Exam 1 Flashcards
Paracelcus
Is is the dose that determines the poison. 1400’s to 1500’s - “on the miner’s sickness and other diseases of miners
Carson
The Silent Spring
Potts
Chimney Cleaners and scrotal cancer
Socrates
Discourse on the diseases of workers
Wiley Bill
Food and Drug admin begins
National Institute of Health Formed when?
1930
Federal Insecticide, Fungicide, Rodenticide Act did what?
Provides for federal regulation of pesticide distribution, sale, and use
Delaney clause of the Food Drug and Cosmetic Act enacted when and did what?
1958 - banned carinogens from being added to food supply for animals and humans
Cuyahoga River did what and when?
Caught fire for the 13th time in June 1969. “oozes rather than flows.” “does not drown, but decays”
What is the LD50 and what does it do?
Its the lethal dose of 50% of people. Kills 50% of people who are poisoned.
What is the TD50 and what does it do?
Toxic 50. Makes 50% of the people who use it sick.
What is ED50 and what does it do?
Effective Dose 50. Works on 50% of people who use it.
What is the TI and how do you figure it out? Whats the equation?
Therapeutic Index. Ratio of the dose required to elicit a toxic and the dose needed to elicit a desired effect. TD50/ED50
What is the margin of safety, and its equation?
Indicator of the magnitude of difference between the undesired and desired effects. LD1/ED99
What are the problems with interpreting dose response curves with mouse studies for humans?
Differences in species. Lack of genetic variability. Different environments. Same food, inbred, other medications for humans.
What is the reference dose equation?
No Observed Adverse Effect Level divided by the uncertainty factor times the modifying factors.
The ADI should be how much safer for humans than mice?
100 times
Explain hormesis? What does a graph showing Hormesis look like?
negative effects and low and high doses, but moderate doses can provide beneficial effects. The graph has a U shape.
What is an additive interaction?
Add both together and creates a total effect. 4+5=90
What is a synergistic interaction?
Combine the two effects for a random number. 4+5=90
What is a potentiation interaction?
One by itself but other does. One number is 0. 4+0=90.
What is an antagonistic interaction?
Sum of effects is less than them by themselves. 4+5=1
Time in Toxicology: Acute Exposure
Less than 24 hours (workplace = single incident/spill)
Time in Toxicology: Subacute Exposure
Repeated exposure for 30 days or less (workplace = not used)
Time in Toxicology: Subchronic
1 -3 months (workplace - weeks or months)
Time in Toxicology: Chronic
Over 3 months (workplace - many months or years)
Where is the no observable adverse effect level on a graph?
Biggest dose that is still produces 0 effects.
Where is the lowest observable adverse effect level on a graph?
Point directly after 0.
Where does a stochastic/Non-threshold graph start?
0
Where does a nonstachastic/threshold graph start?
After 0
What are the four routes of exposure?
Ingestion, Inhalation, Dermal, and Injection
What are the steps of toxicant delivery?
0) Exposure 1) Delivery 2) Reaction 3) Dysfunction 4) Repair or Failure to repair
The term absorption refers to?
Putting chemicals into systemic circulation
What factors influence whether or not a chemical/toxicant is absorbed?
Concentration, Surface area, characteristics of epithelial layer where could be absorbed
Hydrophilic:
Like mixes with like - water soluble.
Hydrophobic
Like mixes with like, not water soluble
SOAP Micelle
Like mixes with like, polar on outside, nonpolar on inside.
Most toxicants cross membranes by what?
Simple Diffusion
What does rate of diffusion depend on?
Lipid Solubility (measured by partition coefficient)
What are some examples of specialized barriers int he body from preventing transport of harmful agents to sensitive organs?
Blood brain barrier, placental, Blood testitis, oocyte.
What two organs in the body are most porous and have large fenestrae?
Kidneys and Liver
What about brain barrier is unlike the kidneys or liver?
Tight capillaries
What are the steps for risk assessment?
1) Hazard Identification 2) Dose Response Assessment 3) Exposure Assessment 4) Risk Characterizations 5) Risk Management Decisions
