MODULE 11
After studying this module, the reader will be able to
For more than forty 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. 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 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.
According to the Hanford Environmental Dose Reconstruction Project (HEDR), 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. HEDR estimates 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 HEDR.
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 used or spent time on the Columbia 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.
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.
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. [2]. 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 200oF 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 twenty 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, 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.
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.
Dams also affected the flow of the Columbia River. In 1944, Bonneville was the only dam downstream from Hanford; by 1971, there were four. 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. [3].
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.
People were exposed to Hanford's radiation via the river pathway if they
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 HEDR 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 [4]. 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 [5]. Not all cities took drinking water from the Columbia. For example, Portland, Oregon, got its drinking water from a reservoir near Mt. Hood.
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." [6]
The second source of exposure in the river pathway was from eating contaminated food: fish, shellfish, and waterfowl [7]. 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 [8].
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 [9].
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 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 [10]. 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, HEDR is planning additional work on the radiation levels that were present in anadromous fish as they came up the Columbia to spawn.
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 [11]. 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 [12]. However, a scenario of a person eating large quantities of sturgeon is entirely reasonable and this diet could have resulted in a higher exposure.
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 [13]. However, some health officials in the past expressed serious concern about the contamination levels in the Columbia River.
During Hanford's early years, Herbert M. Parker was in charge of the health and safety programs [14]. 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) down-river to McNary Dam [15]. 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, Washington."
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." [16]
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." [17] Although not specified in this report, the Lower Columbia was usually referred to as downriver from McNary Dam to below Portland.
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 [18]. This could change if the sediments were dredged (although this is unlikely).
HEDR 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 [19].
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. HEDR's estimates of exposures from the river pathway are generally much lower than those from the air pathway. Because of this, HEDR 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 HEDR 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 back-ground radiation may cause adverse health effects.
Representative dose estimates for the river pathway were not calculated for infants and children [20]. 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.
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 HEDR. The five river pathway radionuclides are presented in alphabetical order.
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).
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 [21].
No health effects specific to exposure from neptunium "have been observed" in human beings [22]. 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 [23].
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 [24].
Once inside the body, phosphorus concentrates in the bone. In experiments on rats, phosphorus-32 was found to be "potent" in causing bone cancer [25].
Based on studies of human patients with polycythemia vera treated with phosphorus-32, there may be an "increased incidence of leukemia." [26] 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 [27].
The Network's research has been unable to find any studies on the effects of exposure specific to sodium-24.
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." [29] One consequence is that exposure to zinc-65 might lead to the formation of autoantibodies. Evidence for this comes from a study on rabbits. [30, 31].
Zinc also readily concentrates in the prostate when administered intravenously [32] Because of this, radioactive zinc may be a factor in prostate cancer [33]
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.
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 HEDR, "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 HEDR. He asserted that HEDR 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 ten 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 HEDR 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 ten 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.
HEDR Technical Steering Panel, Representative Hanford Radiation Dose Estimates, April 21, 1994, Revision 1
HHIN, Potential Health Problems from Exposure to Selected Radionuclides (Released to the Air)
HHIN, Radioactivity in the Body
Many callers to the Hanford Health Information Lines have questions and concerns about the release of plutonium and other radioactive materials from Hanford. Some downwinders have health problems and believe that they are, or might be, related to Hanford. The personal perspectives within this monograph are offered to help readers understand these experiences and concerns. This personal perspective of a member of the Confederated Tribes of the Umatilla Indian Reservation can help readers understand the experiences and concerns of Tribal members.
"I first went to Celilo Falls at age eleven 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 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."
