For more than 40 years, the U.S. government produced plutonium for nuclear
weapons at the Hanford Site in south central Washington state. During that time,
Hanford released radioactive elements and other
materials into the Columbia River. (See map below.)
From World War II until the
early 1970s, the Columbia River downstream from Hanford "held the distinction of being the most
radioactive river in the United States."1 Many people
now wonder what the potential
health
effects might be from exposure to these materials. There is also
concern about the effects of these releases on the fish population and
whether eating contaminated fish increased the risk of adverse health effects in humans.
Hanford also released other radionuclides to the air. According to the Technical Steering
Panel (which directs the Hanford
Environmental Dose Reconstruction Project),2
iodine-131 contributed the most to radiation exposure from the air pathway. You can
read about the potential health effects of iodine-131 in the Network's Health Bulletin. Another Network publication,
Potential Health Problems from
Exposure to Selected Radionuclides, addresses the possible health effects
from five other radionuclides released to the air for which the Hanford Environmental Dose Reconstruction
Project has estimated doses.
Hanford discharged three kinds of pollutants into the Columbia River: heat, chemicals
and radioactive material. River water was used to cool the reactors. Before running the
water through the reactors, Hanford added chemicals to keep pipes clean in the cooling
system. As the cooling water was piped through the reactors, it picked up radiation as
well as heat. All three types of pollution were discharged into the Columbia with the
cooling water. Because the Network's Congressional mandate directs us to focus on
radiation released from Hanford, this report will focus on the radioactive material.
Five radionuclides
contributed the most
to radiation dose from
the Columbia River:
arsenic-76
neptunium-239
phosphorus-32
sodium-24
zinc-65
The Dose Reconstruc-
tion Project estimated
that these radionuclides
accounted for more than
94 percent of the poten-
tial radiation dose from
the river pathway.
According to the Technical Steering Panel of the Hanford Environmental Dose
Reconstruction Project, there were five radionuclides
that contributed the most to
radiation dose from the river pathway (dose is the amount of radiation absorbed by a
person's body). The five radionuclides were phosphorus-32, zinc-65, arsenic-76,
neptunium-239 and sodium-24. The Dose Reconstruction Project estimated that these
radionuclides accounted for more than 94 percent of the potential radiation dose from
the river pathway. There were many other radioactive materials released into the river
as well, but they contributed much less to dose, according to the Technical Steering
Panel.
This report examines the releases of these five radionuclides to the Columbia River and
the potential health effects which might result from people being exposed to these
materials.
What are the possible health problems from exposure to radioactive forms of
phosphorus, zinc, arsenic, neptunium and sodium? Most of the information on health
effects from these materials has come from research on animals. None of these studies
contains information that relates to the specific situation of people who lived or spent
time downriver from Hanford. While comparisons of these studies to the Hanford
situation are uncertain, this report discusses potential health problems which may have
been caused or could be caused by exposure to these radionuclides.
Radiation health scientists assume that any dose of radiation, however small, carries
with it an increased risk of some adverse health
effect, such as cancer or other problems. This does not mean that everyone who receives
an exposure will suffer an effect. It means the risk of a radiation-induced health problem is
increased. Even if a particular person gets sick, it is not possible to determine, with
current scientific methods,
if the illness was caused by radiation exposure.
How Hanford Radiation
Polluted the Columbia
Causes of Contamination
The primary cause of the radioactive pollution of the Columbia River was from the
routine operation of the first eight plutonium production reactors. The first three were
built during World War II and five more were added between 1949 and 1955. The first
reactor began operating in September 1944 and the last one shut down in January 1971.
How radiation entered
the Columbia River
1. River water was used
to cool the reactors, then
was returned to the river
after a brief holding period.
2. Circulating through
the reactors made some
materials in the cooling
water radioactive.
3. When the holding
period was shortened,
there was less time for
radiation to decay
before
cooling water went back
into the river.
4. When fuel coverings
split, some radioactive
fuel went into the cool-
ing water and
the river.
5. "Purges" that cleaned
the cooling pipes sent
additional radioactivity
into the cooling
water
and the river.
The nuclear reactions inside these
reactors created plutonium and great amounts of heat. The cooling system used
water from the Columbia River, ran it through pipes in the core of the reactors, and
then back into the Columbia. This process was called "once-through cooling."
