumberof theseminor Illnesses,but theremaybe no recordof the Impactof this eventon thepopulation.Selectionbias(which peopleseekmedicalcare)wIll affectthenumbersof health

9

outcomesrecordedat clinics and hospitals. The completenessof reporting systems,theexpertisewith which diagnosesaremade,andthe speedat which dataare enteredinto thehealthinformationsystemwill alsoaffect the outcomeassessment.

Lastly, a numberof other biasescan affect the data. Reporting bias, for example,occursbecausehealthcareprovidersreport diseasesdifferently. Someproviders may havebettersystemsfor reporting or greaterInterestin the disease;this is known as diagnostic bias.Misclassification biasIs when onediseaseis mistakenly reportedas another; for example,byssinosismaybe misdiagnosedandreportedaschronicbronchitisor asthma.Detectionbiasoccurswhenadequatemethodsfor ascertainingadiseasedo not exist;for example,casesofpesticide poisoningmaynot be detectedbecauseequipmentis not availablefor measuringcholinesteraseactivity In blood.

2.4 CollectIon and Useof Ethnographic Data

To adaptthe risk assessmentmethodologyto specificdevelopingcountries,anethnographiccomponentwas incorporated.Ethnography—thefield study of culturally specific behaviors,values,andsocialpatterns—providesamechanismto studywhatpeopledo,howtheyexplaintheiractions,andwhattheyperceiveasmeaningfulconstraintson theirbehavior.Ethnographycombinesthe useof qualitativeandquantitativedata,aswell asprimaryandsecondarydata.

The currentapplicationof ethnographictechniquesto risk assessmentrelies heavily on thecollection of primarydatathat tendsto be qualitative.While a reviewof pertinentsecondaryliterature Is necessary,the most critical applicationof ethnographicmethodologiesto riskassessmentrestson the useof the following threetechniquesusedto gatherprimary data:

• Focusgroup research;

• In-depth key informant interviews;

• Semi-structuredobservations.

2.4i Focus Group Research

Focusgroupresearchis atechniqueeffectively usedto gatherdatain a limited timeframe.Afocus groupcan be definedas acarefully planneddiscussiondesignedto obtainInformationon a specific set of topics (Krueger 1988; Aubel andMansour 1989; Eng, Naimoli, andNalmoli 1991). Suchgroupsareusually composedof sevento ten peoplewho arecarefullyselectedaccordingto specificcriteria.The groupshouldbe relativelyhomogenousto facilitaterapid cross-identificationandcommunication.

Multiple focusgroupswork bestwhenusedto build on the resultsof previousgroups(Debus,1989). Participantsshould be selectedfor their knowledgerelative to the research.Forexample,for health risk assessment,community memberswith experiencein occupationalhealthmight be brought togetherto obtainrelevantinformation.

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In order for focus group researchto be effective, the investigatormust carefully selectparticipants,uselocallyknownandrespectedassistants,designappropriateresearchquestionsand“probe” questions,chooseaneutrallocation for the groups,anduseatrainedfacilitator(Kumar 1987; ScrimshawandHurtado 1987).

Analysisof focusgroupdatacantakeseveralforms; however,regardlessof the level of detailrequired, the focus groupsshould be taperecordedand the tapesanalyzedfor linguisticthemes,behavioralcategories,perceptionsof risks, descriptionsof healthsymptoms,andfrequency.Ensuringthe carefulexchangeof informationbetweenthefacilitator (who couldbefrom outsideof theculturebeingstudied)andthe community-basedassistantsis centralto theanalysis.

2.4.2 In-Depth Key InformantInterviews

Theseinterviews areconductedto obtain information thatmay be too complexto acquireduringafocusgroup. Key informantsareindividualstheresearcherknowsandvaluesfortheiropinions and insights. They should be living In the community being studied and haveknowledgerelevanttothe Issuebeingresearched.Oftenkeyinformantshaveprovideddetailedinsight on issuesraisedthroughotherresearchtechniques.

In-depthinterviewsmaytakeseveralhours,or mayrequiremultiple visits. The informationiscarefullynotedandcross-indexedwith relatedtopics. Researchersalsocanconductin-depthInterviewsof community decision-makers,althoughthey do not servethe samefunction asinterviewswith keyinformants.Key informantshelpcross-validateothertypesof Information,andtheycanonly work effectively whenthe researcherhasestablishedahistory of trustandrespect.In-depth interviewswith decision-makers,on the other hand,are mainly to gatheropinionsor to accesssecondaryor quantitativedatacontrolledby the decision-maker’soffice(suchas censusdata).

2.4.3 SemI-StructuredObservations

First-handon-siteobservationsprovide anecessaryreliability checkon informationgatheredfrom other techniques.When people in focus groupsdescribetheir behaviorsrelatedtogarbagedisposal,for instance,theresearchershouldnotetheirdescriptionsandcheckif directobservationsvalidate Information provided through other means.Researchfocusing onenvironmentalhealth risks should Incorporateobservationsof garbagedumps, householdrefuseremoval systems,sanitation facilities, accessto drinking water or other householdpatternsfor waterretrievalandstorage.Foodhandling practices,such as food purchasing,preparation,andstorage,andfamily andhouseholdhygienepractices,suchashandwashingandwasteremoval,alsomay be observed.Observationsmight alsofocuson Informal sectoroccupations,suchas home-basedshoerepairers,ambulantvendors,and woodworkers,orformal sectoroccupations,suchas textile or metal workers.

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2.4.4 Integration of Ethnographic Data

Throughouttheproject,ethnographicdatageneratedthroughthefocusgroups,keyinformantinterviews,andsemi-structuredobservationsareintegratedinto the overall analysesthroughavariety of techniques.Thesetechniquesinclude discussinginformation in teammeetings,performingwritten analyses,rankingfocusgrouptopics,conductingon-siteobservations,andcross-editingwork with othermembersof the team.

