Summaries of research-based knowledge We hope this helps you decide on your most important questions.

Summaries of research-based knowledge

We hope this helps you decide on your most important

questions

RESEARCH SUMMARY CHOICES

Nuclear contaminants Marine mammals:

persistent organic pollutants

Marine mammals: heavy metals

Freshwater fish Marine fish Caribou/reindeer Birds Biological effects

Climate change Exxon Valdez Oil Spill Importance of Native

Foods to Health Human Health:

persistent organic pollutants

Human Health: cadmium

Managing Risk

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Example of Native concern with nuclear waste from Russia

“The elders are wondering about Russian military dumping toxic waste and it is coming over to our side. I’m glad to be here and to understand that we aren’t the only ones to experience these changes.”

Eric Iyapana, Little Diomede E

ric V

eig

ard

Currently, there is no indication that former Soviet Union dumping activities caused elevated concentrations of radionuclides in Alaskan waters.

To date, the predicted concentrations of radionuclides in Alaskan waters from FSU dumping are so low in all cases that it is highly unlikely that any significant ecological impacts will occur in any areas outside the immediate Russian disposal sites.

Russian nuclear wastes

Comparison of Russian Sources with other Sources

0 0.5 1 1.5 2 2.5

Radon

Other background naturalradiation

Projected doses to Russianlocal populations

Dental Xray dosage

Projected doses to Alaskapopulations from Russia

Millisieverts per year

People with a diet high in terrestrial and freshwater foodstuffs receive the highest radiation exposures, from both natural and human sources of radionuclides.

These foodstuffs include caribou/reindeer, freshwater fish, berries, and mushrooms.

People who eat mostly marine foodstuffs have the lowest doses.

Exposure to all sources of radioactivity

Exposures in the Arctic

The Arctic terrestrial system is more vulnerable to radioactive contamination than temperate areas. The exposure of people in the Arctic and subarctic is, for the general population, about five times higher than what would be expected in a temperate area.

However, for part of the population the exposure could be more than 100 times higher than expected for similar fallout in temperate areas.

Major human sources of radiounuclides

The major human sources of radionuclides in the Arctic are global fallout from nuclear bomb tests, releases from European nuclear fuel reprocessing plants, and fallout from the Chernobyl accident.

Drop in Radionuclide Levels

They briefly increased again after Chernobyl

Radionuclide levels dropped after atmospheric testing stopped

Polonium from caribou/reindeer dominates the natural radiation dose, whereas cesium-137 from an array of terrestrial food sources is the most important human sources of radionuclides.

There is some confirmation of naturally occurring potassium 40, polonium 210 and lead 210 in caribou in Alaska. Levels of lead 210 may vary within herds as they do in Canada, but we don’t have data to confirm this.

Radionuclides in Caribou

The highest average exposures to individuals in Native Arctic populations are in Canada and the lowest in Greenland. Consumers of large amounts of caribou/reindeer can have radiation exposures 50 times higher than the average members of their national population.

We lack the data to confirm that Alaska animals have relatively high body burdens of radionuclides compared to similar or related species in temperate regions. We also cannot conclude that Arctic animals may be adapted to relatively high exposure because of the importance of natural sources of these contaminants.

Dosages from Caribou/reindeer

Exposures to radioactivity The greatest exposures to radionuclides occurred in

the 1950s and 1960s (e.g. strontium 90). The long term effects of Strontium 90 in bone perhaps interacting with exposures to organochlorines is not known.

Of all radionuclides, lead-210 and polonium-210, which are natural in origin, may make the greatest contribution to current human radiation doses in the Arctic.

However, the greatest exposures to radionuclides may come from improperly used or maintained radiological equipment.

Both lead-210 and polonium-210 occur in nature as airborne particles and tend to settle out on vegetation (i.e. lichens) thereby entering the terrestrial food chain (lichens-caribou-humans) (308). We should also consider polonium-210 levels in fish

It is likely that Alaska Native consumers of Native foods are exposed to an approximately seven-fold higher radiation dose than non-consumers of traditional food

More than 95% of this increased radiation dose is due to the bioaccumulation of natural radionuclides in the food chain.