There were various chemicals in the cooling water. Some of these occurred naturally in
the river water. Others were added to treat the water before it entered the
reactors and to keep the pipes of the cooling
system clean. Some of these chemicals became radioactive
when they were exposed to
the intense radiation field in the reactor cores. Some of these chemicals
contained phosphorus. Inside the reactor core, some of this phosphorus became
radioactive phosphorus-32. As much as 25 to 40 percent of
the phosphorus-32 released to the river came from the chemicals used for water
treatment.3 The rest of the
phosphorus that became radioactive was naturally occurring.
After leaving the cores, the discharged cooling water, or effluent, went into retention
basins. The purpose of the basins was to allow time for some of the short-lived radiation
to decay
and the reactor-heated water to cool. The cooling water was near
200o F when it left the reactors. It cooled somewhat while in the retention basins, but was still much
hotter than the river temperature when it was discharged back to the river. The basins
were designed to have a retention time that ranged from two to six hours. After flowing
through the retention basins, the cooling water was discharged into the
Columbia River.
In addition to adding five reactors, Hanford
increased the power
levels of all eight reactors to produce more plutonium for the country's nuclear arsenal.
As a
result, more radioactivity was discharged into the Columbia. The reactors needed more
cooling water to operate at higher levels. The greater flow of cooling water reduced the
retention time to as short as
20 minutes. This shorter retention time
contributed to more radioactivity entering
the river. The radioactive contamination levels in the Columbia River were highest
from 1957 to 1964.
The ninth and last plutonium production reactor to be built at Hanford, the N reactor,
had a different cooling system than Hanford's first eight reactors. Like commercial
nuclear power reactors, the N reactor had two cooling systems. The two cooling systems are
designed so that the cooling water that is exposed inside the reactor core is not released
back into its source. The N reactor, therefore, did not
significantly contribute to the pollution
described in this report. The N reactor
operated from 1963 to 1987.
In addition to the increased power levels and the resulting decreased retention time,
there were two other causes of radioactive pollution entering the Columbia River from
Hanford. These were fuel element failures
and reactor purges.
The nuclear fuel consisted of fuel
"elements" which were less than two feet long and encased in metal. There were
thousands of fuel elements in each reactor. The increase in the reactor power levels put
more stress on the fuel elements. Under this stress, the metal covering could split and
allow small chunks of the radioactive fuel to be flushed into the river with the cooling
water. The largest chunk weighed more than a pound. There were nearly 2,000 fuel
element failures during the
operation of the eight original plutonium production reactors.
Purging the reactor piping also contributed to the contamination of the river.
Impurities in the cooling water entering the reactor caused a film to build up on the
inside of the cooling pipes within the
reactor. This film was radioactive.
As it built up in the pipes, it increased the radiation exposure to workers in the reactor
buildings. Periodically, the piping system was flushed with chemicals to strip off the
film. These were called "reactor purges." When the accumulated film was purged, it
went through the retention basins, then into the river and contributed to the
contamination of the Columbia.
Factors Influencing Radiation Exposure
In addition to the causes of radioactive
contamination discussed above, there were two factors which influenced the amount of
radiation people were exposed to: seasonal changes
in the Columbia and the addition of dams.
When seasons change, so does the Columbia. In the spring, the river is swollen with
runoff from the melting snowpack. There is more water flowing and it is moving faster.
This helped dilute the concentration of radioactive material in the river water. The
temperature of the water is also affected: cooler in the large flows of winter and spring,
warmer in smaller flows of summer and fall. The cooler water of winter and spring
decreased the amount of radionuclides absorbed by fish because their metabolisms
slowed and they ate less.
Summer and fall brought smaller flows, warmer water and a resulting higher
concentration of radioactivity. Summer and fall, then, were the times when exposures
likely peaked in river areas near Hanford, especially during September, October and
November.
Why the concentration
of radioactive material
in the Columbia River
differed over time
1. Seasonal changes in
the Columbia and new
dams affected the
amount of radiation to
which people were
exposed.
2. Lower flow in the Columbia River and higher temperatures in
summer and fall led
to higher concentration of radioactivity in those seasons.
3. September, October and November were likely the times of high-
est
exposure in the Columbia near Hanford.
Dams also affected the flow of the Columbia River. In 1944, Bonneville was the only
dam downstream from Hanford. By 1971, there were four. (See
map above.) The dams
changed the way radioactive materials were carried and distributed down the river in
two main ways. First, the dams slowed the flow of the river. This slower flow allowed
more of the radioactive materials to decay before reaching people farther downstream
from the Tri-Cities (Richland, Pasco and Kennewick).
Second, the radioactive materials downstream were further decreased because some
adhered to the sediment trapped behind the dams.4
In short, Hanford polluted the Columbia River by releasing
radioactive materials from the plutonium production reactors. Next, this report will
examine how people were exposed to Hanford's radiation from the Columbia River
pathway.
