[ RadSafe ] Re: U.S. Nuclear Power Industry Workers Study
-HealthyWorker Effect
Flanigan, Floyd
Floyd.Flanigan at nmcco.com
Wed Mar 16 20:10:21 CET 2005
Drs. K.E. van Wyngaarden and E.K.J. Pauwels of the Department. of Diagnostic Radiology and Nuclear Medicine, University Hospital, Leiden, The Netherlands state (1995) that:
"Hormesis is any physiological effect that occurs at low doses and which cannot be anticipated by extrapolating from toxic effects noted at high doses (Sagan 1987). Hormetic effects are normally beneficial but may co-exist with toxic effects. Hormesis may be characterized as a process whereby low doses of an otherwise harmful agent may result in stimulatory or otherwise beneficial effects....A striking example is vitamins, widely accepted to be very beneficial at certain doses, but known to be toxic at higher doses."
"Literature data on radiation hormesis describe the observed beneficial effects at dose levels between 1 and 50 cGy. Many epidemiological studies have been performed to investigate whether threshold dose of ionizing radiation exists. Obviously, it is difficult to find a situation in which a large group of subjects is exposed to ionizing radiation, allowing accurate assessment of the dose. As a consequence of this, beneficial effects may be difficult to quantify. Nevertheless, several epidemiological studies have come to the conclusion that such beneficial effects really exist. These reports are summarized in the following paragraphs.
"In a Canadian study (Abbatt et al 1983) the mortality due to cancer at nuclear power stations was reported to be 58% lower than the national average. One reason for this could be the strict medical tests that the nuclear power workers are subjected to before being offered a job. However, workers in the non-nuclear power industry who underwent comparable medical tests have a mortality due to cancer which amounts to 97% of the national average. It is therefore unlikely that this marked drop in cancer mortality is due to 'the healthy worker effect' alone, as equally 'healthy' workers in the non-nuclear power industry do not have this lower mortality. An epidemiological study of cancer frequency and mortality in nuclear power workers has also been carried out in Britain (Kendall et al 1992). Also in this study it was found that cancer frequency amongst nuclear power workers was lower than the national average, but no definite conclusions were reached.
"In a Chinese study (Wel et al 1990), two groups of people were epidemiologically compared. The first (74,000 people) lived in an area with a relatively high background radiation (2.28 mGy per year), while a second (control) group (78,000 people) lived in an area with less radiation (0.95 mGy per year). The first group had a lower mortality due to cancer. Cancer mortality in the first group was 48.8 x 10-5 (±2.3) per person per year. Cancer mortality in the control group was higher 51.1 x 10-5 (±2.2). The difference is not statistically significant, but if only an older age category is compared (40-70 year olds) a significant difference is observed. The cancer mortality in the first group is 144 x 10-5 (±8.0) per person per year, whereas the control (lower background radiation) group shows the higher rate of 168 x 10-5 (±9.0) per person per year."
"In an U.S. energy department study (Tietjen 1987), the workers at three facilities were exposed to plutonium and other radioactive substances. The purpose of the study was to measure adverse health effects caused by the exposure. The plutonium exposure was mainly by inhalation. It appeared that the standard mortality ratio due to lung cancer was only 14% of the national level and all cancers in general appeared to be 70% of the national level. These figures are too extreme to be caused only by 'the healthy worker effect'. It was also observed that the number of smokers amongst the studied group was comparable with the national average, eliminating this factor as a source of error.
"In a study looking at the effects of a high background radiation in various cities in India (Namby and Soman 1987) it was observed that in areas with a high background radiation level the cancer incidence/mortality was significantly less. Five cities were studied and the higher the level of radiation, the lower the rate of various forms of cancer. Bombay, Nagpur, Bangalore, Pune and Madras were chosen for this investigation. Whereas the radiation levels in Bombay and Pune were much lower (<400 mSv/year, compared to 600-800 mSv/year in Bangalore and Madras), cancer incidence and mortality were higher. The reduction occurs at the rate of 0.03 per mSv/year (per 100000 people) in the Indian population. In the United States, Hickey et al (1981) have also measured the effects of differing levels of background radiation in different areas. From this study it was concluded that total cancer mortality is inversely correlated with background radiation dose with a statistical significance level of 0.05, but the Indian data are based on a larger population."
"Cohen and Colditz (1994) looked at the effects of radon exposure on cancer risk in U.S. homes. It has been suggested that radon in U.S. homes is responsible for about 10000 fatal lung cancers each year (BEIR 1988). This number is, however, based on extrapolations of data on miners who have been subjected to high radon concentrations. This study found that lung cancer rates decreased with an increase in radon levels. Smoking prevalence may have influenced the results, but this was corrected for. Many other confounding factors are considered and dealt with, such as socioeconomic variables and geography. Nonetheless, a very strong negative correlation was found between lung cancer mortality rates and mean radon levels. A British study came to similar conclusions (Haynes 1988). Both these studies support hormetic models for lung cancer mortality.