The focus groupresearchis conductedduring the initial phasesof the field project, and theinformation generatedIs provided to the other membersof the team in informal meetingsduring the early phasesof the field study.By the secondweek in the field, all of the focusgroupsshould be conductedandthedatarecordedaccordingto the categoriesusedby theothermembersof the team(suchaswastewater,occupationalhealth,air pollution, etc.).Asa result of the information provided by the focus groups, team membersshould visitappropriatefield sites, such as homes,workplaces,andgarbagedumps. This will give allmembersof the researchteamactualon-siteexperienceandwill facilitate integrationof theethnographicdata.

Towardthe final portion of thefield study,focusgroupenvironmentalhealthrisksarerankedandthe information incorporatedinto the team’sevaluationof dataandthe developmentofan overall ranking system.Also during thisperiod, teammembersshould readeachother’swork andaddinformation whereappropriate.The result of the focus group rankingshouldthen be returned to key informant membersof the communitiesfor their feedbackandcomments.The Information is then integratedinto the final formal rankingof environmentalhealth risks, determinedby the teamasawhole.

While ethnographicdatacan be rich in information, therearesomelimitations. Selectionofthe communitiesfrom which to drawthe focusgroupparticipants,the selectioncriteriaused,thescopeandloadingof the questions,thechoiceof meetingsite,theidentitiesof community-basedassistants,andthe skill of the facilitator all influence the quality of the informationgathered.A careful researcherrecognizesthe methodologicalconstraintsand attemptstocontrol them.

2.4.5 OrganizIngan EthnographicInvestigation

Thefollowing summarizesthe activitiesthatshould beperformedbefore,during, andafterthein-field portionof an assessmentin order for the ethnographicinvestigationto be productive.

Pre-FieldActivities:

• Decide on criteriafor selectionof focus group participants

• Selectfocus group locations

• Find neutralmeetingsite

• Arrange for local community membersto assistfocus groupfacilitator

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• Developrealistictimeframeand budgetfor focus groups

• Developappropriatetopic-specificquestionsandassociatedprobeswith otherteammembers

• Designanalysisstructure

Field Activities:

• Meetandscreencandidatesfor community-basedassistants

• Train community assistants

• Review meetingsites

• Reviewselectionconstraintsfor participants

• Pretestlinguistic appropriatenessof questionsandprobes

• Pretestfor sequencingof focus group questions

• Conductfocus groups

• Conduct key Informant Interviews

• Selectcriteria for determinationof on-siteobservations

• Do on-siteobservations

• Analyze focus group and key Informant Interview data, and results of on-siteobservations

• Integrateethnographicdatainto teamdatabase

• Returnethnographic-basedranking to key informantsfor their feedback

• Incorporatefeedback

• Analyze all dataanddraft preliminary results

• Cross-editwritten draft with otherteammembers

• Write field report

• Presentreport

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Post-FieldActivities:

• Meet with projectdirectorsandotherteammembersto reviewconceptualissuesanddatalimitations

• Discussfindings

• Presentfindings

• Incorporatenew Information

• Reviseaccordingto feedback

• Producefinal report

2.5 Integrating and Rating Environmental Health Risks

Rating risks requirescomparingawide variety of healtheffectsthatdiffer in occurrenceandseverity. Health endpoints may range from an acute diseaseor fflness that Is not lifethreateningto onethatcausesdeath.In addition,theremaybeawiderangeof dataavailableforeachenvironmentalconcern.Wherehealthoutcomedataarenot available,exposuredatamay haveto be used; andwhereexposuredataarenot available,surrogatesfor exposure,such as informationon useof a hazardoussubstance,mayhaveto be used.As aresult, theconfidence and type of risk estimatesmay also vary greatly, with some risks beingcharacterizedin quantitativeterms, while othersmay be limited to qualitativedescriptions.How to compare“applesand oranges”is often a difficult task. As a result, comparativeriskassessmentis oftensubjectiveandrelieson professionalexperienceandjudgment.This appliesto assessingthe validity of dataandassessingthe certaintyof condusionsdrawnfromvariousstudiesanddatasetsas well. Data must be analyzedand integratedbefore ratingscan beprepared.

Traditional risk assessmentmethods use a qualitative matrix for dassifying risk levels,dependingon (1) the probability of occurrenceand (2) the relativeseverity of an adversehealtheffect. In general,suchmethodsusethreerisklevels (low, medium,andhigh) (Pierson,1991). The field study conductedin Ecuador (Arcia et al., 1993) used a rating systememployingfive scoringlevelsin an attemptto obtaInmoreresolutionin levelsof severityandprobability. Theserankingswereultimately combinedinto a three-tieredsummaryranking.

Thescorefor probability of effect (Table1) Is basedon the percentof the totalpopulationthatIs likely to be exposedto ahazardandeitheraqualitativeor quantitativeestimateof thoseexperiencingan adverseeffect.Forexample,for every100peoplein thecity, 75 (75percent)may be exposed to air pollution. However, only 50 of these 75 people may actuallyexperienceaneffect (i.e., 66.7percentof thoseexposed).Hence,the probability of effect is75% x 66.7% = 50% (probability of effect score = 1). When only qualitativedescriptionsareavailable,the descriptiveterms“very low” to “very high” canbe used.

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Table I

Scoring for Probability of Effect

Probability of Effect

(probability of exposure x

probability of effect

among those exposed)

Score

0-.1O (Very Low) 5

.11-.20(Low) 4

.21-.30 (Medium) 3

.31-.40 (High) 2

.41-1.00 (Very High) 1

The scorefor severityof effect (Table 2) reflects the severityof health effects that, in theinvestigator’sjudgement, are most likely to occur, based on prior laboratory,clinical, orepiderniologicalstudies.Forexample,It Is knownthatexposureto certaintypesof air pollutionmayleadto seriousacuterespiratorydisorders.TheseacutedisordersmayrangeIn severityfrom reducedability to exerciseto increasedIncidenceof bronchitis. Air pollution may alsoresult in respiratorydysfunction,whereinaperson’srespiratorycapacitymaybe significantlyandpermanentlyreduced,or evenmoreseriousandpermanentdiseases,suchaslungcancer.Hence,the severityscoreIs 2.

