Radioactive impact of the Fukushima nuclear accident on Shenyang in the northeast of China

Environmental monitoring was carried out in Shenyang in the northeast of China after the Fukushima Daiichi nuclear accident which was caused by the earthquake and tsunami on 11 March 2011. The fission product radionuclide (131)I was detected as present in the atmosphere on the 20th day after the nuclear accident, while the radionuclides (134)Cs and (137)Cs were found in the atmosphere on the 27th day after the accident. The radionuclides (131)I, (134)Cs and (137)Cs continued to be present in the atmosphere for 25, 4 and 6 days, respectively, with maximum concentrations of 4.60 ± 0.2, 0.29 ± 0.06 and 0.42 ± 0.08 mBq m(-3). The contents of fission radionuclides in vegetables, drinking water and milk from Shenyang were below the detection limits. The atmosphere was slightly contaminated in Shenyang due to the Fukushima nuclear accident, but no contamination was detected in vegetables, milk and drinking water.

Radiation exposure from diagnostic procedures following allogeneic stem cell transplantation--how much is acceptable?

BACKGROUND

Frequent diagnostic radiology procedures in allogeneic stem cell transplantation (SCT) recipients raise concern about the potential harm from incidental radiation.

OBJECTIVES

To determine the cumulative radiation dose from diagnostic studies in allogeneic SCT and its impact on clinical outcome.

PATIENTS AND METHODS

This retrospective cohort study was conducted to determine the cumulative radiation dose from diagnostic studies following SCT. Sixty-four consecutive patients with hematological malignancies in a single tertiary care institution underwent total body irradiation (TBI)-based myeloablative conditioning followed by six of six human leukocyte antigen (HLA)-identical sibling allogeneic SCT. The median follow-up was 3 years. The cumulative effective dose in mSv from diagnostic radiological studies in the peri-transplant period from day -30 to day +200 was calculated for each patient and its impact on overall survival and non-relapse mortality was determined.

RESULTS

The median cumulative radiation exposure from diagnostic radiological procedures was 92 mSv (range 1.2-300), representing about 30× the normal annual background radiation for the population and 10% of the 1200 cGy TBI dose used in conditioning. Sixty-five percent of the cumulative radiation exposure was delivered between day +1 and day 100 and computed tomography scans contributed 88%. In multivariate analysis, diagnostic procedures did not significantly impact clinical outcomes.

CONCLUSIONS

While radiation exposure from diagnostic procedures did not impact clinical outcomes the risk of secondary cancers in long-term survivors is likely to be increased. Our results indicate that patients who are acutely ill for prolonged periods can receive clinically significant radiation doses during their hospital care. Our findings should prompt attempts to limit radiation exposure from diagnostic procedures in post-SCT recipients.

[The use of immunological characteristics of the peripheral blood for the purpose of forensic medical expertise of the subjects exposed to ionizing radiation]

The objective of the present study was the comprehensive evaluation of quantitative and functional metabolic characteristics of human leukocytes following in vitro irradiation of peripheral blood samples at a dose of 0.25, 0.50, 1.0, and 4.0 Gy for the development of a rationale for their application as biological markers of radiation exposure in forensic medical expertise of the subjects affected by supernormal ionizing radiation. The total number of leukocytes, lymphocytes, and their subpopulations as well as the functional and metabolic status of neutrophils were determined. The results of the study indicate the possibility of using a set of functional metabolic characteristics of human leukocytes as the additional forensic medical criteria for diagnostics of radiation impact on living subjects.

[Research on radiation hygiene problems]

The author presents brief historical reference on research in radiation hygiene problems, initiated by scientists in Central Institute for Occupational hygiene and Preventive hygiene (now--Federal State Budgetary Institution "Research Institute of Occupational Health" with Russian Academy of Medical Sciences).

Nitric oxide and lipid peroxidation in children, residents of the contaminated territories

OBJECTIVE

The nitrogen oxide system assessment by the nitrogen oxide stable metabolites assay both with indices of lipid peroxidation and antioxidant protection of children residing on contaminated territories.

MATERIALS AND METHODS

Studies were conducted in children, born and residing in areas of contamination. Assay of nitrogenous species (NO²⁻ and NO³⁻) was performed using a standard method with Griss-reagent. Biochemical assay of the malonic dyaldehide, catalase, and ceruloplasmin was applied to reveal the signs of oxidative stress.

