Term
| Physiological responses to pollutants |
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Definition
Respiration
Cardiovascular
Oxidative metabolism (swimming)
Osmotic and ionic regulation
Feeding & Nutrition
Reproduction
Neurological
Behavioural. |
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Term
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Definition
Can be Measured by O2 consumption or CO2 production.
Respiratory stress caused by Cu is worse in Cypridae than Onchorhyncus mykiss. It is not related to tissue damage but to disruption in ionoregulation. (DeBoeck 2006) |
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Term
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Definition
Heart rate BPM.
Cu increases HR in crabs (Brown 2004)
But this does not measure the stroke volume so circulation may not increase, could be as a clearance measure (Spicer 2007) |
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Term
Oxidative metabolism and swimming
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Definition
Ucrit is a measure of swimming speed.
Environmental ammonia reduced the swimming speed of Onchorhyncus mykiss (Wicks 2002) |
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Term
| Osmotic & Ionic regulation |
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Definition
Ion uptake rate.
Low pH and Al reduce the sodium uptake in pike fry. (Keinanen 2000) Could be because of denaturing channel and ion exchange proteins. |
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Term
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Definition
Vitamin profiles, feeding rates, foraging success. Can be affected by a broad range of contaminants. Ammonia reduces feeding in Onchorhyncus mykiss(Wicks & Randal 2002)
Silver nanoparticles effect gut microbiota (Merrifield 2013)
PCB effect vit A&E profiles in Delphinapterus leucas (DeForges 2013) |
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Term
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Definition
Survival of offspring, No. produced, condition of organs.
Correlation between PCB/DDT concentration and the occurrence of lesions on ovaries in Delphinapterus leucas (Beland 1993).
Oestrogenic compounds can cause intersex in fish.
TBT imposex in Nucella lapulis |
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Term
| Neurological and Behaviour |
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Definition
Lipid soluble compounds can enter neurones via the myelin sheath and may be able to cross the blood brain barrier.
Mercury causes neurone degeneration which can affect behaviours and may be linked to mass strandings of cetacea. Prevents GTP from binding to tubulin. Blocks calcium channels preventing synaptic transfer of action potential. |
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Term
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Definition
Toxicity equivalents. Limits of tolerance. Development of biomarkers. Risk assessment. Pronlem formulation, risk analysis and characterisation.
Where do end points fit in. Which approaches and why. |
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Term
| Dose response relationship |
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Definition
Toxicity is relative: dose and properties determine whether a negative effect is observed.
Environment has a role to play, i.e. availability.
Dose is the amount of substance per body weight or liquid concentration. |
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Term
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Definition
| Can be for one dose at differnt times or set time with different concentrations. |
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Term
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Definition
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Term
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Definition
Toxins effect specific receptor sites.
Dose response is maximal when all receptors are bound to or no more disruption can occur.
Changes in the conformation of enzymes.
Effexts in the nervous system.
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Term
| Dose response assumptions |
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Definition
Response proportional to concentration at target site.
Concentration at target site is related to dose.
The response is causally related to the compound investigated.
DISCUSS THESE HARD!? |
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Term
| End points of dose response |
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Definition
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Term
| Pharmacological use of dose response |
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Definition
Therapeutic index = LD50/ED50
Seperate the lethal and positive effects. |
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Term
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Definition
Lethal concentratio responsible for 50% of the deaths.
Is responsible for most of the deaths but some organisms will be sensitive/resistant. |
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Term
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Definition
Question dependent/
Quantal: death, presence/absence of lesions, behaviours.
Graded: Biochemical change, change in growth rate. |
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Term
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Definition
Threshold dose: no effect is measurable,
Concentration at which the response is not observed. NOAEL
Not observed in carcinogens.
Limited by curve fitting ability and graph making. Number of data points has an effect. |
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Term
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Definition
NOAEL x 10, 100, 1,000 etc.
e.g Acceptable daily intake = NOAEL mg kg-1d-1/100
WQS = NOAEL/1,000 |
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Term
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Definition
NOAEL not always present.
Data analysis- curve fitting, number of data.
With NOAEL: decide on acceptable level above background.
NOAEL doesn't mean safe and long term exposure is much harder to test for.
Often ethical and practical considerations prevent investigation of higher organisms. |
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Term
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Definition
Universally accepted techniques give replicable results.
Gives information about which chemicals are most damaging to organisms inn general. |
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Term
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Definition
| Biological response to chemicals or radiation that gives a measure of exposure at cellular, tissue, organ, individual or population level (Peakall 1994). |
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Term
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Definition
| Frequent or continula gathering of information from a given population that is relevant to that populations health risk. |
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Term
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Definition
| histological, biochemical, physiological, genetic, behavioural. |
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Term
| Chronic multiple exposure |
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Definition
| Long term exposure to multiple contaminants at low levels mean that it is difficult to attribute changes to specific contaminants |
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Term
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Definition
| Natural cycles within organisms may be responsible for any number of physiological changes. E.g Crassostrea gigas haemocytes are governed by the seasons as well as gametogenesis, and other environmental stressors. (Duchemin 2007) |
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Term
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Definition
| Using information from a multitude of biomarkers (give examples) some researchers have attempted to create mathematical models for prediction of pollution gradients. These have mixed success with the largest obstacle being environmental factors and determination of reference sites,(Auffret 2006) |
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Term
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Definition
need to have an understanding of how the organism works and what chemicals do to it.