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Table 2

Scoring for Severity of Effect

Severity of Effect

(seriousness of impairment x duration)

Score

Very mild 5

Mild 4

Moderate 3

Serious 2

Death 1

Using numericalscoresmayimply agreaterdegreeof accuracyandcertaintythan is actuallypresentin the ratings. Subjectiveelementsare inevitably involved in assigninga scoreforprobabilityof effect andseverityof effect.Theexperiencedinvestigatorusesinformationdrawnfrom experiencein othercountries,the uncertaintyassociatedwith dose-responsecoefficientsfor aparticularvariable,andsubjectivejudgmentregardingthe percentageof peopleexpectedto be exposed.In somecases,the scoremaybe basedon the upperlimit percentof peoplelikely to be exposed(e.g., � 75 percent),while in othercases,it maybe basedon alowerlimit (e.g., � 50 percent).In somecases,the quantitativeestimatesareusedasaguide andadjustmentsmay be neededwhen a comparisonis madebetweenenvironmentalhealthproblems.For example,whentwo environmentalhealthconcernsareevaluatedseparately,similar scoresmay be assignedinitially. However, whenthe two arecompared,adjustmentmay be madeto one or the otherif professionaljudgmentindicatesthat the two risksmaydiffer either in severity or probability of effect.

The total scoreassignedto the environmentalrisk Is the sumof the scoresfor likelIhood ofeffectandseverityof effect. AsshownIn Table3, Itemswith highseverityandhigh probabilityof effect will be grouped on the upper left-handcorner of the matrix. Thesearethe itemsposingthe highestenvironmentalhealthrisk to the population.

After risk ratingshavebeenassignedto all of the problemsbeingevaluated,the ratingsshouldbe grouped into low-, medium-, and high-risk categories.The ratings will often dusternaturally into groupsandthe break-pointswill be moreor lessobvious.In the Ecuadorfieldstudy (Arcia et al., 1993), risk ratingsclusteredInto threegroupsandrisk categoriesweredefined as follows:

LowRisk 9tolO

ModerateRisk 7 to 8

I-lighRisk lto6

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For example,anenvironmentalcondition presentingahigh probability of effect (I.e., 1) to atoxicantthatcausesseriouspermanentdamageto an organsystem(severityscoreof 2) wouldhave a total risk scoreof 3 andbe considereda high-risk problem.Conversely,situationsascribing a low probability of effect to toxlcantsthat causeminor healtheffects would begrouped on the lower right-hand corner of the matrix and would be deemedlow-riskproblems. Scores along any diagonal, lower left to upper right, would be consideredequivalent. High-severity low-probability effects are assumedto be equivalentin overallimportanceto low-severityhigh-probabilityeffects,andthe scoringsystemreflectsthis.

Table 3

Matrix Illustrating Sum of Scores ofSeverity of Effect and Probability of Effect

Probability

2.6 Interpreting Results

Severity

Theinvestigatormustbecautiousin interpretingresultsfromthismethodologybecauseit oftenrelieson limited dataandbestestimates.As betterdatabecomeavailable,the methodologyshould be appliedagain andrankingsredone.Nevertheless,this methodologycan provideuseful Information, especiallyon the relativepriority of environmentalhealthproblems.

Investigatorsshould recognizethatthismethodologyhasanumberof limitations,including thefollowing:

• Somedatamaybe out of date;

• Somedatamaybe for a largeror smallergeographicareathanthe one targeted;

• Somedatamay havebeencollectedusing varying definItIons of ifiness, injury, ordisability;

• Sampledatamaynot be representativeof the whole targetpopulation.

IEICIII1 23 4 5 6

2 34 5 6 7

3 4 5 6 7 8

4 56 7 8 g

5 6 7 8 9 10= = = = = =

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In addition, this methodologydoes not take into considerationthe relative importanceofnonenvironmentalhealthproblemsnor the resourcesor approachesfor the preventionandcontrol of environmentalhealthproblemsassessed.

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3

CATEGORIES OF ENVIRONMENTAL HEALTH PROBLEMS

3.1 Water Supply

3.1.1 Background

Contaminateddrinking wateris oneof the mostimportantcausesof environmentallyrelateddiseasein developingcountries.Biological contamination(bacteria,parasites,viruses)causesinfectiousdiseasesincluding diarrheas,cholera,typhoid, hepatitis,andavariety of parasiticinfections.Chemicalcontaminantsmaycausekidney and liver disease,cancer,neurologicaleffects,andotherhealthproblems.Diarrhealdiseasesaretypically amongthetopthreecausesof infant andchild mortality in developingcountries.

Theextentof people’sexposureto contaminateddrinking wateris determinedby waterusagepatternsand the quality of waterused.Dataon both of thesetopicsareneededto evaluatewater’spotential impact on health.

3.1.2 Typesof Data

Dataon waterusagepatternsshould include the following:

• Proportionof populationusingpiped,vended,surface,andgroundwaterandcisterns;

• Numberof units or householdsper waterserviceconnection;

• Location of watersource(s)with respectto dwellings;

• Personalusagepatterns,induding percapitaconsumptionandthe sourcesof waterusedfor eachapplication,i.e., ingestion,cooking, bathing, householdcleaning,anddisposal of humanwaste;

• Regionalusagepatternsinduding domestic,municipal, Irrigation, and industry;

• Cost of vendedandmunicipal water.

The reliability of the water servicecan alter the type and quality of water availableandpotential exposures.Therefore,datashould be obtainedon servicereliability, including thephysicalsystem(e.g.,leakage,maintainingpositivepressure)andsusceptibilitytoupsets(e.g.,poweroutage)or naturaldisasters(e.g.,flooding). Understandingcoping behaviors,suchaschangesin usageor sourceduring seasonalvariations or systemfailure Isalsocritical, since

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theymayplay a largerole in diseaseincidenceandmaybe overlookedif only primary watersourcesareevaluated.

Water quality plays an equally important role in the incidenceof disease.Data should beobtainedfor eachsourceof water;dataon waterquality atthe tap or point of consumptionarepreferredto datacollectedat the watersource,treatmentplant, or point of distribution.Datashould be obtainedon levelsof the following:

• Microorganisms

• Pesticides

• Organicmaterial

• Metals

• Fertilizers

• Biological andchemicaloxygendemand

Wheneverpossible,dataon water usageand water quality should be disaggregatedwithrespectto location andsocioeconomiccategories.

