what 2 heavy metal poisoning incidents led to the replacement of the dilution paradigm with the boomerang paradigm ?
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
Describe the Itai-Itai (ouch-ouch) disease
named for the expression of excruciating pain
when did radionuclides become a cause for concern and why did they ?
1945-present
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 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
2. dissolved metal speciation
Name 2 examples of “points of view” in terms of the biosphere related to the field of ecotoxicology
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