Transcript Environmental Change and Human Health

Human health, food and
environment
CENV 110
A return to health
• Food is good for health
– Well nourished people live longer, grow larger
and presumably are happier
An American family with their weekly food
Two central American families
with their weekly food
But there is such a thing as too
much
Conrad Tolby, 54, is a long-distance truck driver and ex-biker. After two heart attacks, both of them in the cab of his truck,
and a divorce back in Mississippi, Conrad now travels with his best friend and constant companion, a 5-year-old Sharpei dog
named Imperial Fancy Pants, who gets his own McDonald’s burger and splits the fries with Conrad. Estimated calories
pictured: 5,400.
Rick Bumgardener, 54, from Halls, Tenn., uses a wheelchair to leave the house and suffers from back problems and Type 2
diabetes. He is trying to lose weight and now eats a restricted diet of a 12-grain bagel, turkey sausage, whole-wheat pasta,
steamed vegetables, baked chicken and lots of snacks. Estimated calories pictured: 1,600.
Not everyone shares in the
bounty
Food Scarcity
Noolkisaruni Tarakuai, 38, is the third of four wives of a Maasai chief in Narok, Kenya. Her diet for the day includes meager
rations of cornmeal porridge, bananas and black tea with whole milk and sugar. Estimated calories pictured: 800
.
Alamin Hasan, 12, a porter at
the Kamalapur Railway Station
in Dhaka, Bangladesh, sits with
his day's worth of food, which
includes vegetable curries, white
rice, a roll, tea and five
cigarettes. Estimated calories
pictured: 1,400.
Sitarani Tyaagi, a 70-year-old
ascetic Hindu priest, is shown here
with his typical day’s worth of food
at an ashram in Ujjain, India.
Weighing only 103 pounds, he
generally eats only a plateful of
food per day and has water for the
other two meals. Estimated calories
pictured: 1,000.
But food production can be bad
for health
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Moving from hunter gatherer to farmer
Disease transmission
Disease development
Farming accidents
Pesticides/herbicides
Global Transformations as part of
food production
• 40% of ice-free surface area to food
production
• We use ½ of accessible surface freshwater
• Loss of 7-11 million km2 of forest
• Development of ocean fisheries
• Regulating freshwater through 45,000 large
dams
• Invasive species and pollution affecting
existing biota
Major issues
• increasing exposure to infectious disease
• water scarcity,
• food scarcity,
Increasing Exposure to Infectious
Disease
• Biophysical conditions of habitats that can
affect the density or presence of diseaserelated organisms;
• exposure pathways, the way organisms
(including humans) interact with each other;
• the genetics of pathogens;
• the life cycles of pathogens and vectors
• Species composition within a community of
organisms
Biophysical conditions of
habitats that can affect the
density or presence of diseaserelated organisms
• Deforestation or irrigation projects improve
breeding habitat and survival of certain
anopheline mosquitoes that transmit
malaria in Africa, Latin America, and Asia
Distribution of malaria
Factors influencing malaria
• The ecological distribution of the host
mosquitoes
• Mosquito control efforts
• Infrastructure to prevent infection: mosquito
nets, elimination of mosquito breeding
• Infrastructure to treat infected people and
reduce the probability a mosquito will pick
up the parasites
Changes in exposure
pathways
• Incursions into wildlife habitat can lead to
new exposure to zoonotic disease as seen in
Ebola, simian retroviruses, and, probably,
human immunodeficiency syndrome
Ebola Transmission
Changes in the environment
in which organisms live
create genetic alterations,
which can increase disease
transmission
• Livestock management relying on extensive
use of antibiotics in concentrated animal
feeding operations leads to the emergence
of pathogens resistant to numerous
antibiotics.
Diseases from livestock
Development of antibiotic
resistant bacteria
Agricultural chemicals and
human health
The World Health Organization
estimates that there are 3 million
cases of pesticide poisoning each
year and up to 220,000 deaths,
primarily in developing countries.
Water Scarcity
• Demands for irrigation can compete with
domestic supply
Industrialization, food production
and human health
• Industrialization is closely tied to increased
food production
– Fertilizer and the Haber Bosch process
– Production of other farm chemicals
– Production of farm machinery
Industrialization is a mixed
blessing
• Industrialization can bring health
infrastructure such as clean water
• Richer people tend to live longer
• But there are downsides to health
– Higher densities of people
– Various forms of pollution
London 1900
Killer smog New York
Air pollution China
Summary
• Food is essential and up to a limit more
food is good for health
• But food production has health costs
• The question is can we maintain the food
production while reducing those costs
Study guide
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How can too much food be bad for your health?
Name 5 countries where over 30% of the population is undernourished.
Name 4 occupations that have a higher fatal injury rate than farming
Name 2 ways clearing land for farming increase diseases.
How will climate change make parts of the U.S. potential malarial areas?
Name 3 methods that can reduce the incidence of malaria in places it is now common?
What is the key linkage between food and Ebola?
How does livestock production foster new diseases?
Why do some farmers routinely supply antibiotics to animals that are not sick?
How has industrialization benefited human health?
How has industrialization harmed human health?