Health effects and consultations about radon exposure

Radon is a naturally occurring radioactive material classified as a carcinogen by the World Health Organization, and is known to be the factor with the second-greatest impact on lung cancer after smoking. An association between radon and lung cancer has consistently been reported in epidemiological studies on mine workers and residents of homes with indoor radon exposure. However, associations between radon and other diseases, such as leukemia and thyroid cancer, have yet to be confirmed due to a lack of consistent research findings and biological relevance. Such associations are unlikely because there is a very low likelihood that organs other than the lungs are exposed to radon upon inhalation due to the short half-life of radon and its progeny and the low permeability of alpha rays. In spring 2018, the radon bed mattress incident occurred, leading to a spike of concern and interest among the public regarding the health effects of radiation exposure. This paper presents a description of radon exposure and its health effects based on the current literature and provides practical information based on health consultations experienced following the 2018 radon mattress incident.

Prediction of lung cells oncogenic transformation for induced radon progeny alpha particles using sugarscape cellular automata

Alpha particle irradiation from radon progeny is one of the major natural sources of effective dose in the public population. Oncogenic transformation is a biological effectiveness of radon progeny alpha particle hits. The biological effects which has caused by exposure to radon, were the main result of a complex series of physical, chemical, biological and physiological interactions. The cellular and molecular mechanisms for radon-induced carcinogenesis have not been clear yet. Various biological models, including cultured cells and animals, have been found useful for studying the carcinogenesis effects of radon progeny alpha particles. In this paper, sugars cape cellular automata have been presented for computational study of complex biological effect of radon progeny alpha particles in lung bronchial airways. The model has included mechanism of DNA damage, which has been induced alpha particles hits, and then formation of transformation in the lung cells. Biomarkers were an objective measure or evaluation of normal or abnormal biological processes. In the model, the metabolism rate of infected cell has been induced alpha particles traversals, as a biomarker, has been followed to reach oncogenic transformation. The model results have successfully validated in comparison with "in vitro oncogenic transformation data" for C3H 10T1/2 cells. This model has provided an opportunity to study the cellular and molecular changes, at the various stages in radiation carcinogenesis, involving human cells. It has become well known that simulation could be used to investigate complex biomedical systems, in situations where traditional methodologies were difficult or too costly to employ

Radon and environmental diseases

People are generally exposed to radiation from natural sources. Radon is the most important radiation source among natural sources. Radon is a naturally occurring, radioactive noble gas that is odorless and tasteless. Radon is normally found at very low levels in outdoor air and in drinking water from rivers and lakes but higher levels in indoor air in homes, schools, and office buildings, and in well water. When radon undergoes radioactive decay, it expels high-energy alpha particles. The alpha particle radiation dose from long-term exposure increases the chance of developing lung cancer. Radon is the second most important cause of lung cancer after smoking. There is no known threshold concentration below which radon exposure presents no risk. Even low concentrations of radon can result in a small increase in the risk of lung cancer. No study of the radon exposure-lung cancer association has been performed in Korea. What is needed is a large-scale prospective study of the association between residential radon exposure and lung cancer. The cumulative indoor radon exposure is an important environmental health hazard (carcinogen).

SAD phasing with in-house Cu Kα radiation using barium as anomalous scatterer.

Phasing of lysozyme crystals using co-crystallized barium ions was performed using single-wavelength anomalous diffraction (SAD) method using Cu Kα radiation with in-house source of data collection. As the ion binding sites vary with respect to the pH of the buffer during crystallization, the highly isomorphic forms of lysozyme crystals grown at acidic and alkaline pH were used for the study. Intrinsic sulphur anomalous signal was also utilized with anomalous signal from lower occupancy ions for phasing. The study showed that to solve the structure by SAD technique, 2.8-fold data redundancy was sufficient when barium was used as an anomalous marker in the in-house copper X-ray radiation source for data collection. Therefore, co-crystallization of proteins with barium containing salt can be a powerful tool for structure determination using lab source.

