Published on

  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide


  1. 1. Water Pollution #2: Heavy Metals What is it? Where is it? How did it get there? Why is it bad? How do we get rid of it?
  2. 2. Periodic table according to Biology <ul><li>Toxic: mercury, lead, cadmium, nickel, gold, platinum, silver, bismuth, arsenic, selenium, vandium, chromium, thallium </li></ul>
  3. 3. The Two Big “Stars” “Lead” Zeppelin Freddie Mercury
  4. 4. What makes them bad? <ul><li>Toxic dose of Vitamin C? </li></ul><ul><li>How about arsenic? </li></ul><ul><li>Fat (lipid) soluble </li></ul><ul><li>Bioaccumulation- </li></ul><ul><li>Who has more </li></ul><ul><ul><li>Generally, Children or adults? </li></ul></ul><ul><ul><li>A child with exposure or an adult who had childhood exposure? </li></ul></ul>
  5. 5. Lead and Mercury: What you (probably) already know <ul><li>What are the major causes of lead poisoning in children? </li></ul><ul><li>What kinds of food cause mercury poisoning? </li></ul><ul><li>What body system do lead and mercury affect? (digestive,circulatory, etc) </li></ul>
  6. 6. How does it get there? Lead <ul><li>Leaded gasoline used to be used (still in Nascar) </li></ul><ul><li>Lead paint chips get integrated into the soil </li></ul><ul><li>Lead solder to join pipes </li></ul>What groups of people are more likely to be affected?
  7. 7. Why is it bad? Lead
  8. 8. How does lead cause these affects? Mimics zinc in its ability to bind (and block) a glutamate receptor Normal function: excite neurons for plasticity--> learning and memory Continuously excited --> excitotoxicity --> cell death
  9. 9. Lead and Juvenile Delinquency? <ul><li>In children aged 7-11 years above average concentrations of lead in children’s bones is associated with an increased risk of </li></ul><ul><li>Attention deficit disorder </li></ul><ul><li>Aggressive behavior </li></ul><ul><li>Delinquency </li></ul><ul><ul><li>Who is likely to live in high lead areas? </li></ul></ul><ul><ul><li>Environmental Injustice? What do you think? </li></ul></ul>
  10. 10. How does it get there? Mercury <ul><li>Naturally present in soil- volcanic eruptions </li></ul><ul><li>Coal burning power plants </li></ul><ul><li>atmosphere --> water </li></ul><ul><li>Illegal Dumping </li></ul><ul><li>( thermostats, thermometers, monitors) </li></ul>
  11. 11. Why is it bad? Mercury <ul><li>Reproductive failure </li></ul><ul><li>Damage to intestine </li></ul><ul><li>Stomach and kidney damage </li></ul><ul><li>DNA alteration </li></ul><ul><li>Neurological complications- myelin in kids </li></ul>
  12. 12. How does mercury affect the body? <ul><li>Sensory impairment (vision, hearing speech) </li></ul><ul><li>Disturbed sensation (itching, burning, pain) </li></ul><ul><li>Lack of coordination </li></ul><ul><li>Memory issues </li></ul><ul><li>How? Prevents epinephrine break-down </li></ul>
  13. 13. How does it get to us? <ul><li>Ingestion of fish- which fish? </li></ul><ul><li>Vaccines- different form, same effect? </li></ul>
  14. 14. FDA/EPAdvice <ul><li>By following these three recommendations for selecting and eating fish or shellfish, women and young children will receive the benefits of eating fish and shellfish and be confident that they have reduced their exposure to the harmful effects of mercury . </li></ul><ul><li>1. Do not eat Shark, Swordfish, King Mackerel, or Tilefish because they contain high levels of mercury. </li></ul><ul><li>2. Eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury. </li></ul><ul><li>* Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish . </li></ul><ul><li>* Another commonly eaten fish, albacore (&quot;white&quot;) tuna has more mercury than canned light tuna. So, when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of albacore tuna per week. </li></ul>“ But I don’t plan on having kids for 10 years!…”
  15. 15. Results in an aquatic ecosystem Bacteria convert it into methyl mercury- more toxic! What happens as it is passed along the food web? Let’s find out!
  16. 16. Biomagnification <ul><li>Concentrations of bioaccumulative substances are found at much higher concentrations at higher trophic levels </li></ul>