Chapter 3 Environmental Toxicology Flashcards

Vocabulary flashcards covering key terms, historical figures, definitions, processes, and concepts from the lecture on Environmental Toxicology.

Basic Assumption of Toxicology

All substances are poisons; there is none that is not a poison. The right dose differentiates a poison from a remedy.

Toxicology

The study of the adverse effects of chemicals on living organisms.

Paracelsus

One of the founders of modern toxicology; contributed to the concept of the dose-response relationship and notion of target organ specificity of chemicals.

Mathieu Orfila

Authored Trait des poisons (1813); described various types of poisons and their bodily effects, contributing to forensic toxicology.

Toxicologist

A scientist extensively trained to investigate the adverse effects of chemicals in living organisms and assess the probability of their occurrence.

Environmental Toxicology

Examines how environmental exposures to chemical pollutants may present risks to biological organisms such as animals, birds, and fish.

Poison

Any agent capable of producing a deleterious response in a biological system.

Toxicity

The degree to which something is poisonous, related to a material
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fs physical and chemical properties.

Toxicants

Toxic substances that are human-made or result from human (anthropogenic) activity.

Toxin

Usually refers to a toxic substance made by living organisms, such as reptiles, insects, plants, or microorganisms.

Dose

The amount of a substance administered at one time.

Lethal Dose 50 (LD50)

The dosage (mg/kg body weight) causing death in 50 percent of exposed animals, used to compare the toxicities of different chemicals.

Dose

Response Relationship

A type of correlative relationship between the characteristics of exposure to a chemical and the spectrum of effects caused by the chemical.

Dose

Response Curve

A type of graph used to describe the effect of exposure to a chemical or toxic substance upon an organism.

Threshold

The lowest dose at which a particular response may occur.

Routes of Exposure

Ways a chemical can enter the body, including ingestion, injection, dermal contact, and inhalation.

Additivity

A combination of two chemicals produces an effect equal to the sum of their individual effects.

Synergism

The combined effect of exposures to two or more chemicals is greater than the sum of their individual effects.

Potentiation

One chemical that is not toxic causes another chemical to become more toxic.

Antagonism

Two chemicals administered together interfere with each other
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fs actions, or one interferes with the action of the other.

Acute Exposure

A single exposure for less than 24 hours.

Subacute Exposure

Exposure for 1 month or less.

Subchronic Exposure

Exposure for 1 to 3 months.

Chronic Exposure

Exposure for more than 3 months.

Local Effects

Damage where a chemical first contacts the body.

Systemic Effects

Generalized distribution of a chemical throughout the body by the bloodstream to internal organs.

Target Organ Effects

Chemical effects confined to specific organs.

Latency

The time period between initial exposure and a measurable response, ranging from seconds to decades.

Carcinogen

A chemical (or substance) that causes or is suspected of causing cancer.

Risk Assessment

Provides a qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards.

Hazard

The inherent capability of a natural or human-made agent or process to adversely affect human life, health, property, or activity.

Hazard Identification

Examines the evidence that associates exposure to an agent with its toxicity and produces a qualitative judgment about the strength of that evidence.

Dose-Response Assessment

Measures the relationship between the amount of exposure and the occurrence of the unwanted health effects.

Exposure Assessment

A procedure that identifies exposed populations, describes their composition and size, and examines the routes, magnitudes, frequencies, and durations of such exposures.

Risk Characterization

Develops estimates of the number of excess unwarranted health events expected at different time intervals at each level of exposure.

Risk Management

Specific actions taken to control exposures to toxic chemicals in the environment, such as exposure standards or product recalls.