Radon exhalation rates from stone and soil samples of Aravali hills in India

The most popular building materials are soil bricks and different types of stones. Radon is released into ambient air from soil and stones due to ubiquitous uranium and radium in them, thus increasing the airborne radon concentration. The radioactivity in soils is related to radioactivity in the rocks from which the soil is formed. In the present investigation, the radon emanated from soil and stone samples collected from different locations of Aravali range of hills in the Haryana state of Northern India has been estimated. For the measurement of radon concentration emanated from these samples, alpha-sensitive LR-115 type II plastic track detectors have been used. The alpha particles emitted from the radon form tracks in these detectors. After chemical etching the track density of registered tracks is used to calculate radon concentration and exhalation rates of radon using required formulae. The radon concentration in stone samples collected from Aravali range of hills varied from 729 Bq m[-3] to 1958 Bq m[-3] with an average of 1440 +/- 134 Bq m[-3] whereas it varied from 806 Bq m[-3] to 1325 Bq m[-3] with an average of 1040 +/- 101 Bq m[-3] in case of soil samples. Based upon the data, the mass and the surface exhalation rates of radon emanated from them have also been calculated. The measurements indicate normal to some higher levels of radon concentration emanated from the samples collected from Aravali range of hills of north India

Alpha-emitting Radioisotopes Production for Radioimmunotherapy / 핵의학분자영상

This review discusses the production of alpha-particle-emitting radionuclides in radioimmunotherapy. Radioimmunotherapy labeled with alpha-particle is expected to be very useful for the treatment of monocellular cancer (e.g. leukemia) and micrometastasis at an early stage, residual tumor remained in tissues after chemotherapy and tumor resection, due to the high linear energy transfer (LET) and the short path length in biological tissue of alpha particle. Despite of the expected effectiveness of alpha-particle in radioimmunotherapy, its clinical research has not been activated by the several reasons, shortage of a suitable a-particle development and a reliable radionuclide production and supply system, appropriate antibody and chelator development. Among them, the establishment of radionuclide development and supply system is a key factor to make an alpha-immunotherapy more popular in clinical trial. Alpha-emitter can be produced by several methods, natural radionuclides, reactor irradiation, cyclotron irradiation, generator system and elution. Due to the sharply increasing demand of 213Bi, which is a most promising radionuclide in radioimmunotherapy and now has been produced with reactor, the cyclotron production system should be developed urgently to meet the demand.

Alpha radioactivity in Indian cement samples

The essential constituents of cements like lime, silica and alumina are derived from earth's crust in which radioactive elements like uranium, thorium etc are also present in varying amounts almost everywhere. These two elements are considered as the parent elements of uranium and thorium radioactive decay series in which radon and thoron are produced respectively as decay products. In the present study the samples of ordinary Portland cement [OPC], Portland pozzolana cement [PPC] and some other cementious finishing materials like white cement, Plaster of Paris [POP], cement putty etc were collected and analysed for radium and radon concentrations along with radon exhalation rates. Alpha sensitive LR-115 Type II plastic track detectors commonly known as "Solid State Nuclear Track Detectors" were used to measure the radium and radon concentration. The alpha particles emitted from the radon causes the radiation damaged tracks. The Chemical etching in NaOH at 60°C for about 90 minutes was done to reveal these latent tracks, which were then scanned and counted by an optical microscope of suitable magnification. By calculating the track density of registered tracks, the radon and radium concentrations along with exhalation rate of radon, were determined using required formulae. The radon and radium concentration in various brands of cements found to vary from 333 +/- 9.9 to 506 +/- 13.3 Bq m[-3] and from 3.7 +/- 0.1 to 5.6 +/- 0.2 Bq kg[-1] while in various cementious finishing materials used in the construction, these were found to vary from 378 +/- 19.7 to 550 +/- 9.8 Bq m[-3] and from 4.2 +/- 0.2 to 6.1 +/- 0.1 Bq Kg[-1], respectively. Based on the data the mass and surface exhalation rates were also calculated. The measurements indicate that there is marginal variation of the concentration of radium and radon in various brands of cements in India with lower levels in the cement samples having red oxide and higher levels in fly ash based cement samples but overall concentration levels of radon and radium are lower than that of average global values

Aberraciones cromosómicas en trabajadores expuestos a radiaciones ionizantes / Chromosomic aberrations in exposed workers to ionizing radiations

