CLIMATE CHANGE AND HUMAN HEALTH

Heidi E. Brown, Ph.D., M.P.H.University of Arizona School of Geography and DevelopmentCollege of Public Health

Climate and Health

• Climate-related exposures can be the direct cause of illness or death– such as death from hyperthermia

• Climate-related exposures can also be a contributing cause of health problems by exacerbating an already existing medical condition– such as heart disease– or exert indirect effects, as by inducing changes in the

ranges of organisms that transmit disease

Climate Change & Health in the Southwest

• More heat waves and urban warming• Longer and more severe ozone seasons• Increased pollen allergen production w/ earlier season

start• Fungus/mold growth due to swings in precip/temp

extremes• Risk of water-borne pathogens via flooding and higher

water temperatures• Higher rainfall variability moderating rodent-borne

diseases• Marginal shifts in mosquito vector ranges, but w/

potential population impact

Extreme Events

http://www.usgcrp.gov/usgcrp/Library/nationalassessment/LargerImages/SectorGraphics/Health/HeatDeaths.jpg

Heat Related Deaths – ChicagoMaximum Temperature and Heat Index

July 11 -23, 1995

Air Quality

• Rising temps increase concentrations of ozone and possibly PM2.5 – Longer, more severe ozone season– Breathing problems, airway inflammation

http://www.usgcrp.gov/usgcrp/Library/nationalassessment/LargerImages/SectorGraphics/Health/Ozone.jpg

Water- & Food-borne Disease

• Effects of precipitation & temperature

http://www.who.int/globalchange/climate/en/fig4.2.gifhttp://www.niwascience.co.nz/pubs/wa/12-2/images/flood2_large.jpg

Natural flooding and fecal bacteria (E. Coli) Temperature increases and Salmonella cases

Ave. monthly temp (°C)

# Salm

onella

cas

es/m

onth

Wildfires

Credit: Brent Watcher IMET National Weather Service/US Forest Service

Wallow Wildfire, 2011 • Smoke exposure associated with respiratory and eye symptoms, increased ER visits

• Loss of property/home,

• Increased mudslide risk

Conclusions

• Natural and human systems are complex• Warmer & more extreme climate shifts will lead to

direct health impacts and exacerbate pre-existing conditions.

• Effects will be mediated by social & ecological factors– Disadvantaged population bear greater burden

• New work on co-benefits– Climate change mitigation policies that provide

ancillary health benefits