3.2 Sanitation and Wastewater Management

3.2.1 Background

The healthrisksthat result from exposureto contaminateddrinking waterare,for the mostpart, traceableto the original sourcesof the contamination:humanandanimal feces,andchemicalwastescontainedin municipal, agricultural, and industrial wastewaterdischarges.Peoplewho do not haveadequatesanitationfacilities—safeandsecuremeansfor disposingof feces—areat risk of direct contactwith fecal wastesandexposurevia local, contaminatedwatersources(suchasshallowwells).They alsoImposeriskson othersdownstreamwhosharecommonwatersources.Eachof thesepathwaysmustbe consideredin the assessment.

3.2.2 TypesofData

Data should be obtained on the proportion of the population with and without sewerconnections.Thosewithout should be categorizedby typeof sanitationfacility: septictanks,well built and maintained latrines, and inadequatefacilities. These data should bedisaggregatedby neighborhoodor city sectionto the maximumdegreepossible.Informationon the integrity of on-site sanitationsystemsis alsoneeded,including the frequencyofservicingfor septictanksandlatrines,andthefrequencyof flooding or overflow. Furthermore,the existenceof adequatesanitationfacilities does not necessarilysolve the problem of

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exposure;people must use the facilities and practiceappropriatehygiene. Ethnographicmethods(interviews,observation)are usedto collect dataon hygienebehavior.

For thosecommunitieswith municipal sewerage,the potentialfor transientexposureto fecalwastescanbe evaluatedby reviewingdataon systemreliability, including characteristicsof thephysicalsystem(for example,capacityandleakage)andsusceptibilityto upsets(for example,poweroutages,backups,andflooding).

Where sewageis collected and conveyed to a dischargepoint, data should be obtainedconcerningthe location of dischargeswith respectto user populations, the quantity ofwastewaterdischarges,andeffluent parametersof the wastewater.Effluent parametersshouldIncludethe microbial content(fecalandtotal coliform), the biological oxygendemand(BOD),total suspendedsolids (TSS), and nitrogen and phosphoruscontent. If the collectedwastewaterIs treated,Informationshould includedataon plant operationandmaintenance,typeof treatment,andproportionof wastestreated.Exposurepathwaysresultingfromthe useof treatedwastewater(for example,for irrigation) should alsobe considered.

Industrialdischargesmayalsocontributeto environmentalhealthproblems.To evaluatetheirsignificance,inventoriesof thesedischargesshouldbe obtained,including their location (withrespectto populationor wateruse),typeof treatment,if any, quantity of the discharge,andeffluent parametersoutlinedabovefor municipalwastewaterdischarges.Industrialdischargesshould also be evaluatedfor chemicalcontaminants.In the absenceof specific industrialdischargeinformation, dataon industries(location, type, chemicalsand quantity used,andmanufacturingoutput) mayalsoindicatethe potential for harmfulexposures.

3.3 SolId Waste

3.3.1 Background

Improperly disposedor controlledsolid wastecan be an importantsourceof envIronmentalhealthproblems.Solid wastecan leadto diseasethrough direct contact(especiallyfor solidwasteworkersandscavengers),throughcontaminationof groundwateror surfacewaterwithhazardous materials, or by becoming a breeding ground for diseasevectors (such asmosquitoesandrodents).

3.3.2 Types of Data

Initially, the total quantity of waste generatedper capita should be determined. Wastecompositionshouldbe evaluatedto determinethetypesof wastesdiscarded.Different wastesvary In their potential for adverseeffectsandin how they occur. Biological wasternaterialspotentiallycontainpathogens,whichmaydirectly leadto disease,while solid Inert materials,suchas tires,canactasbreedinggroundswith Indirect Impacts.Wastesthatcontainchemicals

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with directexposurepotentialor indirectexposurepotential,by leachinginto groundwater,arealsodangerous.

Solid wastecanresultinexposureandadverseeffectsatvarioustimes.Localizedaccumulationprior to municipal collection can affect thosegeneratingthe wastes.Data on collection ofwaste,type of collection service,frequency,andreliability provIde valuableInformation ondiverse local exposurepatterns.Data on collection can also indicate areasof potentialproblems,areasof nocollection or Infrequentcollection,andthe extentof the problem.Thesedatashould be evaluatedwith on-siteobservations.

Datashouldbe collectedon the disposalof waste(bothcollectedandnoncollected),includingthe location of the disposalanddisposalpractices.Disposalpracticesshould be evaluatedintermsof the extentto which waste Is coveredandformal methodsof rodent, animal, andvectorcontrol. Data canbe obtainedfrom the agencyresponsiblefor solid wastedisposal,including maintenanceandproceduredocuments,thoughthe bestsourceof Information isdirect observation.

Recyclingandreclamationof wastesalsocan result in significantproblems.The mostobviousrelatesto thosepersonswho participatein theseactivitiessincetheir contactis greatest.Howthesewastesarerecycledshould be evaluatedto determineif the potential existsfor moredispersedexposure.Directobservationagainplaysacritical role in datacollectionsincemostcommunitiesdo not havestatisticson the numberof personsor practicesinvolved.

3.4 Food Hygiene

3.4.1 Background

Contaminatedfood is asignificantcauseof environmentalhealthproblems.Foodmaycontainbiologicalcontaminantsor chemicalresidues(suchaspesticides),which mayresultin awiderange of adversehealtheffects. To evaluatefood as a sourceof illness or disease,a widevariety of dataareneeded.

3.4.2 Typesof Data

Dataon local dietandfood consumptionpatternsareessentialandshouldinclude the typesand quantitiesof food consumedand whetherfood is grown locally, or individually, or isImported. Dataon dietary patternsmay be obtainedfrom health departments,especiallynutritionor agriculturaldepartmentoffices.Oncedietarypatternshavebeendetermined,dataonthe quality of thefood shouldbe obtained,including anyfood inspectionandtestingresults(suchasevidenceof metals,microbial,organics,pesticides).Thesedatamaybe obtainedfromhealthdepartmentmonitoringprogramsif theyexistandcanthenbeusedto estimateoverallexposuresandpotentialadversehealtheffects.