"A study involving 700,000 nuclear shipyard workers (108,000 of whom were nuclear workers) by the Johns Hopkins Department of Epidemiology, School of Public Health and Hygiene (Cameron 1992) concluded that both the nuclear workers receiving more than 500 mR and those receiving less than 500 mR had significantly lower mortality (0.76 and 0.81, respectively) from all causes of death than the non-nuclear workers. Non-nuclear shipyard workers' mortality rates were similar to non-shipyard workers, therefore eliminating the healthy worker effect as a bias. This is consistent with other studies of populations in states with higher background radiation (approximately 1 mGy per year more than states with lower background radiation) that demonstrated increased longevity and a 15% reduction in overall mortality (Craig and Seidman 1961; Frigerio and Stowe 1976; Cohen 1980; Webster 1983).
"A study of 31,710 Canadian female tuberculosis patients who underwent fluoroscopy (Miller et al 1989) concluded that the breast cancer risk increased with received radiation dose. According to this report, which comprised examinations performed in the period between 1930 and 1952, a theoretical lifetime excess of 900 deaths due to breast cancer would occur in a hypothetical group of one million women having received 0.15 Gy. The report used a linear model to calculate the hypothetical increased risk at this low close of radiation. A more recent analysis of the data by Pollycove (1994) applying an empirical polynomial function demonstrated that for this dose, 10,000 deaths per million would be prevented rather than 900 excess deaths induced (better than 99% confidence limit).
"Further evidence for the existence of hormesis has been obtained from results emanating from experiments designed to demonstrate low-dose effects at the molecular level, the cellular level and on an organism as a whole (Macklis and Beresford 1991)."
"Observations in humans. In 1987 Matanoski et al (1987) published a study on the mortality amongst radiologists in comparison to other medical practitioners. Radiologists who started practicing before 1940 experienced an increased rate of death due to cancer as well as other diseases. This is in contrast to the mortality found in a group of radiologists who started practicing after 1940: amongst younger radiologists the mortality appeared to be lower than that among other medical specialists of the same age group."
Floyd W. Flanigan B.S.Nuc.H.P.
-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl]On
Behalf Of Syd H. Levine
Sent: Wednesday, March 16, 2005 12:41 PM
To: John Jacobus; John_Sukosky at dom.com
Cc: radsafe
Subject: Re: [ RadSafe ] Re: U.S. Nuclear Power Industry Workers Study
-HealthyWorker Effect
Long's detractors seem far more desperate with respect to massaging the data
than he does. If LNT were correct, and ionizing radiation is as dangerous
as some urge, the Taiwan apartment dwellers, the air crews, the radiation
oncologists, radiographers, etc. would be one bunch of sick puppies, but
they do not seem to be. Instead, Long's detractors seem only to be able to
make reference to selected portions of very few studies to support LNT.
What is it that I am not getting here as a mostly lay observer?
Syd H. Levine
AnaLog Services, Inc.
Phone: 270-276-5671
Telefax: 270-276-5588
E-mail: analog at logwell.com
URL: www.logwell.com
----- Original Message -----
From: "John Jacobus" <crispy_bird at yahoo.com>
To: <John_Sukosky at dom.com>
Cc: "radsafe" <radsafe at radlab.nl>
Sent: Wednesday, March 16, 2005 1:18 PM
Subject: [ RadSafe ] Re: U.S. Nuclear Power Industry Workers Study -
HealthyWorker Effect
>I agree, but I misread your comments.
>
> What you suggest is the what is usually done, or
> should be done. However, that is often not. There
> was a recent "study" of people who lived in apartments
> in Taiwan that were made with Co-60 contaminated
> steel. The comment was that the cancer rate of these
> individuals compared to the general population was
> low. Again, there are probable a number of
> confounding factors that enter into the statistics,
> and the best way to do the study would be to use a
> cohort of apartment dwellers in buildings without the
> contaminated steel. Further, if you look at the
> Japanese atomic bomb studies, the cohort is those who
> probably received little or not radiation exposure,
> but were in the cities at that time.
>
> http://www.rerf.or.jp/eigo/faqs/faqse.htm#faq8
>
> --- John_Sukosky at dom.com wrote:
>
>> I agree that since many factors differ between the
>> worker
>> population and general population, interpretation of
>> these
>> results is limited to calling it a "healthy worker
>> effect".
>>
>> That's why I asked why a comparison cannot be made
>> to
>> non-nuclear power plant workers employed during the
>> same
>> period in order to account for the degree of the
>> healthy
>> worker effect. Wouldn't that adjust for the major
>> confounders between the worker population and
>> general
>> population? That way we may be better able to
>> observe
>> an obvious benefit or harm due to ionizing
>> radiation.