Natural sources of radioactivity

This increased radiation dose gives consumers of Native foods a cancer risk that is approximately 10% higher than that compared with consumers of a southern diet

In Alaska, there is a higher incidence of some cancers (e.g. stomach cancer), but this may

be unrelated.

Health risk of radioactivity

The potential human health risks associated with ingesting Alaskan seafoods containing radionuclides derived from releases associated with Russian nuclear wastes evaluated are extremely low.

Those wastes pose no threat to human health; Alaska Native communities, therefore, need not alter any of their dietary habits associated with subsistence foods obtained from Alaskan waters.

Russian nuclear wastes and Alaskan seafoods

Marine Mammals: Persistent Organic Pollutants (POPs)

There is some data to support the statement that marine mammals including polar bear, ringed seals, beluga, and walrus probably have elevated levels of PCBs and toxaphene, but more data is needed.

PCBs in Alaska

Levels of PCBs tend to be higher in eastern Canada. This may be due to a coupling of a regional cooling trend in eastern Canada with atmospheric PCBs from lower latitudes of North America.

We cannot assume that the trend of decreasing levels of PCBs from eastern to western Canada extends into Alaska, particularly in the Bering Sea.

Canadian results show a large variation in organochlorines in walrus. The presence of many different types of organochlorines in some walrus indicates that the source is not local (and hence of a specific type or types).

Walrus: POPs

The variation may be due to differences in diet. Walrus that eat seals may have higher levels. We need Alaska data to test this idea.

POPs data for Marine Mammals

Geographic coverage of levels of persistent organochlorines in marine mammals is not good in Alaska.

We have not studied contaminant levels in most stocks or populations of beluga, ringed seals, walrus, and polar bears.

Recent research

POP contaminant levels in the blubber of Cook Inlet beluga whales are lower than belugas from the Eastern Chukchi and Eastern Beaufort seas

Scientists have found high levels of the agricultural insecticide DDT in Aleutian Islands bald eagles

Killer whales in Prince William Sound and the Kenai Fiords have been concentrating dangerous industrial pollutants of possible Asian origin in their body fat.

The most severe effects of metals on Arctic ecosystems are from local pollution. The nickel-copper smelters on the Kola Peninsula and in the Norilsk region of Russia have severely polluted nearby terrestrial and freshwater environments.

Most of the smelter emissions are deposited very close to their source. However, they are still the major source of circumpolar contamination. Emissions from the Kola Peninsula are the major source of metals in northern Fennoscandian air, and emissions from the Urals and Norilsk are the most important for air concentrations of metals over Alaska and northern Canada.

Marine Mammals: Heavy Metals from Russia

Metals are taken up by Arctic biota and levels often reflect local geology or local human activities. In the circumpolar assessment, the most troubling findings concern mercury and cadmium, as they occur in concentrations that may have health implications for individual animals as well as human consumers.

Geographic coverage of levels of heavy metals in marine mammals is not good in Alaska. We have not studied contaminant levels in most stocks or populations of beluga, ringed seals, walrus, and polar bears.

Marine Mammals: Natural Sources of Heavy Metals

Mercury seems to be increasing in both lake and ocean sediments. An increase over the past two to three decades is also evident in livers and kidneys from some marine mammals. This may indicate an increased global flux of mercury, which is deposited in the Arctic because of the cold climate.

In some parts of the Arctic, notably Greenland and western Canada, any increase in the mercury load is in addition to high natural levels from the local geology.

Mercury levels in several species of marine mammals seem to be highest in the northwestern part of Canada.

Increases in mercury

Polar bears, ringed seals, and beluga are likely to have elevated levels of mercury, but we need data to understand how the sedimentary geology differs in different areas off Alaska’s coast as compared with the Canadian Beaufort Sea.

Marine Mammals: mercury

Mercury biomagnifies in freshwater and in marine ecosystems. However, in all marine animal populations, even the most exposed ones, selenium is abundant enough to detoxify the mercury.

In some areas, cadmium levels are very high in marine mammals, possibly due to local geology. Cadmium levels seem to be highest in marine animals from northeastern Canada and Northwest Greenland. For certain age groups and populations of marine birds and mammals, the levels might be high enough to cause kidney damage.

