APWH Unit 9.2
Unit 9.2 — Technological Advancements and Limitations—Disease（1900–Present）
Essential Question:
How have environmental factors affected human populations since 1900?
One-glance Review
- Medicine and public health → reduce death rates
- Vaccination campaigns → control or eliminate diseases
- Poverty → helps disease continue spreading
- Epidemics → cause social disruption
- Global cooperation → improves disease control
- Longer life expectancy → increases chronic disease
Core Ideas
Disease Control → Progress but Limits
- Science and medicine saved millions of lives
- But disease did not disappear
- Poverty and inequality remained major causes of suffering
Medical progress improved survival, but access to health care remained unequal.
KEY TERMS BY THEME
ENVIRONMENT: Epidemics
SOCIETY: Disease
TECHNOLOGY: Medical Advances
- Antiretroviral Drugs
- Heart Transplant
- Artificial Heart
- Jonas Salk
- Albert Sabin
- Christiaan Barnard
- Robert Jarvik
1. Disease and Public Health
Medical Progress after 1900
- Advances in science reduced many deaths
- Governments expanded public health systems
- International organizations supported disease control
- Vaccination became one of the most effective tools
Key Concept:
- Public health measures reduce mortality
（公共卫生措施降低死亡率）
Smallpox（天花）
- Smallpox had existed for centuries
- It killed millions as late as the 1960s
- The WHO launched a global vaccination campaign
- In 1979, smallpox was declared eliminated
Smallpox was one of the greatest victories of modern public health.
2. Disease and Poverty
Why Disease Continued
- Some diseases persisted even when treatments existed
- Poverty created conditions for disease spread
- Poor housing increased risk
- Unsafe working conditions increased risk
- Contaminated water spread infection
- Lack of healthcare made treatment difficult
Key Concept:
- Poverty and disease are closely connected
（贫困与疾病密切相关）
Malaria（疟疾）
- Malaria is spread by mosquitoes
- It is common in tropical regions
- It killed hundreds of thousands each year
- Many victims were young African children
Prevention:
- Insecticide-treated mosquito nets
- Public health campaigns
Problem:
- Mosquitoes became resistant to insecticides
Tuberculosis（肺结核）
- Tuberculosis is an airborne disease
- It spreads through coughing and sneezing
- It is strongly associated with poverty
- It also spreads easily in crowded places
Development:
- Effective treatment appeared after 1946
- Antibiotics improved survival
Problem:
- Drug-resistant TB later emerged
New strains showed the limits of medical progress.
Cholera（霍乱）
- Cholera is spread through contaminated water
- It mainly affects poor populations
- It remains common in developing countries
Prevention:
- Boiling water
- Chlorinating water
- Washing hands
Treatment:
- Rapid rehydration can prevent death
Polio（小儿麻痹症）
- Polio is caused by a virus
- It spreads through contaminated water
- It can cause paralysis and death
Vaccines:
- Jonas Salk developed an injectable vaccine in 1955
- Albert Sabin later developed an oral vaccine
Impact:
- Global vaccination campaigns nearly eliminated polio
Key Concept:
- International cooperation can control disease
（国际合作可以控制疾病）
3. Emerging Epidemics
1918 Influenza Pandemic
- The flu spread at the end of World War I
- It moved through troop movement and trade routes
- It infected a large share of the global population
- It killed about 20 million people worldwide
- It caused major demographic disruption
The 1918 flu showed that globalization could also spread disease rapidly.
HIV/AIDS
- AIDS is caused by HIV
- HIV weakens the immune system
- It spread through bodily fluids
- Common transmission included:
- unprotected sex
- blood transfusions
- shared needles
Impact:
- From 1981 to 2014, AIDS killed more than 25 million people
- It caused major social and economic disruption
Antiretroviral Drugs
- By the mid-1990s, treatments were developed
- These drugs could not cure HIV
- But they could help patients live much longer
Problem:
- The drugs were expensive
- Poor countries had limited access
Example:
Brazil
Brazil provided free antiretroviral drugs beginning in 1996.
This showed that government policy could improve access to life-saving treatment.
Ebola（埃博拉）
- Ebola was identified in Congo in 1976
- It spreads through infected body fluids
- It can cause bleeding, organ failure, and death
- A major outbreak occurred in West Africa in 2014
Response:
- International public health efforts contained the outbreak
- The WHO played a leading role
Ebola showed the importance of global emergency response.
4. Diseases Associated with Longevity
A New Pattern
- As life expectancy increased, people lived longer
- More people developed diseases linked to aging
- Chronic illnesses became more important
Key Concept:
- Longer life expectancy changed disease patterns
（寿命延长改变了疾病模式）
Heart Disease（心脏病）
- Heart disease became more common in longer-living populations
- It was linked to lifestyle
- It was also linked to genetics and aging
Medical innovations:
- Heart transplant
- Artificial heart
- Stents
- Valve replacement
- Medications
Important People:
- Christiaan Barnard performed the first heart transplant in 1967
- Robert Jarvik helped design the artificial heart
Alzheimer’s Disease（阿尔茨海默病）
- Alzheimer’s is a form of dementia
- It mainly affects older people
- Patients gradually lose memory
- The disease worsens over time
- Researchers continue searching for a cure
Longer lives created new medical challenges related to aging.
5. Cause and Effect
Medicine → Society
- Vaccines reduced infectious disease
- Public health campaigns lowered mortality
- Life expectancy increased
Poverty → Disease Persistence
- Poor sanitation helped disease spread
- Lack of healthcare limited treatment
- Malaria, TB, and cholera remained serious problems
Globalization → Faster Disease Spread
- Troops carried the 1918 flu
- Transportation networks spread epidemics
- HIV/AIDS and Ebola became international health crises
Longevity → Chronic Disease
- Longer life expectancy increased heart disease
- Longer life expectancy increased Alzheimer’s disease
- Societies faced new health burdens
Exam-ready Phrases and Sentences
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reduce mortality rates
-
expand public health measures
-
improve life expectancy
-
remain closely linked to poverty
-
spread through contaminated water
-
reveal inequalities in access to healthcare
-
demonstrate the importance of global cooperation
-
create new challenges associated with aging
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Advances in medicine and public health reduced deaths from many infectious diseases after 1900.
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However, poverty and poor sanitation allowed diseases such as malaria, tuberculosis, and cholera to persist.
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Vaccination campaigns helped eliminate or nearly eliminate diseases such as smallpox and polio.
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Epidemics such as HIV/AIDS and Ebola caused major social disruption and exposed unequal access to treatment.
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As life expectancy increased, chronic diseases such as heart disease and Alzheimer’s became more common.
LEQ / DBQ 使用思路
可用论点（Thesis Ideas）
- Since 1900, medical and public health advances have greatly improved human survival, but poverty and inequality limited their benefits.
- While new medical technologies helped control many diseases, globalization also allowed epidemics to spread more rapidly.
- As disease control improved life expectancy, societies increasingly faced chronic illnesses associated with aging.