A full length version of the IEER report can be obtained by visiting USA Today's Web site at http://www.usatoday.com/news/poison/docdex.htm or by contacting IEER.

In the IEER report produced for USA Today newspaper, titled Preliminary Partial Dose Estimates from the Processing of Nuclear Materials at Three Plants during the 1940s and 1950s, we analyzed some data in regard to working conditions and radiation exposures of workers at three nuclear materials processing facilities:

• Simonds Saw & Steel Co., Lockport, New York
• Harshaw Chemical Co., Cleveland, Ohio
• Electro-Metallurgical Co., Niagara Falls, New York

All three plants processed uranium during portions of the 1940s and 1950s. Simonds also processed thorium metal. These facilities conducted industrial operations such as metal rolling that would later be conducted at government-owned facilities.

The study, on which this article is based, was a preliminary and partial evaluation of worker exposure in some job categories or locations. Its purpose was to perform screening-type of calculations to ascertain whether the doses to workers in at least some locations or job categories were high enough to cause serious health concerns.

We did not assess external radiation doses. There are clear indications that in some cases, at least, these exposures were substantial. We also have not attempted to assess exposures to non-radioactive toxic materials, which may also have been substantial in many cases. The study is necessarily limited in scope and partial. A thorough effort would require far more documentation and data, time, and resources than were available in this project.

We estimated doses due to inhalation of uranium by calculating the amount of uranium breathed in by a worker in a typical work day at a specific location or in a specific job category. The time-weighted air concentrations to which workers were exposed over a day were estimated by plant personnel taking into account the time spent by the workers in different plant locations. All dose calculations shown here are "committed doses," reflecting the fact that exposures resulting from a single intake are considered over the entire time that inhaled uranium remains in the body.²

Simonds Saw & Steel Co., Lockport, New York

Between 25 and 30 million pounds of uranium metal was rolled into rods at Simonds between March or April 1948 and 1956. Simonds also rolled 30,000 to 40,000 pounds of thorium metal. The work with uranium and thorium was done part-time, and the same machines were used to roll steel for commercial applications the rest of the time.

There is ample evidence that the plant premises became seriously contaminated during processing of radioactive materials. For instance, even air in the lunch areas was far above allowable limits of contamination. As a result, workers were exposed to radiation even when steel processing was going on, for instance through re-suspended particles. We did not attempt to assess the doses to workers during steel processing. We also did not attempt to estimate the consequences of food becoming contaminated as a result of poor industrial hygiene. Including all of these factors would increase the dose estimates.

We used the available data to make estimates of doses from uranium metal processing to August 6, 1954. We do not have survey data covering the rest of the period through the end of operations in December 1956. Thus, the doses presented here are partial exposure estimates that underestimate doses to personnel who worked through the entire period of processing.

We made exposure estimates by job classification. If one person did the job for the entire period, the dose estimate represents a typical expected exposure (see below for discussion of uncertainties). If the personnel doing the job changed, this dose estimate would not apply to any particular individual, but rather to the sequence of individuals who did the particular job over the specified period.

The emissions from the operation at Simonds were typically a mixture of oxides of uranium, whose solubilities ranged from very insoluble to moderately soluble. It may take many months or years for highly insoluble materials to be eliminated once lodged in the lung, while moderately soluble materials may be eliminated within a few weeks. However, more soluble forms of uranium would also get transported to the kidney, resulting in damage due to uranium's heavy metal properties.

Figure 1 shows the lung dose estimates for a range of particular jobs. Workers in the same job may have had doses several times higher or lower than this, depending on specific working times and conditions as well as individual metabolic differences.

Workers were also exposed to thorium dust. Even though the amount of thorium processed was almost a factor of one thousand less than uranium, exposures to workers who processed thorium appear to have been substantial, in part because exposure to thorium results in larger doses than uranium.

Thorium processing operations at Simonds may have taken as little as one week and possibly much longer. Based on available data, it is not possible for us to estimate the total number of full time equivalent days for which the thorium milling operation was conducted. We have therefore calculated thorium doses corresponding to one week of full time work. We estimated that bone surface doses over a one-week exposure ranged from about 400 rem to almost 2,500 rem, depending on working conditions and thorium solubility. We do not have a basis on which to select a mix of solubilities based on the available data. If the work was carried out for several weeks, then the dose estimates would be correspondingly higher.

Overall, it appears that exposures to specific workers who worked on thorium may have been severe. We were not able to assess cumulative thorium exposures in a manner similar to uranium since we lack even minimally adequate air concentration data over the requisite period of time. Our estimate of thorium exposures, based on one week's work, indicates that for some workers, thorium exposures may have been comparable to and perhaps greater than uranium exposures. Finally, if some workers worked with both uranium and thorium, those exposures would be additive.