Marine Mammals: cadmium

While cadmium concentrations in beluga increase from the western to eastern Canadian Arctic, we cannot assume that the trend extends across the Alaska Beaufort, Chukchi Seas, or into the Bering Sea and Gulf of Alaska. The mineral composition of sediments may differ from those in the western Canadian Arctic.

There are likely high levels of mercury and cadmium in sea birds and marine mammals as observed in Canada. The biological implications for the animals themselves is, however, unknown. Given that the levels of cadmium, for example, are among the highest ever reported in marine mammal tissues, further efforts are needed to examine possible physiological effects.

Heavy metals in Marine Mammals

Example of concerns about deformities in fish

“Where we are finding reported and proven contamination (tar, gasoline, fuel oil), we are also finding deformities in the fish.” Guy Martin, Nome

“My dad noticed that maybe one in ten or two in ten king salmon were filled with pus. Last summer it was seven in ten were filled with pus.” Paul Erhart, Tanana

Mines are sources of local contamination, but only a few mines have been assessed.

We don’t know if mercury levels in freshwater fish are relatively high or low in Alaska. Higher mercury levels are probably the result of both natural environmental conditions and human activity.

Increases in mercury concentrations in sediments in this century may indicate increased human sources. The correlation of selenium with mercury does not necessarily indicate that the source of mercury is natural.

Freshwater fish: mercury

Mercury seems to be increasing in both lake and ocean sediments

Several uncertainties about the observed time trends must be resolved before firm conclusions are drawn

For example, the gradients in sediments might be caused by natural processes. For biota, lack of information about the natural variation of mercury levels complicates the interpretation of results.

Freshwater fish: mercury

From a research point of view, further studies of the increase in mercury are a high priority. It is important to verify time trends and also to investigate the sources or processes behind the increase, as well as any biological effects.

Freshwater fish: mercury

Toxaphene is the major organochlorine contaminant in all freshwater fish in northern Canada. We do not know if this is the case in Alaska. It may be true that high toxaphene levels are related to differences in food web structure (i.e. fish eating other fish that are also predators)

Freshwater fish: POPs

Diagram Source: AMAP, 1997, p. 45

Toxaphene concentrates in fish livers

Toxaphene concentrates in fish livers. Burbot with high levels of toxaphene in their livers may have concentrations in their flesh that are comparable to other fish.

There is likely to be a wide variation of PCBs in freshwater fish by location and weight of the fish. In northern Canada, lakes with the highest concentrations of PCBs (e.g. Lake Labarge) have local sources of PCBs and DDT.

We need data to know if this pattern is also true in Alaska.

Freshwater fish: POPs

Primary Concerns:

In northern Canada, fish of primary concern due to their contribution to Native diets include: burbot, lake trout, arctic char, northern pike, and whitefish.

We cannot assume that these species are of primary concern in Alaska; rather, all species consumed are of potential concern, including salmon.

Freshwater fish

We also cannot assume that PCBs, toxaphene, and mercury are the primary contaminants of concern in freshwater fish

Geographic coverage of contaminants in freshwater fish in Alaska is poor.

Marine fish: POPs

The major source of persistent organic pollutants in the Arctic is long-range transport via air currents, as demonstrated by monitoring of air concentrations.

There may also be significant sources of some contaminants, such as PCBs, DDT, and hexachlorocyclohexane, within the AMAP region, but these are not well documented.

Data from river water and sediments indicate that a substantial input from Russian rivers into the Arctic marine environment, but these data must still be verified.

Available data point to some geographic trends. In general, the levels of PCBs and DDT seem to be higher around Svalbard, in the southern Barents Sea, and in eastern Greenland than in, for example, the Canadian High Arctic.

Very limited data from Russia and Alaska are available for this assessment.

The lack of circumpolar data limits our understanding of sources, transport pathways, and mechanisms for focusing contaminants. The role of sea ice in transporting contaminants and then releasing them during melting warrants further investigation.

