Toxicity tests Flashcards
What are the three ways of measuring toxicity?
Early life stages
Biomarkers
Behaviour
Points on ELS
Uses organisms at sensitive period of time i.e eggs, larvae, juvenile and tests varying concentrations of toxins on their development
Allows for short tests on long lived species
Time of study species dependent
Most commonly used species - fathead minnow (Pimephales promelas)
What is the most commonly used fish in ELS expetiments
Fathead minnow (Pimephales promelas)
Advantages of ELS
Most sensitive stages Cheap Simple to do Requires less space Repeatable Allows for short tests on long lived species
Disadvantages of ELS
Can be time and resource intensive
Additional Reading ELS - Effective organisms in ELS testing
Birge et al., 1983
Fish and amphibians shown to be effective for checking toxicity in ELS tests
Additional Reading ELS - Growth
Woltering, 1984 review
Showed that growth is rarely effected in ELS tests and so should be scrapped in order to save time and money
Additional Reading ELS - fathead minnow
Benoit et al., 1982
Larval growth and survival rate are the most sensitive indicators of toxic stress in Fathead minnows
Points on Behaviour as a toxicity test
Toxicity can be measured by studying induced behavioural changes outwith the normal variability
Fish behaviour is very sensitive to environmental variables and toxic substances
Behavioural changes measured can include locomotive, feeding and social interactions
Advantages of Beh.
Non invasive More sensitive to lower concentrations Can be done in the field Toxic effects can be directly seen on organisms Looks at secondary/tertiary effects
Disadvantages of Beh.
Time consuming
Subjective
Organism must be well studied
Additional Reading Beh. - microorganisms
Gilron et al., 1999
Showed protozoan behaviour can be effected by toxins
Additional Reading Beh. - worms
Anderson et al., 2004
Showed that nematodes (C.elegans) subjected to heavy metals reduced movement in comparison to controls
Additional Reading Beh. - Crabs
Krang and Ekerholm, 2006
Showed that male shore crabs (Carcinus maenus) subjected to copper showed reduced mating behaviour
Points on Biomarkers
Biomarkers are physiological or biochemical changes brought on through interaction with a contaminant which leads to altered structure or function of a cell or organ Common biomarkers include Body Condition Index (BCI) Gonadosomatic Index (GSI) Measures of Oxidative Stress Acetlycholinesterase activity Gill Na+K+ATPase activity
Points on Oxidative stress as a biomarker + study
Exposure to toxicants can alter oxidative stress
Sayeed et al., 2003
Showed that in Snakehead fish (Channa puntatus) pyrethroid exposure lead to an increase in the oxidative stress within the fish
Points on Acetylcholinesterase activity + study
Pollutants have been shown to interfere with acetylcholinesterase, the main component of acetylcholine breakdown.
Lionetto et al., 2003
Showed that AChE levels could be used in mussels found in Italian coastline to measure both metal and pesticide contaminants
Points on Na+K+ATPase + study
Na+K+ATPase important in osmoregulation
McCormick, 2011
Showed that tests on NaBLA levels can be a non-lethal test of toxicity using Atlantic salmon (Salmo salar) and removing a small portion of the gill now subsequent harm came to the fish as a result and toxins could be measured effectively
Advantages of Biomarkers
Can be less invasive
Can be done in the field
More accurate
Disadvantages of Biomarkers
Some lethal Most expensive Too focused Time consuming Specialised
Additional Reading - ELS
Matta et al., 1998
- O.mykiss larvae exposure to PCB at concentrations of 1,5 and 20 mg/L
- no significant difference in accumulation (2.1-2.5 micrograms) in any of the test subjects
- Significant difference though in gonadal abnormalities between test and control
- Levels of accumulation commonly seen in wild, if not more so
ELS - Additional Reading List
Birge et al., 1983 Woltering 1984 Benoit et al., 1982 Hirao et al., 1995 - iron exposure (O.mykiss) Fry and Toone, 1981 - Gull eggs Matta et al., 1998 - PCB O.mykiss
Biomarker Reading List
Inverts
Schulte-Oehlmann et al., 1996+1997
Lionetto et al., 2003
Birds and Reptiles Giullette et al., 1998 Fry and Toone., 1981 Fry et al., 1968 Hellander et al., 1982
Fish Zhang et al., 2016 Ferraro et al., 2004 Sayeed et al., 2003 Tyler et al., 2008 McCormick 2011
Mammals
Facemire et al., 2005
Wiig et al., 1998
Cattet et al., 1988
Additional Reading - List of Biomarkers
Norin and Hansen 2013
