About UNSCEAR. UNSCEAR s estimates provide the scientific basis for the development of radiation protection standards UNSCEAR

Transcription

1 About UNSCEAR UNSCEAR is a Committee of the General Assembly of the United Nations It was established in 1955 UNSCEAR is the UN body with a mandate to provide estimates on the levels and effects of radiation exposure UNSCEAR s estimates provide the scientific basis for the development of radiation protection standards

2 UNSCEAR 2000 Report SOURCES Dose assessment methodologies ANNEX A Exposures from natural radiation sources ANNEX B Exposures to the public from man-made sources of radiation ANNEX C Medical radiation exposures ANNEX D Occupational radiation exposures ANNEX E EFFECTS DNA repair and mutagenesis ANNEX F Biological effects at low radiation doses ANNEX G Combined effects of radiation and other agents ANNEX H Epidemiological evaluation of radiation-induced cancer ANNEX I CHERNOBYL Exposures and effects of the Chernobyl accident ANNEX J All available at

3 SOURCES OF RADIATION EXPOSURE Natural Man-made Members of the public Occupational workers

4 UNSCEAR Questionnaires Sources of Exposure NATURAL (country-wide averages; high background areas) MANMADE MEDICAL OCCUPATIONAL

5 NATURAL RADIATION SOURCES WORLDWIDE AVERAGE DOSES Source Effective dose Typical range (msv per year) (msv per year) External exposure Cosmic rays Terrestrial gamma rays Internal exposure Inhalation (mainly radon) Ingestion Total

6 Natural and man-made made radiation sources WORLDWIDE AVERAGE DOSES Radiation source Effective dose Comments (msv per year) Natural background 2.4 Typical range 1-10 msv/a Diagnostic medical 0.4 examinations Typical range msv/a at lowest and highest level of health care. Atmospheric nuclear testing Maximum 0.15 msv (1963) Chernobyl accident Maximum 0.04 msv (1986) Nuclear power production

7 HEALTH CARE LEVELS 0 30 U. S. A. 30 North Pacific Ocean Hawaiian Islands French Polynesia (Fr.) 60 U.S.A. Canada Arctic Ocean United States of America Mexico Guatemala El Salvador Costa Rica Galapagos Islands (Ecuador) Banks Island Cuba Belize Jam. Honduras Nicaragua Panama Ecuador South Pacific Ocean Victoria Island Colombia Peru 120 Ellesmere Island Severnaya Zemlya The Bahamas Dominican Republic Haiti Puerto Rico (US) Dominica Barbados Trinidad and Tobago Venezuela Chile Bolivia Argentina Baffin Island Guyana Suriname French Guiana (Fr.) Brazil Paraguay Uruguay Island of Newfoundland Greenland (Den.) Iceland North Atlantic Ocean Morocco Canary Islands (Sp.) Senegal The Gambia Guinea-Bissau Ireland Portugal Algeria Western Sahara (Mor.) Mauritania Guinea Arctic Ocean Jan Mayen (Nor.) Faroe Is. (Den.) Mali Burkina Faso Benin Sierra Leone Côte D Ivoire Liberia Ghana Togo Eq. Guinea Norway Gabon Sao Tome & Principe Congo Tunisia Niger Namibia South Atlantic Ocean Svalbard (Nor.) Libya Nigeria Cameroon Finland Sweden Estonia United Kingdom Latvia Den. Lithuania Neth. Belarus Germany Poland Bel. Czech. Ukraine Aus. Slovak. France Hung. Moldova Slov. Cro. Romania Yugo. Bos. Italy Mac Bulgaria Spain Albania. Greece Turkey Chad C. A. R. Zaire Angola Rwanda Botswana Franz Josef Land Cyp. Leb. Israel Egypt Sudan Uganda Malawi Zambia South Africa Lesotho Novaya Zemlya Syria Tanzania Zimbabwe Jordan Iraq Ethiopia Kenya Burundi Swaziland Kuwait Qatar Saudi Arabia U. A. E. Yemen Djibouti Mozambique Iran Somalia Russia Kazakhstan Georgia Uzbekistan Armenia Azerbaijan Turkmenistan Eritrea Seychelles Madagascar Oman Mauritius Afghanistan Pakistan Kyrgyzstan Tajikistan Maldives India Nepal Indian Ocean Arctic Ocean Mongolia Bhu. Bang. Sri Lanka New Siberian Islands China Myanmar (Burma) Laos Thailand Vietnam Andaman Islands (India) Cambodia Singapore Brunei Malaysia Indonesia Wrangel Island N. Korea S. Korea North Pacific Ocean 30 Taiwan Philippines Marshall Islands Federated States of Micronesia Guam (USA) Kiribati Papua New Guinea Solomon Islands Fiji New Caledonia Australia Japan 60 Aleutian Islands (USA) Kuril Islands 30 New Zealand 0 Falkland Islands (Islas Malvinas) (adm. by UK, claimed by Argentina) Tasmania Îles Crozet (France) South Georgia (adm. by UK, claimed by Argentina) Antarctica Health care level I: at least one physician per 1000 population Health care level II: one physician for population Health care level III: one physician for population Health care level IV: one physician for more than population