Availability of Data

We have a poor understanding of how organochlorines move within the marine food web

There is very limited information on levels of organochlorines and aromatic hydrocarbons in marine fish stocks in Alaska waters

Military sites along Alaska’s coast are likely to be local sources of PCBs and DDT contamination of the nearshore environment. While there is some Alaska

data to support this conclusion, more data is needed.

Sources of POPs

Example of concerns about caribou

“The only problem is that all those caribou and other animals wander all over that hillside. What they are eating is grass from the hillside. If they are eating grass up there where the site is contaminated, isn’t it going to affect us?” Myrtle Johnson, Nome

Example of concerns about caribou

“This year at Onion Portage, there were caribou with swollen joints, bad white liver spots, and lungs stuck to the ribs. 12-15% (50% increase) show these signs.” Enoch Shiedt, Kotzebue

In some areas, cadmium levels are very high in terrestrial mammals, possibly due to local geology. For example, in reindeer/caribou, the highest cadmium levels have been recorded in the Yukon territory in Canada, which is known to have cadmium-rich geology.

Caribou: cadmium

Applying the Canadian experience to Alaska

We do not have the data necessary to conclude that an observed increase in cadmium levels in caribou kidneys from eastern to western Canada continues into Alaska.

We therefore cannot say that the levels in Alaska are comparable to those in northern Quebec and Norway, which is the case in western Canada. The source of cadmium is probably natural and may be related to soil and winter forage.

It is likely that cadmium levels in caribou kidneys in some Alaska herds are higher than the Canadian guideline of 30 micrograms per gram, but we don’t have the data.

We concur with Canadian researchers that the potential effects of high doses of metals such as

cadmium on caribou are not clear

Caribou: cadmium

Polonium from caribou/reindeer dominates the natural radiation dose, whereas cesium-137 from an array of terrestrial food sources is the most important anthropogenic radionuclide.

There is some confirmation of naturally occurring potassium 40, polonium 210 and lead 210 in caribou in Alaska. Levels of lead 210 may vary within herds as they do in Canada, but we don’t have data to confirm this.

Radionuclides in Caribou

The highest average exposures to individuals in Native Arctic populations are in Canada and the lowest in Greenland. Consumers of large amounts of caribou/reindeer can have radiation exposures 50 times higher than the average members of their national population.

We lack the data to confirm the Canadian conclusion that Arctic animals have relatively high body burdens of radionuclides compared to similar or related species in temperate regions. We also cannot conclude that Arctic animals may be adapted to relatively high exposure because of the importance of natural sources of these contaminants.

Dosages from Caribou/reindeer

Caribou: POPs

We do not have data to know whether the trend of decreasing PCB levels in caribou from eastern to western Canada extends to Alaska.

We can’t say, as the Canadians can, that TCDD toxic equivalent concentration (TEQ) levels observed in caribou are comparable to levels observed in domestic animals in Canada.

Birds: POPs

Geographic coverage of levels of persistent

organochlorines in seabird populations in Alaska is poor Biomagnification is one major factor contributing to the

high levels and biological effects of persistent organic pollutants in Arctic animals. Another biological pathway is via migratory birds that overwinter in polluted environments

We don’t know how organochlorine levels vary in birds. We cannot say whether the Canadian observation of lower organochlorine levels in the western Arctic extends to Alaska.

We don’t have data to confirm the Canadian observation of lower levels of organochlorines in Glaucous gulls in the western Arctic. Factors affecting organochlorine levels in the Bering Sea may be different, for example

Glaucous Gulls

O.J. Bustnes

We need to confirm observed trends of declining concentrations of organochlorines in marine mammals and sea birds from the 1970s to the 1980s and a leveling off of concentrations during the mid-1980s to the

mid-1990s

Declining Organochlorine Levels

It is likely that the observed decline in SDDT in peregrine falcons is greater than that in arctic sea birds, but we need data to confirm this Canadian finding

There is limited data on changes in organochlorines such as toxaphene, chlordane, and chlorobenzenes in marine biota. What Canadian data there is for the 1980s and 1990s suggests that there has been no significant decline in concentrations of these contaminants in marine mammals or sea birds. We do not have comparable temporal data for Alaska.

