Climate change and public health:

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Climate change and public health a challenge to
urban centres Carlos Corvalan and Diarmid
Campbell-Lendrum World Health Organization,
Geneva, Switzerland. XI WORLD CONGRESS ON PUBLIC
HEALTH VIII BRAZILIAN CONGRESS ON COLLECTIVE
HEALTH Riocentro Convention Center Rio de
Janeiro, 21 - 25 August, 2006
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URBANIZATION Proportion of global population
living in cities has increased dramatically in
past Century. 1900 15. Now 50
Population growth and urbanization, 1900-2005
6
5
Rural
4
3
2
Urban
1
0
1900
2005
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Challenges from climate change for developing
country cities Geographical location e.g.
many are located on coasts, vulnerable to both
sea level rise and storms Built environment
e.g. many cities experience a significant urban
heat island effect, exacerbating the impacts of
heatwaves Co-exposures e.g. many cities
have high levels of air pollution, which interact
with high temperatures to increase mortality and
morbidity Weak infrastructure e.g. high
population density and poor sanitation
waste/disposal promotes transmission of important
infections.
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Does climate change have a large impact on health?
Burden of disease by region Climate change and
urban air pollution Disability Adjusted Life Year
per million. World Health report 2002.
Climate change Air
pollution
Africa region South-East Asia region Eastern
Mediterranean region Latin America and
Caribbean region Western Pacific
region Developed countries

• Cardio- pulmonary diseases
• Respiratory infections
• Trachea/ bronchus/ lung cancers

• Diarrhoeal diseases
• Malaria
• Unintentional injuries
• Protein-energy malnutrition

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Health vulnerabilities

• Heatwaves
• Urban heat island effect
• Interaction with air pollution
• Weak social networks
• Lack of early warning systems and public health
  information

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Heat Island effect
http//adaptation.nrcan.gc.ca/perspective/health-0
3_e.asp
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12-day Heatwave, 3-14 Aug, 2003 Maximum
Temperature, Aug 10
Excess Mortality France gt 14,000 Italy
10,000 Spain Portugal 5,000 Etc.
Total 35,000
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Health impacts Heatwaves
Heatwave in France, 2003. Over 14,000 people died
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Health vulnerabilities

• 2. Floods and storms
• Largest cities are on the coast
• Degradation of natural protection
• Poor quality housing in exposed areas
• Inadequate disaster response plans

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Health Impacts of Floods

• Immediate deaths and injuries
• Non specific increases in mortality
• Infectious diseases leptospirosis, hepatitis,
  diarrhoeal, respiratory, vector-borne diseases
• Exposure to toxic substances
• Mental health effects
• Increased demands on health systems

Philip Wijmans, LWF/ACT Mozambique, March 2000
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Hurricane Katrina
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Health vulnerabilities

• 3. Infectious disease
• Inadequate water and sanitation provision
• High population density and high contact rates
• High levels of imported infections
• Inadequate disease warning, control and
  treatment

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Urban infectious disease Dengue
Modelling studies suggest that climate change
would increase the proportion of the global
population exposed to dengue from about 35, to
50-60, by 2085. This on top of likely increased
risks from unplanned development and mixing of
pathogens. Hales et al, Lancet 2002 268
830-834
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Urban infectious Disease Diarrhoea
Diarrhoea increases by 8 for each 1 degree
centigrade increase in temperature. (Reproduced
with permission from Checkley et al., Lancet,
2000)
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Health vulnerabilities
4. Air pollution How big are potential health
co-benefits of improved energy policies?
Outdoor Air pollution only 700,000 deaths in
2020 (Davis et al, 1997) 64,000 deaths between
2000 to 2020, in Mexico City, Santiago, Sao Paulo
and New York (Cifuentes et al, 2001) Not yet
considered Proportion of 1.2 million annual
deaths from traffic accidents? Proportion of 1.7
million annual deaths from IAP? Proportion of 1.9
million annual deaths from physical inactivity?
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Different routes are possible
Atlanta
Bangkok
Singapore
Houston
Zurich
Sao Paulo
Washington
Hong Kong
London
Beijing
Kenworthy, 2003
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Protecting health while reducing Emissions
Buildings Indoor air pollution Heat and cold
protection
Transport Air pollution Traffic injuries Physical
inactivity
Greenhouse Gas Emissions
Industry Occupational risks, mining and transport
Energy supply conversion Occupational
risks Construction and transport
Agriculture Nutrition, Water / vector-borne
disease
Waste Occupational, chemical
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Conclusions

• Adaptation to climate change
• Urbanization is occurring rapidly, changing
  nature of health vulnerabilities to climate
  variability and climate change
• Vulnerabilities can be reduced both by general
  development and health provision, and (sometimes)
  by targeted climate information
• Climate Change Mitigation
• Policies concerning urban energy sources and use
  (e.g. transport), have strong direct links to
  globally important health impacts.
• Health considerations should be central in
  energy (CC) decisions
• City-level actions are critical to the future of
  health adaptation to Climate Change and also to
  CC mitigation

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Thank you http//www.who.int/globalchange