>>
>> John M. Sukosky, CHP
>> Dominion
>> Surry Power Station
>> (757)-365-2594 (Tieline: 8-798-2594)
>>
>>
>>
>>
>>
>>
>> John Jacobus
>>
>>
>> <crispy_bird at yaho To:
>> John_Sukosky at dom.com, radsafe
>> <radsafe at radlab.nl>
>> o.com> cc:
>>
>>
>> Sent by:
>> Subject: Re: [ RadSafe ] U.S. Nuclear Power
>> Industry Workers Study - Table 2
>> radsafe-bounces at r
>>
>>
>> adlab.nl
>>
>>
>>
>>
>>
>>
>>
>>
>> 03/16/2005 10:39
>>
>>
>> AM
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Simply stated, the worker population does not
>> represent the general population. Consider the
>> absence of breast cancers. Ergo, no or few women
>> workers. Also, how many of the workers are under 18
>> or over 65?
>>
>> --- John_Sukosky at dom.com wrote:
>> > Below, I've reproduced Table 2 from the "Analysis
>> of
>> > the
>> > Mortality Experience amongst U.S. Nuclear Power
>> > Industry
>> > Workers after Chronic Low-Dose Exposure to
>> Ionizing
>> > Radiation".
>> > (Howe, et al., 2004)
>> >
>> > Based on these results, the authors stated that:
>> > "...The cohort
>> > displays a very substantial healthy worker
>> effect,
>> > i.e.,
>> > considerably lower cancer and noncancer mortality
>> > than the
>> > general population...".
>> >
>> > Does anyone know why a comparison cannot be made
>> to
>> > non-nuclear
>> > power plant workers employed during the same
>> period
>> > in order to
>> > account for this "very substantial healthy worker
>> > effect"?
>> >
>> >
>> > John M. Sukosky, CHP
>> > Dominion
>> > Surry Power Station
>> > (757)-365-2594 (Tieline: 8-798-2594)
>> >
>> >
>> > TABLE 2
>> > U.S. Nuclear Power Industry Workers Study (Howe et
>> > al., 2004):
>> > Standardized Mortality Ratios (SMRs) by Cause of
>> > Death, 1979ââ,¬â?o1997
>> >
>> > Cause Observed
>> > Expected(a) SMR 95%CI
>> > All causes 1,190 2922.4
>> > 0.41 0.38, 0.43
>> > All solid cancers 368 564.3
>> > 0.65 0.59, 0.72
>> > Stomach cancer 16 19.7
>> > 0.81 0.47, 1.32
>> > Colon cancer 36 47.8
>> > 0.75 0.53, 1.04
>> > Pancreatic cancer 18 29.0
>> > 0.62 0.37, 0.98
>> > Lung cancer 125 210.4
>> > 0.59 0.49, 0.71
>> > Prostatic cancer 14 23.2
>> > 0.60 0.33, 1.01
>> > Kidney cancer 14 17.7
>> > 0.79 0.43, 1.32
>> > Brain and other CNS(b)cancer 23 27.0
>> > 0.85 0.54, 1.28
>> > All lymphopoietic cancer 49 75.7
>> > 0.65 0.48, 0.86
>> > Multiple myeloma 6 9.5
>> > 0.63 0.23, 1.37
>> > Leukemia 29 27.2
>> > 1.07 0.71, 1.53
>> > All noncancers 773 2282.3
>> > 0.34 0.32, 0.36
>> > Nervous system diseases 20 39.9
>> > 0.50 0.31, 0.77
>> > Circulatory system diseases 350 832.7
>> > 0.42 0.38, 0.47
>> > Arteriosclerotic heart
>> > disease including CHD(c) 248 524.6
>> > 0.47 0.42, 0.54
>> > All vascular lesions of CNS 24 89.5
>> > 0.27 0.17, 0.40
>> > All respiratory diseases 37 129.1
>> > 0.29 0.20, 0.40
>> > All pneumonia 8 48.1
>> > 0.17 0.07, 0.33
>> > Digestive system diseases 32 148.9
>> > 0.21 0.15, 0.30
>> >
>> > (a) Expected number of deaths based on age-,
>> > gender-, calendar year-
>> > and cause-specific mortality rates for the
>> U.S.
>> > population during
>> > 1979ââ,¬â?o1997.
>> > (b) Central nervous system.
>> > (c) Coronary heart disease.
>> > > _______________________________________________
>> > You are currently subscribed to the radsafe
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>> >
>>
>> +++++++++++++++++++
>> "A positive attitude may not solve all your
>> problems, but it will annoy
>> enough people to make it worth the effort." Herm
>> Albright
>>
>> -- John
>> John Jacobus, MS
>> Certified Health Physicist
>> e-mail: crispy_bird at yahoo.com
>>
>>
>>
>> __________________________________
>> Do you Yahoo!?
>> Yahoo! Small Business - Try our new resources site!
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>> _______________________________________________
>>
> === message truncated ===
>
>
> +++++++++++++++++++
> "A positive attitude may not solve all your problems, but it will annoy
> enough people to make it worth the effort." Herm Albright
>
> -- John
> John Jacobus, MS
> Certified Health Physicist
> e-mail: crispy_bird at yahoo.com
>
>
>
> __________________________________
> Do you Yahoo!?
> Yahoo! Small Business - Try our new resources site!
> http://smallbusiness.yahoo.com/resources/
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