Trends over time

As in Canada, there are no data in Alaska on toxaphene in terrestrial animals and in waterfowl and seabirds, despite that fact the likelihood that toxaphene may be a major organochlorine contaminant in arctic air, seawater, fishes and

marine mammals

Toxaphene

Birds: heavy metals

We don’t know if the Canadian conclusion that there are low levels of heavy metals in birds applies in Alaska (lead not tested)

There are likely high levels of mercury and cadmium in sea birds as observed in Canada. The biological implications for the animals themselves is, however, unknown.

Biological effects All persistent organic pollutants in AMAP’s monitoring

program have been found in the Arctic. The levels are generally lower than in temperate areas, but for several substances they are still in concentration ranges in which effects on some animals are expected.

There could be effects on reproduction of birds from DDT and of some marine mammals from PCBs and dioxin-like compounds.

Current concentrations in several Arctic species are also close to or above thresholds known to be associated with effects on the immune and nervous systems. The most vulnerable animals are those high in the food web, such as polar bear and birds of prey.

We do not have the data to verify the Canadian observation that most organochlorine pesticides and PCBs are found at very low levels and that these levels decrease as you go north

At observed levels in the north, the Canadians do not suspect any effect on reproduction.

PCB’s and Organochlorines

Beluga and Ringed Seals It is likely that organochlorine contaminant levels in

arctic beluga are 10 to 20 fold lower than in St. Lawrence Estuary (Eastern Canada) beluga. In the case of St. Lawrence beluga, there is preliminary evidence of a link to immune system dysfunction due to high PCB exposure.

It may be true, but we also lack data to confirm that concentrations of PCBs in blubber lipids of ringed seals are 10 to 20 fold lower than concentrations associated with poor reproductive success in captive harbor seals.

As is usually the case with arctic animals, there is a lack of experimental data linking dosage with effects.

There is particularly a need to study biological effects on the immune system of mammals that are predators.

Lack of experimental data on biological effects

The Canadian Northern Contaminants Program concluded that, with the possible exception of peregrine falcons, contaminant levels or biochemical indicators of effects have not been linked to effects on arctic animals at the individual or population level.

The lack of research of this type in Alaska makes it impossible to conclude whether or not there have been effects of contaminants on arctic animals

Local observations of possible effects of contaminants on the environment are needed.

Lack of research to link contaminants with biological effects

It is likely true that marine mammal females and their offspring may be most vulnerable when the female draws on her fat reserves. POPs tend to concentrate in fat. This drawing on fat happens at a crucial point in the growth and development of the young.

Overall, the MFO enzyme data in Canada for polar bear and beluga suggest that:

Even the relatively low levels of contaminants present in the arctic animals may have biological effects, especially during years of poor feeding.

Marine mammals

More work is needed to confirm observed correlations of non-ortho and mono-ortho PCB concentrations with CYP1A1 activity in polar bear and beluga livers. There is also a need to combine MFO measurements with other biochemical indicators of effects of PCBs such as retinol levels

Given that some of the persistent organochlorines such as o,p’-DDE, p,p’-DDE and –DDT have estrogen activity, information is needed on steroid and thyroid hormone levels in polar bears and beluga

Biological effects: some details

We concur with Canadian researchers that the potential effects of high doses of metals such as cadmium on caribou and beluga are not clear

There are likely high levels of mercury and cadmium in sea birds and marine mammals as observed in Canada. The biological implications for the animals themselves is, however, unknown.

Given that the levels of cadmium, for example, are among the highest ever reported in marine mammal tissues, further efforts are needed to examine possible physiological effects.

Mercury and Cadmium

We lack the data to confirm the Canadian conclusion that Arctic animals have relatively high body burdens of radionuclides compared to similar or related species in temperate regions

We also cannot conclude that Arctic animals may be adapted to relatively high exposure because of the importance of natural sources of these contaminants.

Radionuclides

Example of Native concerns about climate change

“Is there going to be some conclusion at the end of three years about the effect of climate change on the observations people are making? When the winds and weather patterns are different, it will bring a lot of change. It could change how contaminants travel.”

