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Safety of workers at the Fukushima Daiichi nuclear power plant

2011; Elsevier BV; Volume: 377; Issue: 9776 Linguagem: Inglês

10.1016/s0140-6736(11)60519-9

1474-547X

Tetsuya Tanimoto, Naoyuki Uchida, Yuko Kodama, Takanori Teshima, Shuichi Taniguchi,

Radiation Dose and Imaging

The 9.0 magnitude earthquake and following tsunami on March 11, 2011, destroyed many coastal cities in the northeastern part of Japan.1The LancetJapan: health after the earthquake.Lancet. 2011; 377: 968Summary Full Text Full Text PDF Scopus (3) Google Scholar It swamped emergency generators at the Fukushima Daiichi nuclear power plant operated by the Tokyo Electric Power Company in Fukushima prefecture, disabling the cooling systems.2Butler D Radioactivity spreads in Japan.Nature. 2011; 471: 555-556Crossref PubMed Scopus (64) Google Scholar Since these catastrophic events, hundreds of nuclear workers have been trying to remove the radioactive water from the tsunami-ravaged nuclear compound and restart the regular cooling systems for the overheated nuclear fuel.3Tabuchi H Japanese workers braved radiation for a temp job. New York Times.http://www.nytimes.com/2011/04/10/world/asia/10workers.html?src=me&ref=homepageDate: April 10, 2011Google Scholar On March 15, the Japanese Government announced that the permissible cumulative radiation exposure for nuclear workers was increased to 250 mSv per year from 100 mSv per year. The purpose of this increase seems to be merely to extend the time nuclear workers could legally spend in a radioactive area. On April 12, the Nuclear and Industrial Safety Agency of Japan decided to raise the severity level of the crisis to 7—the highest level and equal to the 1986 disaster at Chernobyl in the former Soviet Union. We emphasise the need to predict potential scenarios in Fukushima and to prepare medical care providers for how to respond in cases of accidental high radiation exposure, since this operation is estimated to take months to years. Generally, rapidly dividing cells, such as intestinal-tract and haemopoietic cells, are most vulnerable to radiation.4Mettler FA Voelz GL Major radiation exposure—what to expect and how to respond.N Engl J Med. 2002; 346: 1554-1561Crossref PubMed Scopus (264) Google Scholar Radiation accidents can result in localised or whole-body exposure and in internal or external deposition of radioactive materials. On March 24, three workers at the Fukushima nuclear power plant were exposed accidentally to high localised radiation while standing in contaminated water.5Martin A No. 3 cool pump test-run readied. Japan Times Online.http://search.japantimes.co.jp/member/member.html?mode=getarticle&file=nn20110324x2.htmlDate: March 24, 2011Google Scholar Fortunately, this accident did not cause major injuries, but the danger of a future accidental radiation exposure is not passed, since there has been a series of serious aftershocks even this April. A clinically significant haemopoietic syndrome can occur after whole-body doses of 2 Gy or higher as a result of bone-marrow depression. If the haemopoietic cells are not completely damaged, a recovery phase can be enhanced through use of haemopoietic growth factors. In cases of radiation exposure of more than 5 Gy, haemopoietic stem-cell rescue is essential. Indeed, in the Chernobyl disaster in 1986, nine patients who were exposed to high levels of radiation underwent intraosseous injections of allogeneic bone-marrow cells.6Klymenko SV Belyi DA Ross JR et al.Hematopoietic cell infusion for the treatment of nuclear disaster victims: new data from the Chernobyl accident.Int J Radiat Biol. 2011; (published online March 16.)https://doi.org/10.3109/09553002.2011.560995Crossref PubMed Scopus (12) Google Scholar In the radiation accident at a nuclear fuel processing plant in Tokaimura, Japan, in 1999, two victims received allogeneic stem-cell transplantation.7Hirama T Tanosaki S Kandatsu S et al.Initial medical management of patients severely irradiated in the Tokai-mura criticality accident.Br J Radiol. 2003; 76: 246-253Crossref PubMed Scopus (91) Google Scholar, 8Chiba S Saito A Ogawa S et al.Transplantation for accidental acute high-dose total body neutron- and gamma-radiation exposure.Bone Marrow Transplant. 2002; 29: 935-939Crossref PubMed Scopus (29) Google Scholar However, allogeneic stem-cell transplantation has major limitations, such as time-consuming donor searching, graft failure, graft-versus-host disease (GVHD), or profound immune suppression after transplantation, despite the reduced mortality associated with recent techniques.9Gooley TA Chien JW Pergam SA et al.Reduced mortality after allogeneic hematopoietic-cell transplantation.N Engl J Med. 2010; 363: 2091-2101Crossref PubMed Scopus (1150) Google Scholar On March 25, we proposed the collection and storage of autologous peripheral-blood stem cells (PBSCs) for the nuclear workers in Fukushima in case of accidental major radiation exposure.10Taniguchi S Health care planning for nuclear workers. MRIC Mail Magazine.http://medg.jp/mt/2011/03/vol85.html#moreDate: March 25, 2011Google Scholar This scheme has several advantages. First, autologous PBSC transplantation does not cause GVHD, which further exacerbates gut