Download 2 o C - Healthy India

Foundation Day Lecture 2008
“Human population health
is a very important
component of climate
change debate……..our
economy, physical
infrastructure, production
capabilities and material
growth risk are also
things that bear on
human health
-Prof A J McMichael
Prof. Anthony J McMichael
Environment, Climate and Health:
An Expanded Public Health Research
and Policy Agenda for the 21st Century
Public Health Foundation of India
March 28, 2008
A.J. McMichael
National Centre for
Epidemiology and Population Health
The Australian National University
Canberra
Human Wellbeing and Health:
Key Criterion of ‘Sustainability’
For humans, the central criterion/measure
of ‘sustainability’ is the capacity of a
society’s way of life to sustain the wellbeing
and good health of the population ….
across generations, and without detriment
to health in populations elsewhere (now
and in future).
Outline
 Environment: ‘Cinderella’ of disease causation
• Population Perspective: thinking ‘ecologically’
 Large-scale, human-induced, environmental change
• Systemic character; new concepts
 Climate change – recent science
 Health impacts
• Categories and examples of research
• Food, nutrition, health
• Infectious diseases
 Mitigation and Adaptation: research needs
 Conclusion
Population Strategy for Improving Health
Population distribution for some specified risk factor
Impact of Social Policies:
Environment
Urban Planning
Technology choices
Public health programs
Health Promotion
Etc.
No. of
persons
Main focus of
Health-Care
System
Medium-Risk Gp,
accounts for 80%
of cases
20%
Low risk
75%
Medium risk
Disease Risk 'Score’
e.g. blood pressure, relative weight
High-Risk Gp:
accounts for 20%
of cases
5%
High risk
Rise-and-Fall of ‘Urban Health Penalties’
The Developed Country experience
Health
risk/impact
(indicative)
Infectious
diseases
Urban air pollution
Road
trauma
Greenhouse gas
emissions 
climate change
Obesity
Time
1800
Industrialisation
McMichael, 2007
1900
2000
Modernisation
Future
Globalisation
Estimated Atmospheric PM10 (respirable particulates)
Concentration in World Cities (popn >100,000)
PM10
(µg/m3)
. 5-14
. 15-29
. 30-59
. 60-99
. 100-254
Cohen AJ et al. 2004
PM10 Annual Average Ambient
Concentrations in Asian Cities, 2005
160
concentrations in µg/m3
140
120
100
80
60
40
20
WHO 2005 Guideline Value for Annual Average of PM10 = 20 µg/m3
0
City
Life expectancy (years)
Life expectancy at birth, by GDP per head, 2000
Source: Deaton, 2004
GDP per head, 2000 (purchasing power parity, in $US)
Obesity, diabetes, rising fast
• Number of overweight and obese (~I billion) likely
to reach 1.5.billion by 2015
• Obese children: already 155 million worldwide
• Prevalence of (type 2) diabetes, ~120 million, may
increase three-fold by 2030
• Accounts for 7% of all deaths
• Highest prevalence rates in India, China, USA,
Indonesia, Russia, Japan, Pakistan, Brazil, Italy
International Obesity Task Force 2005
New York Herald Tribune 12 September 2005
WHO, World Heart Day, September 2005
Prevalence of overweight varies with
wealth, by State, in India
(r = 0.81, P = 0.000)
30
Percent
overweight
20
(i.e., BMI
> 25)
10
0
Poor States
0
10000
Rich States
20000
30000
40000
50000
Per capita State GDP
Econ Survey India, 1999, NFHS-2 1998-99
From M Vaz, St. John’s, IPHCR
Epidemiology since ~1850: Changes in
emphasis on different levels/units of analysis
Molecules and genes
Individuals
Sub-groups
Esp. occupational
groupings
Populations
Germ Theory
Micronutrients
1800
1850
1900
Non-Infectious Dis:
Individual-level Sustaining
risk factors
population health:
SocialUnderstanding
epi
effects of
1950
2000
systemic changes
We Are Now Living Beyond Earth’s Limits
[WWF “Living Planet Report 2006”]
Three Ecological Footprint Scenarios, to 2100
1.8
No. of 1.6
Planet
Earths 1.4
needed
to meet 1.2
human 1.0
demands
Ecological
Footprint, 1961-2003
Moderate ‘business
as usual’ (to 2050)
Slow shift in economic
and social practices
0.8
Rapid transition to
environmental sustainability
No. of
Planet 0.6
Earths
0.4
available
0.2
1961
2003
1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100
Year
Source: World Wildlife Fund, 2006
See also Wackernagel et al, PNAS, 2002
Global Environmental Changes: paths, health risks
Stratospheric
ozone depletion
Climate
change
Skin damage/cancer
Eyes (cataracts, etc.)