Charlie Johnson, Nome

Examples of Native concerns about climate change

“Our river - we've noticed that it doesn't freeze across in the last 10 years. The temperatures are warmer. The lakes are drying up. The water is low in June, affecting the fish run - over the last two years. Sockeyes are much smaller and so are hatchery fish.” Gloria Stickwan, Copper Center

“What's happening is that because the winters are warmer, the lakes don't freeze all the way down and more of the young beaver survive. That's what is causing them to proliferate.” Paul Erhart, Tanana

Link to

Bering Sea Anomalies

Climate link to environment

We often think of climate change as global warming

Alaska has been getting warmer since 1966

Source: Bering Sea Impact Studies (BESIS) http://www.besis.uaf.edu/

But the climate varies a lot from year-to-year (and decade-to-decade), and not just in temperature

Source: Gordon H. Kruse (1998)

The N. Pacific experienced deeper low pressures between 1977 and 1988, and again in 1997 and 1998

Stronger “Aleutian Lows often” mean:

Increased winter storms More nutrients mixed into surface

waters Northward movement of warmer

water. And stronger Aleutian Lows can

occur in association with El Niño events.

Source: Gordon H. Kruse (1998)

And these conditions often mean:

Higher production of phytoplankton and zooplankton;

Increased salmon productivity.

Source: Gordon H. Kruse (1998)

The 1997/98 El Nino was unusual:

It had 2 peaks: August-Sept. 1997 and Feb.-March 1998.

Highest global mean temperature anomalies since recording started in 1880.

N. Pacific Ocean temperatures were up to 10 degrees Fahrenheit higher than average in Aug-Sept. 1997

Deep ocean temperatures off Seward have been 3-4 °F higher than average since Jan. 1998

Source: Gordon H. Kruse (1998)

In 1997, aquamarine waters were recorded for the first time in the Bering Sea

This shows the Bering Sea bloom and the sediment plume from the Yukon River.

Source: http://visibleearth.nasa.gov/Regions/Bering_Sea/

It was a massive “bloom” of a tiny phytoplankton

coccolithophores

Source: www.soc.soton.ac.uk/SOES/STAFF/tt/eh/index.html

Co

pyr

igh

t: J

ess

Go

rick

The bloom may have made it harder for seabirds to detect prey

Thousands of short-tailed shearwaters died in early August 1997, apparently from starvation.

But they appeared to adapt in 1998 by eating more fish.

Source: T.C. Vance et al (1998); Saar (2000)

Conditions including fewer storms, lower nutrient supplies, less sea ice, and higher sea surface temperatures may have caused poor salmon runs in 1997 and 1998

Source: Gordon H. Kruse (1998)

What’s causing these changes?

We don’t know, but we have some ideas about changes in climate:– Changes in solar activity (7-17 year

shifts with an average of 11 years plus a 22 year cycle)

– Changes in the position of the moon (18.6 year tidal cycle)

– Variations in the Aleutian low– Atmospheric pressure “regime” shifts

(20-28 years)

Then how are Native food resources affected?

Water temps affect phytoplankton and zooplankton growth, indirectly affecting fish and marine mammals

Fish and marine mammals may change their distribution

Changes in sea ice cover is a major cause of 1 and 2.

Water temps may affect fish production But we also need to take into account

human harvests of species and environmental changes.

Alaska lands and streams are also experiencing climate change

Increased insect infestations in forests

Increased risk of catastrophic wildfires in settled areas and in coastal forests

Coastal stream changes affecting fish

Thaw of large areas of permafrost More forested areas over long term

Source: Berman, Juday, Burnside 1999

Are people the cause of climate change? In cases like the Exxon Valdez, yes.

Most scientists think that greenhouse gases will contribute to climate change

For a scientists’ position statement, see http://www.agu.org/sci_soc/policy/climate_change.html

But not all scientists agree. Native people are participating in efforts to

address environmental concerns in the Arctic. See http://arctic-council.usgs.gov/98rep.html

Exxon Valdez Oil Spill

The Exxon Valdez Oil Spill Trustee Council has a ten year report on the web: http://www.oilspill.state.ak.us/index.html

NOAA has a web site summarizing it’s Long Term Monitoring research: http://response.restoration.noaa.gov/bat/about.html

The PWS RCAC has a 1998 report on its Long Term Environmental Monitoring Program on the web: http://www.pwsrcac.org/

We can only touch the surface of this wealth of research-based information.

