Lecture Notes on Pollution and Environmental Toxins

Flashcards about pollution, toxins, and environmental contamination.

What is pollution?

The presence of substances and/or heat in environmental media (air, water, land) whose nature, location, or quantity produces undesirable environmental effects.

Name four different 'flavors' of toxins.

Neurotoxin, carcinogen, teratogen, and mutagen.

What is a neurotoxin?

A toxin that specifically attacks nerve cells, disrupting or altering their activities.

What is a carcinogen?

A toxin that concentrates in fats and cell membranes, causing cancer.

What is a teratogen?

A toxin that causes abnormalities during embryonic growth.

What is a mutagen?

A toxin that damages or alters genetic material (DNA, RNA) in cells, which can lead to birth defects or tumors.

What are EDCs (Endocrine Disrupting Compounds), and what is their major source?

Synthetic hormones, like those in birth control pills; major source is wastewater effluent.

What are the general health impacts related to EDC (Endocrine Disrupting Compounds)?

Feminization of male fish due to hormonal interference, and disruption of normal endocrine functions.

What is TRIS (Tris(2,3-dibromopropyl) phosphate), and where was it commonly used?

A flame retardant used in children’s pajamas in the 1970s.

What is PBDE (Polybrominated Diphenyl Ethers), and where is it commonly found?

Flame retardants found in electronics and furnishings; used to replace TRIS. Commonly found in anything carrying electrical current, building materials and textiles.

What are the generalized effects of PBDE's?

Hormone disruption and decreased fertility (fecundability)

What are PAHs (Polycyclic Aromatic Hydrocarbons), and where do they come from?

Combustion byproducts, solvents, components of fuels; come from burned organic matter (like meat, fuel).

What are the general health impacts of PAH's?

Highly carcinogenic; likes to concentrate in fats and cell membranes.

Why are pharmaceuticals so hard to regulate as a chemical class?

They are numerous, diverse, and often used in small but persistent doses.

What was the DDT 'problem'?

Widespread use of DDT without understanding its environmental persistence and bioaccumulation.

What impact did the DDT problem have in the area of pollutant contamination?

Realization that even non-acute toxics can be dangerous due to persistence and long-term exposure, especially in fat-rich tissues. Led to greater attention on environmental fate.

What is environmental fate?

How a chemical moves and persists in the environment—whether it stays in water, air, or biota.

What are the Three 'T's of environmental fate?

Transport, Transformation, and Transfer.

Define Transport in the context of environmental fate.

How a chemical moves through air, water, or soil and remains in one compartment.

Define Transformation in the context of environmental fate.

Structural change or breakdown of a chemical by an agent.

Define Transfer in the context of environmental fate.

Movement of a chemical between compartments.

What is bioaccumulation?

When a substance builds up in an organism over time, typically from the environment (e.g., fish absorbing contaminants from water).

What is biomagnification?

Increase in contaminant concentration as you go up the food web (e.g., from plankton → small fish → large fish → humans).