8 Annual number of diagnostic medical x-ray examinations in relation to number of physicians MEDICAL X-RAY EXAMINATIONS Level I Level II Level III Level IV PHYSICIANS 10 7

9

10 Number of nuclear weapons tests in the atmosphere and underground Atmospheric tests Underground tests NUMBER

11 Total yield of nuclear weapons tests in the atmosphere and underground Atmospheric tests Underground tests 110 YIELD (Mt)

12 OCCUPATIONAL EXPOSURES Man-made sources AVERAGE DOSES TO WORKERS Radiation source Number of workers Average dose (msv per year) Man-made sources Nuclear fuel cycle 800, Industrial uses of radiation 700, Defence activities 420, Medical uses of radiation 2,320, Education/veterinary 360, Total 4,600,

13 Occupational Radiation Exposure: OBJECTIVES To assess long-term trends in occupational radiation exposures Identifying the main contributors to these exposures Distributions of exposures within various work categories

14 Trends in worldwide average annual effective dose (msv msv) Average annual effective dose (msv) Nuclear fuel cycle Defence activities Industrial Medical Education Total

15 Trends in worldwide annual number of monitored workers Average number of monitored workers (thousands) Nuclear fuel cycle Defence activities Industrial Medical Education

16 Trends in worldwide average annual collective effective doses 3500 Average annual collective effective doses (man Sv) Nuclear fuel cycle Defence activities Industrial Medical Education

17 OCCUPATIONAL EXPOSURES Enhanced natural sources AVERAGE DOSES TO WORKERS Radiation source Number of workers Average dose (msv per year) Enhanced natural sources Mining (excluding coal) 760, Coal mining 3,900, Air travel (crew) 250,000 3 Mineral processing 300, Above ground workplaces (radon) 1,250, Total 6.500,

18 Occupational Radiation Exposures AVERAGE DOSES TO WORKERS Radiation source Number of monitored Effective dose workers (msv per year) Man-made sources Nuclear fuel cycle 800, Other industry 700, Defence activities 420, Medicine 2,320, Education/veterinary 360, Total 4,600, Enhanced natural sources Mining (excluding coal) 760, Coal mining 3,910, Aircrew 250, Mineral processing 300, Above ground workplaces 1,250, Total 6,500,

19 Average Annual Exposures (msv) Natural exposures World average 2.4 Man-made exposures Atmospheric nuclear testing Nuclear power production (local) 0.01 Chernobyl accident (First year; Eastern & Central Europe) Medical radiation exposures Industralized countries 1.1 World average 0.3 Occupational radiation exposures Man-made sources 0.6 Natural sources 1.8

20 EPIDEMIOLOGY OF CANCER RISKS LIFE SPAN STUDY UNSCEAR s estimates Lifetime cancer mortality risk after 1 Sv 0.9% for leukaemia 11.2% for solid tumours (compared to 1.1% for leukaemia and 10.9% for cancer in 1994)

21 EFFECTS AT LOW DOSES Ongoing and future studies in animal sciences and epidemiology will not solve the uncertainties surrounding the effects in humans of low-dose radiation. The statistical power is insufficient, and it is not scientifically valid to equate the absence of a statistically observable effect at low doses with the absence of risk. There is a continued need for judgements based on data from cellular/molecular studies on the biological mechanisms.

22 UNSCEAR s Chernobyl studies and initiatives UNSCEAR 1988 Report International Chernobyl Project UNSCEAR 2000 Report UNSCEAR 2001 Report (Hereditary effects) UNSCEAR (2006/7) Report

23 UNSCEAR 2000 Report Annex J: Chernobyl 1800 cases of thyroid cancer in children exposed at the time of the accident If current trend continues, more cases could occur during the next decades

24 UNSCEAR 2000 Report Annex J: Chernobyl There can be no doubt about the relationship between the radioactive materials released from the Chernobyl accident and the unusually high number of thyroid cancers observed in the contaminated areas during the past 14 years.

