Thyroid cancer rates in Pennsylvania (USA) soared in recent decades and radiation from nuclear power plants may be the cause. This is the result of a study which was recently published in the International Journal of Health Services. Its author, Joseph Mangano, is the executive director of the Radiation and Public Health Project. He calls the observed growth in thyroid cancers "an epidemic." And there is much more evidence of the true risks of low level radiation.
WISE Amsterdam - Pennsylvania's incidence of thyroid cancer in the mid-1980s was 40 percent below the national rate, and now the rate is 44 percent above the national rate, he said, adding: "Something occurred to change Pennsylvania's rate from low to high, and one of these possible factors is radiation from reactors." Some of the highest thyroid cancer rates occur in eastern Pennsylvania, which has the nation's largest concentration of nuclear reactors, including the Susquehanna Steam Electric Station in Salem Township, he said. Other reactors are Three Mile Island in Dauphin County, Peach Bottom in York County and Limerick in Montgomery County. Seven continue to operate.
Some of the highest thyroid cancer rates - 80 percent above the national rate - are in Sullivan, Luzerne, Carbon, Northampton, Lehigh and York counties, according to his research.
Mangano noted that the radiation released from these reactors is relatively low, and not the high levels associated with the Chernobyl accident or the atomic bomb at Hiroshima. But the effects of low-level radiation needs to be explored further as a public health concern, he said, because radiation exposure is the only known cause of thyroid cancer. Mangano pointed to a 1999 study by the National Academy of Sciences that found more than 200,000 Americans developed thyroid cancer from above-ground atomic bomb tests in Nevada, which emitted low levels in the 1950s and 1960s.
Nuclear reactors also release low levels of radiation and these small metal particles come into contact with humans through the air, rain and snowfall and also enter the food chain. Once radiation enters the body, it seeks out the thyroid gland, damaging or killing cells, reducing hormones and causing disease and cancer, according to Mangano. Nuclear power plants emit extremely low levels of radiation - far below background levels in the area, said Joseph Scopelliti, a spokesman for PPL, which operates the Susquehanna plant. Mangano released similar study results in November pointing to high thyroid cancer rates in the counties surrounding the Indian Point nuclear power plant, which is 35 miles north of Manhattan in New York State. Those rates were also among the highest in the country, according to a news release.
In the late 1980s and early 1990s, several studies revealed increased incidences of childhood leukemia near UK nuclear facilities. However, official estimated doses from released nuclides were too low, by 2 to 3 orders of magnitude, to explain the increased leukemias.
Recent epidemiological studies have reopened the childhood leukemia debate. Baker and Hoel(*1) carried out a meta-analysis of 136 nuclear sites in the UK, Canada, France, US, Germany, Japan and Spain and found cancer death rates for children were elevated by 5 to 24 per cent depending on proximity to nuclear facilities. Hoffmann et al (*2) found 14 leukemia cases between 1990 and 2005 in children living within 5 km of the Krümmel nuclear plant in Germany, significantly exceeding the 0.45 predicted cases.
Most important, however, is the KiKK study (Kinderkrebs in der Umgebung von Kernkraftwerken = Childhood Cancer in the Vicinity of Nuclear Power Plants) Spix et al (*3) and Kaatsch et al (*4). The main findings were a 60% increase in solid cancer risk and a 120% increase in leukemia risk among young children living within 5 km of all German nuclear reactors. These are big increases in risk.
The KiKK report is significant because it is a large and well-conducted study; because it is scientifically rigorous; because its evidence is particularly strong; and because the German Government, which commissioned the study, has confirmed its findings. Over 60 other studies world-wide have investigated child leukemias near nuclear facilities (*5). The large majority of these studies have found increased incidences of leukemia: this lends considerable support to the KiKK findings.
The KiKK observations are presently the subject of intense research and discussion throughout the world, including at least three studies in the UK. Last November, the Department of Health requested the Government’s Committee on the Medical Aspects of Radiation in the Environment (COMARE) to examine the German study and report back.
Also last November, in a case of unfortunate timing, the UK Department of Energy and Climate Change (DECC) published a Consultation paper justifying the radiation exposures from its proposed new nuclear stations. The problem is that COMARE’s report will not be finished until after the Consultation’s February 22 deadline, and DECC has refused public requests to extend its deadline until the COMARE report is finished. This is unfortunate and it is an unreasonable position for DECC to take. It is clearly important that we get to grips with the KiKK evidence before decisions are made on building more nuclear power stations.
