toxicology- The study of the adverse effects of chemicals on living organisms.
Xenobiotic- A chemical foreign to the biological system.
Toxicity- The degree something is poisonous, the amount to produce a harmful effect.
Toxicant- Toxic substance produced by humans toxic substance made by a living organism.
Toxicologist- scientist who has received extensive training in order to investigate in living organisms “the adverse effect of chemicals and assess the probability of their accurance.
Hepatotoxins- damage the liver (carbon tetrachloride, nitrosamines).
Nephrotoxins- damage the kidney (halogenated hydrocarbons, uranium).
Neurotoxins- damage the nervous system (mercury, lead, carbon disulfide).
Hematopoietic agents- damage the blood system (carbon monoxide, cyanide).
Pulmonary agents- damage the lungs (silica, ashestos, chlorine).
Teratogens- damage the fetus (load, ethyl alcohol).
Cutaneous hazards- damage the skin (ketones, chlorinated compounds).
Eye hazards- by organic solvents, acids.
Dose- the amount of a substance administered at one time.
LD50- lethal dose- The dosage causing death and 50% of animals.
Threshold- The lowest dose at which I response occurs, a sub threshold those, has no response.
Acute- Usually a single exposure for less than 24 hours.
Subacute- exposure for one month or less.
Subchronic- Exposure for 1 to 3 months.
Chronic- Exposure for more than three months.
Latency- The time period between initial exposure and a measurable response.
Biomarkers- or chemicals or genetic changes that relate to an exposure.
Risk- Is the probability.
What separates a poison from a remedy? The Dose
Indigenous people- identified plant and animal toxins.
Ludius Cornelius Sulla- Issued the first law against poisoning.
Paracelsus- First identified the dose response relationship and the notion of target Oregon specifically.
World War 1- Gases such as chlorine, phosgene and mustard were used to kill 100,000 soldiers, phosgene gas was the most deadly.
What is a dose response curve? A graph used to described the effect of exposure to a chemical or tocsin on an organism such as an experimental animal.
What are the routes of entry for toxic chemicals? Intravenous, inhalation, ingestion and dermal.
Intravenous- blendstream and Fastest.
Inhalation- lungs and 2nd fastest.
Ingestion- G.I. tract, slow affect.
Dermal- through the skin, slowest effect.
What does the actual dose that a person receives depend on? The concentration of the chemical, The frequency of exposure and The duration of exposure.
4 Effects of interactions? additive, synergistic, potentiation and antagonistic.
Additive Effect- combination effect is equal to the individual effect added together. (Ex. Taking both aspirin and acetaminophen.)
Synergistic Effect- Combination effect is greater than some of the individual effects. (Smoker & asbestos are 50 to 90 times more likely for lung cancer).
Potentiation Effect- A non-toxic chemical causes another chemical to be more toxic.
Antagonistic Effect- Chemicals inhibit each others actions.
What factors influence Individual sensitivity? Age, sex, race, nutrition habits, physical condition, obesity, medical conditions, drinking, smoking, and pregnancy.
What is sensitization? an allergic reaction to a chemical (rash, itching, burning eyes, sore throat).
What causes cancer? A Series of mutations in a cells DNA, the latency period may take as long as 40 yrs.
What are some known human carcinogens? Arsenic, Asbestos, Benze, codmium, chromium, estrogen therapy Ethyl alchohol, formaldehyde, Hep B and C, Nickel, Golar radiation, Vinyl chloride.
What is risk assessment? Provides a qualitative/Quantitive estimation of the likelyhood or adverse effects that may result from exposure to specified health hazzards or from the absence or beneficial influences.
Identify and explain the 4 steps to risk assessment?
Hazzard identification- Biological becteria, chemical- carcinogen, Physical- radiation, Mechanical- noise, Psychosocial- work related stress, Fatigue.
Dose-response assessment- measuring the amount of exposure and the subsequent response.
Exposure Assessment- Identify and describe the population exposed, Determine where and how the exposure occurs and Determine the degree of exposure.
Risk characterization- integrates information from hazzard identification, dose response, relationship and exposure assessment. Performed to provide policy makers with a Synopsis of all info about the nature of the risk at enables an eval of it.
What are examples of biomarkers? -Metals can be identified in blood, bone, hair. Radiation exposure can be identified by chromosome aberrations. Volatile organic compounds can be found in blood and breath.
What is risk management and when is it done? Done AFTER Risk Assesment. Actions taken to control exposure and reduce or avoid the risk.
Identify and explain the simple formula for risk? Toxicity X exposure = duration of exposure X concentration of the agent.
What is significant of the 2007 European study of Parkinson's Disease? People who had been exposed to low levels of pesticides were Found to be 1.13 times more likely to have P.D. compared to those not exposed. High levels were 1.41 x more likely to have P.D. PD occurred 1.35 X more freq in people who had been knocked unconscious & rose 2.53 more frequent in those who had been Knocked out more frequent.