Environmental Biotech

  1. What is toxicology
    The study of the effects of poisons
  2. Phytotoxins
  3. Zootoxins
  4. Bacteriotoxins
  5. Toxicant
    The specific poisonous chemical
  6. Xenobiotic
    • Man-made substance and/or produced by but not nornally fond in the body
    • May be naturally occurring chemicals produces by plants, microorganisms, or animals
    • Poisons are xenobiotics, but not all xenobiotics are poisonous
  7. Who is the farther of modern toxicology
  8. True or False: All substance are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy
  9. Paul Ehrlich
    Developed staining procedures to observe cell and tissues and pioneered the understanding of how toxicants influence living organisms
  10. Rachel Carson
    Alarmed public about dangers of pesticides int he on environment (DDT and soft egg shells)
  11. Toxicity
    The adverse effects that a chemical may produce
  12. Dose
    The amount of chemical that gains access to the body
  13. Exposure
    Contact providing opportunity of obtaining a poisonous dose
  14. Hazard
    The likely hood that the toxicant will be expressed
  15. Toxicant
    Substance that produce adverse biological effects of any nature; may be physical r chemical in nature; effects may be various types
  16. Toxin
    Specific protein produced by living organisms; most exhibit immediate effects
  17. Poisons
    Toxins that cause immediate death or illness when experienced in ver small amounts
  18. Exposure dose
    Amount of xenobiotic encountered in the environment
  19. Absorbed dose
    Actual amount of the exposed dose that enters the body
  20. Administered dose
    Quantity administered usually orally or by injection
  21. Total dose
    Sum of all individual doses
  22. Fundamental Rules of Toxicology
    • Exposure must first occur for the chemical to present a risk
    • The magnitude of risk is proportional to both the potency of the chemical and extent of exposure
    • The dose makes the poison
  23. Acute exposure
    Less than 24hrs; usually entails a single exposure
  24. Repeated exposure
    • Subacute: repeated up to 30 days
    • Subchronic: repeated for 30-90 days
    • Chronic: repeated over 90 days
  25. Prevention of the actions of xenobiotics
    • Redistribution
    • Excretion
    • Metabolism
  26. Xenobiotics cause toxicity by
    • Binding and damaging proteins
    • Binding and damaging DNA
    • Binding and damaging lipids
    • Form free radicals with in the cell
  27. Types of toxic effects
    • Death (arsenic, cyanide)
    • Organ damage (ozone, lead)
    • Mutagenesis (UV light)
    • Carcinogenesis (benzene, asbestos)
    • Teratogenesis (thalidomide)
  28. Systemic toxin
    Affects the entire body or many organs rather that a specific site
  29. Specific site toxicants
    Target tissues or certain organs
  30. What is risk
    The chance of harmful effects of human health or to ecological systems resulting from exposure to an environmental stressor
  31. Stressor
    • Any physical, chemical, or biological entity that can induce and adverse response
    • May adversely affect specific natural¬†resources or entire ecosystems, including plants and animals, as well as the environment with which they interact
  32. Probability
    Likelihood of an event happening
  33. Scatter
    How much the data deviate for an ideal pattern
  34. Error bounds
    Range of values where some measurement is most likely to fall
  35. Correlation
    How well two sets of data relate to each other
  36. Probability
    • Number of ways something can happen
    • Number of ways everything can happen
  37. What is the issue with real world probability
    • Far too complex to calculate directly
    • Estimate from observation of events
  38. Erros tend to follow _____ patterns
  39. Corrolation
    Is not causation and is never perfect in the real world
  40. Statistical Significance
    • Differences b/t measurements whose scatter doesn't overlap
    • Data sets with very sting correlation
  41. Not Statistically Significant
    • Differences b/t measurements whose scatter overlaps
    • Data sets with weak correlation
  42. Two common types of bad data
    • "Gee Whiz" facts
    • Anecdotal Evidence
  43. Anecdotal Evidence
    Evidence based on single noteworthy events or observation
  44. To be valid, anecdotal evidence
    • Must be true
    • Must be representative¬†
  45. Perceived Benefit
    People underestimates risk, overestimate likelihood of benefit
  46. Perceived harm
    People overestimate risk
  47. Unites to measure chemicals in the environment
    • PPM - parts per million
    • PPB - parts per billion
    • PPT - parts per trillion
  48. Standard temperature and pressure
    23 degrees and 15 psi

    • 1cc = 1ml = 1g
    • 1L of water = 1kg
    • 1mg/kg = 1ppm
    • 1mm3/L = 1ppm
    • 1mg/L = 1ppm
  49. Measure of Toxicity
    • Determined in the lab
    • Normal procedure is to test on animals
  50. How is toxicity measuered
    Clinical endpoints that include: mortality(death), teratogenicity(ability to cause birth defects), carcinogenicity(ability to cause cancer) and mutagenicity(ability to cause heritable change in the DNA)
  51. LD50
    • The amount (dose) of a chemical which produces death in 50% of a population of test animals to which it is administered by any of a variety of methods
    • Normally expressed in mg/kg
  52. LC50
    • Concentration of chemical in an environment which produces death in 50% of an exposed population of test animals in specified time frame
    • Normally expressed in mg/L
  53. Primary routes of exposure to pesticides
    • Oral
    • Dermal
    • Inhalation
Card Set
Environmental Biotech
2013 Environmental