Investigation and assessment of 40K accumulation in the segments of an ordinary carrot (Daucus carota L.) and Red Beet (Beta vulgaris L.) /

The article deals with an alteration in specific activity and transfer factor of naturally occurring radionuclide 40K from soil with a loamy structure to the segments of root vegetables – an ordinary carrot (Daucus carota L.) and red beet (Beta vulgaris L.). The paper establishes the specific activity of 40K in soil and vegetable segments and evaluates transfer factors (TF). The obtained data show that the transfer factor of naturally occurring radionuclide 40K from soil to the segments of the ordinary carrot (Daucus carota L.) varied from 0,28 to 0,99 while that of the red beet (Beta vulgaris L.) – from 0,53 to 0,96. The results of the study could be used for estimating 40K transfer in the system “soil-plant” and accumulation of radionuclide in composting garden waste. Santrauka Straipsnyje nagrinėjama gamtinės kilmės radionuklido 40K savitojo aktyvumo ir pernašos faktoriaus kaita iš turinčių priemolio struktūrą dirvožemių į šakniavaisinių daržovių – paprastųjų morkų (Daucus carota L.) ir raudonųjų burokėlių (Beta vulgaris L.) – segmentus. Nustatytas savitasis 40K aktyvumas dirvožemyje ir daržovių segmentuose, įvertinti pernašos (PF) faktoriai. Gauti duomenys rodo, kad gamtinės kilmės radionuklido 40K pernašos faktorius iš dirvožemio į paprastosios morkos (Daucus carota L.) segmentus kito nuo 0,28 iki 0,99, o į raudonojo burokėlio (Beta vulgaris L.) – nuo 0,53 iki 0,96. Remiantis eksperimentinių tyrimų duomenimis bei atsižvelgiant į vykdomos veiklos radioaktyviąją dirvožemio užtaršą, galima įvertinti 40K pernašą dirvožemis-augalas sistemoje bei kaupimąsi daržininkystės atliekose. Raktiniai žodžiai: 40K; šakniavaisiai; paprastoji morka (Daucus carota. L); raudonasis burokėlis (Beta vulgaris L.); savitasis aktyvumas; pernašos faktorius; dirvožemis; priemoli

The 15-Country Collaborative Study of Cancer Risk among Radiation Workers in the Nuclear Industry: Estimates of Radiation-Related Cancer Risks

International audienceA 15-Country collaborative cohort study was conducted to provide direct estimates of cancer risk following protracted low doses of ionizing radiation. Analyses included 407,391 nuclear industry workers monitored individually for external radiation and 5.2 million person-years of follow-up. A significant association was seen between radiation dose and all-cause mortality [excess relative risk (ERR) 0.42 per Sv, 90% CI 0.07, 0.79; 18,993 deaths]. This was mainly attributable to a dose-related increase in all cancer mortality (ERR/Sv 0.97, 90% CI 0.28, 1.77; 5233 deaths). Among 31 specific types of malignancies studied, a significant association was found for lung cancer (ERR/Sv 1.86, 90% CI 0.49, 3.63; 1457 deaths) and a borderline significant (P = 0.06) association for multiple myeloma (ERR/Sv 6.15, 90% CI <0, 20.6; 83 deaths) and ill-defined and secondary cancers (ERR/Sv 1.96, 90% CI -0.26, 5.90; 328 deaths). Stratification on duration of employment had a large effect on the ERR/Sv, reflecting a strong healthy worker survivor effect in these cohorts. This is the largest analytical epidemiological study of the effects of low-dose protracted exposures to ionizing radiation to date. Further studies will be important to better assess the role of tobacco and other occupational exposures in our risk estimates. © 2007 by Radiation Research Society

Risk of cancer after low doses of ionising radiation - Retrospective cohort study in 15 countries

Objectives: To provide direct estimates of risk of cancer after protracted low doses of ionising radiation and to strengthen the scientific basis of radiation protection standards for environmental, occupational, and medical diagnostic exposures. Design: Multinational retrospective cohort study of cancer mortality. Setting: Cohorts of workers in the nuclear industry in 15 countries. Participants: 407 391 workers individually monitored for external radiation with a total follow-up of 5.2 million person years. Main outcome measurements: Estimates of excess relative risks per sievert (Sv) of radiation dose for mortality from cancers other than leukaemia and from leukaemia excluding chronic lymphocytic leukaemia, the main causes of death considered by radiation protection authorities. Results: The excess relative risk for cancers other than leukaemia was 0.97 per Sv, 95% confidence interval 0.14 to 1.97. Analyses of causes of death related or unrelated to smoking indicate that, although confounding by smoking may be present, it is unlikely to explain all of this increased risk. The excess relative risk for leukaemia excluding chronic lymphocytic leukaemia was 1.93 per Sv (< 0 to 8.47). On the basis of these estimates, 1-2% of deaths from cancer among workers in this cohort may be attributable to radiation. Conclusions: These estimates, from the largest study of nuclear workers ever conducted, are higher than, but statistically compatible with, the risk estimates used for current radiation protection standards. The results suggest that there is a small excess risk of cancer, even at the low doses and dose rates typically received by nuclear workers in this study

The 15-country collaborative study of cancer risk among radiation workers in the nuclear industry: Estimates of radiation-related cancer risks

Papel. - Artículo publicado en La Nación (Buenos Aires). - Procedencia: fondo Miguel de Unamuno. - Conservación: Buena