Immune suppression
Thermal stress: death, disease events, injury
Direct
Storms, cyclones, floods, fires
impacts
Sea-level rise: physical hazards, displacement
Land cover
(forest, etc)
Land use
Water–sheds,
systems
Urbanisation;
human settlements
Human
predation
Biodiversity
changes, &
ecosystem
disruption
Food-production
systems
Infectious
disease risks
Changes in host species,
vectors (mosquitoes, etc.)
e.g. pollination
Food yields:
nutrition
and health
Avian ‘flu,
Nipah virus,
etc.
Poverty, slum, hygiene; physical hazards;
infectious disease risks (mobility, density)
UNDP Human Development
Report, 2007/2008
‘Fighting Climate Change:
Human Solidarity in a Divided
World’
Excerpt from
UNDP Press
Release, Nov 27
Projected warming, to 2100: for six future global greenhouse
gas emissions scenarios
Intergovernmental Panel on Climate Change, 2007: Wkg Gp I
3 of the 6 emissions
scenarios
Uncertainty
range: 1
standard
deviation
Warming already in ‘pipeline’ from
recent/current GHG levels (~0.6oC)
+ 4oC
A1F1
A2
1.8 - 4.0 oC
A1B
Warming
(oC)
+ 2oC
23 models
(tested against
recent record)
1980-99
baseline
temperature
B1
A1T B2
A1F1
16-21 models
No. of
used for models
each
used
scenario
1900
2000
Year
2100
6 different GHG
emissions scenarios
More Variable Weather in Future
Intergovernmental Panel on Climate Change (2007)
“…very likely that hot extremes, heatwaves and
heavy precipitation events will continue to
become more frequent.”
UN World Meteorological Organization (2007)
“…increasing trend in extreme events observed
over the last 50 years. …. Record extremes in
many regions across the world since Jan 2007.”
Extreme rainfall event, 2006, in
Somalia/Kenya border region
Flooding, after drought,
produced cholera outbreak,
and high abundance of
mosquitoes
Ethiopia
Somalia
Kenya
Mogadishu
Nairobi
CO2 atmos concentration
Solid lines =
observed
Dashed lines =
1990s projections
Climate Change: Now
Faster than Expected
IPCC Report 4 (2007) is
already conservative/out-dated
Recent research shows
increasing rates of:
Av Surface Temp
Global GHG emissions
Surface temperature rise
- esp. polar regions
Sea-level Rise (cm/decade)
Ice melt (Arctic, Antarctic,
mountain glaciers)
Sea-level rise
Rahmstorf, Church,
et al., Science 2007
1975
1985
1995
2005
Saturation of carbon
‘sinks’ (oceans, terrestrium)
Arctic Sea Ice Meltdown: A hundred years
ahead of schedule?
IPCC Projections: Serious under-estimates?
IPCC central
projection
Satellite
observations
projection
Bjeknes Centre
for Climate
Research,
Svalbard,
Norway (2008)
Environmental/Climate Change: Health
Impacts, Responses – and Research Needs
Adaptation:
Reduce impacts
Natural
processes and
‘forcings’
Pressure on
environment
Human society:
• culture, institutions
• economic activity
• demography
c
Feedback change
Global Environmental
Changes, affecting:
• Climate
• Water
• Food yields
• Other materials
• Physical envtl. safety
• Microbial patterns
• Cultural assets
Impacts on human
society:
• livelihoods
a
• economic productivity
• social stability
• health
Feedback change
Mitigation: Reduce
pressure on environment
Based on: McMichael et al., Brit med J, 2008
b
Climate Change and Health
Five ‘Core’ Research Categories
Empirical databased studies
1.