En la prevención del cáncer todas las acciones son importantes para disminuir los casos. El objetivo es describir si existen aberraciones cromosómicas en los trabajadores de la salud ocupacionalmente expuestos a bajas dosis de radiación ionizante y explorar la posibilidad de utilizar estas pruebas como seguimiento biológico dentro de un sistema de vigilancia.Materiales y métodos: Se realizan cultivos celulares de linfocitos de sangre periférica, teñidos con quinacrina y lectura en metafases de cada caso. Se toman promedios de dosimetrías de uno a cuatro años y se comparan los resultados con las dosis recibidas y el tiempo de exposición, así como también con relación a cancerígenos comunes, antecedentes familiares y personales.Resultados: se encontraron un promedio de 1,93 aberraciones por individuo. En relación con el tiempo de exposición y la presencia de aberraciones, se encontró: 39 por ciento entre 1 y 10 años de exposición, 27 por ciento entre los 11 y 20 años de exposición y 46 por ciento entre los 21 y 30 años de exposición). No se encontró relación entre dosis y presencia de aberraciones, pues éstas representaron indistintamente a la dosis recibida.Conclusiones: los hallazgos sugieren que la exposición a bajas dosis de radiación ionizante, internacionalmente permitidas, puede ocasionar daños cromosómicos y está en relación directa con el tiempo de exposición y la sensibilidad individual, mas no con la cantidad de radiación recibida. Los trabajadores expuestos deben tener un seguimiento biológico adicional a la dosimetría.

Recent Advances in Radionuclide Therapy

Radionuclides are naturally occurring unstable atoms that undergo radioactive decay. There are ways of radioactive decay emitting different types of radiation based on their physical properties. Radiation for medical purposes include gamma rays, characteristic X-rays, negative and positive electrons, and alpha particles. Different from external radiotherapy, radionuclide therapy internally delivers therapeutic doses of radiation to the targeted tissue. Historically, P-32 orthophosphate was used for the management of myeloproliferative disorders. I-131 has been used for the treatment of hyperthyroidism as well as thyroid cancer for decades. It is one of the most commonly used therapeutic radionuclides in the current practice and its usefulness has been well established by selectively ablating thyroid tissue. For bone pain by osteoblastic metastases, phosphorus-32, strontium-89, samarium-153, or rhenium-186 could be effectively used in combination with narcotics. Another well known radionuclide therapy is I-131 MIBG for the palliation of patients with inoperable tumors of neural crest origin. In contrast to systemic administration of radioactive materials, local control of malignant tumors could be done by delivering radiation through an intratumoral or intraarterial route. In addition, radioactive skin patch or stent has a promising role in killing skin cancers, esophageal cancer, or malignant biliary strictures. Recently, I-131 or Y-90 conjugated with monoclonal antibodies increases the efficacy of radiation damage to lymphoma tissue employing the targeting effect of monoclonal antibodies. Likewise, radionuclide therapy in combination with gene therapy seems to be promising albeit tumor specific ways of gene delivery should be further investigated. Other possible candidates in radionuclide therapy are radioactive peptides and antisense oligonuclides.

Depleted uranium: an overview of its properties and health effects

There has been much debate about the use of depleted uranium in the Gulf War and its health effects on United States and European war veterans. However, studies on the impact of this radioactive substance on the residents of the surrounding Gulf region are far from adequate. Depleted uranium introduces large quantities of radioactive material that is hazardous to biological organisms, continues to decay for millennia and is able to travel tens of kilometres in air. If depleted uranium were used in the Gulf War, its impact on the health of people in the area would have been considerable. This review of depleted uranium-its origin, properties, uses and effects on the human environment and health-aims to trigger further research on this subject

Pesquisa de daño genotoxico en personal medico y paramedico del hospital Obrero N§ 1: gestión 2000 - 2002 / Genotoxic damage in the staff of the hospital Obrero N§ 1. periodo 2000 -2002

