Societal Risks and Responses: climate and

health in a Risk Assessment Framework

Jonathan Patz, MD, MPHUniversity of Wisconsin -

Madison

Summer Colloquium on Climate and Health

July 17-21, NCAR, Boulder

Risk is defined as the probability that an event will occur. It can also be defined as the probability that a health effect will occur after an individual has been exposed to a specified amount of a hazard. Risk assessment is the process of gathering all available information on the toxic or adverse effects of a physical, chemical or biological agent and evaluating it to determine the possible risks associated with exposure.

Elements of Risk Assessment and Risk

ManagementResearch Risk

AssessmentRisk Management

Lab & field observations

Extrapolation from Models

Exposure estimates and population susceptibility

Hazard identification

Dose-response assessment

Exposure assessment

Risk characterization

Development of regulatory options

Evaluation of interventions

Reformulation or improvements of policies

4 Steps of Risk Assessment

• Hazard identification– Does the agent cause adverse effects?

• Dose-response assessment– What is the relationship btw dose

and adverse outcomes

• Exposure assessment– What are the types of and pathways

and levels of exposure

Risk characterization

– What is the estimated probability or incidence of adverse effects? How robust is evidence? How certain is the evaluation?

Assess the Risks Here!

Dose-response

Dose

ResponseLinear

Threshold

Exposure InternalDose

Biologically Effective

Dose

EarlyBiologic

Effect

AlteredStructure/Function

ClinicalDisease

Exposure and Effect Biomarkers

Susceptibility Markers

Exposure-dose-effect continuum

CLIMATE

CHANGE

Temperature Rise 1

Sea level Rise 2

Hydrologic Extremes

Urban Heat Island Effect

Air Pollution

Vector-borne Diseases

Water-borne Diseases

Water resources & food supply

Environmental Refugees

Heat StressCardiorespiratory failure

Respiratory diseases, e.g., COPD & Asthma

MalariaDengueEncephalitisHantavirusRift Valley Fever

CholeraCyclosporaCryptosporidiosisCampylobacterLeptospirosis

MalnutritionDiarrheaToxic Red Tides

Forced MigrationOvercrowdingInfectious diseasesHuman Conflicts

1 3°C by yr. 21002 40 cm “ “IPCC estimates

HEALTH EFFECTS OF CLIMATE CHANGE

HEAT WAVE - EUROPEHEAT WAVE - EUROPE

Heat Index Summer 2003

40,000 40,000 DeathsDeaths in in just 11 daysjust 11 days

Relationship between temperature and malaria parasite development time inside mosquito (“extrinsic incubation period” or EIP). EIP shortens at higher temps, so mosquitoes infectious sooner.

USA: Combined sewer overflows (CSOs)

1.2 trillion gal. of sewage & stormwater a year1.2 trillion gal. of sewage & stormwater a year discharged during combined sewer overflows – would keep Niagara Falls roaring for 18 days CCCCeeeennnntttteeeerrrr ffffoooorrrr WWWWaaaatttteeeerrrr aaaannnndddd HHHHeeeeaaaalllltttthhhh

CWHCWHJOHNS HOPKINS UNIVERSITYJOHNS HOPKINS UNIVERSITY

Courtesy: K. Schwab

Results• 67%67% of waterborne disease outbreaks were preceded by precipitation above the 80th percentile (across a 50 yr. climate record), p < 0.001

• 51%51% of outbreaks were preceded by precipitation above the 90th percentile, p < 0.002

• Surface water-related outbreaks had strongest correlation with extreme precipitation in the month of outbreak; groundwater-related outbreaks lagged 2 months following extreme precipitation.

Curriero, Patz*, Rose, Lele, 2001.

Relative vs Attributable Risk

Health ImpactsWeather-related MortalityInfectious DiseasesAir Quality-Respiratory Illnesses

Agriculture ImpactsCrop yieldsIrrigation demands

Water Resource ImpactsChanges in water supplyWater qualityIncreased competition for water

Impacts on Coastal AreasErosion of beachesInundate coastal landsCosts to defend coastal communities

Forest ImpactsChange in forest compositionShift geographic range of forestsForest Health and Productivity

Species and Natural AreasShift in ecological zonesLoss of habitat and species

Potential Climate Change Impacts

Climate Changes

Sea Level Rise

Temperature

Precipitation

Source: EPA, Global Change Research Program

USGCRP National Assessment of the Potential

Consequences of Climate Variability and Change

• QUESTIONS:– 1) What is current status of sector or region?

– 2) What are climate sensitivities or projections of climate change for sectors or regions?

– 3) What is our capacity to adapt to climate-induced change?

– 4) What are the key knowledge gaps?

National Assessment (cont.)

– Sectors:• Agriculture• Coastal Zones• Forestry• Human Health• Water

– Regions:• 19 geographic regions & Native Americans

Five National Climate Research SectorsFive National Climate Research Sectors

Human HealthHuman HealthHuman HealthHuman Health AgricultureAgriculture

Coastal AreasCoastal AreasCoastal AreasCoastal Areas

ForestryForestry

Water ResourcesWater Resources

Mid AtlanticMid AtlanticSouthern Great PlainsSouthern Great PlainsMetropolitan East CoastMetropolitan East CoastSoutheastSoutheastGulf CoastGulf Coast

South Atlantic CoastSouth Atlantic CoastNew EnglandNew EnglandGreat LakesGreat Lakes

Northern Great PlainsNorthern Great PlainsEastern MidwestEastern MidwestAppalachiansAppalachians