Determine
Scenario-based health
risk projections
2. Detect
4.
baseline
impacts
climate/health 3. Estimate current
relations
CC-related burden
Past
Present
5. Adaptive
strategies
Prediction of
future risks
(modelling)
Future
Heatwave:
August 2003
Land surface temperatures, summer of 2003, vs.
summers of 2000-04. NASA satellite spectrometry
35-50,000 extra
deaths over a 2week period
Seasonal variation in daily
mortality, Delhi, 1991-94
60
Daily deaths
summer
40
20
winter
0
1991
1992
1993
1994
From: ISOTHURM Study, McMichael et al., in press
Heat-related daily mortality, Delhi,
1991-94 Generalised additive model, cubic-spline smoothing
Relative
mortality
140
120
100
Uncertainty
range: 95% CI
80
0
10
20
Daily mean temperature, oC
30
40
Delhi:
Decadal changes, 1960s-present, in key
climate variables and heat index ‘WBGT-at-work’
35.0
Temp, max
Degrees C, hPa, m/s
30.0
WBGT
25.0
Temp, average
20.0
Abs Humidity
Temp, min
x
15.0
10.0
5.0
Wind speed
0.0
1960-79
1980-89
1990-99
Decade
2000-07
From: Kjellstrom T, Lemke B,
Hales S, unpublished
Fully workable days in Delhi per year,
with future temperature increases of
Delhi, reduced
upworkable
to 7odays
C with climate
change
300
250
200 Watts (light)
Number of fully 200
workable days
150
100
500 Watts (heavy)
50
0
Av temp
2000-07
Increase in WBGT-at-work
From: Kjellstrom T, Lemke B,
Hales S, unpublished
‘Disease Burden’ attributable to Climate Change: 2000, 2030
Selected conditions in developing countries
Deaths
Total Burden
Floods
Malaria
Now (2000)
Diarrhoea
Future (2030)
Malnutrition
120 100 80
60
40
20
Deaths (thousands)
0
2
4
6
8
10
DALYs (millions)
2000
2030
McMichael et al/WHO, 2004
Estimated Regional Mortality* Attributable to
Climate Change in Year 2000
*
(relative to 1961-90
average
climate)
,
Deaths per
million
population
0-2
2-4
4-70
70-120
No data
* Deaths from malaria &
dengue fever, diarrhoea,
malnutrition, flooding and (in
OECD countries) heatwaves
Based on: McMichael et al.,
2004 (WHO Comparative
Risk Assessment 2000)
Cartogram: Emissions of greenhouse gases
Countries scaled according to cumulative emissions in billion tonnes carbon
equivalent in 2002. (Patz, Gibbs, et al, 2007)
Cartogram: Health impacts of climate change
Deaths from malaria & dengue fever,
diarrhoea, malnutrition, flooding and
(OECD countries) heatwaves
WHO regions scaled according to estimated mortality (per million people) in
the year 2000, attributable to the climate change that occurred from 1970s to
2000 (Patz, Gibbs, et al, 2007)
Two Major Risks to Health
Food and Nutrition
Decreased food yields, affordability 
malnutrition
Infectious Disease Patterns
Geographic range, seasonality and
outbreak rates
March 2008: UN World
Food Program anticipates
global hunger crisis
Threat of widespread malnutrition due to dramatic
rise in world food prices
Price increases of up to 40% in 2007
(highest on record)
WFP head, J Sheeran, describes price rise as
“due to perfect storm” …
- demand for animal feed (China, India, etc.)