How People Were Exposed to Radiation from Hanford
People were exposed to Hanford's radiation via the river
pathway if they:
drank contaminated water;
ate contaminated food (fish, shellfish or waterfowl); or
spent time along the shoreline of or swam in the contaminated stretches of the
Columbia River.
Contaminated drinking water was the largest contributor to a typical person's
dose from
the river pathway. Eating contaminated foods was the next significant contributor to
dose, followed by exposure while boating or swimming. The contribution from eating
crops that had been irrigated by Columbia River water was estimated by the Dose
Reconstruction Project to have been so small that it was not
included in the dose estimates.
People who drank
water from the Columbia River downstream of Hanford between 1944 and 1972 would
have been exposed to radiation.5 Some communities drew
drinking water from the Columbia. The water treatment system of Pasco had special
filters that captured some of the radioactive materials. The city of Richland did not draw
its water from the
Columbia until October 1963. Prior to this, its water supply came from the Yakima
River.6 Not all cities took
drinking water from the Columbia. For example, Portland, Oregon got its drinking water
from a reservoir near Mt. Hood.
People were exposed
to radiation in the
Columbia River by
drinking contaminated
water from the river;
eating contaminated fish, shellfish or water-
fowl;
spending time along
the shoreline of contami-
nated stretches of the
river;
boating or swimming
downstream from the
Hanford reactors; and/or
eating fresh produce
irrigated with contami-
nated water.
Other people drank untreated river water. One example is those who worked on barges
transporting goods along the river. The
common practice of the barge crews was to drop a bucket into the river to get their
drinking water. In 1956, Hanford officials considered issuing restrictions on drinking
untreated river water. They concluded that restrictions were "not essential." They also
noted that "public relations might suffer from such restrictions."
7
The second source of exposure in the river pathway was from eating contaminated food:
fish, shellfish and waterfowl.8
As is discussed later in the next section, Columbia River fish were contaminated.
The radiation in the Columbia also reached the Pacific Ocean, contaminating shellfish
along the Washington and Oregon coasts. The levels of zinc-65 in the oysters of Willapa
Bay
on the Washington coast were monitored
beginning in 1959. According to a 1959 Hanford document, the levels of zinc-65 in
Pacific oysters were more than 300 times higher than in Japanese or Atlantic coast
oysters.9
Ducks and geese that nested or fed along the Columbia became contaminated.
Waterfowl also picked up radioactivity from waste ponds on the Hanford site. The
contamination levels were higher in birds collected on the Hanford site than in those
from the areas surrounding Hanford. In early 1970, several ducks collected from waste
ponds near the reactors were found to be very contaminated. If someone had
immediately eaten one-half pound of the most contaminated duck, the radiation dose
to the bone would have been four times higher than the annual acceptable standard at
the time.10
People with unique lifestyles may have eaten other kinds of contaminated food. For
example, Native Americans ate shoreline
roots and berries.
The third source of exposure was from spending time along the shore, swimming or
boating downstream from the Hanford
reactors. Most of this exposure was in the form of external,
whole-body radiation. Some
people have recalled that in the 1950s and 1960s, they preferred swimming near Hanford
because the water felt warmer there than
further downstream.
Hanford and Columbia River Fish
Hanford scientists began studies on
Columbia River fish in 1945. They wanted to learn if the reactor effluent which was
discharged to the river had any effect on fish. They constructed a laboratory at Hanford
near the reactors. Young fish were exposed in tanks to various concentrations of
effluent, usually at levels much higher than Hanford was releasing to the Columbia River.
There are two kinds of fish in the Columbia River: anadromous and resident.
Anadromous fish are those that hatch in fresh water and return there to spawn, but
spend most of their lives in the ocean. Some
examples of anadromous fish are salmon and steelhead trout. These two types of
anadromous fish are the most valuable to the region's economy and to Native
Americans.
The early Hanford studies were concerned primarily with young Chinook salmon and
steelhead trout. Eggs and young fish were exposed to higher
concentrations of effluent than were actually present in the river. Many died. However,
Hanford scientists determined that the cause of death was not exposure to the radioactivity. The
fish deaths were determined to be due mainly to the chemicals added to pretreat the
cooling water and the increase in water temperature.11
The studies did not examine the long-term effects of exposure in the fish.
When mature anadromous fish return from the ocean to fresh water, they do not feed.
Since they are not exposed by eating contaminated smaller fish, they are not thought to
accumulate much radioactive contamination. Due to significant public concern, the
Dose Reconstruction Project
is planning additional work on the radiation levels that were present in anadromous
fish as they came up the Columbia to spawn.
