Regional and global pollution: DDT and ozone

But first, thoughts on David Battisti

• Historically, famines have not been caused by a lack of food! (See Amartya Sen’s economics Nobel prize-winning analysis of Bangladesh—key areas exported food during the 1970s famines.)

• Famines are actually caused by…• …lack of money! When crops fail, poor

farmers have no income and no food.• No diversification (like Enron employees)

Will malnutrition increase? Maybe not.

1. There will be more diversification and less poverty as China et al. modernize.

2. Rising food prices will provide incentives to increase supply by modernization, by drip irrigation, by using GM crops, etc.

3. Rising food prices will provide incentives to decrease demand by reducing waste, driving up the price of meat, etc.

Pollution: Think hard about…

1) Data, hypotheses, and hypothesis testing

2) Disciplinary and interdisciplinary perspectives

3) Policy approaches and implications (for the world and for you)

“Silent Spring” is a metaphor referring to

Aquife

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g dry

An im

agin

ary

pollute

d...

Loss

of s

ongbird

s

1%

42%

57%1. Aquifers running dry

2. An imaginary polluted city near Washington DC

3. Loss of songbirds

According to Tina Rosenberg, Rachel Carson didn’t consider

DDT

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n far..

.

DDT

impac

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n mal

aria

DDT

impac

ts o

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life

12%4%

84%1. DDT impacts on

farmworkers

2. DDT impacts on malaria

3. DDT impacts on wildlife

Think hard about… data, hypotheses, and hypothesis testing• “Ignorance is not a solvable problem, but

rather an inescapable part of the human condition. The advance of knowledge always carries with it the advance of some form of ignorance.” (David Orr)

Epidemiology: Scientific detective work

• “Germ theory” of disease vs. “miasma theory” (“bad air” / “mal aire” / “malaria”)

• John Snow’s map of London in 1854, showing cholera deaths

• Clustered around Broad Street pump!

Generating and testing hypotheses about cancer

• What could cause cancer incidence rates to increase or decrease?

• What could cause cancer death rates to increase or decrease?

• How to test hypotheses about cancer?• These are not academic questions!

– Breast cancer: 1 in 8 will get it, 1 in 33 will die from it. – Prostate: 1 in 6 will get it, 1 in 34 will die from it.

• PSA: self-exams for breast, testicular cancers.

Annual % change in incidence and death rates, 1994-2003 (cancer.gov)

Think hard about… disciplinary and interdisciplinary perspectives

• Example: Pesticides and other chemicals involves biology, economics, public health, medicine…

• Rachel Carson (1907-1964)

• Silent Spring (1962)

Bioaccumulation

• Each food chain step involves ≈90% loss of energy, e.g., 1 pound of snake comes from 10 pounds of frog.

• If 0% of chemicals are lost, then 1 pound of snake contains the chemical load of 10 pounds of frog.

                                                                  

If 10lbs of corn makes 1lb of beef, a $0.10/lb rise in corn prices means

A $0.01 rise inbeef prices

A $0.10 rise inbeef prices

A $1.00 rise inbeef prices

8%

89%

3%

1. A $0.01 rise in beef prices

2. A $0.10 rise in beef prices

3. A $1.00 rise in beef prices

PBDEs in human breast milk

Evolutionary connection #1: Biological similarities

• To what extent can we design chemicals that harm insects without harming humans?

• To what extent do insects and humans share biological processes?

• “The organic phosphorus insecticides …destroy enzymes… Their target is the nervous system, whether the victim is an insect or a warm-blooded animal.” (p. 18)

Evolutionary connection #2: Resistance

Think hard about… policy implications and approaches

• Cost-benefit vs. precautionary principle? • Precautionary Principle: “When an activity

raises threats of harm to human health or the environment, precautionary measures should be taken, even if some cause-and-effect relationships are not fully established scientifically.” (Wingspread Statement, 1998)

• But how do put this into practice?

Case study: Toxics (http://www.epa.gov/tri/)

Case study: Toxics

• Only a quarter of the 82,000 chemicals in use in the U.S. have ever been tested for toxicity. Each year industry seeks to add 1,700 new compounds.

• What does the Precautionary Principle suggest for this “uncontrolled experiment”?

• To what extent does the “absence of evidence” indicate the “evidence of absence”? (Think about pollution as well as other issues such as ????)

Case study: DDT

• “In her 297 pages, Rachel Carson never mentioned the fact that by the time she was writing, DDT was responsible for saving tens of millions of lives, perhaps hundreds of millions. DDT killed bald eagles because of its persistence in the environment. Silent Spring is now killing African children because of its persistence in the public mind.” (Rosenberg 2004)

Pollution: Think hard about…

1) Data, hypotheses, and hypothesis testing

2) Disciplinary and interdisciplinary perspectives

3) Policy approaches and implications (for the world and for you)

Comments on ozone (O3)

• Close to the ground, ozone is a local air pollutant connected to smog.

• In the stratosphere (think 10 miles up), ozone absorbs ultraviolet (UV) radiation, protecting us from skin cancer &etc.

• These are separate problems, and as far as I know ground-level ozone and stratospheric ozone don’t interact.

Comments on ozone (O3)

• Also (mostly) unrelated: Climate change and either ground-level ozone or stratospheric ozone.

• Minor detail #1: CFCs, which caused the ozone hole, are also a greenhouse gas.

• Minor detail #2: Global warming makes ground-level ozone problems worse.

Comments on ozone (O3)

• The 1987 Montreal Protocol was an international treaty to reduce CFCs, which destroy (stratospheric) ozone.

• Hailed as a success story and a possible model for climate change treaties.

• The U.S. (under President Reagan) led the way in pushing for the Montreal Protocol, and Europe resisted…

We should use DDT on malaria

Stro

ngly Agree

Agree

Neutra

l

Disa

gree

Stro

ngly Disa

gree

5%

53%

5%

19%18%

1. Strongly Agree

2. Agree

3. Neutral

4. Disagree

5. Strongly Disagree

We should use nuclear power

Stro

ngly Agree

Agree

Neutra

l

Disa

gree

Stro

ngly Disa

gree

11%

26%

9%

26%28%

1. Strongly Agree

2. Agree

3. Neutral

4. Disagree

5. Strongly Disagree

We should use GM foods

Stro

ngly Agree

Agree

Neutra

l

Disa

gree

Stro

ngly Disa

gree

7%

36%

15%19%

22%

1. Strongly Agree

2. Agree

3. Neutral

4. Disagree

5. Strongly Disagree