Environmental Toxicology Overview

The potential for a chemical's toxicity to cause harm in a specific situation.

A foreign substance or compound that is not naturally found in the body.

The inherent ability of a chemical to cause harm to a living organism.

The amount of a substance an organism is exposed to.

The adverse effects that occur in an organism after exposure to a chemical.

The lowest dose of a chemical that causes a measurable adverse effect.

The likelihood of a specific adverse effect occurring in a population.

The classification of chemicals based on their toxic effects.

The amount of a substance present in a specific tissue.

The amount of a substance (usually a metabolite) bound to the critical molecule.

The combined effects of exposure to multiple chemicals where the individual toxicities are simply added together (1+1=2).

An interaction between chemicals where the combined effect is less than the sum of the individual effects (1+1 < 2).

The time between the first exposure to a substance and the appearance of a detectable effect.

The air concentration of a pollutant inhaled during a specific time period.

The amount of a substance present in the body at a certain time.

The length of time a person is exposed to a chemical.

The total amount of chemical a person is exposed to over their lifetime.

The highest level of chemical a person is exposed to within a short period of time.

The average amount of chemical a person is exposed to over a longer period.

The concentration of a chemical in the environment and the duration of exposure.

The relationship between the amount of a substance administered (dose) and the magnitude of its effect on an individual.

A graphical representation showing the relationship between the dose of a substance and the percentage of individuals in a population exhibiting a specific effect.

A type of effect where there is either a complete response or no response at all, regardless of the dose.

A dose-response curve with an S-shape representing the increasing response with increasing dose, eventually reaching a plateau.

The range of doses where there is no observable effect on individuals.

The lowest dose that produces a measurable effect.

The variation in susceptibility among individuals in a population to a specific substance.

A factor used in risk assessment to account for uncertainties in toxicity data, often applied to extrapolate from high-dose animal studies to low-dose human exposures.

Predicting toxicity at levels or conditions where no data is available, often based on mathematical models or data from similar substances.

Toxic effects that occur in tissues distant from the point where the substance enters the body.

The primary or most sensitive organ affected by a toxic substance.

Toxic effects that occur after a short exposure period and are experienced soon after exposure.

Toxic effects that develop after long-term exposure and may persist even after exposure ends.

A decreased response to a toxic substance after repeated exposures, often due to the body's ability to adapt.

A dose level below which no observable effect occurs. This is often considered for acute toxic effects but not for carcinogenic effects.

The dose causing 50% lethality in an animal population. A higher LD50 means a substance is less toxic.

The dose causing a specific effect other than death in 50% of the animals.

The highest dose that does not cause a toxic effect. Requires multiple doses and a large population to be sure.

An arbitrary number used to divide the NOEL or LOEL (from animal experiments) to get a safe dose for humans. Used in food and occupational toxicology.

The effects of exposure to a substance can occur long after exposure has stopped.

A common feature of carcinogenic effects, where tumors may not appear until long after exposure.