Fish were exposed by:
eating smaller fish;
eating algae, insects or
other small aquatic
creatures; and /or
having water pass through their gills.
Waterfowl were
exposed by:
nesting or feeding
along the Columbia
River; and /or
nesting or feeding at
waste ponds on the
Hanford site.
Resident fish are those that live their
entire lives in fresh
water. Examples of resident fish are crappie, bass, river trout, whitefish and sturgeon.
Due to spending more time in the contaminated portions of the Columbia River than
anadromous fish, the resident fish collected higher concentrations of radioactivity. Most
of the radiation in the fish came from eating smaller aquatic creatures such as algae and
insects. The algae could concentrate
the radiation up to 100,000 times the levels of contamination in the river water.
Resident fish in the Hanford area readily
accumulated the radioactive phosphorus in their bodies because the levels of natural
phosphate in the river were low.12 The whitefish had the highest concentrations of phosphorus-32. Because of this, Hanford researchers selected whitefish as the focus of their fish monitoring efforts.
The Hanford Health Information Network has received several questions about the
radioactivity levels in sturgeon. The concern is raised because sturgeon feed off the
bottom of the river where radioactive sediments are found and because sturgeon can
live more than 100 years. Based upon studies conducted by Hanford, scientists
concluded that eating sturgeon would have given a lower
dose than eating crappie,
perch or bass. This lower exposure was due to lower concentrations of radioactivity in
the sturgeon and people catching fewer sturgeon than other fish.13 However, a scenario
of a person eating large quantities of sturgeon is entirely reasonable and this diet could
have resulted in a higher exposure.
Official Concerns in the Past
Did Hanford pose a danger to the fish and to people who ate fish? The historical record
is not consistent. Based on the laboratory studies and the monitoring of the river,
Hanford scientists and government officials concluded that "the effluents were diluted
to relatively safe levels" based on standards at the time. 14 However, some health officials
in the past expressed serious concern about the contamination levels in the Columbia River.
Hanford exposure and fish
Fish living in the Columbia year-round
("resident fish"), such as crappie, bass, river trout, whitefish and sturgeon, had higher
concentrations of radioactivity than fish that only hatched and spawned in the
Columbia ("anadromous fish").
Resident fish near Hanford easily collected radioactive phosphorus in their bodies
because the Columbia was low in natural phosphate. Whitefish had the highest
concentrations of phosphorus-32.
The Dose Reconstuction Project will look further at the radiation levels that were in
anadromous fish as they came up the Columbia to spawn. Anadromous fish include
salmon and steelhead trout.
During Hanford's early years, Herbert M. Parker was in charge of the health and safety
programs.15 In 1954, as he
considered the projected increases in radiation being released into the Columbia
from the reactors, Parker suggested that it might be necessary to
impose a public fishing ban from just above Hanford (Priest Rapids) downriver to
McNary Dam.16 Parker
noted that the "public relations impact would be severe." According to a report
by the Hanford Education Action League, a nonprofit organization
based in Spokane, Wash., "Although no fishing ban was ever imposed, the radiation
levels in Columbia River fish surpassed the point at which Parker had considered a
fishing ban during the years 1957, 1958, 1960, 1961, 1963 and 1964."
17
Nor was concern focused only on the
section of the Columbia nearest to Hanford. In 1964, the U.S. Public Health Service
recommended that immediate action be taken to cut in half the radioactivity
levels in "the Lower
Columbia River."18
Although not specified in this report, the Lower Columbia was usually
referred to as downriver from McNary Dam to
below Portland. (See map above.)
Current Concerns
Many people have expressed concerns about the radioactive materials from past
releases that are trapped behind Columbia River dams, especially McNary. However, a
Washington Department of Health report has concluded that the risk for adverse health
effects is less than that associated with federal and state drinking water standards.19
This could change if the sediments were dredged (although this is unlikely).
downwinder
perspective
Many callers to the Hanford Health Information Lines
have questions and concerns about the release of radioactive
materials to the Columbia River and possible effects on humans and on fish. Some
downwinders
have health problems that they believe are, or might be, related to Hanford.
The following personal perspective is offered to help readers understand these
experiences and concerns.
"I'm a member of the Confederated Tribes of the Umatilla Indian Reservation, located
some 60 air miles southeast of the Hanford Nuclear Reservation.
"My mother was born at Plymouth, Wash., across the Columbia River from Umatilla in
Eastern Oregon, just downstream from where McNary Dam is now. My mother's
immediate and extended family practiced extensive use of the river and its inhabitants.
