Takako Tominaga, M.D.

Transcription

1 ANSN WS /10/03 Takako Tominaga, M.D. Radiation Emergency Medical Assistance Team (REMAT) NIRS

2 About Polonium-210 (1) Almost pure alpha particle emitter A radioactive element that occurs naturally and is present in the environment at extremely low concentrations Highly radioactive and chemically toxic element; direct damage occurs from energy absorption into tissues from alpha particles 2

3 About Polonium-210 (2) Half-life: days Biological half-life: 50 days 4 GBq = 40 µg of 210 Po chloride Properties; water-soluble, colorless

4 Overview of Polonium incident in London On the 23rd of November 2006, Alexander Litvinenko died in London allegedly from poisoning by 210 Po The spread of radioactive contamination involved locations in London arising from the poisoning The event required a multi-agency response 4

5 Managing the Response Health Protection Agency (HPA); public health response Metropolitan Police Service (MPS); identified many locations Civil Contingencies Committee (CCC) Cabinet Office Briefing Rooms (COBR) Strategic Co-ordinating Group (SCG) Recovery Working Group (RWG) Framework strategy Remediation and clearance of locations 5

6 Hospitalisation and Recognition 1 On 3 November, Mr. Litvinenko was admitted to a north London general hospital with vomiting, diarrhoea and abdominal pain His condition deteriorated and he was transferred to a specialist hospital in London Mr. Litvinenko said to broadcast interview, I had defected from a foreign security service and I had been poisoned 6

7 Hospitalisation and Recognition 2 Contamination and dose rate measurements had been made of Mr. Litvinenko and his surrounds in the hospitals But the presence of radiation was not detected! Alpha contamination was not expected in a medical environment and the monitors used were not designed to detect alpha contamination 7

8 Hospitalisation and Recognition 3 Police requested the assistance of their scientific advisers and the HPA in identifying what could have caused the clinical picture Mr. Litvinenko had a significant quantity of Po-210 in his body! HPA indicated that an intake in excess of 1 GBq of Po-210 would have been required to explain the clinical course 8

9 Public Health Response Strategy HPA developed key objectives for the public health response To prevent further exposure of the public: work closely with the police to aid their criminal investigation and identify sites and individuals that might be contaminated develop an environmental monitoring strategy to support this assess and advise on public access and remediation of contaminated sites To assess risks to those potentially exposed: develop and implement risk assessment criteria offer, implement and report on personal monitoring though urine analysis; To provide advice and reassurance to those exposed and the general public 9

10 Environmental Monitoring and Assessments Hospital low level of contamination from body fluids from Mr. Litvinenko Staff some intakes were detected but were relatively low The routine use of Personal Protective Equipment (PPE) and procedures to avoid infection 10

11 Polonium Contamination in Locations More than 40 locations (hospitals, hotels, offices, restaurants, bars, transportation) were identified that had to be monitored and assessed HPA co-ordinating the monitoring programme using resources from several organisations across the UK At the peak there was 70 monitoring staff working in shifts 11

12 Remediation Criteria No action unless VERY easy to remove and it is practicable to dispose of waste generated 10 Bq/cm 2 Increasing contamination level Must carry out risk assessment to decide what action is necessary, if any. Factors to be considered in risk assessment are: degree to which contamination exceeds 10 Bq/cm 2 easy of removal nature of item/surface contaminated how appropriate to cover and seal activity in situ type and use of venue dose implications for all contractors implications for environment and waste wishes of owners of the premises/items Po-210 half-life (insignificant contamination in 4-5 years) 12

13 Public Health Response 1 On 25 November, HPA requested to the media asking members of the public who were in specific potentially contaminated locations in a specified period to call NHS Direct (a 24-hour National Health Service helpline) A questionnaire was used to assist the collection of key information from callers 13