NOAA’s Long Term Monitoring

Generally, the ecosystem of Prince William Sound has proved surprisingly resilient, but

Impacts from the spill remain in Prince William Sound, in the form of oil still leaching from beaches and populations of plants and animals that haven't yet completely recovered.

NOAA’s Long Term Monitoring

Although little of the spilled oil remains, oily vestiges are still evident on many beaches.

Source: NOAA http://response.restoration.noaa.gov/bat/about.html

EVOS research results The plant and animal populations of the Sound seem

to still be adjusting themselves in response to the spill.

Rockweed cover, for example, increased after the spill, then decreased in 1994-95.

Source: NOAA http://response.restoration.noaa.gov/bat/about.html

Species still recovering include

Pink salmon, mussels, clams, pacific herring, sea otter, sockeye salmon, black oystercatcher, common murre and marbled murrelet

According to the Oil Spill Trustee Council, “There is still concern about egg mortality in some streams in the western part of Prince William Sound.”Source: Oil Spill Trustee Council. 1999

Species not recovering yet include

Harbor seals, killer whales, common loon, commorants, harlequin ducks, and pigeon guillemots.

According to the Oil Spill Trustee Council, “Harbor seals in Prince William Sound and the Gulf of Alaska have lost 80 percent of their population over the last 20 years.”

Source: Oil Spill Trustee Council. 1999

People’s harvest and consumption of Native foods has changed

According to the Oil Spill Trustees Council, People of PWS. “continue to be concerned over a scarcity of some important resources, including harbor seals, herring, clams, and crab.”

Source: Oil Spill Trustee Council. 1999

The future

The last big chunk of money from the Exxon Valdez oil spill settlement will be rolled into a $115 million endowment to finance decades of research into how weather, climate, fish, birds and sea mammals all interact in the Gulf of Alaska.

Importance of Native Foods to Human Health

Native foods are widely consumed within communities. Marine mammals, large ungulates, and fish account for a large proportion of Native foods consumed. Consequently, potential exposure of Alaska Natives to contaminants in Native foods is widespread in Alaska

Increases in consumption of imported foods by Alaska Natives has been associated with decreased physical activity, obesity, dental caries, anemia, lowered resistance to infection, heart disease, and diabetes.

Dietary survey data in Alaska is limited to 12 communities. While there are data on harvests for many Alaska Native communities, these data do not contain information on variations in consumption patterns among individuals (e.g. consumption of organs, frequency of consumption, method of preparation)

Consumption of Native foods varies by season and by year. Dietary surveys which measure consumption for 2 or 3 24 hour periods may not reliably estimate consumption of Native foods

Consumption of Native foods varies by region, income, access to urban centers, and by factors such as age and gender.

Data on Native Diets

Dietary lipids are a concentrated source of energy, act as carriers of fat-soluble vitamins, and are a source of essential fatty acids (polyunsaturated fatty acids that are essential to health but cannot be synthesized by the human body)

Fish and marine mammals which form a significant portion of the diet of Alaska Natives contain many n-3 polyunsaturated fatty acids which are not easily found in imported foods

Omega-3 fatty acids are found at high levels in fish and marine mammal tissues and have been associated with a decreased incidence of thrombotic and ischaemic disease.

Importance of marine mammals and fish to human health

For a number of persistent organic pollutants, health concerns include child development, reproductive impacts, and effects on the immune system.

Some contaminants may cause health problems by disrupting hormones.

Human health: Persistent Organic Pollutants

The developing fetus and breast fed infants are likely to be more sensitive to the effects of POPs than adults. Infants are the age group at greatest risk in the Arctic.

Fetus/infant intakes POPs through human cord blood and milk are of primary concern.

But we are uncertain about the toxic effects.

Concern about infant health

We are uncertain about the toxic effects of persistent organic pollutants on infants, but we know the benefits of breast-feeding.

Therefore, there is good reason for Alaska Native women who eat substantial quantities of marine mammals to continue to breast feed unless told otherwise by their health care provider.

However, this advice should be decision of Alaska Native communities made in the context of a collaborative program of research and assessment.