This background is what interested my ensuing relationship with the Columbia River.
"I first went to Celilo Falls at age 11 in the early 1940s. Here I caught and handled a lot of
salmon during the span of three fall fisheries.
"First, I was a fish buyer for my uncle and secondly, an enterprising fisherman. Since I had
no scaffold of my own to fish, I moved around to available places and had a lot of fun. My
family wasn't dependent upon the fisheries, but we consumed a lot of salmon.
"To the best of my knowledge, there have been little ill effects to myself or my immediate
family from Hanford's radioactive releases into the Columbia River. However, the river is
very sick.
"There are many questions from Tribal members who have spent more
of their time around the river, about the deaths of their relatives. They have many
unanswered questions about what happened at Hanford and how it could affect us.
"At this point we don't have any definite answers that say this was a result of something
that was released to the water or air from Hanford. All we know about radionuclides is,
you can't see them, hear them, smell them or taste them - but they can affect you."
-
Name withheld by request
Hanford Dose Estimates
The Dose Reconstruction Project
has calculated "representative dose
estimates." For the
river pathway,
these are estimates of dose for three typical lifestyles with variations in
food and water consumption and place of residence.
The lifestyles of actual individuals, such as those who subsisted on fish, might be
different than the "representative" categories. Many Native Americans rely heavily on
fish, especially salmon, for food. The Columbia River Inter-Tribal Fish Commission
(CRITFC) recently surveyed the fish consumption of Native Americans in the
Columbia River Basin. The results show that the average fish consumption rate for
Native Americans using the Columbia River is "approximately nine times greater"
than for the general U.S. population.20
COLUMBIA RIVER FISH CONSUMPTION
(pounds per year)
Native American Survey (CRITFC)
Average 47
Highest greater than 137
Hanford Dose
Reconstruction Project
"Typical Individual" 4-5
"Maximum Individual" 93
Although the Network's previous report
on the radionuclides
released to the air
contained the range of representative dose estimates for each radionuclide, the same
level of information for radionuclides released
to the river is not available. The Dose
Reconstruction Project's estimates of exposures from the river pathway are generally
much lower than those from the air pathway.
Because of this, the Dose Reconstruction Project did not go into as much detail for the
dose estimates via the river pathway.
The cumulative (1944-1971) representative dose estimates for adults from the five
radionuclides released to the river range from near zero to about 1.5
rem EDE
(Effective Dose
Equivalent-whole-body dose). The dose
estimates to specific organs (red bone marrow and lower large intestine) are higher.
These estimates are in Dose Reconstruction Project reports but only for the period 1950
through 1971. In most cases, the farther downstream from Hanford, the lower the
exposure.
In order to give a sense of how large a dose 1.5 rem EDE is, a comparison with
background radiation is sometimes made. During the same period (1944-1971), an
average adult would have received a dose of about 9 rem EDE (whole body) from
background radiation.
The sources of background radiation include
radon,
medical procedures and cosmic
rays. Please note that exposure to background
radiation may cause adverse health effects.
Representative dose estimates for the river pathway were not calculated for infants and
children.21 For the air
pathway, the highest representative dose estimates were for infants and children. Also, dose estimates for the air pathway were reported in a range
that was descriptive of the uncertainty in the estimates. The uncertainty range was not
reported for the river pathway.
Possible Health Problems
Please keep the following points in mind
when reading the sections on the possible
health problems connected with the following five radionuclides:
Most of the research associated with these radionuclides has been done on animals.
Comparing the health effects on animals and on people exposed to radiation from
Hanford is difficult for three main reasons:
The life span of human beings is much longer than that of the animals used in
studies. Some diseases, such as cancer, may not be detected for several decades.
It is uncertain if humans are affected in the same way as animals.
Most of the animal studies involved exposure to very high levels of radiation over a
short time (equivalent to a human exposure of thousands of rem). Hanford exposed
people to lower levels of radiation but over a long time.
Due to the very small amount of information available on the health effects
specific to these five radionuclides, people are advised against making direct comparisons to
people exposed to radioactive releases from Hanford.
Since the release of the first 19,000 pages of Hanford historical documents in 1986, much
has been learned. However, the information available is not enough to form a complete
assessment of the impact of Hanford's releases. This section provides information about
each of five radionuclides. The same categories of information are presented for each:
a general description of the
radionuclide;
the estimated amount released from Hanford from 1944 to 1971;
the organs estimated to have
received the main dose from the Hanford exposures; and
a summary of health studies.
