Properties of pollutants

Question 1

State of matter

Answer 1

Is polluting material solid, liquid, or gas

- affects ability to be dispersed, solid close to source, gases transported easily in atmosphere.

Question 2

Energy form

Answer 2

E.g. noise, heat, ionising radiation or light

- varying impacts cos way energy behaves.

Question 3

Density

Answer 3

Density of material effects its dispersal.

- denser materials require more kinetic energy to keep suspended, so more likely close to source.

Question 4

Persistence

Answer 4

Measure of length of time that pollutant remains in environment before it degrades.
- measured in half-life
high persistence - CFCs, Organochlorine insecticides
low persistence - Sewage, Pyrethroid insecticides

Question 5

Toxicity

Answer 5

How poisonous substance is to living organisms.

- lead inhibits enzyme action in nerve cells.

Question 6

Specificity

Answer 6

Property of toxic pollutants, its how specific toxins are more toxic to some groups than others.
Non-specific pollutants have similar toxicities to all groups.

Question 7

Reactivity

Answer 7

Affects severity of pollution caused

- either increasing or reducing problems caused.

Question 8

Primary/Secondary pollutants

Answer 8

Primary pollutant - released by human activities.
Secondary pollutant - produced from chemical reactions between 1 or more primary pollutants and often with non-pollutants.

Question 9

Adsorption

Answer 9

How pollutants can become attached to surface of materials e.g. soil particles, or aquatic sediments.

Question 10

Solubility in lipids/water

Answer 10

Substances with high water solubility easily dispersed in water bodies e.g. nitrates
- can reduce pollutant concentration, may affect larger area.
Substances that dissolve in lipids may pass through cell membranes & stored in oil or fat deposits e.g. mercury.

Question 11

Bioaccumulation

Answer 11

Process by which amount of substance within organism increases.

• often involves long term ingestion of small doses which eventually build up reaching toxic level.
• Liposoluble pollutants more likely to bioaccumulate cos the can be stored in lipids.
• Water-soluble pollutants excreted from body easier.

Question 12

Biomagnification

Answer 12

Substances that bioaccumulate may become more concentrated passing along food chain.
Organisms in later trophic levels often have longer lifespans so build up higher concentrations - ingest more of pollutant.

Question 13

Synergism

Answer 13

Involves two or more pollutants where their EFFECTS interact to create a different effect, usually more serious one.
- E.g. ozone damages leaf cuticles > enables sulfur dioxide to cause mo damage to newly exposed living cells.

Question 14

Mutagenic action

Answer 14

Mutagens cause changes in chemical structure of DNA.

• Gonadic
• Somatic

Question 15

Teratogenic action

Answer 15

Teratogens cause birth abnormalities by preventing normal gene expression.
- INHIBIT FUNCTION OF PROTEINS & ENZYMES normally controlled by DNA.
Teratogenic pollutants e.g. Mercury

Question 16

Mobility

Answer 16

Ability of pollutant to move in environment, depends on:
State of matter, Density, Solubility in water.
More mobile > likely to travel greater distances & affect larger areas. ( dilution may reduce severity of effect).

Question 17

Gonadic effects

Answer 17

Mutations in egg, sperm cells or embryo.

Question 18

Somatic effects

Answer 18

Mutations in general body cells

- consequence of DNA mutation in general body cells not killed is cancer.

Question 19

Liposoluble pollutants

Answer 19

More likely to bioaccumulate cos the can be stored in lipids.

Question 20

Water-soluble pollutants

Answer 20

Excreted from the body easier.