This can lead to the use of inappropriate sentinel organisms. For example mytilus are well studied and used in ecotoxicological experiments due to their economic importance. However there are molluscs that have increased sensitivity to pollutants that would be more suitable but are not used e.g Cerrastoderma edule (Giron-Perez 2009) |
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Term
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Definition
| Need to be fully understood. No use using an organism as a biomarker for a pollutant if it is completely insensitive or impermeable to that contaminant. |
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Term
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Definition
| Expensive and lengthy investigations to develop best protocols. Need to be agreed upon. Differences between sexes need to be accounted for. |
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Term
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Definition
| Use the most sensitive stage of the organism to indicate what the worst impast are |
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Term
| Trophic level in biomarkers |
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Definition
HIgher levels will show more damage from persistent bioaccumulated chemicals. Lower are more easily used- ethical issues, abundance, husbandry.
Some organisms employ different feeding strategies within species. For example orca can be divided into marine mammal feeders and piscivores. If antioxidant activity in blubber samples was used for a biomarker indicating mercury poisoning than the higher trophic level marine mammal eaters would be more likely to display an effect so it would be necessary to distinguish between the two subspecies. |
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Term
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Definition
| Problematic due to range of exposure as they travel through different environments. Can still be used where biological effect is short term such as HSPs but not for something like organ damage. |
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Term
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Definition
| Difficult to determine for gene expression and enzyme activity but not for histopathology, though this requires euthanasia of organisms. |
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Term
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Definition
| Well studied and understood. Genome known, sensitivities known but not suitable for in situ studies. |
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Term
| Biomonitoring VS Chemical assay |
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Definition
| Less specific but more directly linked to ecosystem health. Can detect impacts of combined contaminants. Cannot id contaminants |
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Term
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Definition
| Demonstrate presence of bioavailable contaminants and extent of exposure |
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Term
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Definition
| Indicate potential human effects |
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Term
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Definition
| long term effect on ecosystem |
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Term
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Definition
| Neutral red dye retention assay used in black sea molluscs to determine stability of lysosome. Low times indicate membrane damage but not which chemical caused it. |
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Term
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Definition
| Across body surface, through GEO, through GIT |
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Term
| Integument of aquatic organisms |
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Definition
Fish: epidermis, dermis (scales), hypodermis.
Crustacea: cuticle, exoskeleton, moult cycle.
Soft bodied inverts: Epidermal layer. |
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Term
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Definition
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Term
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Definition
| Thinner and more permeable then mammals. Maybe be very thin layer to the systemic circulation. Mucosal layer presents no barrier to diffusion of ions (Shephard 1981) |
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Term
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Definition
| Depends on: frequency of exposure & effects on blood flow and distribution |
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Term
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Definition
| influence blood:tissue equilibrium |
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Term
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Definition
| Utilise pores in capillaries. May Dissolve in the lipid membrane |
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Term
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Definition
| Can diffuse through calcium or sodium ion channels. May also diffuse across the cell membrane at physiological pH |
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Term
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Definition
| Induction of metal chaperones and & oxidative stress. Cu is particularly bad. |
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Term
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Definition
| local damage of muscles-point of entry. Depends upon point or diffuse source from the environment. |
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Term
| Gastro intestinal tract (GIT). GUT |
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Definition
| Broadest range of contaminant exposure and absorption. |
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Term
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Definition
| Contaminants that bioaccumulate on or within food items. |
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Term
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Definition
| Ingest contaminants in sediment and water that is eaten. |
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Term
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Definition
| Bioactivation of compounds by bacteria. Make compounds bioavailable and/or more toxic. Also negatively impacted by contaminants e.g. silver nanoparticles (Merrifield et al 2013), which alter the community composition as they are toxic to some,potentially beneficial, of the gut microbiome. |
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Term
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Definition
| In the runoff from land (faecal and aquaculture waste). |
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Term
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Definition
| Anatomical and feeding behavioural. Tilapia stir up sediment while feeding and zebra fish feed in the water column, differences in Hg concentration in the fish tissue. |
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Term
| Water chemistry differences |
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Definition
| As salinity increases Cd uptake in Fundulus heteroclitus decreases as determined by radioisotope measurements of concentration in tissue. Also found that Cd decreases in gills and head but increases in the viscera indicating that increase in drinking for osmoregulation is maintaing some Cd (Dutton & Fisher 2011). |
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Term
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Definition
Lipid soluble-Throughout GIT.