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Foodpreparation,which includescleaning,boiling, andcooking,canexaggerateor minimizeexposure.Theseactivitiesshouldbeevaluatedbecausetheycansignificantly reducethe levelsof biological or chemicalexposures.Ideally, dataon diet andfood testingwould be available;however,thisis typically not thecase,soothersourcesof datamustbe pursued.Waterplaysan Important role in food preparation,and details on water quality can provide usefulinformation in assessingthe hazardsrelatedto food. Wateruse Issuesto be investigatedinclude Irrigation, water source,quantity used,generalwater quality and availability, andbrown waterusagein food preparationor deaning.Pesticideusage(typeandquantity) alsocan revealthe type and extentof chemicalcontaminationin food. In many cases,fieldobservationsare essentialto understandingthe extentof food contaminationandresultingexposure.

3.5 Occupational Health and Safety Hazards

3.5.1 Background

Occupationalhealthandsafetyhazardsaccountfor a wide rangeof Illnessesand injuries,rangingfrom respiratorydisordersto neurologicalproblems,from acuteInjuries to cumulativetraumadisorders.In theory,all of theseconditionscanbe prevented.Developingcountriesfaceanumberof challenges,however, In recognizing,evaluating,treating, andpreventingtheseproblemsbecauseof inadequatenumbersof trainedpersonnel,inadequateinstitutionaldevelopment,hazardousindustries and wastesimported from developedcountries, andnonoccupationalendemicdiseases.

3.5.2 Typesof Data

A rapid investigationof occupationalhealthhazardswill necessitatethe useof secondarydataas the main sourceof Information. Since many developingcountries haveonly recentlybecomeawareof occupationalhealthproblems,however, theymaylack sophisticationandexperiencein datacollection andanalysis.As aresult,reportsmaynotfocuson potentialrisksin the workplace,appropriatehealth outcomes,or cause-and-effectrelationships.

Both public andprivate institutionscanprovide data on occupationalrisks. The Ministry ofHealthandthe Ministry of Laborandtheirattendantsubdivisionsusuallyhaverepositoriesofdata,andtheymaymonitoroccupationalhazards.The Ministry of HealthIs likely to focusonIncidenceof injuries or resultanthealth outcomesand Illnessesprovoked by factorsIn theworkplace,whereas,the Ministry of Labor Is likely to be interestedin numbersof workerstemporarilyor permanentlydisabled.The responsibilityfor follow-up tothesereportsmayvaryfrom onecountry to another,however. In private industry, industrial enterprises,researchinstitutes,anduniversitiesarelikely to investigatespecific issuesthatmayhavebeenbroughtto light by public or privatereports.Nevertheless,when an industry conductsoccupationalhealthstudies,somebiascanpotentially enterthe methodology.Investigationconductedby

23

an independentgroup, such asauniversity,maysuffer from lack of accessto the workplaceor lack of funding.

Public sourcesalso include the socialsecuritybureau,which registersworkers in the formalsector;however,workersin the Informal sector,who maybe at greaterrisk for occupationalhazards,are not registeredwithin the social securitybureau.The workers’ compensationbureaumaintainsrecordsof workersinjured on thejob, but Its recordsmaybe incompletefora variety of reasons.Moreover,workersarereluctantto reportjob-relatedinjuries or Illnessesin fearof losing wagesor jobs.

The natureof occupationalhealthhazardsmakesfor achallengingassessmentof risksIn theworkplace.Foremostis basicknowledgeof the processesinvolvedwithin aparticularindustry.Becauseindustrieshaveseveralstepsfrom raw productto finished product, the investigatorneedsto know whatexposuresexistateachstepandwhich workersareatrisk. Thischallengeis compoundedby delaysbetweenexposureandoutcome,suchasin cancers,whereoutcomemaynot bemanifesteduntil severalyearsafterexposure,andby dose-responseuncertainties.In addition, when sick employeesdrop out, the healthy worker effect occurs. Remainingworkersare not yet affectedby the exposureto the degreeof thoseabsent.This Is aform ofselectionbias. It is difficult to trackcohortsof exposedworkersoverseveralyearsbecauseofout-migrationpatterns.Suchtrackingcanbemadeeasierdependingon the employer’srecordkeepingandthe specific information those recordscontain, such as exact nature of job,materials (such aschemicalsor machinery)usedin the job, andchangesin processingandproceduresby the companyor industry over time.

Reportingsystemson occupationalhealthin developingcountriesarelimited becauseof lackof funding, staffing, and interestlevel. In addition, higherprioritiesdivert resourcesto otheractivities.Consequently,surveillancesystemsforoccupationalhazardsareusuallypassiveandhamperedby underreportingandlackof monitoringfor quality control of datacollection,caseconfirmation, casefollow-up, and intervention follow-back.For asystemto work, adversehealth outcomesmust be recognizedand offending agents detected. (This can lead todetectionbias.)Theremustalsobeamechanismfor reportingthe event.(Misdassificationbiasof either exposureor outcomecan occur at this stage.)Also requiredis a mechanismforanalyzing,disseminating,andusingthe dataobtained.

Whenlarge industrieshavetheir own dinics, the investigatormaybe able to extractdataonsite. However, whenworkersmustseekcareat outsideinstitutionsandclinics, only acarefuldatasearchthroughrecordswill revealwhich outcomesarejob-related.In manyinstances,itIs usefulto visit the site understudy. This allows direct observationof the typesof processesperformed,the kinds of safetymeasuresrecommended,and whetherthesemeasuresareimplemented.

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3.6 Traffic Hazards

3.6.1 Background

As acity’s populationgrows,thenumberof vehiclesandtraffic-relatedhazardsincrease.Somecities experiencingrapidurbanizationmayfind that an increasein traffic-relatedaccidentsanddeathsstrainsthe medicalcaredelivery system.

