1. Chapter Twenty: The Environment and Human Health

2. Section One: Pollution and Human Health
Environmental Effects on Health
Pollution causes illness by
Directly by poisoning
Indirectly by spreading infectious diseases
People in developing countries suffer more and usually become ill due to polluted water

3. Section One: Pollution and Human Health
Toxicology
The study of the harmful effects of substances on organisms
Is the concentration of the chemical in the environment high enough to be harmful?
Dose: the amount of a harmful chemical to which a person is exposed
Dose-response curve: shows the relative effects of various doses of a drug or chemical on an organism

4. Section One: Pollution and Human Health
Epidemiology
the study of the spread of diseases
Helps scientists try to trace the disease to find the origin
Risk Assessment: an estimate of the risk posed by the action of a substance
What is the chance that you will get the disease?

5. Section One: Pollution and Human Health
Pollution from Natural Sources
Some pollutants occur naturally in the environment
Particulates: particles in the air that are small enough to breath into the lungs
Ex: dust and soot
Heavy metals
Elements like arsenic, cadmium, lead and mercury
Occur naturally in the rocks and soil
Dangerous in high amounts

6. Section One: Pollution and Human Health
Pollution from Human Activities
Humans activities release thousands of chemicals
Regulations made by the government have helped reduce some pollutants
Some scientist believe chemical pollution may be the cause of Parkinson’s and Alzheimer’s diseases
Burning fuels causes many health defects
Pesticides
Waste Disposal
Industrial Chemicals
Used in building materials, carpets, cleaning fluids, and furniture

7. Section Two: Biological Hazards
The Environment’s Role in Disease
Pathogens: organisms that cause disease
Host: an organism in which the pathogen lives all or part of its life
Waterborne Disease
Diseases transmitted through water
Vectors: organisms that transmit diseases
Mosquitoes
Cholera
Caused by water polluted with human feces
Malaria
Caused by parasitic protists found in mosquitoes

8. Section Two: Biological Hazards
Environmental Change and Disease
Many ways we alter the environment make it more suitable for pathogens
Antibiotic Resistance
The overuse of antibiotic has led to pathogens developing resistance to them

9. Section Two: Biological Hazards
Environmental Changes and Disease
Malaria
Transmitted through mosquitoes
Mosquitoes breed in water
Have developed resistance to pesticides
Emerging Viruses
AIDS and HIV
No drugs for treatment of viruses
Only vaccine to prevent certain viruses
Cross-Species Transfer
Pathogens can move from one species to another
Many diseases started in wild animals and were transferred to humans