The amounts released, calculated doses
and organs receiving the main dose are
estimates of the Hanford Environmental Dose Reconstruction Project. The five river
pathway radionuclides are presented in alphabetical
order.
Possible Health Effects: No studies were found specific to arsenic-76.
Organs Receiving Main Dose: Gastrointestinal
tract, stomach for infants
Summary of Health Studies
The Network's research has been unable to find any studies on the effects of exposure
specific to arsenic-76. Chemically, arsenic, in sufficient concentrations, is a poison and
can cause cancer. Chronic exposure
to arsenic can cause the following cancers: lung, skin
and stomach (from the chemical toxicity).
Neptunium-239
Description: Neptunium-239 has a half-life
of 2.4 days. It emits beta and
gamma radiation.
Neptunium-239 decays into plutonium-239 which has a half-life of 24,000
years and emits alpha radiation. The amount of neptunium-239 released to the
Columbia River decayed to about
1.7 curies of plutonium-239.
Summary of Health Studies
Most of the neptunium that is retained in the body deposits in the bones. Some is also
retained in the liver. Several studies report "relatively high concentrations" of
neptunium in adrenal glands of laboratory animals.22
No health effects specific to exposure from neptunium "have been observed" in human
beings.23 Roy C. Thompson,
Biology Department of Battelle Pacific Northwest Laboratory in Richland, conducted an extensive review of studies involving
neptunium.
This review included Russian studies that found an
increase in the number of bone tumors in
animals receiving bone doses as low as a few rad.
Thompson concluded that "there can
be little doubt" that neptunium can cause cancer in bone.24
In 1984, a team of German scientists
reported preliminary results of an experiment with mice designed to measure the
combined effect of having neptunium-239 deposit in
bone and decay into plutonium-239. These
initial results found evidence that the buildup
of plutonium-239 (as the neptunium decayed) increased the number of bone tumors
compared to those expected from exposure to
neptunium alone.25
Phosphorus-32
Description: Phosphorus-32 has a half-life
of 14.3 days. It emits beta radiation.
Biologically, nonradioactive phosphorus is vital to living things because it enables the
transfer of energy in metabolism. It is also an important ingredient in bones.
Summary of Health Studies
Once inside the body, phosphorus concentrates in the bone. In experiments
on rats, phosphorus-32 was found to be "potent" in causing bone cancer.26
Based on studies of human patients with a blood disease treated with phosphorus-32,
there may be an "increased incidence of leukemia."27
A review article of several studies of people with the same blood disease who were followed until death reported that of those
treated with phosphorus-32, 16 percent had developed acute leukemia compared with
only 1.6 percent of those not treated.28
Sodium-24
Description: Sodium-24 has a half-life
of 15 hours, the shortest half-life of the five
radionuclides. It emitsbeta and
gamma radiation.
Summary of Health Studies
The Network's research has been unable to find any studies on the effects of exposure
specific to sodium-24.
Zinc-65
Description: Zinc-65 has a half-life
of 245 days, the longest half-life of the five
radionuclides. It emits beta and
gamma radiation. Biologically, nonradioactive zinc is
needed. "Too little zinc in the diet can lead to poor health, reproductive problems and
lowered ability to resist disease."29
Summary of Health Studies
The principal health effect of zinc-65 is from the radiation exposure. If zinc-65
decays
into copper while it is in an enzyme in the
body, it can possibly have "drastic consequences."30 One consequence is that exposure to zinc-65 might lead
to the formation of autoantibodies (proteins that act against the protection mechanisms within one's own
body). Evidence for this comes from a study on rabbits.31,32
Zinc also readily concentrates in the
prostate when administered intravenously.33 Because of this, radioactive zinc may be a factor in prostate cancer.34
Summary
To conclude, we know that Hanford's
plutonium production did cause extensive
contamination of the Columbia River and parts of the Pacific Ocean along the coasts of
Washington and Oregon. Fish and other
wildlife using these waters were exposed to
radioactive materials and other kinds of
pollution. People using the waters and the aquatic resources were also exposed to
measurable levels of radiation.
What remains uncertain is if and how the radiation released into the Columbia River
affected human health. Many people have asked the Network questions about whether
their exposure to the radioactive contamination in the Columbia River
harmed their
health. Unfortunately, there is not enough information
to answer their questions.
Unresolved Issues
During the preparation of this report, the technical reviewers raised several points that
could not be resolved.