Weak acids-Stomach.
Weak bases and acids-Small intestine.
Strong asids/alkali-Carrier mediated throughout.
Phagocytosi e.g botulinum |
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Term
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Definition
Affects uptake. Oesophagus-Neutral
Stomach-pH 2
Anterior intestine-pH 6 |
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Term
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Definition
Lipophilic compounds in fatty tissues.
Metals to the gills, liver and kidney.
Mostly non polar molecules affect the brain.
Expression of chaperones.
Biliary excretion. |
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Term
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Definition
Contaminants sequestered in bile then reabsorbed via the biliary duct and hepatic portal vein.
Toxic metabolites returned to the gut.
Increases hepatic exposure.
Saturated bile can cause liver necrosis.
Increases the half life of contaminants. |
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Term
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Definition
| G.E.O. with large SA/V ratio. Short diffusion distance and excellent blood supply, only a few layers of cell between environment and circulatory system. |
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Term
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Definition
| Offer some protection but reduce efficiency of the gills exchange processes. |
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Term
| Contaminants cross the gill |
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Definition
| Lipophilics, metals and small molecular weight organics. |
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Term
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Definition
Damage to gill secondary lamellae e.g. hyperplasia caused by irritation.
Rapid distribution thoughout body.
Reduced excretion and gas exchange capability.
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Term
| Distribution through circulation |
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Definition
Some contaminants such as copper can bind to plasma proteins, in Cu case albumin.
These restrict distribution to organs but enhance uptake to blood by lowering the plasma concentration.
Saturation of the blood may be the toxic threshold. |
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Term
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Definition
| System of glands producing hormones that are distributed throughout the body to taget systems using the circulatory system for transport. Glands: Hypothalamus: Pituitary: Pineal: Adrenal: Gonadal: Thyroid: Parathyroid: Pancreas: GIT. |
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Term
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Definition
| Occurs when an exogenous substance intereacts with any element of the endocrine system causing change in function. |
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Term
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Definition
| Peptides, Steroids or Amines. |
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Term
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Definition
| Made from lipids such as cholesterol, most sensitive to anthropogenic chemicals. Produced mainly in the gonads. |
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Term
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Definition
| Testosterone, Estradiol and Glucocorticoids. |
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Term
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Definition
Genomic: Steroid binds to receptor and translocates across cell membrane then diffuses into nuclear membrane and directly effects gene expression.
Non genomic: Steroid binds to receptor on cell surface and initiates autophosphorylation such as cAMP, producing an effect such as membrane bound ion channel modulation (Steinman & Trainor 2007). |
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Term
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Definition
| Blockers and mimics. Blockers prevent steroid binding. Mimics bind and cause an insufficient or excessive response that is generally inappropriately timed. |
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Term
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Definition
Jansen 2004
Increase expression of hormone receptors by inhibitting the action of histone deacetylase which would otherwise reduce expression.
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Term
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Definition
| Endocrine disrupting effects have been well studied in some species. For example tributyltin TBT causes imposex in the dog whelk (Nucella lapulis) (Smith 2006). In females a penis developed to block the oviduct eventually leading to sterility. |
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Term
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Definition
| Exposure to DDT causes a reduction in shell mass. This is likely caused by the 65% in Ca-ATPase activity. (Kolaja 1977) |
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Term
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Definition
| Critical for growth and development particularly brain and nerone development. |
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Term
| Thyroid disruption in Orca |
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Definition
| Villanger et al 2011 recorded that the blubber concentration of PCB PBDE and HCB were inversely correlated to thyroid hormone levels. |
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Term
Alligator example
DDT DDE DDD |
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Definition
Metabolite of DDT apear to have caused changes in the levels of sex hormones in alligators in lake apopka.
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Term
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Definition
| Reproductive issues. Hormone imbalance. Low hatching rates, physical abnormalities e.g. multiple eggs in one folicle. Genitals not producing properly. Increased estrogen to testosterone ratios in both sexes. ( DDT metabolites interacting with sex organs during development (Harrison 1999). |
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Term
| Crassostrea gigas fisheries in france. |
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Definition
| TBT an antifoulant caused massive reductions in spatfall. This suggests that TBT was acting on the settling mechanism. Shell deformities in adults could be due to calcium metabolism being altered. (Rulz 1999) |
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Term
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Definition
| Endogenous estrogen immitation by exogenous compound. Males with developing eggs. Vitellogenin synthesis initiated in liver. This is precursor to egg yolk. Caused by estrogen contamination from sewage (contraceptives)(Larsson 1999). |
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Term
| Dioxins and vitellogenin induction |
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Definition
| Dioxins stop vitellogenin production. They cause AHR to form a complex with a nuclear translator and disrupt the estrogen receptor α (ERα) autoregulatory transcriptional loop (Bemanian 2004). |
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