Radionuclides in the Columbia River:
Possible Health Problems in Humans and Effects on Fish

How Hanford Radiation
Polluted the Columbia

How People Were Exposed
to Radiation from Hanford

Hanford and Columbia River Fish

Downwinder Perspective

Hanford Dose Estimates

Possible Health Problems


Unresolved Issues


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:





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.
The Columbia River and the Hanford Site

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

2. Lower flow in the
Columbia River and
higher temperatures in
summer and fall led to
higher concentration of
radioactivity in those

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-

spending time along
the shoreline of contami-
nated stretches of the

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

(pounds per year)
Native American Survey (CRITFC) Average
greater than 137
Hanford Dose Reconstruction Project "Typical Individual"
"Maximum Individual"

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:

  1. 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.
  2. It is uncertain if humans are affected in the same way as animals.
  3. 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:

  1. a general description of the radionuclide;
  2. the estimated amount released from Hanford from 1944 to 1971;
  3. the possible health effects;
  4. the organs estimated to have received the main dose from the Hanford exposures; and
  5. 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.


Description: The half-life of the radionuclide arsenic-76 is 26.3 hours. It emits beta and gamma radiation.

Estimated Amount Released: 2,500,000 curies

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).


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.

Estimated Amount Released: 6,300,000 curies

Possible Health Effects: Bone cancer

Organ Receiving Main Dose: Gastrointestinal tract

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


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.

Estimated Amount Released: 230,000 curies

Possible Health Effects: Bone cancer, leukemia

Organ Receiving Main Dose: Red bone marrow

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


Description: Sodium-24 has a half-life of 15 hours, the shortest half-life of the five radionuclides. It emitsbeta and gamma radiation.

Estimated Amount Released: 12,000,000 curies

Possible Health Effects: No studies were found specific to sodium-24.

Organ Receiving Main Dose: Stomach

Summary of Health Studies

The Network's research has been unable to find any studies on the effects of exposure specific to sodium-24.


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

Estimated Amount Released: 490,000 curies

Possible Health Effects: Damage to enzymes and hormones

Organ Receiving Main Dose: Whole body

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


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.


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

Related Reading

Potential Health Problems from Exposure to Selected Radionuclides (Released to the Air)

Radioactivity in the Body


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