25 UNSCEAR 2000 Report Annex J: Chernobyl THYROID CANCER QUESTIONS Short follow-up Influence of screening Effect of age at exposure Doses higher than estimated Role of short-lived radioiodines

26 UNSCEAR 2000 Report Annex J: Chernobyl Apart from childhood thyroid cancer, no evidence of a major public health impact attributable to radiation exposure 14 years after the accident Risk of leukaemia does not appear to be elevated, even among recovery operation workers No scientific evidence of increases in overall cancer incidence or in non-malignant disorders that could be related to the accident

27 UNSCEAR 2000 Report Annex J: Chernobyl The most highly exposed individuals are at an increased risk of radiation-associated effects The great majority of the population are not likely to experience serious health consequences from radiation from the Chernobyl accident

28 UNSCEAR s Chernobyl studies and initiatives UNIATF on Chernobyl (United Nations inter-agency Task Force on Chernobyl) CHERNOBYL FORUM IAEA, WHO, UNSCEAR, World Bank, 3 MARs ICRIN (International Chernobyl Research Information Network) Uses Chernobyl Forum s expert scientific groups

29 Why is there such confusion about the real health effects of the Chernobyl accident? Well-intentioned people confused about causality People are not numerate Other changes occurring in the FSU Type of epidemiological study Descriptive vs. analytic Radiological vs. non-radiological effects Scientific reports that lack credibility Other factors

30 UNSCEAR 2001 Report HEREDITARY EFFECTS OF RADIATION Risks to offspring following prenatal exposure Total risk = % per Gy to the first generation (3000 to 4700 cases per gray per 10 6 progeny) Includes multifactorial diseases 1/10 the risk of fatal carcinogenesis Constitutes % of baseline frequency of these diseases

31 Congenital malformations Absolute numbers (brackets) and incidence (per 1000) of obligatory registered congenital malformations in Belarus, pre- and post-chernobyl periods Contaminated areas (17) >15 Ci/km 2 Control areas (30) Overall Anencephaly (10) 0.3 (54) 0.6 (23) 0.5* (137) 0.8* (224) 0.7 Spina bifida (21) 0.7* (98) 1.2* (43) 0.9 * (231) 1.3 * (393) 1.2 Cleft lip and/or palate (29) 1.0 (121) 1.4** (33) 0.7** (241) 1.4** (424) 1.3 Polydactyl (6) 0.2** (119) 1.4** (20) 0.4** (157) 0.9** (302) 0.9 Reduction defects of limbs (14) 0.5 (59) 0.7** (13) 0.3 (78) 0.4** (164) 0.5 Oesophageal atresia (1) 0.03 (11) 0.1 (8) 0.2 (32) 0.2 (52) 0.2 Rectal atresia (6) 0.2 (14) 0.2 (4) 0.1 (20) 0.1 (44) 0.1 Down s syndrome (30) 1.0** (69) 0.8 (27) 0.5** (183) 1.0** (309) 0.9 Multiple congenital malformations (30) 1.0 (197) 2.4** (55) 1.1** (332) 1.9** (614) 1.8 TOTAL (147) 5.0** * Significant differences p<0.05. ** Significant differences p<0.01. (742) 8.9** (226) 4.6** (1411) 8.0** (2526) 7.4

32 UNSCEAR - New Programme of Work Started 2001 New data on exposures from natural, man-made and occupational Medical exposures, especially new high-dose procedures Radon in homes and workplaces Radioecology and effects of radiation on environment Consequences for development of cancer risk of newly identified cellular responses to radiation Radiation effects at level of tissues/organs Extend epidemiological evaluation of cancer risks Diseases other than cancer in relation to radiation Continue studies on radiological health effects from Chernobyl accident

33 UNSCEAR - Current Programme of Work Sources-to-Effects Assessment for Radon in Homes and Workplaces Medical Radiation Exposures Exposures of Workers and the Public from Various sources of Radiation --Accidents Radioecology and Methodologies for Dose Assessment Effects of Radiation on Non-Human Biota

34 UNSCEAR - Current Programme of Work (continued) Epidemiological Evaluation and Dose Response of Diseases Other than Cancer Epidemiological Studies of Radiation and Cancer Non-Targeted and Delayed Effects of Exposure to Ionizing Radiation Ionizing Radiation and the Immune System Health Effects Due to Radiation from the Chernobyl Accident