16 pollution in the arctic Flashcards
what is the outline of this lecture?
-nature and scope of the issue
-how/why is this occurring?
-why is this a significant environmental problem?
-environmental/human implications
what is the book “the changing arctic environment”?
what is AMAP?
the artic monitoring and assessment program
-established in 1991 for monitoring and assessing arctic pollution
mandate: provide reliable and sufficient information on the status of, and threats to, the Arctic environment, and scientific advise on actions to be taken in order to support arctic governments in their efforts to take remedial and preventive actions relating to contaminants and adverse effects of climate change
what is the NCP?
the northern contaminants program
-was established in 1991 in response to concerns about human exposure to elevated levels of contaminants in wildlife species that are important to the traditional diets of northern indigenous peoples
-early studies found a wide variety of substances, many of which had no Arctic or canadian sources, but which were, nevertheless, reaching unexpectedly high levels in the arctic ecosystems
what are the types of contaminants in the Arctic?
-organics (e.g. POPs)
-metals (e.g. Hg, Cd, Pb)
-radionuclides
source regions:
-industrial and agricultural areas further south in Eurasia, North and Central America
what are POPs?
-compounds and mixtures that include industrial carbon-based chemicals such as PCBs, pesticides like DDT, and unwanted wastes such as dioxins
-synthetic products and by-products of industrial processes
-persistent and resistant to degradation
what are some POPs?
what are some new POPs?
new POPs: chemicals listed under the Stockholm Convention between 2005-2019
what was the case study in Canadian Arctic?
POPs and metals in the freshwater biota of the Canadian Subarctic and Arctic
what is the concentration of POPs in arctic char?
what are the levels of chlorinated compounds in char and lake trout?
what are the POP transport pathways to the arctic?
POPs are found even in the most remote places in the Arctic
what is the table of POPs mobility in a global context?
what is the global distillation model?
what is the grasshopper effect?
why is this process called global distillation?
figure: in a process resembling a distillation, organic compounds become latitudinally fractioned according to their volatility as they condense at different ambient temperatures
what are the key points in the global distillation model?
-POPs migrate from source regions to colder climates
POPs migrate in a few “jumps” (the grasshopper effect)
-at higher temperature they are picked up by wind as gases
-condense when temperature drops
-re-volatize when weather changes
-POPs of different volatilities migrate at different velocities
-the composition of contaminant mixtures will change along a latitudinal gradient
what is the latitudinal change in HCH distribution in northern hemisphere?
what are the temporal change in PCB distribution in North America?
what is the transport within the arctic ocean?
role of ice:
-act as an important vehicle
-entrap and transport POPs
-ice melting coincides with the period of maximum primary productivity
what are the pathways of POP accumulation in marine food web?
what are the pathways of POP accumulation in arctic terrestrial food web?
what are the tissue concentrations of POPs in biota?
what is the current state of knowledge on biological effects from contaminants on arctic wildlife and fish?
-extend of information is quite limited
-recent biomonitoring studies indicate POPs impair immune response capacity and cause oxidative stress, and endocrine disruption (thyroid and steroid hormone imbalance) in arctic mammals
-overall, current biomarkers-based evidence suggests POPs exposure causes growth and metabolic disruption, and reproductive impairments in arctic mammals (also in humans)
what is the conceptual understanding of biomarkers?
what are the types of biomarkers?
what is biomarker assessments in Beluga whales from canadian arctic?
what is the risk assessment for PCB-mediated effects on immune and hormone systems in key arctic species?
what is the human exposure to POPs?