14 Public Health Response 2 NHS Direct : 3,837 calls questionnaire HPA follow-up : 1,844 Public Health Team Assigned to each of the main locations and site specific risk assessments and questionnaires developed to identify those at risk and requiring monitoring using an alpha spectrometry technique on 24 hour urine samples. Clinical Assessment Team Triaged individuals identified from any source who reported symptoms which could be associated with radiation effects, or were seriously concerned. 14

15 Individual Monitoring Programme HPA developed a monitoring technique and protocols Urine samples from 752 persons Minimum Reporting Level was set at 30 mbq/ 24h RL - 1 msv: msv: 36 > 6mSv: 17 The highest assessed dose was for the family member caring for Mr. Litvinenko at about 100mSv 15

16 Following up Foreign Visitors A large number of those potentially exposed to Po-210 were overseas visitors who had stayed in, or visited, one of the hotels or other locations involved in the incident HPA Overseas Advice Team and IAEA made appropriate contacts in the various countries In total 664 individuals from 52 countries and territories 16

17 Results of Foreign Individuals RL 1 msv: msv: 5 > 6 msv: 0 Results were received for about a quarter of the identified individuals 17

18 Communicating with the Public and Media HPA announced in the first press conference on 24 November; Test on Mr. Litvinenko had detected a significant quantity of Po-210 The nature of alpha radiation and how Po-210 was only a hazard it if was ingested inhaled or absorbed through wounds The proactive monitoring that was being carried out at the locations identified by the police HPA released press statements each day in the weeks as well as responding to thousands of media calls and ensuring the website was up-to date with information 18

19 Clinical course sever vomiting, diarrhea, abdominal pain Hospitalization (Dehydration, Gastrointestinal symptoms) Bone Marrow Examination (No cells) Hepatic disorder Antibiotic G-CSF Whole body erythema 803 KeV -ray Thrombopenia Neutropenia Renal disorder Death Intake Detection of Clostridium toxin Possibility of poison (Wife and himself) Epilation + Mucositis lasting Fever Antiviral agents PB Abnormal ECG Move to ICU CPA Hypouresis/anuria (CPA

20 Summary of the incident in Lodon Incident of alpha particle emitter Incident has been occurred in an amount of 10 9 times of Po in nature Response needed multi-agency activities The Health Protection Agency (HPA) had a leading role in co-ordinating and managing the public health response 20

21 Internal contamination accident of Polonium-210 in Russia

22 Contamination accident in Russia June 28, 1954 In some facilities, 210 Po leaked in the work area from the container, 41-yearold man has been working for 5 hours in high concentration of 210 Po (aerosol) Vomiting began after 5-6 hours, and lasted three days

23 Clinical course (1) Inhalation day (first day) findings: Epigastric pain, shortness of breath, headache, irritative symptoms, fever (38 º C) PR /min, BP110/80mHg, and bloody sputum and cough Chest percussion; Drum sound, Auscultation; rough, dry rales No hepatomegaly Urine volume is normal

24 Clinical course (2) 7 days after exposure Leukopenia, platelet: 8 x 10 4 /mm 3, typhuslike rash, bleeding of the tonsils, hyperemia of bilateral conjunctiva 10 days after exposure Coma, bleeding in the skin of chest and abdomen and mucous, progressive bone marrow suppression, hematuria, proteinuria, jaundice

25 Clinical course (3) 13 days after exposure Death, caused by cardiac and respiratory failure Autopsy Bone marrow suppression, pneumonia with the bleeding, systemic bleeding, and kidney and liver atrophy

26 Dose assessment Internal contamination of Po-210 Total excretion: MBq Urine: 25.5%, feces: 33.8%, vomitus: 32.4%, saliva: 7.1%, perspiration: 1.2% Lung: MBq Kidney: MBq Liver: MBq Whole body: 99.9 MBq (Lethal dose; 70 MBq)

27 Conclusion Internal exposure does not occur acute radiation syndrome Internal contamination of Polonium causes acute radiation injury It is difficult to diagnose internal exposure and detect surface contamination in an accident/incident of alpha emitter