Central Great PlainsCentral Great PlainsPacific NorthwestPacific NorthwestRocky Mountains and Great BasinRocky Mountains and Great BasinCaliforniaCalifornia

U.S. Global Change Research Program:U.S. Global Change Research Program:National Climate Change Assessment RegionsNational Climate Change Assessment Regions

SouthwestSouthwestNative Peoples: Covered NationallyNative Peoples: Covered Nationally

Source: USGCRPSource: USGCRP

• “An increasing body of observations gives a collective picture of a warming world and other changes in the climate system.”– Global average surface temperature has increased about 0.6oC– Temperatures have risen during the last 40 years in the lowest 8 km of the atmosphere

– Snow cover and ice extent have decreased– Global average sea level has risen 10-20 cm during the 20th century and ocean heat content has increased since the late 1950s

– Some aspects of climate have changed (e.g., precipitation, cloud cover, temperature extremes), others appear not to have changed (e.g., Antarctic sea-ice, tropical storms, tornadoes)

IPCC Third Assessment Report Conclusions

…and what about synergistic synergistic

effectseffects that can determine local vulnerability of

populations

Johns Hopkins University School of Public HealthCourse: Global Environment and Health

The Heat IslandDark surfaces such as asphalt roads or rooftops can reach temperatures 30-40°C higher than surrounding air

New Orleans

after Hurricane Katrina

1839187019932020

wetland loss in the Mississippi delta (1839 to 2020)

Barataria-Terrebonne Estuary Program

~ 9,600 people perished, widespread water- and vector-borne diseases followed, and nearly one million people were left homeless.

Areas with extensive deforestation or degraded hillsides suffered the greatest morbidity and mortality and point to the importance of vegetation cover and as a buffer to severe floods, and the long-term prevention of injuries and fatalities

DPSEEA framework of WHO

• Driving force ACTION– Population growth <-------------- Economic and social policy

– Economic activity Clean technologies• Pressure

– Resource depletion <-------------- Hazard management

– Waste release• State <------------- Environmental improvement

– Natural hazards & pollution – Depleted resources

• Exposure <------------- Education & awareness – External exposure & absorbed dose

• Effect <------------- Surveillance & treatment – Well-being– Morbidity & Mortality

Biological DiversityBiological Diversity

Climate ChangeClimate Change DesertificationDesertification

•Nutritional changes•Disease Regulation• Medicinal products• Water purification

•Extreme weather events•Heat waves &air pollution•Malnutrition•Water- & Food-borne disease• Vector-borne diseases

•Water scarcity and safety•Agro-ecosystem productivity•Food scarcity•Droughts

Health and the Health and the Rio ConventionsRio Conventions

Human health

Human health

•Climate induced Biodiversity loss

•Deforestation effects on climate

•Land degradation, deforestation• • Desertification hastened by landcover change

•Precipitation changes leading to droughtSource: WHO, 2006

The Sustainability Triangle

Social justice Equitable

distribution

Vibrant economy

Provides services

Healthy environment

Mod

ified

pre

ssur

eSu

stai

ned

serv

ices

for a

ll Distributed

consumption

Investment in sustainable technologies

Courtesy: F. Westley

Nelson Inst., UW - Madison

Problems of Problems of UnderdevelopmentUnderdevelopment

Problems of Problems of OverdevelopmentOverdevelopment

poverty hunger

environmental degradation

compromised educational and medical infrastructure

poor maternal health, infant mortality, infectious diseases

overpopulationglobal warming

Co2 emissions

industrial growth

global market for food and resourcessubsidies

international loans

food and resource export

international debt repayment

overharvesting of resources

Courtesy: F. Westley

Desertific

ation &

CBD

UN FCCC

Levels of PreventionLevels of Prevention

Primary - remove hazard or its effectSecondary - surveillance and early response

Tertiary - treatment to avert adverse outcome

SOURCE: Colin CheneySOURCE: Colin CheneyDirector | Earth Pledge Green Director | Earth Pledge Green Roofs InitiativeRoofs Initiative

GREEN ROOFSGREEN ROOFSresponds to:

•stormwater runoff stormwater runoff

•urban heat island urban heat island effecteffect

•regional warming regional warming due to global climate due to global climate changechange

““US Mayors’ Climate US Mayors’ Climate Protection Agreement” Protection Agreement” across 160 US cities to across 160 US cities to reduce greenhouse gas reduce greenhouse gas emissionsemissions

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Can Madison become the most “modern” city in Can Madison become the most “modern” city in the World?the World?

(modern….as in more bikes and biketrails (modern….as in more bikes and biketrails than cars and roads.)than cars and roads.)Madison already ranks among top 5 Madison already ranks among top 5 biking cities in USbiking cities in US

1 third of US bike retail is based just 1 third of US bike retail is based just in Madison!in Madison!

Win-win solutions ideal….. But win-win-Win-win solutions ideal….. But win-win-win even better!win even better!

1 - Personal Fitness1 - Personal Fitness

2 - Reduced Local Air 2 - Reduced Local Air PollutionPollution

3 - Reduced Greenhouse Gas 3 - Reduced Greenhouse Gas EmissionsEmissions

The “Triple-Win Biking The “Triple-Win Biking Project”Project”

http://www.ecohealth.nethttp://www.ecohealth.net

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

EcoHealth ONE Oct. 7-10, EcoHealth ONE Oct. 7-10, 2006 Madison, Wisconsin2006 Madison, Wisconsin

THEME: THEME: “Promoting Global “Promoting Global Health-Sustaining Natural Health-Sustaining Natural Resources”Resources”

THANK YOU &

Visit the website