- biofuels production
- climate change
- rising costs of fertiliser and fuel-energy
Global Hunger Map, 2005-06
Sources: FAO 2005; WHO
2006; UNICEF 2005
Global Hunger Index
Most
Least
No data
Not included
Drought: Recent and likely future
expansion under climate change
Percentage of world’s land area in drought
50
Severe drought (5% circa 2000)
Extreme drought (1% circa 2000)
40
% land in drought
30
20
10
0
1960
1980
2000
2020
2040
2060
2080
2100
Burke EJ, Brown SJ, Christidis N. 2006. Journal of Hydrometeorology
General Relationship of
Temperature and Photosynthesis
100%
Photosynthetic
yield
2oC 
2oC 
0%
20o C
30o C
40o C
C Field, D Lobell. Env Res Letters, 2007:
A 1oC increase reduces global cereal grain crop yields by 6-10%.
So, a rise of 2oC could cause 12-20% fall in global production.
[Note: this estimate is higher than most others.]
Expected climate change impacts
on global cereal grain production,
1990-2080 (% change)
World
-0.6
to
-0.9
Developed countries
+2.7 to
+9.0
Developing countries
-3.3
to
-7.2
Southeast Asia
South Asia
Sub-Saharan Africa
Latin America
-2.5
-18.2
-3.9
+5.2
to -7.8
to -22.1
to -7.5
to +12.5
Based on: Tubiello and Fischer 2007
Poor Countries: More vulnerable to
Climate Change impacts on food production
• Geography (hotter, less rain, more variable weather)
• High dependence on agriculture and natural
resources (forests, wetlands, fisheries)
• Limited infrastructure (e.g. 95% of agriculture in
SSAfrica is rain-fed)
• Poverty, poor access (‘entitlement’)
• Existing malnutrition, infectious disease
• Overall, lower adaptive capacity (professional,
technical, health-care system, etc.)
Pattern of Influence of Seasonal Rainfall,
Surface Water, and Crowding on Cholera
Occurrence, Madras region, 1901-40
Based on: Ruiz-Moreno et al, EcoHealth 2007;
4: 52-62. Study of 26 districts, Madras
Presidency, south-east India, 1901-1940.
Ro = ‘reproductive number’
Cholera
Risk
Ro primary
(water-borne)
transmission
water
dilution
effect
human
crowding
effect
Ro secondary
(human-to-human)
transmission
1.0
1.0
Shallow
Water Depth
Flood
Nipah Virus Disease: Outbreak in
Malaysian Pig Farmers, 1997-1999
Fruit bats (with “their”
virus: ~40% positive)
Fruit orchards
Forest clearing
Apparent combination
El Niño drying
Pig farming
Deforestation
El Niño conditions
Smoke haze
 Decline in fruit
Rain Forest,
with seasonal
fruiting – bat
Forest-fire smoke ?
diet
Virus-contaminated
fruit, bat droppings
Eaten by pigs
Infected
(sick) pigs
265 humans infected:
JE-like illness
~40% fatal
~105 deaths
Ross River Virus, Rainfall and Mosquito Density:
Queensland, 1998-2001
Rainfall,
mosquito density and RRV in Brisbane
18
900
Incidence rate of RRV
600
Incidence rate of RRV
Ross River Virus, Rainfall
and Mosquito Density:
RRV
Rainfall
Queensland
Disease
Mosquito density
Mosquito
Density
12
800
500
700
600
400
RRV
Disease
10
Mosquito
Density
8
Mosquito density/Rainfall (mm)
2
900
500
300
400
200
300
6
Rainfall
4
200
100
Rainfall
2
100
0
0
0
N
1
ov
-9
Ja 8
n9
M 9
ar
-9
M 9
ay
-9
9
Ju
l-9
Se 9
p
N -9
ov 9
N -98
J aov
n- -9
9
JMa 9 9
rn99
M -0
a
M y -9 0
a 9
Jur-0
MS l-99 0
eapy
-9-0
N 90
Jouv9
J a l-90
Sen-0 0
M p0
ar -0
NM 00 0
aoyv
-000
J
J aul- 0
0
Se n-00
M p -00 1
Na
ovr-00
MJa 0 1
any-0
M -10
a 1
J r-0
M ul-1
ay 0
Se -01 1
J up
l-0-0
1
NSep 1
ov-0
N -10
ov 1
-0
0
(mm)
/ Rainfall
Mosquito Density
Mosquito
density/Rainfall
(mm)
Rainfall (mm)
Density;
Mosquito
4
14
RRV Incidence (per 105)
6
Incidence rate of RRV (1/100,000)
16
8
700
18
12
10
800
Positive relationship between rainfall and
Rainfall
mosquito density, with
increased mosquito
density after lag ofMosquito
1-2 months.