Advice on Breast Feeding

There is a higher incidence of infectious diseases and ear infections among Alaska Native infants

This may be due to a complicated set of factors It is unknown whether fetus and infant exposure

to PCBs is one of these factors, nor is the extent of exposure known. But see: http://ehpnet1.niehs.nih.gov/docs/2000/108-3/toc.html or the article based on this publication in the “notes” section below

Infectious diseases and ear infections

Human health: cadmium Although a major source of human exposure to

cadmium is smoking tobacco, some individuals who frequently eat kidneys of caribou and marine mammals (e.g. once a week year round) may ingest significant amount of cadmium.

However, only a small percentage of cadmium (about 5 percent) is absorbed through ingestion compared with direct absorption through smoking tobacco.

Smoking may make people’s kidneys less effective in handling cadmium exposures from frequent consumption of organs, particularly among the elderly and diabetics. More study is needed to accept this theory.

Managing Risk

Importance of Native observations

Alaska Natives have observed changes in the health of some animals and fish.

They worry that these changes may be due to contaminants.

We need to ask knowledgeable Natives to share these observations in order to see patterns of change.

Importance of Customary and Traditional Foods in Alaska

A substantial proportion, on the order of a third or more, of the meat and fish eaten by rural Alaska Natives comes from local harvests of fish and game. We do not have consumption data for most Alaska Native communities.

Sharing of Native foods is a common practice in Alaska. Harvesting, sharing, processing, and consuming Native foods is an opportunity to practice and teach humility and spirituality.

Imported sources of meat and fish are expensive and lower in protein, thiamin, riboflavin, niacin, and vitamin B12 than Native foods.

If Alaska Natives were to stop eating Native foods, they would experience nutrition and protein deficiencies.

Native foods are as important to Native social well-being as they are to physical health.

Values of Customary and Traditional Foods in Alaska

The diets of Alaska Natives are more likely to include predators which may concentrate contaminants. Alaska Native diets are also more likely to be higher in fats. These fats may contain higher concentrations of organochlorines.

Slower growing plants such as lichen can result in higher contamination levels through consumption of caribou.

Important Environmental Concerns

Contaminants reach the Arctic through long range atmospheric transport and exposure of migrating species exposed to non-local sources of contaminants.

Local sites and the natural environment may be sources of contaminants.

We need more data to understand the processes which move contaminants through the food chain. It is possible that accelerated processes during the spring may move contaminants through the food chain more quickly.

Sources of Contaminants

Traditional foods have known nutritional value.

There is as yet little conclusive scientific evidence directly linking effects in adults to the levels of exposure that have been observed in the Arctic.

Therefore it is not always clear what public health measures should be taken to reduce the exposure of populations who rely on traditional foods.

Weighing Benefits and Risks

Although there is both scientific and public concern that breast feeding will transfer contaminants from the mother to her child, present knowledge clearly indicates that the known benefits of breast feeding outweigh the currently-known risks from contaminants. To date, there have been no proposals to limit the duration of breast feeding.

Breast Feeding

The goal of public health actions should be to reduce exposure to contaminants without threatening the social, cultural, spiritual, and physical well-being that is connected to collecting, sharing, and consuming traditional foods.

The current traditional diet of Alaska Natives provides a substantial proportion of energy and protein requirements as well as most vitamins, essential elements, and minerals. The high consumption of fish and marine mammals may contribute to the lower incidence of heart disease among indigenous peoples in Alaska, Greenland, and Arctic Canada.

Health Goals

Weighing these known benefits against the suspected, but not yet fully understood, effects of contaminants, the conclusion at present is that consumption of traditional foods should continue.

However, consideration should be given to developing dietary advice to promote the use of less-contaminated traditional food items which will also maintain nutritional benefits.

Such guidelines should be developed at the local level within the context of local cultures.

Continued Consumption of Native Foods

The long-term reduction of exposure to persistent organic pollutants can only be accomplished through international conventions on bans and restrictions in production and use of these substances.

The relative importance of natural and anthropogenic sources of heavy metals in the Arctic needs to be determined, and appropriate controls implemented.

International Action

Where to go next

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