Do Now

1. Do Now • Thinking outside the box. With only using four lines and not picking up your pen or pencil. Connect all the dots below: * * * * * * * * *

2. Answer • Thinking outside the box. With only using four lines and not picking up your pen or pencil. Connect all the dots below: * * * * * * * * *

3. Homework • Due Friday –Vocab 1-95 • 91. Photovoltaics • 92. Law of Averages • 93. Habitat versus Niche • 94. Directional Selection • 95. Disruptive Selection • Test Friday & Saturday on Chapters 13 & 14. • Read pages 383 starting at Airborne substances…to 388 stop at Dose – response…

4. Lead poisoning • Lead poisoning = caused by lead, a heavy metal • Damages the brain, liver, kidney, and stomach • Causes learning problems, behavior abnormalities, and death • Exposure is from drinking water that flows through lead pipes or from lead paint • Education led to declines in poisoning, but China still used it in toy paint until recently

5. Remember the video about the computers be recycling? • Polybrominateddiphenyl ethers (PBDEs) = has fire-retardant properties • Used in computers, televisions, plastics, and furniture • Persist and accumulate in living tissue • Mimic hormones and affect thyroid hormones • Also affect brain and nervous system development and may cause cancer • Concentrations are rising in breast milk • Now banned in Europe, concentrations have decreased • The U.S. has not addressed the issue

6. New Material • Despite our technology, disease kills most of us • Disease has a genetic and environmental basis • Cancer, heart disease, respiratory disorders • Poverty and poor hygiene foster illnesses

7. New Material • Infectious diseases kill 15 million people/year • Half of all deaths in developing countries • Public health decreases some infectious diseases such as (AIDS) and is spreading

8. New Material • Our mobility spreads diseases • Remember Spanish Influenza during WW I. • West Nile Virus spread from Africa to all lower 48 U.S. states in 5 years • And early on AIDS • New diseases are emerging such as • H5N1 avian flu, H1N1 (Swine Flu)

9. Toxicology studies poisonous substances • Toxicology = the study of the effects of poisonous substances on humans and other organisms • Toxicity = the degree of harm a toxicant can inflict • Toxicant = any toxic substance (poison) • “The dose makes the poison” = toxicity depends on the combined effect of the chemical and its quantity • Environmental toxicology = deals with toxic substances that come from or are discharged into the environment • Studies health effects on humans, other animals, and ecosystems

10. Toxicology studies poisonous substances • What is the most dangerous place in a home for poisonous substances? • Under the kitchen sink?

11. Chemicals are in the air, water, and soil • 80% of U.S. streams contain 82 contaminants • Antibiotics, detergents, drugs, steroids, solvents, etc. • 92% of all aquifers contain 42 volatile organic compounds (from gasoline, paints, plastics, etc.) • Less than 2% violate federal health standards for drinking water • DDT - Rachel Carson’s Silent Spring (1962) showed DDT’s risks to wildlife, and ecosystems and possibly people

12. Toxicants • Carcinogens = cause cancer • Hard to identify because of the long time between exposure and onset of cancer • Mutagens = cause DNA mutations • Can cause cancer • Teratogens = cause birth defects in embryos • Neurotoxins = assault the nervous system • Allergens =overactivate the immune system • Endocrine disruptors =affect the endocrine (hormone) system

13. Endocrine disruptors • Hormones stimulate growth, development, sexual maturity • Synthetic chemicals • Can Block hormones and / or mimic hormones

14. Bisphenol A • Bisphenol A binds to estrogen receptors • Phthalates in plastics disrupt hormones • Found in toys, perfumes, makeup • Can cause Birth defects, cancer, reproductive effects

15. Airborne substances • Chemicals can travel by air • Their effects can occur far from the site of use • Pesticide drift = airborne transport of pesticides • Synthetic chemicals are found globally • In arctic polar bears, Antarctic penguins, and people in Greenland

16. Some toxicants persist • Toxins can degrade quickly and become harmless or they may remain unaltered and persist for decades • Rates of degradation depend on the substance, temperature, moisture, and sun exposure • Breakdown products = simpler products that toxicants degrade into may be more or less harmful than the original substance • DDT degrades into DDE, which is also highly persistent and toxic.

17. New Material • Toxicants in the body can be excreted, degraded, or stored fat-soluble toxicants are stored in fatty tissues • Bioaccumulation = toxicants build up in animal tissues • Biomagnification = concentrations of toxicants become magnified • Near extinction of peregrine falcons and bald eagles

18. Not all toxicants are synthetic • Toxic chemicals also exist naturally and in our food • Don’t assume natural chemicals are all healthy and synthetic ones are all harmful. For example mushrooms • Environmentalists say synthetic toxins: • Are harder to metabolize and excrete • Persist and accumulate • Enter people in ways other than in food

19. Human studies • Case history approach = studies individual patients • Autopsies tell us about lethal doses • Don’t tell about rare, new, or low-concentration toxins • Don’t tell about probability and risk • Epidemiological studies = large-scale comparisons between exposed and unexposed groups • Studies can last for years • Yield accurate predictions about risk • Measure an association between a health hazard and an effect – but not necessarily the cause of the effect