Harshaw Chemical Co. conducted a number of chemical operations to produce uranium hexafluoride (UF₆) for uranium enrichment operations. Part-time operations began during the World War II Manhattan Project, during which highly enriched uranium was used to make the nuclear bomb that was dropped on Hiroshima. UF₆ production at Harshaw was scaled up after the war and substantially expanded in 1947.

The chemical forms of uranium present at Harshaw range from the highly soluble (uranium hexafluoride) to the highly insoluble (uranium dioxide). Industrial hygiene was very poor, with air contamination exceeding the maximum allowable in some cases by several hundred fold, averaged over the entire working day.

Assuming that workers were exposed to the same mix of uranium compounds as seen at the Fernald nuclear weapons plant near Cincinnati, as would be likely for at least some portion of the plant personnel, the radiation doses to the lungs of workers in moderately exposed categories would be in the hundreds of rem, cumulative. A bar chart of worker doses at Harshaw is shown in Figure 2.

Our calculations assumed an eight hour work day and 20 work days per month averaged over a year. In the case of the most severely exposed workers -- who worked for long periods or in highly contaminated conditions or, in the worst cases, both -- cumulative lung doses were thousands of rem.

Many workers were exposed to more than the prevailing dose limit, which at that time period was 15 rem per year to the lung. The estimated mean lung dose in the highest exposure category (8,400 rem) would be equivalent to an effective dose of approximately 1,000 rem. Using the cancer risk factor established by the International Council on Radiation Protection (ICRP) of 0.04%, or four deaths per 10,000 rem, we can estimate that a worker would have a 40% chance of dying from cancer as a result of an exposure of 1,000 rem. This is an increase of 200 percent in fatal cancer risk compared to unexposed persons.

If the uranium were to be of more soluble compounds, the estimated radiation doses and cancer risk would be smaller and the likelihood of severe nephrotoxic effects would be far larger. Plant documents indicate that such kidney damage was reported.

We did not attempt within the scope of this limited study to systematically quantify external exposures. However, even a cursory review of Harshaw documents shows that for at least some workers, external exposures, in particular from thorium-234 and protactinium-234, which give rise to beta radiation exposures, may have been high, thus compounding the problems resulting from internal uranium exposure.

Also, the manufacture of uranium hexafluoride involves the use of severely toxic chemicals, including fluorine. Moreover, when uranium hexafluoride makes contact with the humidity in the air (which would be high in the Cleveland area during at least some parts of the year), it readily combines with water vapor to yield uranyl fluoride and hydrofluoric acid, which is highly toxic.

Uranium metal was fabricated at Electromet from uranium tetrafluoride (also called "green salt"). The process involves the mixing of green salt with magnesium metal flakes, and the insertion of the mixture into a furnace, where the green salt is reduced to metal. Historically, the process was typically troublesome, sometimes involving blow-outs, especially under the conditions of production pressure that characterized the first two decades of the nuclear era. The uranium would typically be a mixture of moderately soluble and insoluble compounds, with the former predominating, since green salt belongs in this category.

We did not have adequate data covering the entire time period of Electromet operation, which began during the Manhattan Project and ended in 1953. We know that full time uranium metal production was occurring in the late 1940s, for which we have some data on the range of air concentrations found in working areas, as well as air concentrations weighted over the working day. We performed dose calculations using these figures for one individual over 240 working days (a working year of 48 weeks, 5 days per week). Actual exposure for personnel who worked for a large portion of the period for which the plant operated can be expected to be considerably higher. However, we cannot assume that actual exposures would be a simple multiple of the calculated doses, since air concentration data are not available in the detail needed to make even an approximate calculation for the entire period.

Industrial hygiene at Electromet was very poor. Many workers were evidently severely overexposed, since highly contaminated environmental conditions persisted in the workplace for prolonged periods. We estimate that for production workers, committed lung doses due to exposure over a single twelve-month period would range from over 50 rem to well over 6,000 rem. The most severely exposed workers would have a very high probability of contracting cancer. One would also expect to find some heavy metal toxicity to the kidneys due to exposure to green salt.

There are two types of uncertainties in our estimates. First, there are variations in conditions experienced among the workers, differences in physiology leading to different metabolic rates, and so on. For instance, some workers at Harshaw would likely have encountered mainly insoluble types of uranium, while others would have encountered mainly soluble types of uranium. Largely because doses depend greatly on the assumed solubility of the material that is inhaled, a bewildering array of dose estimates can be produced from the same data on air concentrations.

The second type of uncertainty relates to the uncertainties in the measurements of air concentrations, in fluctuations in such concentrations from one day to the next, in the estimates of dose conversion factors for any particular chemical form of uranium, and in estimates of the effects of radiation exposure.

