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

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Do now

Do Now

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

    ***

    ***

    ***


Answer

Answer

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

    ***

    ***

    ***


Homework

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…


Lead poisoning

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


Remember the video about the computers be recycling

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


New material

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


New material1

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


New material2

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)


  • Toxicology studies poisonous substances

    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


    Toxicology studies poisonous substances1

    Toxicology studies poisonous substances

    • What is the most dangerous place in a home for poisonous substances?

    • Under the kitchen sink?


    Chemicals are in the air water and soil

    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


    Toxicants

    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


    Endocrine disruptors

    Endocrine disruptors

    • Hormones stimulate growth, development, sexual maturity

    • Synthetic chemicals

      • Can Block hormones and / or mimic hormones


    Bisphenol a

    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


    Airborne substances

    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


    Some toxicants persist

    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.


    New material3

    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


    Not all toxicants are synthetic

    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


    Human studies

    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


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