David C. Kocher, Ph.D., was concerned that the presentation of the risk of possible
health effects of
the five radionuclides
was incomplete. Readers should understand that,
given the low dose
estimates of the Dose Reconstruction Project,
"there is no reason to
believe that there was an observable increase in health effects in nearby residents due to
releases to the river." Scientists are not now able to observe (or measure) health effects
due to exposure to background
radiation. Since the dose estimates for the river pathway
are lower than background, scientists could not measure "health effects even if they
existed, because the effects would be substantially less than those caused by natural
background." Kocher is with the Health
Sciences Research Division of Oak Ridge
National Laboratory in Tennessee.
Norm Buske, M.S., was mainly concerned that possible health effects could not be
"reliably appraised until Hanford's major
releases have been identified." His assessment is that Hanford's
dose reconstruction
work has probably overlooked important radiological releases to the Columbia River. Buske
suggested that the significance of these
releases was "probably greater than anything yet reported" by the Dose Reconstruction
Project. He asserted that the Dose Reconstruction Project should have included other
radionuclides, such as chromium-51 and iron-59, in the dose calculations. Buske has
presented his concerns to Hanford officials and is awaiting a response. He has a degree
in oceanography and has done research on Hanford radioactive releases and the
Columbia River over the last 10 years.
Greg deBruler served as the public representative on this report's Technical Review
Panel. One of his major concerns is the dose estimates used in this report. "There is
enough scientific uncertainty with the Dose Reconstruction Project that the
representative dose estimates
should not be treated as if they were scientifically proven
facts. The HEDR dose estimates could be off by orders of magnitude of 10 or more."
DeBruler reminds us of the statement in an HHIN document: "The basic assumption of
radiation protection standards is that any exposure to radiation poses a health risk." The
review of this document does not reflect all of the comments or concerns he submitted.
DeBruler is a technical consultant to Columbia River United, a nonprofit organization
based in Hood River, Oregon.
Notes
1 Oregon Health Division, Radiation Protection Services.
"Environmental Radiological Surveillance Report on Oregon Surface Waters,
1961-1993." Dec. 1994, p. 1.
2 The Hanford Environmental
Dose Reconstruction Project is the only study
estimating the doses from radiation received by people exposed to Hanford's releases of
radioactive materials. The public has access to the work of the Dose Reconstruction
Project and is invited to attend the meetings of the Technical Steering Panel, which
directs the study. When using information from the Dose Reconstruction Project and
other studies, readers should keep in mind that research results depend on a number of
factors, such as the information available, and the methods and type of analysis used.
3 WH Walters, et al. "Literature and Data Review for the Surface-Water Pathway:
Columbia River and Adjacent Coastal Areas." PNL-8083, Battelle: April 1992, p. 5.5.
4 For further reading on radiation trapped in sediments, see D Wells, "Special Report:
Radioactivity in Columbia River Sediments and Their Health Effects." Washington
Department of Health, Division of Radiation Protection; Mar. 1994.
5 Although the amounts are much smaller, radioactive material continues to enter
the Columbia River from Hanford's contaminated groundwater. This publication
covers only the years 1944-1972, as directed by the Network's mandate.
6 WT Farris et al. "Columbia River Pathway Dosimetry Report, 1944-1992."
PNWD-2227; July 1994, p. 4.4.
7 "Radiation Aspects for River Navigation Through Hanford Project." HW-47152;
Dec. 7, 1956, p. 2.
8 For additional information, see RW Hanf et al. "Radioactive Contamination of Fish,
Shellfish, and Waterfowl Exposed to Hanford Effluents: Annual Summaries,
1945-1972." PNWD-1986; July 1992.
9 RL Junkins, et al. "Evaluation of Radiological Conditions in the Vicinity of Hanford
for 1959." HW-64371. Also "Quarterly Progress Report: October-December 1959."
HW-63643; pp. 19-20.
10 JP Corley. "Environmental Surveillance at Hanford for
CY-1970." BNWL-1669; Sept. 1973, pp. 3, 35. Due to changes in how doses are calculated,
it was not possible to make a comparison with current standards.
11 CD Becker. Aquatic Bioenvironmental Studies: The Hanford Experience,
1944-1984. Studies in Environmental Science, Volume 39. Amsterdam: Elsevier, 1990,
pp. 96-97, 100, 110. Becker was in the Geosciences Department of the Pacific Northwest
Laboratory at Hanford which is operated by Battelle.
12 CD Becker, p. 175.
13 DD Dauble et al. "Radionuclide Concentrations in White
Sturgeon from the Columbia River." PNL-8221, Rev. 1;
November 1993, p. 18.
14 CD Becker, p. 110.
15 Parker earned a Masters of Science in physics from the University of Manchester
in England (1931). He then worked on using radiation to treat cancer in both England
and the United States. For the four years immediately prior to World War II, Parker
worked under Simeon Cantril at the Swedish Hospital Tumor Institute in Seattle.
