Ch 1 & 2a Flashcards
what 2 heavy metal poisoning incidents led to the replacement of the dilution paradigm with the boomerang paradigm ?
- Methyl mercury in Minamata Bay
2. Itai-Itai disease in Japan
What is the boomerang paradigm ?
What you throw away can come back & hurt you
What was the dilution paradigm ?
the solution to pollution is dilution
Explain what happened in regards to the Minamata Bay
mercury poisoned hundreds - chronic symptoms which included headaches, fatigue, loss of smell & taste & forgetfulness
- in utero effects like lac of neurological development, poor speech & walking, poor muscular coordination all seen in babies from healthy mothers
- resulted in 2 million square meters of the bad being dredged & land filled to clean up areas with >25 ppm of mercury
Describe the Itai-Itai (ouch-ouch) disease
named for the expression of excruciating pain
- very brittle bones that can break during movement
- mining in the jinzu river basin for zinc, copper & lead began in 1500s
- mining company built a holding pond, the waste rock contaminated the river
- cadmium from metal mine wastes contaminated irrigation water used for rice
when did radionuclides become a cause for concern and why did they ?
1945-present
- because fission products begin to rapidly accumulate in food chains
- Human body burdens go 137Cs increased rapidly between 1960-65
- cause for concern due to deposition in developing bones
How is radiation measured ?
measured in curies or in Becquerels
what does dpm and dps stand for ?
dpm = disintegrations per minute dps = disintegrations per second
what is the conversion for curries to dpm and dps and Becquerels
1 curie = 2.2 x 10^6 dpm
1 curie = 3.7 x 10^4 dps
1 curie = 3.7 x 10^4 Bq
1 Bq = 1 dps
what did The Curies discover ? and what did Henri Becquerel discover ?
Curies = radium
Henri Becquerel = radioactivity
Example of an accidental release of radioactive elements
Plutonium processing - Windscale Fire (1975) England, 20,000 curies 131 I released during an attempt to control heat build up in air cooled graphite controlled reactor pile.
- Radioactivity was released during the fire & fighting the fire
How did the windscale fire incident affect the food and how was it dealt with ?
food chain bioaccumulation, vegetables –> cows milk –> humans –> cancer
over 2 million L of milk dumped into ocean or rivers
Name 3 of the accidental/intentional releases from the Hanford, Washington States reactor complex
- In a span of 3 years released 440,000 curies of 131 I to atmosphere
- 1963 20,000 curies into Columbia River
- Cooling water releases at may points
in 2002, who conducted the Columbia River Basin Fish Contaminant survey & why ?
Conducted by First Nations & EPA, because there was nonradioactive contamination like PCBs in fish & highest amounts were found in section of the river that runs through the site, Fish is a major part of First Nations diet, children eating fish from river had 100 tines the risk of immune diseases & central nervous system disorders compared to other children.
1 in 50 chance of contracting cancer among First Nations people eating fish from river
What was the final event that pushed towards the paradigm shift & why ?
Pesticide DDT
because
-it accumulates as it moves up the food chain
- relatively degradation resistant
- inhibits Ca2+ dependent ATPase in bird shell glands leading to the shell thinning, damage to eggs after laying (eggs can’t support the weight of parents)
- reproductive failure for raptors and fish eating birds
What does DDT do to birds?
by products of DDT such as DDD & DDE resulted in negative impacts to birds by accumulating in the brain of Western Grebes and resulted in Axon dysfunction in birds which caused their death
Why do we need ecotoxicology
because despite the regulations in place, transnational & global scale problems still occur.
The US gov for example still deals with high level radioactive waste storage sites
AND ecotox & environment are converging as more research is done
why do we need a to have good knowledge of ecotoxicology
because expertise in it is essential for cost benefit analysis of technology & industries
Define Environmental Toxicology (1995 definition)
The study of the impacts of pollutant upon the structure and function of ecological systems (molecular to ecosystems)
Define Ecotoxicology (1998 definition)
The science of contaminants in the biosphere & their effects on constituents of the biosphere including humans
Name 2 examples of “points of view” on a molecular scale in the field of ecotoxicology
- enzyme inactivation
2. dissolved metal speciation
Name 2 examples of “points of view” in terms of the biosphere related to the field of ecotoxicology
- global warming
2. global movement of pesticides
Define pollutant
substance that occurs in the environment at least in part due to human activities & which has a deleterious effect on living organisms
Define contaminant
A substance released by human activity
Define xenobiotic
A foreign, usually manufactured, chemical or material not produced in nature and not normally considered a constitutive component of a specified biological system
Define stress
A response to or an effect of a recent disorganizing or detrimental factor at any level of ecological organization. This can be cellular stress or “fight or flight” responses.
Define Stressor
Anything that produces stress
Define: The Lorax Incongruity
The delusion of selfless motivation in environmental stewardship & advocacy
Why can the Lorax incongruity lead to problems
- decisions are generally based on the perceived value of services provided by intact ecosystems relative to technological goods & services
- May produce well-intentioned narrow-mindedness
- May create problems based on differential views
What are the 3 goals of ecotoxicology
- Scientific goals
- Technical goals
- Practical goals
What do these 3 goals result in
Results in different methodologies & assessments being used for different purposes
What is the scientific goal
to organize knowledge based on explanatory principles about contaminants in the biosphere
Scientific goals are based on the development of scientific method, what historical explanation was used
precipitate explanation used
- facts fit into a ruling theory
- as the “expert”
- uncritical method
after the historical explanation, moved towards the working hypothesis, list 3 facts
- never accepted as true
- provides a focus for the falsification procedure
- weakness: Tends to favor a central theory
After the working hypothesis, it moved towards the multiple working hypothesis, list 5 facts
- consider all plausible ideas simultaneously
- useful in questions with multiple interactions
- although a hypothesis is never assumed true, survival tends to enhance its status
- must avoid weak testing of the hypothesis
- must avoid imprecise or biased measurements
Define a hypothesis as a paradigm
defined as a generally accepted concept that have survived vigorous testing
Define Normal Science
Incremental increase in facts & ideas which reaffirm, revise or replace paradigms, methodical fact gathering
Define Innovative Science
It questions paradigms & formulates new ones, it requires normal science. Balance between both forms is required
What are Technological goals
overall: to develop & apply tools & methods to acquire a better understanding of contaminant fate & effects in the biosphere
- Benefits tend to be more immediately apparent.