injury mediated by radiation exposure. Second, it does not require immunosuppressants, which make radiation victims more susceptible to severe infections. Third, PBSCs can induce more rapid haemopoietic recovery than can haemopoietic growth-factor support alone or bone-marrow cells. Fourth, they are easy to store by cryopreservation. Fifth, the short-term and long-term safety of this PBSC-collecting procedure has been confirmed in a large number of healthy donors for patients with haematological cancers.11Siddiq S Pamphilon D Brunskill S et al.Bone marrow harvest versus peripheral stem cell collection for hemopoietic stem cell donation in healthy donors.Cochrane Database Syst Rev. 2009; 1 (CD006406.)PubMed Google Scholar Finally, long-term autologous PBSC banking might also have a therapeutic role for possible leukaemia in future, because radiation is a well known carcinogen in the long term. Several important limitations of this scheme should also be noted. Autologous PBSC transplantation is not a perfect strategy to treat radiation victims; it can rescue injury of bone marrow only, but not other tissues, such as gastrointestinal tract, skin, or lung. Additionally, there are adverse events for healthy individuals by administration of mobilising agents and apheresis procedures.12Japan Society for Hematopoietic Cell TransplantationThe statement from Japan Society for Hematopoietic Cell Transplantation (JSHCT) on recent earthquake disaster and subsequent nuclear power plant accident in Japan.http://www.jshct.com/english/Google Scholar Another concern must be medical costs, but several pharmaceutical companies offer donations for this scheme and the financial burden is alleviated. On March 29, the Japan Society for Haematopoietic Cell Transplantation released a statement that “107 transplant teams are standing by to collect and store haemopoietic stem cells from the peripheral blood for workers who are striving to restrain the radiation.”13Pulsipher MA Chitphakdithai P Miller JP et al.Adverse events among 2408 unrelated donors of peripheral blood stem cells: results of a prospective trial from the National Marrow Donor Program.Blood. 2009; 15: 3604-3611Crossref Scopus (200) Google Scholar The European Group for Blood and Marrow Transplantation also announced that this plan makes sense and more than 50 hospitals in Europe have agreed to help the workers if required. On the other hand, several experts have stated their objections to this scheme.14Fujita A Interview with Dr. Robert Gale. Asahi-shinbun.https://aspara.asahi.com/blog/kochiraapital/entry/H09GQUXUMxDate: March 29, 2011Google Scholar, 15Sample I Japanese officials consider cell transplants for nuclear workers. The Guardian.http://www.guardian.co.uk/world/2011/mar/29/japan-cell-transplants-nuclear-workers?INTCMP=SRCH#history-link-boxDate: March 29, 2011Google Scholar The Nuclear Safety Commission of Japan, an advisory panel made up of non-government experts, reportedly stated that there is no need to collect and store autologous PBSCs. The reasons given are the physical and psychological burden for nuclear workers, no consensus among international authoritative bodies, and no sufficient agreement among the Japanese public.16Anon“No need for hematopoietic stem cell harvesting” by Nuclear and Industrial Safety Agency. Sankei-shinbun.http://sankei.jp.msn.com/politics/news/110403/plc11040301310001-n1.htmDate: April 3, 2011Google Scholar The nuclear power industry of Japan is facing its worst-ever crisis. Not only the Japanese people but also people all over the world have a sense of distrust towards the industry, which is seen as insufficiently transparent in terms of information disclosure. Furthermore, the officials and authorities related to the industry seem to be reluctant to admit the seriousness of the problem to protect the industry's reputation as much as possible. However, the most important mission is to save the nuclear workers' lives and to protect the local communities. Such an approach would be the industry's best defence: if a fatal accident happened to the nuclear workers, the nuclear power industry of Japan would collapse. It would also cause serious damage to the industry and the nuclear power policy all over the world. Therefore, we should prioritise support for the nuclear workers' health. The process to completely shut down the reactors in Fukushima is expected to take years. The risk of accidental radiation exposure will thus accumulate for the nuclear workers and banking of their autologous PBSCs will become increasingly important. A judgment of right or wrong on this scheme must be determined from the standpoint of the nuclear workers and their families, not from a point of view of cost–benefit balance in ordinary times. Toranomon Hospital in Tokyo is ready to harvest and bank autologous PBSCs for the nuclear workers upon request. We declare that we have no conflicts of interest Department of ErrorTanimoto T, Uchida N, Kodama Y, Teshima T, Taniguchi S. Safety of workers at the Fukushima Daiichi nuclear power plant. Lancet 2011; 377: 1489–90—In this Correspondence (April 30), the page numbers for reference 9 should have been “2091–101”. This correction has been made to the online version as of June 24, 2011. Full-Text PDF