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Background Information for “Toxicity Testing with California Blackworms and Alcohol” Created by Stefani D. Hines with modifications by Debbie Gevirtzman, SWEHSC, University of Arizona. INTRODUCTION TO TOXICOLOGY. What is it? How is it used?. Toxicology .
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Background Information for “Toxicity Testing with California Blackworms and Alcohol” Created by Stefani D. Hines with modifications by Debbie Gevirtzman, SWEHSC, University of Arizona INTRODUCTION TO TOXICOLOGY
What is it? How is it used? Toxicology
The study of harmful effects of chemicals on living systems Toxicology
Biology Chemistry Physiology Physics Statistics Immunology Ecology Forensic Medicine Clinical Treatments Drug Development Public Health Industrial Hygiene Veterinary Science Agriculture Environmental Science Toxicology
You are already toxicologists! CONGRATULATIONS!
A chemical substance, physical agent, or biological agent that can harm the health of people Hazard
Contact with a hazard Exposure
Ingestion – chemicals can enter the body by eating or drinking Inhalation – chemicals can be breathed into the lungs Absorption - chemicals can enter the body by moving through the skin Routes of Entry
Dose is the amount of a chemical that gets inside of your body. Measured in mg of chemical/kg or lb of weight Dose
Who took the largest dose of Tylenol? Weight: 125 lb 135 lb 20 lb 5 lb Tylenol: 300 mg 600 mg 100 mg 50 mg
Calculating Dose: 50 mg 5 lb = 10 mg/lb 300 mg 125 lb = 2.4 mg/lb
“What is it that is not a poison? All things are poisons and nothing is without poison. It is the dose only that makes a thing not a poison.” Paracelsus, 1493-1541 The Dose Makes The Poison
Most hazardous substances exhibit a “dose-response” relationship. What does this mean? A. The harm caused by the hazard increases as the amount of hazard entering the body (dose) increases. B. It does not matter how big a dose you receive, you will always have the same amount of harm/sickness. C. Exposure to the hazard always results in harm.
Dose-Response Curve for Alcohol Death Labored breathing Unconscious Deep sleep Response Sleep Giddy No effect No effect Dose
Dose-Response Curve for Vitamin D Toxic Healthy Response Unhealthy Dose
Exposure Frequency– how often Exposure Duration– how long Exposure Concentration– how much Exposure
Exposure Dose For a Chemical to Affect You
Acute Toxicity– a high toxicant dose over a short period of time Chronic Toxicity– a small dose of a toxicant over a long period of time Toxicity
Extrinsic Factors– occur outside the body Intrinsic Factors– occur within an individual organism Factors Affecting Toxicity
Age Genetic Difference Body Size Intrinsic Factors
Our biggest chemical risks are with things we have control over Control
Food Exposure to Known Hazards in Daily Lifestyle Cigarettes Alcohol Preventable Poisonings Control
Diet ~35% Tobacco ~30% Occupational exposures & pollution ~5% Infection (viruses) ~10% Other ~20% Genetic susceptibility Sun/radiation Alcohol Factors Contributing to Cancer Risk in the U.S.