RESULTS AND CONCLUSIONS

The assay of nitric oxide metabolites in the blood serum of children-residents of contaminated territories revealed a reduction of nitrite and no significant changes in the content of both nitrate and total NO metabolites. There was an activation of the intracellular antioxidant catalase with the absence of significant changes in the basic serum ceruloplasmin antioxidant. All that was not accompanied with an increase of serum concentration of malonic dyaldehide i.e. the TBA-active product of lipid peroxidation being indicative to the adequacy of compensatory capacity of antioxidant defense.

Effective dose and risks from medical X-ray procedures

The radiation risks from a range of medical x-ray examinations (radiography, fluoroscopy, and computed tomography) were assessed as a function of the age and sex of the patient using risk models described in Publication 103 (ICRP, 2007) and UNSCEAR (2006, Annex A). Such estimates of risk based on typical organ doses were compared with those derived from effective doses using the International Commission on Radiological Protection's nominal risk coefficients. Methodologically similar but not identical dose and risk calculations were performed independently at the Institute of Radiation Hygiene (Russia) and the Health Protection Agency (UK), and led to similar conclusions. The radiogenic risk of stochastic health effects following various x-ray procedures varied significantly with the patient's age and sex, but to differing degrees depending on which body organs were irradiated. In general, the risks of radiation-induced stochastic health effects in children are estimated to be higher (by a factor of ≤ 4) than in adults, and risks in senior patients are lower by a factor of ≥ 10 relative to younger people. If risks are assessed on the basis of effective dose, they are underestimated for children of both sexes by a factor of ≤ 4. This approach overestimates risks by a factor of ≤ 3 for adults and about an order of magnitude for senior patients. The significant sex and age dependence of radiogenic risk for different cancer types is an important consideration for radiologists when planning x-ray examinations. Whereas effective dose was not intended to provide a measure of risk associated with such examinations, it may be sufficient to make simple adjustments to the nominal risk per unit effective dose to account for age and sex differences.

Genetic effects of ionizing radiation--some questions with no answers

There are a lot of questions about genetic effects of ionizing radiation, the main one is does ionizing radiation induce mutations in humans? There is no direct evidence that exposure of parents to radiation leads to excess heritable disease in offspring. What is the difference between human and other species in which radiation induced mutations are easily registered? During evolution germ cell selection ex vivo has been changed to a selection in vivo and we cannot observe such selection of radiation damaged cells in human. Low radiation doses - are they harmful or beneficial? The "hormesis" phenomenon as well as radioadaptive response proves positive effects of low radiation dose. Can analysis of chromosomal aberration rate in lymphocytes be used for dosimetry? Many uncontrolled factors may be responsible for significant mistakes of this method. Why did evolution preserve the bystander effect? This paper is discussion one and its goal is to pay attention on some effects of ionizing radiation.

Radiation effects

International Commission on Radiological Protection (ICRP) Committee 1 (C1) considers the risk of induction of cancer and heritable disease; the underlying mechanisms of radiation action; and the risks, severity, and mechanisms of induction of tissue reactions (formerly 'deterministic effects'). C1 relies upon the interpretation of current knowledge of radio-epidemiological studies; current information on the underlying mechanisms of diseases and radiation-induced disease; and current radiobiological studies at the whole animal, tissue, cell, and molecular levels. This overview will describe the activities of C1 in the context of the 2007 Recommendations of ICRP. In particular, the conclusions from the most recent C1 Task Group deliberations on radon and lung cancer, and tissue reactions will be discussed. Other activities are described in summary fashion to illustrate those areas that C1 judge to be likely to influence the development of the risk estimates and nominal risk coefficients used for radiation protection purposes.