density
14
RRV Incidence (per 105)
Incidence rate of RRV (1/100,000)
16
Year
Year
Year
Year
Tong et al, date?
Tong et al
Tong S, McMichael A, et al
Dengue’s principal vector: Aedes aegypti
Effects of Temperature Rise
on Dengue Transmission
 Faster viral incubation in mosquito
 Shorter mosquito breeding cycle
 Increased mosquito feeding frequency
 More efficient transmission of dengue
virus from mosquito to human
(WHO)
Countries/areas at risk of dengue transmission, 2007 (DengueNet,
WHO)
1990
2085
Estimated
regions at
risk of
Dengue
Fever under
climate
change:
2085 vs
1990
Probability
Hales et al.
Lancet, 2002
Zhou X-N, Yang G-J, et al. Potential Impact of Climate
Change on Schistosomiasis Transmission in China
Now
2030: + 0.9oC
“Recent data suggest that schisto2050: + 1.6oC
somiasis is re-emerging in some
settings that had previously reached the
[successful disease control] criteria of
either transmission control or
transmission interruption. …. Along with
other reasons, climate change and
ecologic transformations have been
suggested as the underlying causes.”
‘Mitigation’ and ‘Adaptation’
Mitigation (avoiding the unmanageable)
First-order task
Especially since climate change is accelerating
…. Also: assess health impacts (hopefully mostly benefits) of
mitigation strategies
Adaptation (managing the unavoidable)
Necessary transitional task
Spontaneous adaptation (need to study/understand)
Planned adaptation  near-term and long-term
health protection
Implement and evaluate adaptive strategies
Health
Promotion
linking the
individual with
the planet!
“Think Global,
Act Local”
CC and Health: Main Types of
Adaptive Strategies
Public education and awareness
Early-alert systems: heatwaves, other impending weather extremes,
infectious disease outbreaks
Community-based neighbourhood support/watch schemes
Climate-proofed housing design, and ‘cooler’ urban layout
Disaster preparedness, incl. health-system ‘surge’ capacity
Enhanced infectious disease control programs
vaccines, vector control, case detection and treatment
Improved surveillance:
Risk indicators (e.g. mosquito numbers, aeroallergen concentration)
Health outcomes (e.g. inf dis outbreaks, rural suicide rates, seasonal asthma peaks)
Appropriate workforce training and mid-career development
Use of climate-health time-series data to develop a
Malaria Early Warning System (Botswana)
Observed summer
(Dec-Feb) rain
Forecast (advancemodelled) summer rain
Log malaria incidence
Highest
malaria
incidence
years
(versus)
Lowest
malaria
incidence
years
Precipitation anomaly (mm / day)
Relationship between
summer rainfall and
subsequent annual
malaria incidence …
Summer Precipitation (mm / day)
Thomson M, et al. Summer rain and subsequent malaria
annual incidence in Botswana. Nature 2006; 439: 576-9
Climate Change and Health
Triple Purpose of Research
1. Recognition of health risks will potentiate true
primary prevention – i.e. reduction of GHG
emissions (mitigation).
2. Mitigation acitivities can/should provide health
benefits … and may, thus, help revitalise Health
Promotion.
3. Health risks already exist, and more are
unavoidable. So, we must define them in order
to develop and evaluate adaptive (secondary
prevention) strategies.
My best wishes to the
Public Health Foundation
of India – an important,
bold and very timely
initiative