Term
| basic assumptions of toxicology |
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Definition
| all substances are poisons; there is none that is not a poison. the right dose differentiates a poison from a remedy. "the dose makes the poison" |
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Definition
| the study of the adverse effects of chemicals on living organisms |
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Term
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Definition
--one of the founders of modern toxicology
--active during time of da Vinci and Copernicus (early 16th century)
--contributions included the dose-response relationship and the notion of target organ specificity of chemicals |
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Definition
--1800s, he authored a number of significant works, among them "Trait des poisons" (1813)
--this work described various types of poisons and their bodily effects, a development that contributed to the foundations of forensic toxicology |
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Term
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Definition
| scientist who has recieved extensive training in order to investigate in living organisms "the adverse effects of chemicals...(including their cellular, biochemical, and molecular mechanisms of action) and assess the probability of their occurrence. |
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Definition
-regulatory
-forensic
-clinical
-environmental
-reproductive
-developmental |
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Term
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Definition
examines how environmental exposures to chemical pollutants may present risks to biological organisms, particularly animals (including humans), birds, and fish.
--exposures
--pollutants |
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Term
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Definition
any agent capable of producing a deleterious response in a biological system
--effects: lethal, sublethal |
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Term
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Definition
--refers to the degree to which something is poisonous
--denotes the amount (mass) of a substance that can produce a deleterious effect |
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Definition
--usually refers to a toxic substance made by living organisms, including reptiles, insects, plants, and microorganisms
--examples: bacterial toxins, mushroom toxins, foxglove, rhubarb, nicotine |
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Definition
| toxic substances that are man-made or result from human (anthropogenic) activity |
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Definition
| refers to the amount of a substance administered at one time |
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Term
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Definition
-exposure dose
-absorbed dose
-administered dose
-total dose
-external dose
-internal dose
-biologically effective dose |
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Term
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Definition
| the dosage causing death in 50% of exposed animals. used to compare the toxicities of different chemicals. |
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Term
| dose-response relationship |
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Definition
--a type of correlative relationship between the characteristics of exposure to a chemical and the spectrum of effects caused by the chemical.
--one of the ways we understand toxicity is the presence of a relationship between the amount of the dose and the biological response |
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Term
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Definition
| a type of graph used to describe the effect of exposure to a chemical or toxic substance upon an organism such as an experimental animal |
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Term
| two types of dose-response curves |
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Definition
1. one for the responses of an individual to a chemical
2. one for a population |
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Term
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Definition
| refers to the lowest dose at which a particular response may occur |
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Term
| factors that affect the concentration and toxicity of a chemical |
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Definition
1. route of entry into the body
2. received dose of the chemical
3. duration of exposure
4. interactions that transpire among multiple chemicals
5. individual sensitivity |
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Term
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Definition
1. gastrointestinal tract
2. bloodstream
3. lungs
4. skin/eyes/mucous membranes |
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Term
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Definition
1. ingestion (consumption of contaminated food or drink)
2. injections into the bloodstream
3. contact with the surface of the skin
4. inhalation |
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Definition
| the study of the internal kinetics of all toxic substances |
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Term
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Definition
--the process by which drugs and toxicants gain entrance into the body
--several factors affect the likelihood that a xenobiotic will be absorbed
--the most important are: route of exposure, concentration of the substance at the site of contact, and chemical and physical properties of the substance |
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Term
| 4 principle mechanisms involved in contaminant movement across membranes |
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Definition
1. passive diffusion
2. facillitated diffusion
3. active transport
4. endocytosis |
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Term
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Definition
| --important mechanism for the passage of most contaminants across all membranes and is a function of: lipid solubility, concentration gradient, molecular size of the contaminant, membrane thickness, and degree of ionization |
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Term
| metabolism of organic contaminants involves 2 reactions |
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Definition
1. reactions in the metabolism of organic contaminants in which reactive groups are added or made available. (addition of an OH group. P450s)
2. reactions in which conjugates are formed that inactivate the compound and foster elimination. (addition of other groups. GST, ST, UGT) |
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Term
| Effects of chemical mixures |
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Definition
1. additive
2. synergism
3. potentiation
4. antagonism |
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Term
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Definition
the combination of two chemicals produces an effect that is equal to their individual effects added together
***most common*** |
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Definition
| indicates that the combined effect of exposures to two or more chemicals is greater than the sum of their individual effects |
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Definition
| happens when one chemical that is not toxic causes another chemical to become more toxic |
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Definition
| two chemicals administered together interfere with each other's actions, or one interferes with the action of another. |
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Term
| terms that describe exposure duration |
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Definition
1. acute
2. subacute
3. subchronic
4. chronic |
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Term
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Definition
| usually a single exposure for less than 24 hours |
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Term
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Definition
| exposure for one month or less |
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Definition
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Definition
| exposure for more than 3 months |
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Term
| direct adverse effects of exposure to chemicals |
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Definition
1. local effects
2. systemic effects
3. target organ effects |
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Term
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Definition
| damage at the site where a chemical first comes into contact with the body |
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Term
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Definition
| generalized distribution of the chemical throughout the body by the bloodstream to internal organs |
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Term
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Definition
| some chemicals may confine their effects to specific organs |
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Definition
| the time period between initial exposure and a measureable response (can range from a few seconds to decades) |
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Definition
| a chemical (or substance) that is suspected of causing cancer, a disease associated with unregulated proliferation of cells in the body. |
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Term
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Definition
| subjects include: volunteers who have had normal or accidental exposures, animals exposed purposeively (in vivo experiments), and cells derived from human, animal, or plan sources (in vitro experiments) |
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Definition
| provides a qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences |
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Term
| process of risk assessment |
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Definition
1. hazard identification
2. dose-response assessment
3. exposure assessment
4. risk characterization |
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Term
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Definition
| inherent capability of an agent or situation to have an adverse effect |
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Term
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Definition
| examines the evidence that associates exposure to an agent with its toxicity and produces a qualitative judgement about the strength of that evidence |
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Term
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Definition
| measures the association between the amount of the exposure and the occurrence of unwanted health effects |
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Term
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Definition
| as used in risk assessment, are factors, usually of 10, to decrease a No Observed Adverse Effect Level (or LOAEL) in order to compensate in a conservative direction for uncertainty. |
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Term
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Definition
1. what populations are exposed?
2. what is the route of exposure?
3. what is the magnitude of exposure?
4. how frequently do these exposures happen?
5. how long do the exposures last? |
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Term
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Definition
--develops estimates of the number of excess unwarranted health effects expected at different time intervals at each level of exposure (probability)
--details adequacy of the data used in the statement of risk, uncertainty involved in the conceptual model, and weight of causal evidence between exposure and effect |
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Term
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Definition
--follows risk characterization
--seeks to control exposures to toxic chemicals in the environment |
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