During the Manhattan Project, Parker worked to develop radiation protection
procedures at Chicago, Oak Ridge and Hanford.
16 HM Parker. "Columbia River Situation-A Semi-Technical
Review." HW-32809; August 19, 1954.
17 J Thomas. "Atomic Deception: Oh, What a Tangled Web!" HEAL Perspective.
Summer/Fall 1992; (10-11): p. 7.
18 US Public Health Service. "Evaluation of Pollutional Effects
of Effluents from Hanford Works." May 13, 1964.
19 D Wells. "Special Report: Radioactivity in Columbia River Sediments and Their
Health Effects." Washington Department of Health, Division of Radiation Protection.
Mar. 1994; p. 41.
20 CRITFC (Columbia River Inter-Tribal Fish Commission).
"A Fish Consumption Survey of the Umatilla, Nez Perce, Yakama, and Warm Springs
Tribes of the Columbia River Basin."
CRITFC Technical Report No. 94-3, October 1994; p. 59.
21 WT Farris et al. "Columbia River Pathway Dosimetry Report, 1944-1992."
PNWD-2227; July 1994, p. 4.8.
22 Roy C Thompson. "Neptunium-The Neglected Actinide:
A Review of the Biological and Environmental Literature." Radiation Research. April
1982; 90: p. 18.
23 Thompson, p. 21.
24 Thompson, p. 24.
25 WA Müller, EH Schäffer,
U Linzner, and A Luz. "Incorporation Experiments
with Combined Application of Different Bone Seekers." Radiation Environment
Biophysics. 1984; 23 (2):
p. 115. The scientists were from Abteilung fÅr Pathologie, Gesellschaft fÅr
Strahlen-
und Umweltforschung, Neuherberg, Germany (in association with EURATOM).
26 Marvin Goldman, Ph.D., Laboratory for Energy-Related Health Research,
University of California-Davis. "Experimental Carcinogenesis in the Skeleton." In
Radiation Carcinogenesis,
AC Upton, RE Albert, FJ Burns and RE Shore, eds. 1986; p. 220.
27 J Visfeldt, G Jensen and E Hippe. "On Thorotrast
Leucaemia: Evolution of Clone of
Bone Marrow Cells with Radiation-Induced Chromosome Aberrations." ACTA
Pathologica et Microbiologica Scandinavica. July 1975; 83 (4): p. 377. Visfeldt is with the
University Institute of Pathological Anatomy in Copenhagen, Denmark. Jensen is with
the Institute of Pathology, Frederiksberg Hospital in Copenhagen. Hippe is with the
Medical Department C at the Bispebjerg Hospital, also in Copenhagen.
28 G Rothstein and MM Wintrobe. "Preleukemia." Advances in Internal Medicine.
1975; 20: p. 367. Both authors were with the Department of Internal Medicine at the
University of Utah College of Medicine in Salt Lake City.
29 Agency for Toxic Substances and Disease Registry
(ATSDR). "Toxicological Profile
for Zinc." Feb. 19, 1993; p. 2.
30 HF Schulte, Los Alamos Scientific Laboratory. Book review of The Toxicology of
Radioactive Substances, Volume 5:
Zinc-65. Health Physics. September 1971; 21 (3): p. 481.
31 PP Filatov. "The Effect of Chronic Exposure to Radioactive Zinc on Antibody
Formation." The Toxicology of Radioactive Substances, Volume 5: Zinc-65. AA Letavet
and EB Kurlyandskaya, eds. Oxford: Pergamon, 1970, pp. 138ff.
32 MF Cottrall. "Medical Research and Auger
Cascades"(letter). The Lancet. Oct. 26,
1985; 2 (8461), pp. 942-943. Cottrall was with the Academic Department of Medical
Physics at the Royal Free Hospital School of Medicine in London.
33 GR Prout et al. "Radioactive Zinc in the Prostate: Some Factors Influencing
Concentrations in Dogs and Men." JAMA. April 11, 1959; 169 (15): pp. 1703-1710. Prout
was with the Urologic Service of the Sloan-Kettering Institute.
34 A Hilson. "Prostatic Cancer and Radionuclides: Evidence Implicates Zinc-65"
(letter). BMJ. January 22, 1994; 308:
p. 268. Hilson is in the Department of Nuclear Medicine at London's Royal Free
Hospital.
Related Reading
Potential Health Problems from Exposure to Selected Radionuclides (Released to
the Air)
Radioactivity in the Body