What could Technological goals include the development of (3)
- analytical instrumentation
- standard methods
- computation/ analytical methods
what are 2 examples of a technological goal
- application of biomarkers
- using changes in biochemistry as early warnings or to detect pollutants - GIS systems for study of non point source contamination over large areas
what are the (7) qualities aimed for by technological goals
- effectiveness
- precision
- accuracy
- appropriate sensitivity
- consistency
- clarity of results
- ease of use
What are practical goals (regulatory goals)
overall: the application of available knowledge, tools & procedures to solving or documenting specific problems
What are some (3) tools involved with practical goals
- guidelines
- quality standards & criteria
- step-by-step approaches
Define criteria
estimated [toxicant] based on current literature, that are considered protective for organisms or a defined purpose, if not exceeded.
Define Standards
legal limits thought sufficient to protect the environment
In practical goals, what (10) things are value placed on
- effectiveness
- precision
- accuracy
- sensitivity
- consistency
- clarity
- ease of use
- unambiguous results
- safety
- clear documentation of progress
give (9) reasons why toxicity tests on organisms may be done
- determine if conditions are suitable for life
- determine favourable/unfavourable conditions (DO, pH, salinity, temp etc..)
- determine the effect of environment on toxicity
- Determine the toxicity to a given species
- determine relative sensitivities of organisms
- determine amount & type of waste treatment necessary to meet control requirements
- monitor effectiveness of treatments
- monitor discharge rates
- check compliance
What do standards methods & analysis ensure ? (3)
- uniformity
- reproducibility
- utility of results
what do quality assurance & quality control procedures include (4)
- guidelines for sampling/handling samples
- source/condition of test organisms
- use of reference tests
- test procedures
Define Acclimate
at accustom test organisms to different environmental conditions
Define Response
the measures biological effect of the variable tested
ex - for acute toxicity, the response is usually death or immobilization
Define Control
treatment that duplicates all the conditions of the test but does not contain the test material
Define Range-finding Tests
preliminary tests to establish approximate toxicity
- single replicates, multiple widely spaced concentrations & exposure 8 to 26 hours
Define screening test
Toxicity test to determine if an impact is likely to be observed
- use 1 concentration, multiple replicates & exposure 24 to 96 hours
Define Definitive test
Toxicity test to establish concentration at which an end point occurs
- longer exposures, multiple concentrations, close intervals & multiple replicates
Define Dose
The amount of toxin entering an organism
Define Toxicity
What its a result of
& what may effect it
Potential of a test material to cause adverse effects on living organisms
- result of dose or exposure concentration & exposure time
- may be effected by temperature, chemical form & availability
Define Exposure time
Time that test organism is in contact with the test solution
Define acute toxicity
Relatively short term lethal or other effect test
Define chronic toxicity
Stimulus lasts 1/10 life span or longer
- may involve reduced growth, reproduction & death
Lethal Concentration (LCp)
Toxicant concentration estimated to produce deat in a given proportion of organisms
- ex - LD50 kill 50% of organisms, time limit often attached 24h or 48h
Effective concentration (ECp)
Toxicant concentration estimated to cause a specific effect in a given proportion of the population
- ex - EC25, time limit given, usually a su lethal effect lie a change in respiration or loss of equilibrium
Inhibition Concentration (LCp)
Toxicant concentration estimated to cause a specified percentage inhibition or impairment of a qualitative biological function
Ex - reduction in growth of larva - use for any test which measures a change in rate
Define NOEC
No observed effect concentration - the highest toxicant concentration in which the values are not significantly different from the control
Define LOEC
Lowest observed effect concentration - lowest toxicant concentration in which the values for the measured response are significantly different from the control
Define a static test
Solutions + the organism in a container stay there for the duration of the test
Ex- copepod assay
Define renewal test
Organisms are exposed to solutions of the same composition which are renewed at intervals (24hour)
Define a flow through test
Solutions are continuously replaced during the test
When preparing for toxicity testing, selection of organisms should consider what (8) things ?
- Sensitivity of toxicant
- Geographical distribution, abundance, availability
- Recreational, economic & ecological importance
- Abiotic requirements
- Culture methods
- Knowledge of life cycle, nutrition
- Physical condition
- Health
What is a typical test in Experimental design
Typical test is 5 concentrations + at least one control, need duplicates for analysis and QA/QC
How should organisms be distributed into test solutions
RANDOMLY
- distribute 1 at a time if <11/container
- distribute 2 at a rime if >12/container
How should organisms be distributed for a short term static test
should be in an intermediate container & should all be moved to test solution all at once
how many organisms in the control must survive the entire test period (for fish & invertebrates)
90% must survive
TRUE or FALSE if long exposures or life stages are used, lower survival rates may be acceptable
TRUE
What is the recommendation for 95% confidence interval
Should be less than plus or minus 30% of mean
For what kind of organisms will a 95% confidence interval less than plus or minus 30% of the mean not be attainable
for organisms without a culture method