The estimates of partial doses within any group of workers could easily be several times lower or higher than those estimated here. Since we did not have the data to perform individual worker dose assessments, or even to determine whether such assessments could be reliably performed, a relatively low dose in a particular job category may not correspond to a low dose for a specific worker. The limited nature of the study and the preliminary and partial nature of the calculations do not justify extensive effort on a formal uncertainty analysis. We recommend that a more formal effort with a more complete set of data be undertaken. However, there is enough evidence to come to a reasonably certain conclusion that due to poor working conditions, exposures to many workers were very high and far above then-prevailing regulations.

In addition to these uncertainties, our estimates are partial since we have not included external doses, and since we have not been able to estimate doses over the entire working period in several cases. This factor would result in dose estimates that would be systematically higher than the numbers given above.

There is ample evidence that plant authorities as well as the government of the United States, which contracted with these private companies to process material for its nuclear weapons program, were well aware that workers at these plants were being severely overexposed over prolonged periods of time. There is also evidence that the US government deliberately misled workers about health and safety issues by concealing the facts of very poor working conditions from them and by failing to undertake the needed level of radiation dose surveillance, including frequent and widespread urine sampling, that was warranted.

A number of documents discuss inadequate controls of contamination and recommendations for improvement that were only sometimes taken into account. For example, in discussing the problems at Harshaw, one document states that:

In some cases, there was a hesitation to spend money to correct problems in plants that were expected to be placed on stand-by and no longer be in use for production. At least a year before the Electromet facility was to transition to stand-by, one Atomic Energy Commission document notes that:

One document points clearly to the practice of keeping information about the health risks of their jobs from the workers. In a January 1948 letter to the vice-president of Harshaw Chemical Co., the Manager of the New York Operations Office of the US Atomic Energy Commission wrote: "...it is obvious that concentrations considerably above the preferred level are common in Area C." In the same letter he states that the employees in Area C were told and should continue to be told "that all of our records indicated that no unusual hazard existed..."

Working conditions at these three plants were very poor and among the most terrible reported for any plant in the United States. Based on our screening calculations, doses to many workers are likely to have exceeded the dose limit to the lung of about 15 rem per year that was established in 1949. The data and our calculations also suggest that the highest exposed workers had a high probability of cancer mortality as the result of the exposure. It must be remembered that we have arrived at this conclusion even though our dose calculations are partial and do not cover the entire periods of plant operation and all types of doses. Other types of health problems, including kidney damage, would also be likely among those workers exposed to the more soluble forms of uranium.

We do not have comparable data from nuclear weapons plants that processed uranium in the Soviet Union during the late 1940s and early 1950s. Some external dose data for workers at a reactor and a reprocessing plant in the southern Ural Mountains have been reported. Heretofore, we have assumed based on available evidence that worker exposures were far higher in the Soviet Union that in the United States.⁵ However, the partial estimates that we have made here are so high that this assumption may need to be revisited for many of the workers at these forgotten nuclear weapons plants.

We should also note that the extent of the health damage may have extended to the families of workers and to the general public in ways that we have not assessed in the preliminary report.

One new conclusion that emerges from our study of the Simonds plant is that radiation exposures as a result of thorium-232 processing were severe. Such processing occurred at several other places (including the Fernald plant, for instance). This is an issue that needs to be more carefully evaluated, since it is possible that exposures to workers, their families, and members of the general public from thorium processing may have been larger than suspected, despite the relatively small amounts (compared to uranium) of thorium that were processed.

It is clear that the effects of the nuclear weapons enterprise on society are far vaster than imagined. The tasks of health monitoring and medical care for affected populations and of clean-up appear even more complex than previously anticipated.

1. Makhijani is president of IEER. Franke is a scientific director at ifeu (Institut für Energie und Umweltforschung GmbH) in Heidelberg, Germany. Zerriffi was senior scientist at IEER during production of the report.
2. We used dose conversion factors established by the U.S. Environmental Protection Agency (K.F. Eckerman et al., Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion, Federal Guidance Report Number 11. Washington, DC: US Environmental Protection Agency, 1988). For methodological details and assumptions, as well as additional references, please refer to the full report on USA Today's Web site at http://www.usatoday.com/news/poison/docdex.htm.
3. Monthly Status and Progress Report for December 1948. Submitted by the New York Operations Office of the Atomic Energy Commission by W.E. Kelley, Manager. January 5, 1949. p. 17
4. U.S. Atomic Energy Commission, New York Operations Office. Health Hazards in NYOO Facilities Producing and Processing Uranium (A Status Report - April 1, 1949). Prepared by NYOO Medical Division. Issued April 18, 1949. p. 31
5. Arjun Makhijani et al., eds., Nuclear Wastelands: A Global Guide to Nuclear Weapons Production and Its Health and Environmental Effects. Cambridge, MA: MIT Press 1995, Chapter 7, p. 367.