Monitoring synchrotron X-ray-induced radiolysis effects on metal (Fe, W) ions in high-temperature aqueous fluids

Radiolysis-induced effects on aqueous tungsten ions are observed to form a precipitate within seconds upon exposure to a synchrotron X-ray micro-beam in a WO(3) + H(2)O system at 873 K and 200 MPa. In situ Fe K-edge energy-dispersive X-ray absorption spectroscopy (ED-XAS) measurements were made on Fe(II)Cl(2) aqueous solutions to 773 K in order to study the kinetics of high-temperature reactions of Fe(2+) and Fe(3+) ions with transient radiolysis species. The radiolytic reactions in a fluid sample within a hydrothermal diamond anvil cell result in oxidation of the Fe(2+) ion at 573 K and reduction of Fe(3+) at temperatures between 673 and 773 K and of the Fe(2+) ion at 773 K. The edge-energy drift evident in the ED-XAS data directly reflects the kinetics of reactions resulting in oxidation and/or reduction of the Fe(2+) and Fe(3+) ions in the aqueous solutions at high temperatures. The oxidation and reduction trends are found to be highly consistent, making reliable determinations of reaction kinetics possible.

Harnessing genomics to identify environmental determinants of heritable disease

Next-generation sequencing technologies can now be used to directly measure heritable de novo DNA sequence mutations in humans. However, these techniques have not been used to examine environmental factors that induce such mutations and their associated diseases. To address this issue, a working group on environmentally induced germline mutation analysis (ENIGMA) met in October 2011 to propose the necessary foundational studies, which include sequencing of parent-offspring trios from highly exposed human populations, and controlled dose-response experiments in animals. These studies will establish background levels of variability in germline mutation rates and identify environmental agents that influence these rates and heritable disease. Guidance for the types of exposures to examine come from rodent studies that have identified agents such as cancer chemotherapeutic drugs, ionizing radiation, cigarette smoke, and air pollution as germ-cell mutagens. Research is urgently needed to establish the health consequences of parental exposures on subsequent generations.

Dual-age-class population model to assess radiation dose effects on non-human biota populations

In the present paper, a two-age-class group, logistic growth model for generic populations of non-human biota is described in order to assess non-stochastic effects of low linear energy-transfer radiation using three endpoints: repairable radiation damage, impairment of reproductive ability and, at higher radiation dose rates, mortality. This model represents mathematically the exchange between two life stages considering fecundity, growth and mortality. Radiation effects are modeled with a built-in self-recovery pool whereupon individuals can repair themselves. In acute effects mode, the repairing pool becomes depleted due to radiation and the model tends to lethality mode. A base calibration of the model's two free parameters is possible assuming that in acute mode 50% of the individuals die on 30 days when a radiation dose equal to the LD(50/30) is applied during that period. The model, which requires 10 species-dependent life-history parameters, was applied to fish and mammals. Its use in the derivation of dose-rate screening values for the protection of non-human biota from the effects of ionizing radiation is demonstrated through several applications. First, results of model testing with radiation effects data for fish populations from the EPIC project show the predictive capability of the model in a practical case. Secondly, the model was further verified with FREDERICA radiation effects data for mice and voles. Then, consolidated predictions for mouse, rabbit, dog and deer were generated for use in a population model comparison made within the IAEA EMRAS II project. Taken together, model predictions suggest that radiation effects are more harmful for larger organisms that generate lower numbers of offspring. For small mammal and fish populations, dose rates that are below 0.02 Gy day(-1) are not fatal; in contrast, for large mammals, chronic exposure at this level is predicted to be harmful. At low exposure rates similar to the ERICA screening dose rate of 2.4 × 10(-4) Gy day(-1), long-term effects on the survivability of populations are negligible, supporting the appropriateness of this value for radiological assessments to wildlife.

Risky business: challenges and successes in military radiation risk communication

Given the general public's overall lack of knowledge about radiation and their heightened fear of its harmful effects, effective communication of radiation risks is often difficult. This is especially true when it comes to communicating the radiation risks stemming from military operations. Part of this difficulty stems from a lingering distrust of the military that harkens back to the controversy surrounding Veteran exposures to Agent Orange during the Vietnam War along with the often classified nature of many military operations. Additionally, there are unique military exposure scenarios, such as the use of nuclear weapons and combat use of depleted uranium as antiarmor munitions that are not found in the civilian sector. Also, the large, diverse nature of the military makes consistent risk communication across the vast and widespread organization very difficult. This manuscript highlights and discusses both the common and the distinctive challenges of effectively communicating military radiation risks, to include communicating through the media. The paper also introduces the Army's Health Risk Communication Program and its role in assisting in effective risk communication efforts. The authors draw on their extensive collective experience to share 3 risk communication success stories that were accomplished through the innovative use of a matrixed, team approach that combines both health physics and risk communication expertise.