In 2009, the UK Health Protection Agency submitted a memorandum (*6) on health risks from radiation to the Government’s Consultations. This seeks to diminish the KiKK study and devotes only half a page to the lengthy KiKK report. The HPA’s criticisms are cursory, poorly argued and misleading. For example, the HPA memorandum seeks to argue that the KiKK study merely found an association between nuclear power plant proximity and risk, ie and not between dose and risk - implying that radiation exposures were not a causative factor. This is unpersuasive: childhood leukemia is well known to be closely associated with radiation exposures. The HPA memorandum also states that a UK study and a French study “have not replicated” the KiKK findings. This is misleading as the two studies actually did find small leukemia increases in children near nuclear power plants. Their data were not statistically significant but this was due to the smallness of the studies and not the absence of effect. The HPA’s view remains that official estimated doses from NPP releases are much too small to result in the observed levels of leukemia. But the CERRIE report (*7) showed that there could be very large uncertainties in official dose estimates from inhaled and ingested radionuclides.
CERRIE was an independent Committee established by the UK Government in 2001, following concerns about the risks of internal radiation, including reports of increased incidences of cancer near nuclear sites and after Chernobyl. The Committee operated between October 2001 and October 2004. Although the commission found no clear evidence to date that current radiation risks were substantially wrong, it advised that greater attention should be paid to uncertainties and tougher action is needed to allow for new information about the risks from internal radiation. Uncertainties about the risks mean that in some cases we might be exposed to 10 times the risk previously thought, while in other cases the risk may be almost zero. Uncertainties in current methods of estimating risks from internal radiation require policy makers and regulators to adopt a precautionary approach when dealing with exposures to internal radiation. The CERRIE report warned also that newly discovered effects of radiation, genomic instability (ongoing, long-term increase in mutations within cells and their offspring), bystander effects (cells next to those that were irradiated can also be damaged), and minisatellite mutations (inherited germline DNA changes) are real biological events that need further research.
The nuclear establishment approach (the ICRP – International Commission on Radiological Protection - an advisory body providing recommendations and guidance on radiation protection) and the hormesis approach treat radiation as if it were equally distributed in the body.
The nub of the issue is that there are some kinds of radiation exposure which are uniform, that is evenly distributed in the body. This applies to forms of external radiation, eg. x-rays and gamma rays. But internal radionuclides which are inhaled or ingested may not be evenly distributed, so that their damage is concentrated in some areas and not others. Auger emitters and low range beta emitters such as tritium are examples.
In these circumstances, as the CERRIE Report hinted in 2004, the concept of “dose” may be meaningless for internal emitters. So we should be very careful when using “dose” to describe the effects of internal radiation.
The main reason the nuclear establishment sticks to using dose is they got used to using it for external radiation and tried to extend it to internal radiation. But it really should not be used for this: internal concentrations of radionuclides (Bq per kg) should be used instead.
*1- "Meta-analysis of standardized incidence and mortality rates of childhood leukaemias in proximity to nuclear facilities", European Journal Cancer Care. 2007;16:355–363.2007
*2- "Childhood Leukemia in the Vicinity of the Geesthacht Nuclear Establishments near Hamburg, Germany", Environmental Health Perspectives. Vol 115, No 6, June 2007
*3- "Case-control study on childhood cancer in the vicinity of nuclear power plants in Germany 1980 – 2003. European Journal Cancer. 2008 Jan; 44(2) pp 275-84)
*4- "Leukaemia in young children living in the vicinity of German nuclear power plants". International Journal Cancer. 2008; 122(4) pp 721-6
*5- Fairlie I and Körblein A: "Review of epidemiology studies of childhood leukaemia near nuclear facilities: Commentary on Laurier et al". Radiation Protection Dosimetry (2009) Vol 137, Number 3-4 doi:10.1093/rpd/ncp246
*6- Mobbs et al: "An introduction to the estimation of risks arising from the exposure to low doses of ionising radiation", HPA-RPD-055. Health Protection Agency. Oxford, UK
*7- “Report of the Committee Examining the Radiation Risks of Internal Emitters”, www.cerrie.org 2004
(Thanks to Ian Fairlie and Karin Wurzbacher)
Sources: Press release CERRIE, 20 October 2004 / Ian Fairlie, Evidence to House of Commons Committee on Energy and Climate Change, 19 January 2010 / Standardspeaker.com, 22 January 2010: "Study: Nuclear plant radiation may be to blame for cancer spike"
Radiological Risk Theories
- "Linear NoThreshold" (LNT). This theory is used by the world’s radiation authorities — UNSCEAR, ICRP, UK HPA, US BEIR, etc – to estimate risks at low doses. It presumes that risks decline proportionately as you lower the dose all the way down to zero, and that the only dose with no effect is zero mSv. In other words, under LNT there is no safe dose of radiation: no matter how low it is, a small risk remains. The LNT model's virtue is its simplicity as radiation exposures can be added from different times/sources to compare with dose limits, and can be added to form population (ie collective) doses.
- “Sub-linear”: which postulates that low levels of radiation are proportionately less harmful than a linear relationship
- “Hormesis” approach: exposure of a cell or organism to a low dose results in an adaptive stimulatory/beneficial outcome, while exposure to a high dose results in an inhibitory / detrimental outcome: "radiation is good for you"
- “Supra-linear”: the often ignored hypothesis that low levels of radiation are proportionately more harmful than a linear relationship