Urbanandrural areashandletraffic hazardsdifferently. Urbanareastendto documentvehicleregistrationandtraffic accidentsbetterthanrural areas.The natureof accidentsdiffers aswell.Populationandvehiculardensitymaycreatehigher risksfor urbanareas,whereasrural areasmaybe affectedby lax regulationof traffic safety.Wherepublic transportationis heavily used,althoughtheremay be lessaccidents,more peopleareinvolved per accident.Geographicconditionsalsocancauseaccidents;forexample,mountainousareasmaypresenthazardousdriving conditions.

3.6.2 Types of Data

Severalsourcesof Information about traffic hazardsmayexist,dependingon how organizedthe local policeandtransportationsafetyagenciesare.Theinvestigatorshouldbe awarethatsomeof theseagencies’databasesmayusegeographicunits of analysisthatdiffer from theonesof interest.In someinstances,investigationmayrequireeitheramanualsearchthroughpolicedocumentsor acomputer-assistedsearchfor datarelevantto the unit of analysis,suchas by city, province, or region. In addition, recordsof the Division of Motor Vehiclesandtraffic deathsrecordedin agovernmentstatisticsunit canprovide usefuldata.

Theinvestigatormustbeawarethatpoliceandmunicipal officesmaycollect andtabulatedatain formatsthat are useful to thembut not necessarilyapplicableto epidemiologicresearchpurposes.As an example,police may want traffic accidentdatacorrelatedwith geographiclocationof accidentor vehldetype.In contrast,the investigatormayfind the cross-tabulationof type of accident(pedestrianor vehicular)with typeof injury or occurrenceof deathto bemorepertinent.As anotherexample,the agedistribution of victims of traffic accidentsIsnotalwaysavailableIn annualpolicereports;it mayrequiremanualsearchesof individual policereports. This kind of information may be useful to an investigatorseekingage-specificmorbidityandmortality datathatreflecthigh-riskpopulationson theroad:the youngorelderlypedestrian,whomaylack judgmentor agility In crossingstreets,aswell as the adolescentoraging driver who maymisjudgeroadsituationsthat require quick action.

The investIgatorshouldattemptto collectthefollowing typesof datafor achosengeographicunit:

• Numbersandtypesof traffic accidents—injuriesanddeaths;

• Descriptive information (time, place,andperson)on injuries anddeaths;

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• Number of accidentsinvolving vehicles(collisions);

• Numberof accidentsinvolving pedestriansandvehicles;

• Numberof noncollision accidents;

• Cause-specificdata (for example,drunkenness,speeding);

• Denominatordataon numbersof vehicles,drivers, andpedestrians.

If thedataareavailableandthe investigatorhasthetime, he or sheshould considera trendsassessmentof traffic hazards.It maybeinstructiveto examinethe impactof populationdensityandvehicledensityon the ratesof motor vehicle accidents.

Therearesomechallengesto datacollectionandanalysisdueto theinherentlimitations in theInformation system.For example,derivingdenominatordatamayrequirecomputer-assistedmanipulation when repositorieshave provincial-baseddata setsandthe study researchesmunicipal-basedstatistics.As anotherexample,hospitaldischargerecordsmaycodethemaindiagnosticcategoryratherthanan underlyingcause,so it maybe hard to determinethat apatientwith a fracturedfemur was injured in a traffic accident.

Becauseannualtraffic safetyreportsmaygroupdatafor reportingpurposes,somecategoriesmaybe collapsed,hiding the natureof certainrelationships.As anexample,aggregateddatamight not indicatewhich accidentshaveled to injuries andwhich havenot; they aresimplytotalled. Accidents that do not result in either injury or deathmay not be reported, andreportingfrom multiple centersmay differ.

3.7 Air Pollution (Outdoor and Indoor)

3.7.1 Background

Outdoorandindoorairpollution causemuchsicknessandsomedeaths.Sulfurdioxide,oxidesof nitrogen,particulates,andotheroutdoorair pollutantscauseavariety of healthproblems,from respiratory tract Irritation to exacerbationof the symptoms of chronic obstructivepulmonary disease. In recent years, It has been recognized that indoor air Is oftencontaminatedwith a variety of dusts, fumes,andgases,rangingfrom carbonmonoxide toasbestos,from tobaccosmoketo formaldehyde.Theseindoor air pollutants may alsocausesignificantacuteandchronichealthproblems.

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3.7.2 Typesof Data

An assessmentof air pollution shouldconsider(a) the natureof pollutantsandthelevelsanddurationsof exposureto themand(b) the occurrenceof respiratoryailmentsIn relationto airquality (and otherfactors).

Sourcesof information about indoor air pollution are usually limited to censusdata onresidentsperhousehold(crowding),dataon homeventilation,homesize (numberof rooms),andcooking and heatingfuels usedin the home. Information on smokingcan supplementthesesources.

Sourcesof outdoor air pollution dataareprimarily the reportsgeneratedby local air qualitymonitoring stations.Thesereportsshould include locally usedstandardsfor air quality.

In the data analysis, the investigatormust considerthe following: location of monitoringstations; air sample collection (methods,volumes sampled, timing and frequency); andlaboratory analysis techniques.Location of monitoring stationsis critical to representativesampling of air quality. In some instances,Instrumentsare placedfor convenience,notscientific validity. The methodologyof air samplingIs critical. Air samplesmustbe collectedin astandardizedfashion: for specifiedvolumesanddurationsof collection, andat specifiedfrequencies.Variations overestimateor underestimatetrue values. Lastly, the laboratorymethodsusedin analysisshouldbe scrutinized.Standardsfor laboratoryproceduresmustbefollowed exactly.

It is often difficult to demonstratethe adversehealtheffectsof poor air quality. However, bothacuterespiratorydiseaseandexacerbationof chronic respiratorydiseaseIncreasewith airpollution. Thesituationis complex;theInvestigatorcanmakeprojectionsfromothersituations,but mustconsiderthe extentof smokingandunderlyingchronic respiratorydisease.A trendsassessmentwith seasonalvariationsmayhelpelucidatethis, but the Investigatorwill haveadifficult timesupportingthe hypothesisthata certainpercentageof illness is directly relatedtoair pollution over aparticularperiod of time.

