1. Chapter 17: Environmental Hazards and Human Health
Kelsey Kushner
Megan Stellini

2. Global HIV/ Aids Aquired immune deficiency syndrom (AIDS)
Caused by infection of human immunodeficiency virus (HIV)
Cripples the immune system
Spread around the world, mostly in African Countries
No way to cure it -> only help people to live longer

3. Health Hazards we Face 5 major types of Hazard:
Risk are usually expressed as Probabilities
Risk = the probability of suffering harm from a hazard that can cause injury, death, disease, economic loss, or damage
5 major types of Hazard:
Biological hazard: bacteria, viruses, parasites, protozoa, and fungi
Chemical hazard: harmful chemicals in air, water, soil, and food.
Physical hazard: fire, earthquake, volcanic eruptions, floods, and storms
Cultural Hazard: unsafe working conditions, unsafe highways, poverty, criminals
Lifestyle Hazard: smoking, overeating, alcohol, unsafe sex

4. Disease can Spread
Nontransmissible disease = caused by something other than a living organism and does not spread from one person to another (asthma, diabetes, malnutrition)
Infectious Disease = caused when a pathogen such as bacterium invades the body and multiplies in cell and tissue (flu, HIV, malaria)
- Leading cause of Disease in 1900
Transmissible disease = infectious disease that can be transmitted from one person to another (HIV, flu, measles)
DALYs – (disability adjusted life years) measure total disease burden in a population

5. World Health Organization = developing Global Health Atlas which contains database and map based on health statistics in the World

6. Genetic Resistance Genetic Resistance to Antibiotics
Lack of preventing disease because of the reproductive rate of bacteria that allows bacteria to become genetically resistant to an increasing number of antibiotics in natural selection
Spread of Bacteria
Overuse of Pesticides
Overuse of Antibiotics (MRSA)

7. Animal to Human Wildlife moves infectious disease to humans
Ecological medicine = tracking down the connections between wildlife and humans -> prevent spread of disease
Clearing of forests -> results in movement of animals such as mosquitoes (Malaria)
Global Warming
Bush Meat trade -> dead animal blood may contain viruses that are then exposed to humans
Factory meat – E coli bacteria transferred from animals to humans when consumed

8. SOULTIONS WHO (World Health Organization) Solutions:
Increase research on tropical diseases and viruses
Reduce Poverty
Decrease malnutrition
Improve drinking water
Reduce use of unnecessary antibiotics
Educate people taking antibiotics
Require hand washing

9. Chemicals cause Cancer
Toxic chemicals- cause permanent/ temp. harm or death
Carcinogens (chemicals, radiation, or viruses that cause cancer)
Mutagens (chemicals, radiation, or viruses that cause mutations)
Teratogens (chemicals, radiation, or viruses that cause birth defects)
PBCs
Chlorine containing organic compounds used as lubricants, hydraulic fluids and electrical insulators
Banned because cause Liver cancer
Found in water, air, food chain, and soil

10. Affect our Systems Immune System (disease)
- Infectious bacteria, viruses, and protozoa
2. Nervous System (brain, spinal cord, peripheral nerves)
- Retardation, ADD, learning disabilities, paralysis, and death
3. Endocrine System (glands that release hormones)
- Learning behavior, growth, sexual reproduction, development

11. Mercury (Hg) is a teratogen and potent neurotoxic
Interferes with nervous system
Released into the air from rocks, soil, volcanoes, and vaporization from ocean (fish)
Brain damage in children
Harm kidneys, heart, and immune system in adults

12. Toxicology
The study of the harmful effects of chemicals on humans and other organisms
Study of poisons
Toxicity: a measure of how harmful a substance is (ability to cause injury, illness, or death)
Harmful if ingested in a large enough quantity

13. At what level of exposure to a toxic chemical will it cause harm?
Dose: amount of harmful chemical that a person has ingested, inhaled, or absorbed through skin
Age (children to adults)
Genetic makeup
Multiple Chemical Sensitivity (MCS)
Solubility and Persistence (resistance to breakdown)
Biological magnification: concentrations of toxins increase through the trophic levels
Response: damage to health resulting from exposure
Acute (immediate) or chronic (permanent)

15. Protecting Children from Toxic Chemicals
Infants and young children are more susceptible
1. breathe more air, drink more water, eat more food per unit of body weight
2. exposed to toxins in dust or soil (mouth)
3. usually have less well-developed immune systems and body detoxification processes
EPA (2003)  children face a risk 10 times higher than that faced by adults

16. Estimating Toxicity Live laboratory animals Dose-response curve:
Mammals systems are like humans (small and reproduce quickly)
2-5 years/hundreds to thousands of test animals/$2 million per substance test
Dose-response curve:
lethal dose
Median lethal dose (kill 50% within 18 days)
Nonthreshold dose-response model: any dosage causes harm that increases with the dosage
Threshold dose-response model: threshold dosage must be reached before any detectable harmful effects occur

18. Alternatives to Animal Testing
Computer simulations
Testing with tissue cultures, chicken egg membranes, and individual animal cells
High-speed robot testing devices can now measure the biological activity of more than one million compounds a day to help determine their possible toxic effects

19. Are Trace Amounts of Toxic Chemicals Harmful?
Honestly: in most cases we don’t know
Too little data
Difficulty of determining the effects of low levels of these chemicals
Argument  life expectancy has been increasing in most developed countries for decades

20. Comparative Risk Analysis (1)
High risk Health Problems
Indoor/outdoor air pollution
Worker exposure to industrial/farm chem
Pollutants in drinking water
Pesticide residues on food
High risk environmental problems
Global climate change
Stratospheric ozone depletion
Wildlife habitat destruction/alteration
Species extinction/loss of biodiversity

21. Comparative Risk Analysis (2)
Medium-risk Ecological Problems
Acid deposition
Pesticides
Airborn toxic chemicals
Toxic chemicals, nutrients, and sediment in surface waters
Low-risk Ecological Problems
Oil spills
Groundwater pollution
Radioactive isotopes
Acid runoff to surface waters
Thermal pollution

23. Poverty, Gender, and Lifestyle
High death toll resulting from poverty:
Malnutrition, increased susceptibility to normally nonfatal infectious diseases, and often-fatal infectious diseases transmitted by unsafe drinking water
AVOID risks like….
Smoking, exposure to smoke, overconsumption of foods containing cholesterol and saturated fats, drinking more than two glasses of alcohol per day, excess sunlight, unsafe sex

24. Death From Smoking
World’s most preventable major cause of suffering and premature death among adults
Kills an average of 14,800 people per day
By 2030, the annual death toll is projected to reach more than 8 million (average of 21,900 deaths per day)
Only 1 in 10 people succeed in quiting
Passive Smoking: second-hand smoke
Children more likely to develop allergies/asthma
In 2006, CDC estimated 3,000 lung cancer deaths and 46,000 heart disease caused by second-hand smoke

25. Encouraging News
Average # of cigs smoked per person in the US declined by 56% between 1976 and 2006
Dropped globally by 16% between 1988 and 2006

26. How People Evaluate Risks
1. Fear
2. The Degree of control we have
3. Whether a risk is catastrophic, not chronic
4. Optimism bias (same risks don’t apply to them)
5. Instant gratification (fake tanning)

27. How to ACTUALLY Evaluate Risks
1. Compare risks
2. How much risk are you willing to accept?
3. Determine the actual risk involved
4. Concentrate on evaluation and carefully making important lifestyle choices