ensc lecture 5

Environmental Compartments

Different areas in the environment where substances can transfer and exist.

Lifetime of a Toxicant

The average time a toxicant spends in a particular environmental compartment, also known as residency time.

Persistence

The tendency of a toxicant to remain in a specific compartment over time.

Persistent Organic Pollutants (POPs)

Organic molecules that are toxicants with a lifetime or half-life greater than one year and do not break down easily.

Bioaccumulation

The accumulation of toxicants in the biological organic compartment, involving concentration within living organisms.

Bioconcentration

The partitioning of toxicants into biological organisms from the surrounding environment.

Biomagnification

The amplification of toxicant concentration in organisms when one organism consumes another contaminated organism.

Bioconcentration Factor (BCF)

A measure of how much of a toxicant partitions into an organism from the external environment under controlled laboratory conditions.

Hydrophobicity

A chemical property that describes the tendency of a substance to repel water.

Bioaccumulation Factor (BAF)

A measure that includes all exposure routes of a toxicant, not just from water but also from food.

Case study of DDD

An example illustrating the bioaccumulation of DDD in wildlife, particularly in western grebes after spraying in Clear Lake, California.

DDT Bioaccumulation

The increase in DDT concentration observed as one moves up the food chain or with the age of an organism.

PCB Characteristics

PCBs are hydrophobic organic compounds known for their persistence in biological tissues and sediments.

Kow (octanol-water partition coefficient)

A model that predicts the distribution of a toxicant between lipid tissue and water based on hydrophobicity.

Risk Assessment

The process of estimating potential outcomes and adverse effects of contaminants on ecosystems.