3.8 Hazardous Substances(Nonoccupatlonal exposures)

3.8.1 Background

As developedcountriesare becomingmore aware of the adversehealtheffects of somechemicalsusedin industry,agriculture,andthe home,theyarestartingto studyor monitorthe useandexposureto thesechemicalsaswell as relatedhealtheffects.

Recognitionof adversehealtheffects associatedwith hazardoussubstancesand hazardouswastesmaybe delayedfor many reasons,Induding lack of healthInformation, Ignorance,reluctanceto report cases,and lack of awarenessof reporting systems.People may beunawareof the manifestationsof Illnesscausedby an exposureto ahazardoussubstance.Insome instances,the symptomsmaybe dismissedas flu or generalmalaise.Peoplemaynot

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know whereto report informationon healtheffectsapparentlydueto hazardoussubstances.Occasionally,the local mediaarethe first to learnof clustersof adverseevents.

Eventhoughthe numberof potentially hazardoussubstancesis great,the investigatormayberestrictedto studyingafewspecifichazardoussubstancesbecauseof limitedInformation.Rapidassessmentmaydictatefocusingon oneor twoimportantandprevalenthazardoussubstances,such as pesticidesandlead.

3.8.2 Types of Data

Agricultural Institutions,poisoncenters,andgovernmentdatabaseson morbidity andmortalityare sourcesof information; however, their coding systemsmay not be specific for thehazardoussubstanceof interest.

Limitations to effectivereporting include lack of recognition by patientor clinician of toxiceffect,lagtimebetweenexposureandeffect,underreporting,“healthyworker” (survival) effect,reluctanceto reportcasesfor economicreasons,and lack of accessor availability to healthcare.

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4

PLANNING AN ENVIRONMENTAL HEALTH ASSESSMENT

4.1 Staffing

The consultantteamshould include anexpertin risk assessment,an epidemiologistor otherhealthprofessionalexperiencedin the collection andanalysisof healthoutcomedata,andananthropologistto organizethe collectionof ethnographicdata.Theteamshould alsoindudeoneor morelocal consultantsto Identify andgatherdatabeforethe teamarrives,andoneormore local contactsto help establishan “in” to thosecommunitieswherethe ethnographicinvestigationwill be conducted.It maybe appropriateto includeotherexpatriateprofessionalswho haveworkedIn the locale if theycanhelpaccessdataor communicatethe resultsof thestudyto policymakersin relevantagencies.This staffingpatternassumesthat the consultantteamwill conductall aspectsof the El-IA. Longer-termefforts to conductthe assessmentincollaborationwithhostcountryprofessionalsandtherebytransfertherelevantskillswould needto include additional personnelandtime for training, collaboration,andevaluation.

4.2 Schedule

An El-IA of the scopedescribedIn this reportcan be conductedin approximatelyfour to sixmonthsfrom initial planningthroughfinal reporting (seeTable4). The timerequiredandtheextentof the analysisdependon the amountof dataavailable.Collecting original dataonenvironmentalconditions will generally improve the analysis and extend Its duration.Collaboratingwith hostcountryprofessionalstoconductacollaborativeassessmentwouldtakelonger,but will haveimportantpayoffs.More timewould alsobe requiredandmorebenefitsrealizedby increasingthe amountof effort devotedtocollectingethnographicdataandgettingcommunity organizationsinvolved In the assessment.

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Table 4

Suggested Schedule for an Environmental Health Assessment

Time StepRequired

4-6 weeks Define geographical and technical scope of analysis, prepareassessment plan, and identify team.

2 weeks Team leader and local consultants meet with local officials, sectorprofessionals, and community leaders to identify environmental healthproblems of concern. Define data collection requirements for theassessment.

6-8 weeks Local consultants identify and gather data, regularly consulting withother team members. Refine scope and conduct preliminary dataanalyses. Prepare analytical models and worksheets for problems beingidentified. Identify local assistants and make arrangements forethnographic investigation.

1 week Consultant team meets to review summaries of available data and planfield assessment.

3-4 weeks Full team conducts the assessment. Preliminary results are developedand communicated in departure debriefings.

2-4 weeks Local consultants gather supplemental data as required to fill gaps inanalysis. Review and revise in-field analyses as required, complete finalreport.

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5.

CONCLUSIONS

Healthrisk assessmenttechniqueswereoriginally developedto predictthe long-term publichealthimpact of environmentalhealthproblemswith long latencyperiods,such ascancer.Predictivemethodsare neededbecausethe impact of exposureto carcinogenscannot bemeasureddirectly. Overtime, environmentalregulatoryinstitutionsin the United Statehavemovedbeyondthe Initial useof risk assessmentfor settingIndividual standardsandarenowusingcomparativerisk assessmentasan importanttool for establishingpriorities andsethngpublicpolicy. Moreandmore,public officials, privateadvocates,andacademiciansareurgingthatrisk assessmentbe adoptedasabasicframeworkfor settingenvironmentalhealthpolicy.

A.I.D. Is exploring the potential for using comparativerisk assessmenttechniquesto helpdevelopingcountrygovernmentssetprioritiesin theirenvironmentalhealthprograms.A.I.D.hassponsoredtwo risk assessmentstudIesto date: thefirst In Bangkok,Thailand,conductedIn 1990andsponsoredby theOffice of Housing, incollaborationwith theU.S.EnvironmentalProtectionAgency;thesecondIn Quito, Ecuador,conductedin 1992by the Office of Health.

Usingriskassessmenttechniquesin developingcountriespresentsseveralchallengesthathavenot beenconfrontedto the samedegreein applicationsIn the United States. The mostImportantof thesearesummarizedin Table5. A.I.D.’s risk assessmentstudiesIn BangkokandQuito haveinvolved first attemptsto deal with some of thesechallenges.This report hasdescribedthe approachesusedin the EHA in Quito to evaluateinfectious diseasesandinjuries,aswell ascancer;touseinterviews,focusgroups,andobservationsasacriticalsourceof informationforaugmentingthe minImalquantitativedataavailableon environmentalqualityandexposure;andto dealwith the limitations in dataaccessibility.Otherchallengeswill beaddressedin future efforts, particularly the needto transferrisk assessmentskills to hostcountry institutions, as well as to involve community groups and nongovernmentalorganizationsin the conduct, interpretation,anduse of risk assessments.Thesechallengesdefinethe contextfor A.I.D.’s continuing effort to developrisk assessmentmethodsthatareappropriatefor use in developingcountries.

