Lecture #3

Question 1

toxin

Answer 1

a naturally produced toxic chemical

Question 2

toxicant

Answer 2

a manmade toxic chemical

Question 3

Chemicals by Function: Flame Retardants

Answer 3

• PBDE (polybrominated diphenylethers)
• HBCDD (hexabromocyclododecane)
• TBBPA (tetrabromobisphenol-A)

Question 4

Chemicals by Function: Pesticides

Answer 4

• OCPS (organochlorine pesticides like DDT)
• OPs (organophosphates)
• neonicotinoids

Question 5

Chemicals by Function: Pharmaceuticals/ Personal Care

Answer 5

• nitromusks (fragrances)
• antibiotics
• drugs and hormones (EX: birth control pills)

Question 6

Chemicals by Function: Misc. Industrial Chemicals

Answer 6

• CFC (chlorfluorocarbon)
• PFC (perfluorocarbon)
• PCBs (polychlorinated biphenyls)

Question 7

Chemicals by Function: Plastics/Plasticizers

Answer 7

• plastic constituents (like BPA)

- plastic plasticizers (like pthalates)

Question 8

Chemicals by Function: Hydrocarbons

Answer 8

• polyaromatic hydrocarbons
• alcohols, phenols
• alkanes and alkenes

Question 9

endocrine disrupting chemicals

Answer 9

any chemical that interferes/interacts with the hormone systems (usually sex hormones)

Question 10

teratogens

Answer 10

chemicals that affect embryo development

Question 11

carcinogens

Answer 11

chemicals that promote cancer

Question 12

neurotoxins

Answer 12

chemicals that poison the nervous system

Question 13

USEPA Toxic Release Inventory

Answer 13

keeps track of all toxic releases

Question 14

environmental chemodynamics

Answer 14

• the study of the path of chemicals in the environment, how they move and where they end up based on physical properties
• chemicals are trying to reach equilibrium

Question 15

fugacity

Answer 15

• the escape potential of a compound
• has units of pressure
• way to predict the sizes of the arrows between compartments
• some chemicals, like DDT, are happier in fish than in water
• more accurate than concentration for predicting the movement of chemicals

Question 16

4 behaviors of chemicals that govern their partitioning

Answer 16

1. adsorption
2. dissolution
3. volatility
4. photostability

Question 17

adsorption

Answer 17

• tendency to bind or stick to sediments and other substrates
• most inorganic mercury in the ocean is bound to sediments
• the binding constant (Ks = conc. in sand/conc. in water) is only true AT EQUILIBRIUM

Question 18

volatilization

Answer 18

• every substance has a vapor pressure dependent on temperature
• moving into atmosphere
• Henry’s constant (conc. air/conc. water) describes the volatilization of organic molecules from water
• ~Hc > 10^-5 is volatilizing

Question 19

dissolution

Answer 19

• solubility
• water is a nearly universal solvent but it prefers polar compounds
• pH and salinity affect solubility

Question 20

photostability

Answer 20

• many compounds absorb energy from sunlight, mostly from UV, which will change their properties
• can make more or less potent

Question 21

4 properties of the environment that govern partitioning

Answer 21

1. dispersion
2. advection
3. atmospheric/oceanic transport
4. biotransport

Question 22

bioconcentration

Answer 22

• passive movement of chemical into organism

- akin to solvent switching

Question 23

biomagnification

Answer 23

• increase in concentration as you go up the food chain

- akin to solvent depletion

Question 24

bioaccumulation

Answer 24

sum of bioconcentration and biomagnification

Question 25

How to measure pollutant levels directly

Answer 25

extract the lipid soluble component from fish slurry and run it through a mass spectrometer

Question 26

bioconcentration factor (BCF or BAF)

Answer 26

conc. in animal/conc. in environment expressed on a log scale log BCF = 6 means there's 1 million times as much chemical in the organism as in the environment

Question 27

solubility of organic compounds

Answer 27

- very nonpolar - usually much more soluble in lipids than in water - octanol used to estimate solubility in fats

Question 28

UV light reacting with CFCs

Answer 28

- chlorofluorocarbons - the radiation strips off a chlorine, which then reacts with ozone to make ClO and O2 - degrades ozone layer