CT enterography: review of technique and practical tips

CT enterography is a new non-invasive imaging technique that offers superior small bowel visualisation compared with standard abdomino-pelvic CT, and provides complementary diagnostic information to capsule endoscopy and MRI enterography. CT enterography is well tolerated by patients and enables accurate, efficient assessment of pathology arising from the small bowel wall or surrounding organs. This article reviews the clinical role of CT enterography, and offers practical tips for optimising technique and accurate interpretation.

Computerized tomography in the workup of pediatric appendicitis: why are children scanned?

Physicians increasingly use computerized tomography (CT) for the evaluation of suspected acute appendicitis (AA) in children despite increasing awareness of the potential dangers of CT-associated radiation exposure. Many studies demonstrate the value of CT in the diagnosis of AA, but none have determined what factors influence the decision to perform a CT. We investigated factors associated with the use of CT during initial workup of children who subsequently underwent appendectomy. This is a retrospective review of all patients aged 0 to 17 years who underwent appendectomy for AA by pediatric surgeons over 11 years. Both univariate and multivariable logistic regression models were created to predict use of CT. A total of 546 children underwent appendectomy for AA, of which 293 (53%) underwent CT. In univariate analysis, seven variables were significantly associated with the use of CT: female gender, Hispanic ethnicity, initial presentation to referring hospitals, lower Alvarado scores, delays from onset of symptoms to hospital presentation, migration, and rebound tenderness. In multivariable analysis, four variables significantly independently predicted the use of CT: initial presentation to a referring hospital [odds ratio (OR) 3.50), female gender (OR 1.49), increased latency from symptom onset to presentation (OR 1.34), and the presence of rebound tenderness (OR 0.23), which had a protective effect; the overall model was statistically significant (P < 0.0001). This model is the first to define variables that significantly predict CT utilization in the pediatric population. Continued investigation will be necessary to develop effective algorithms for judicious use of CT for suspected AA.

Retrospective dosimetry with alumina substrate from electronic components

Alumina substrate can be found in electronic components used in portable electronic devices. The material is radiation sensitive and can be applied in dosimetry using thermally or optically stimulated luminescence. Electronic portable devices such as mobile phones, USB flash discs, mp3 players, etc., which are worn close to the body, can represent  personal dosemeters for members of the general public in situations of large-scale radiation accidents or malevolent acts with radioactive materials. This study investigated dosimetric properties of alumina substrates and aspects of using mobile phones as personal dosemeters. The alumina substrates exhibited favourable dosimetry characteristics. However, anomalous fading had to be properly corrected in order to achieve sufficient precision in dose estimate. Trial dose reconstruction performed by means of two mobile phones proved that mobile phones can be used for reconstruction of personal doses.

Radiation effects in generic populations inhabiting a limiting environment

A generic population model is formulated for radiation risk assessment of natural biota. The model demonstrates that effects of radiation on the population survival do not follow directly the effects on individual organisms. Dose rates resulting in population extinction can be analytically calculated. Besides individual radiosensitivity, two key parameters were found to determine the survival potential of a population under chronic radiation stress: the ratio “biomass losses/biomass synthesis,” and the lump amount of limiting resource in the environment. A benchmark scenario “Population response to chronic irradiation” developed within the IAEA Programme EMRAS II was calculated for generic populations of mice, hare/rabbit, wolf/wild dog, and deer/goat chronically exposed to different levels of ionizing radiation. In the conditions of the benchmark scenario, model populations survived normally (>90% of the control value) at dose rates below the following levels: 3 mGy day(-1) for wolf/wild dog; 10 mGy day(-1) for deer/goat; 14 mGy day(-1) for hare/rabbit; and 20 mGy day(-1) for mice. The model predictions showed a relatively high survival potential of short-lived and productive species such as mice. At the same time, populations of long-lived animals with slow and radiosensitive reproduction such as wolf/wild dog were candidates to extinction at chronic exposures above 5 mGy day(-1). Recovery of short-lived and productive species took a much shorter time compared with long-lived and slow reproductive species.