Pregunta de investigación. ¿Se habrá producido daño genotoxico en el material genético del personal médico y paramédico de los servicios de radiología y oncología del hospital Obrero N§ 1 de la ciudad de La Paz, por la constante exposición a las radiaciones ionizantes?. Objetivos. Evaluar la magnitud de daño genotóxico y citotóxico que producen las radiaciones ionizantes en personas expuestas continuamente por razones laborales. Diseño Corte transversal con casos y controles Lugar. Hospital Obrero N§ 1, servicio de Radiologia y Oncología , Informática y Farmacia. Participantes. Grupo A (casos): Personas expuestas a radiaciones ionizantes del Hospital Obrero N§ 1 Grupo B (controles): Personas no expuestas a radiaciones del mismo hospital. Los casos y controles fueron seleccionados por muestreo aleatorio simple y según criterio de inclusión y exclusión, ambos grupos respondieron a un cuestionario personal. Se aplico también un cuestionario validado para el hábito de fumar. Métodos. Se extrajo una muestra de sangre por punción venosa, para el estudio de daño cromosómico se utilizó la prueba de micronúcleos (celulas binucleadas bloqueadas utilizando cytocalasina B) en linfociatos de sangre periférica. Resultados. De acuerdo a la identificaicón de micronúcleos por 1000 células binucleadas por placa, se identifica variables de respuestas como si existe o no daño genotóxico en aumento de micronúcleos; variables de exposición son el área de trabajo y tiempo de trabajo, variables control de, sexo tipo de exposición. Al realizar la preuba de T de student se observó que existen diferencias significativas entre el promedio de micronúcleos en el grupo expuesto con el grupo no expuesto a rayos X y cobalto (p<0,001), además que existe asociación significativa (chi2) entre el hábito de fumar y las alteraciones de micronuúcleos de pacientes expuestos y no expuestos, valor p<0,007.

Dosimetria interna de radioinmunoterapia: consideraciones generales / Radioimmunotherapy internal dosimetry: general considerations

La Radioinmunoterapia ha atraído rápidamente el interés como modalidad potencial en el tratamiento del cáncer. Este presente trabajo revisa varios aspectos dosimétricos que involucran la efectividad de la técnica, así como, los procedimientos empleados en la obtención de la información dosimétrica, el tipo de radionucleido seleccionado, las limitaciones y posibilidades de los métodos de estimación dosimétrica; y proporciona un estudio detallado sobre los modelos radiobiológicos que con potencialidad pueden ser utilizados en la prescripción de la dosis en un sistema de planificación que permita establecer una relación dosis/respuesta del tratamiento

Anestesia y cuidados críticos en pacientes con injuria por radiación / Anesthesia and critical care in patients with injury by radiation

La amenaza de una guerra o un accidente nuclear nos llena de curiosidad e indiferencia. En general esto se refleja a nivel mundial con muy poca bibliografía disponible que nos dé información sobre estos eventos y las conductas más aconsejadas para su control y tratamiento. Veremos en este trabajo las características de las distintas radiaciones, nociones de lo significativamente importante para el especialista que son los efectos sobre el individuo y los criterios para diagnóstico, pronóstico y tratamiento.

Estimation of single-strand breaks induced in the dried film of DNA by high energy alpha particle from a cyclotron.

DNA extracted and purified from Vibrio cholerae OGAWA 154 cells and prepared in the form of a dry thin film was exposed in air to a beam of alpha particles obtained from a Variable Energy Cyclotron. The number of single-strand breaks per DNA unit exhibited a linear dose-effect relationship indicating the occurrence of single-hit kinetics. The efficiency and yield of alpha-induced single-strand breaks were approximately 72 eV/break and 1.39 respectively.

Significado fisiológico dor parâmetros de freqüência e amplitude do EEG humano e valor informativo comparativo das análises espectral e de periódo / Physiological meaning of frequency and amplitude parameters in human ECG and comparative informative value of spectral and the period analysis

Em trechos prolonados do EEG, verificamos, através de análise fatorial, que a freqüência e a amplitude da análise de período (em 4 faixas padrão) fornecem parâmetros com diferentes significados fisiológicos. Em determinadas tarefas psicofisiológicas e clínicas (relacionadas ao estudo da atividade mental), estes parâmetros aparentam ser mais adequados e informativos do que os mais usados características espectrais dessas mesmas faixas.