Ecotoxicology

Question 1

What is Ecotoxicology?

Answer 1

• the study of the behaviour, fate, exposure and adverse
  effects of chemicals and other potentially toxic substances
  on the structure and function of natural ecosystems and
  their biological components
• a multi-disciplinary science

Question 2

What does REACH stand for?

Answer 2

Registration, Evaluation and the Authorisation of Chemicals

Question 3

What are some of the ABIOTIC components of ecotoxicology?

Answer 3

PHYSICAL SCIENCES
Geology
Oceanography
Atmospheric Chemistry
Climatology

Geography
Hydrology
Soil Science
Sedimentology

Colloid Chemistry
Physical Chemistry
Analytical Chemistry
Organic Chemistry
Inorganic Chemistry

Question 4

What are some of the BIOTIC components of ecotoxicology?

Answer 4

LIFE SCIENCES
Global Ecology
Landscape Ecology
Systems Ecology
Environmental Microbiology
Community Ecology
Metapopulation
Biology
Population Biology
Genetics
Epidemiology
Physiology/Anatomy
Behavior
Teratology
Neurology
Pharmacology
Endocrinology
Immunology
Pathology
Oncology
Biochemistry/Biophysics
Molecular Genetics

Question 5

What are the two paradigms?

Answer 5

• Dilution paradigm= old
  –> “dilution is the solution to pollution”
  does not work if everyoone spread it out, then you still get high concentrations

Boomerang paradigm: new way to think
–> “what you throw away can come back and hurt you”

Question 6

What is “Dose descriptor”?

Answer 6

term used to identify the relationship between a specific effect of a chemical substance and the dose at which it occurs

Question 7

What is DNEL

Answer 7

Derived No-Effect Level
: defined as the level of chemical
exposure above which humans should not be exposed

Question 8

What does SF stand for?

Answer 8

Slope factor

Question 9

What does RfD stand for?

Answer 9

Reference Dose

Question 10

What does TLV stand for?

Answer 10

Threshold limit value
: for chemical substancens it is defined as concentration in air (inhalation or skin exposure)

Question 11

What are the three types of TLVs for chemical substances?

Answer 11

• Time weighted average (TLV-TWA): average exposure on the basis of a 8 h/day, 40 h/week
  work schedule
• Short-term exposure limit (TLVSTEL): spot exposure for a duration of 15 min, that cannot
  be repeated more than 4 times per day
• Ceiling limit (TLV-C): absolute
  exposure limit that should not be exceeded at any time

Question 12

What does NOEC stand for?

Answer 12

No Observed Effect Concentration:
the concentration in an environmental compartment (water, soil, etc.) below which no statistically significant effects on population is likely to be observed

Question 13

What does LOEC stand for?

Answer 13

Lowest Observed Effect
Concentration:
the lowest of the concentrations with statistically significant effects

Question 14

What is ECX?

Answer 14

effective concentration: the conc of a compound where X% of its maximal effect is observed

Question 15

What is LCX?

Answer 15

lethal concentration: the conc where X% of the
population of the tested organisms are
expected to die during the observed period

Question 16

What is TU?

Answer 16

Toxic Unit:
Concentrations of toxicants expressed in units of lethality or effect

Question 17

What is the assessment factor used for?

Answer 17

As a safety factor
The more insecure your data is, the higher the assessment factor

Question 18

What are the ways of conventional ecotoxicologial risk assesment?

Answer 18

• hazard identification
• assessment of exposure (predicted environmental concentrations, PEC)
• hazard characterization (predicted no effect concentrations, PNEC)
• risk characterization based upon the risk quotient (PEC/PNEC for water, sediment, and biota)

Question 19

What are the most important drawbacks of the conventional ecotoxicologial risk assesment?

Answer 19

• large uncertainties in extrapolating data across doses, species, and life stages
  (uses 1 type of alge or 1 type of insect)
• poor assessment of contaminants with non monotonic dose–response relationship
• the lack of data (e.g., environmental degradation) for emerging contaminants
• the non inclusion of adaptation in polluted environments
• Not many different concentrations are tested–> some species can have specific reactions on specific concentrations
• there could be a cumulative effect

Question 20

What is BCF?

Answer 20

Bioconcentration factor:
if 10 times higher concentration in fish then water–> BCF = 10

Question 21

What is BMF?

Answer 21

Bio magnification factor:
how much the concentration rises in each trophic level (Ex. alge 1 ng –> *10–> fish 10 mg)

Question 22

What is BAF?

Answer 22

Bio accumulation factor

Question 23

What is PBT?

Answer 23

Persistant Bio Magnification toxicity