Theauthorsof thisreportbelievethatthe EHA methodologyholdsmuchpromise.It hasbeendevelopedwith the specific intent of adaptingthe rationale and approachof health riskassessmentto developingcountries.It hasbeentestedin an urbanandarural setting,whereit provedhelpful in Identifying andprioritizing environmentalhealthproblems(Arda et al.,1993). It should now be applied in other developingcountries to assistthose countriesInassessingandprioritizing their environmentalhealthproblems.

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Table 5

Methodological Issues in Environmental Health Assessment for Developing Countries

ISSUE RESPONSE { APPLICATION

Scope of assessment includesinfectious diseases, for which thereare no dose-response models.

• Use clinical data toestimate disease rates.

• Use ethnographic datato estimate and confirmsignificance of impact.

Bangkok &Quito

Quito only

All three types of datawill not be available:sources, exposures, andoutcomes.

• Combine riskassessment andepidemiologicmethods.

• Use ethnographictechniques also.

Bangkok &Quito

Quito only

Data are not computerizedand are not accessibleeasily. They areaggregated at inappropriategeographic levels.

• Involve localconsultants.

• Allow long period forup-front data gathering.

Bangkok &Quito

Quito only

Assumptions fordetermining exposuremay be inappropriatedue to culturaldifferences,

• Conduct specialstudies and useethnographic methodsto describe health-related behavior.

Attempted inQuito study

Assessment mustreflect localjudgments and policychoices.

• Involve localinstitutions in design,conduct, andinterpretation of study.

Future direction

Donors cannot perform allof the assessments needed.

• Develop domesticinst’I capacity forrisk assessment.

Future direction

Involving community groupsin conduct and use of astudy makes environmentalmanagement moreeffective.

• Involve communities andNGOs in design,conduct, interpretation,and use of study.

Future direction

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REFERENCES

Agency for Toxic Substancesand DiseaseRegistry. Public Health AssessmentGuidanceManual. Atlanta: US Departmentof HealthandHumanServices,Public HealthService,1992.

Arcia, G., E. Brantly, R. Hetes, B. Levy, C. Powell, J. Su~rez,and L. Whiteford.EnvironmentalHealthAssessment:A CaseStudyin the City of Quito andthe CountyofPedroMoncavo. PichinchaProvince.Ecuador.WASH Field ReportNo. 401. Mington,Va: WASH Project. 1993.

Arcia, G., G. Bustamante,andJ. Paguay.Poblaclony Medio Amblente. Quite, Ecuador:Direccion de Planificacion. I. Munidpio de Quito. 1992.

Aubel, J. andM. Mansour.“Qualitative CommunityHealthResearch:A TunisianExample.”’Health Policy and Planning4(3):244-251,1989.

Debus,M. MethodologicalReview: A Handbookfor Excellencein FocusGroup Research.Washington,D.C.: Academyfor EducationalDevelopment.1989.

Eng, E., J. Naimoli and G. Nalmoli. “Acceptability of Childhood Immunizationto TogoleseMothers:ASoclobiologicalPerspective.”HealthEducationQuarterly18(1):97-110,1991.

Jamison,D.T., and W. H. Mosely. “DiseaseControl Priorities in Developing Countries.”AmericanJournalof Public Health 81(1):15, 1991.

Krueger,R. FocusGroups: A PracticalGuideto Applied Research.SagePublications,1988.

Kumar, K. Conducting Group Interviews in Developing Countries. U.S. Agency forInternationalDevelopment:ProgramDesignandEvaluationMethodologyReportNo. 8,1987.

National ResearchCouncil. Risk Assessmentin the FederalGovernment:Managing theProcess.Washington,D.C.: NationalAcademyPress,1983.

PIerson,T.K. TheRole andMethodologyof EnvironmentalRisk Assessment;A Frameworkfor DevelopingCountries.StaffWorking Paper,Centerfor InternationalDevelopment,ResearchTriangleInstitute. ResearchTriangle Park,North Carolina, 1991.

Scrimshaw,S. and E. Hurtado. Rapid AssessmentProceduresfor Nutrition and PrimaryHealthCare.Los Angeles:UCLA Latin AmericanCenterfor Publications,1987.

U.S. Agency for International Development.Rankinq Environmental Risks In Bangkok

.

Thailand. Office of Housingand UrbanProgramsWorking Paper.1990.

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U.S. Agencyfor InternationalDevelopment.TowardsaHealthierEnvironment:A Strategyfor EnvironmentalHealth In LDCs. Office of Health. 1991.

U.S.EnvironmentalProtectionAgency.Risk AssessmentGuidelinesof 1986.Office of Healthand EnvironmentalAssessment.EPA 600-8-87/045. 1987.

U.S. Environmental ProtectionAgency. Facingthe Future: ComparingRisks and SettingPriorities. In pressfor 1993.

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I

*

The Environmental Health Project (EHP) provides technical assistance to~USAID missions and bureaus and other development organizations innine areas: tropical diseases, water and sanitation, wastewater; solidwaste, air pollution, hazardous waste, food hygiene, occupational health,and injury. It is part of the Office of Health and Nutrition’s response torequests from USAID missions and bureaus for an integrated approachto addressing environment-related health problems. In addition to EH~this effort includes an Environmental Health Requirements Contract arida PASA (Participating Agency Support Agreement) with the U.S. Centersfor Disease Control and Prevention. A wide range of expertise is madeavailable by EHP through a consortium of specialized organizations (seelist below). In addition to reports on its technical assistance, EHP pub-lishes guidelines, concept papers, lessons learned documents, and cap-sule reports on topics of vital interest to the environmental health sectorFor information on the reports available, contact EHP headquarters.

ENVIRONMENTAL HEALTH PROJECT