Indoor radon exposure and lung cancer: a review of ecological studies

Lung cancer has high mortality and incidence rates. The leading causes of lung cancer are smoking and radon exposure. Indeed, the World Health Organization (WHO) has categorized radon as a carcinogenic substance causing lung cancer. Radon is a natural, radioactive substance; it is an inert gas that mainly exists in soil or rock. The gas decays into radioactive particles called radon progeny that can enter the human body through breathing. Upon entering the body, these radioactive elements release α-rays that affect lung tissue, causing lung cancer upon long-term exposure thereto. Epidemiological studies first outlined a high correlation between the incidence rate of lung cancer and exposure to radon progeny among miners in Europe. Thereafter, data and research on radon exposure and lung cancer incidence in homes have continued to accumulate. Many international studies have reported increases in the risk ratio of lung cancer when indoor radon concentrations inside the home are high. Although research into indoor radon concentrations and lung cancer incidence is actively conducted throughout North America and Europe, similar research is lacking in Korea. Recently, however, studies have begun to accumulate and report important data on indoor radon concentrations across the nation. In this study, we aimed to review domestic and foreign research into indoor radon concentrations and to outline correlations between indoor radon concentrations in homes and lung cancer incidence, as reported in ecological studies thereof. Herein, we noted large differences in radon concentrations between and within individual countries. For Korea, we observed tremendous differences in indoor radon concentrations according to region and year of study, even within the same region. In correlation analysis, lung cancer incidence was not found to be higher in areas with high indoor radon concentrations in Korea. Through our review, we identified a need to implement a greater variety of statistical analyses in research on indoor radon concentrations and lung cancer incidence. Also, we suggest that cohort research or patient-control group research into radon exposure and lung cancer incidence that considers smoking and other factors is warranted.

Indoor 222Rn and 220Rn variations: evidence for Boyle's law

Radon and its daughter product are a major source of natural radiation exposure, the measurement of radon concentration in dwellings is assuming ever increasing importance. It is known from recent surveys in many countries that radon and its progeny contributes significantly to total inhalation dose and is well established that radon when inhaled in large quantity causes lung disorder. In view of this the authors have measured 222Rn and 220Rn levels in dwellings of different volumes at Bangalore Metropolitan, India. Integrated and long duration measurements of radon were carried out using twin cup dosimeters with Solid State Nuclear Track Detector technique. Results showed that concentrations of 222Rn, 220Rn, their progenies and dose rates in dwellings decreased with increase in room volume. Conclusions: The annual effective inhalation dose due to 222Rn, 220Rn and their progenies from the study ranged between 0.2-4.4 with an arithmetic mean of 1.7 +/- 1.1 mSv y-1. The dwellers of lower volumes are posed to high dose rates

Flooding in Thailand and the problem of radioactive elements leakage

Sir, the big flooding in Thailand in 2011 is one of the problematic flooding in Asia. It causes several destroying to many things in the disaster areas. An important concern is on the effect on the setting with the radioactive elements usage. In Thailand, there are some places with radioactive elements including to the university, hospital as well as radioactive research center. Luckily, during the disaster period, there is no report on radioactive elements leakage. The interesting focus is on the way that each setting protect itself from flooding. In many places with small usage of radioactive elements, the replacing of the radioactive substances and machines is done. The cases of hospital is very interesting, some hospitals with radiotherapy unit were flooded but they previously replace the radioactive elements and machine to the safe place. The more problematic place as the radiation research center had to make more serious preventive means. The use of heavy big and high giant barrier to protect the building was used and the good first structural plan of the building helped a lot in prevention of the problem. However, there is the problem of transportation of the radioactive element for using in medical purposes. This caused the delay for treatment of many cancerous patients. Indeed, the flooding might be the cause of uncontrolled distribution of radioactive elements and can be serious public health problem [1, 2]. Although there is no problem in this disaster, it is suggested that any site should have their own preventive protocol to correspond to the possible flooding and other disaster

Results of treatment of hemangioma by radioactive P-32

During 5 years, from 1993 to 1997, we have treated 1042 cases of hemangioma of the skin, most of the patients are children under 1 year old. 70% of patients are the girls and 2/3 of them live in Ho Chi Minh city, almost in the 1st, Binh Thanh, Go Vap district. In 83.5% of cases, the hemangioma were seen at the time of birth, and appear on the 1st or the 2nd child of family. More than 84% of patients have only one lesion, and about half of them are on the head and neck region of the body. The tuberous form are more than the plane form. The mean time of treatment was 5 months with the average dose of 160 Gy, we got a good result on 94.8% of cases, with very small complications, and very rare recurrent cases. This is oldest but efficiently method for the treatment of the superficial Hemangioma of the children. It still has a big disadvantage: the treatment time is very long, makes difficulty to the children going everyday to hospital for the treatment

An evaluation of the radioactive safety in some X-ray facilities in some local hospitals

20 X-ray Departments of hospitals in the north, centre and south of Vietnam and base of nutural radiation in those areas were examinated. The results have shown that the working places of health staffs were well protected, but X-ray level in some waiting places of patients were higher than allowed limitation because of poor protection. The X-ray were not penetrated in to the next rooms because the wall and ceiling were well protected

Situation of using the radioactive resource and the safe current radioactive situation of Vietnam

An evaluation of the situation of the country’s nuclear medicine department and the use of radioactive resources in Vietnam was implemented. Currently Vietnam has 200 equipments for X-ray generation, 28 radioactive resoureces; 7 centres and 22 facilities of the nuclear medicine which served millions patients everyear. This study also evaluated the networks of X-ray machines and other related medical equipment. From which the orientation and solutions for use of the radioactive resources and radioactive safety in Vietnam were recommendated

Hipertiroidismo: tratamiento con yodo radioactivo / Hipertiroidismo: treatment with radio-active iodine

Presentamos una revisión general del hipertiroidismo, incluyendo sus causas, patogenia, manifestaciones clínicas y las modalidades terapéuticas: tratamiento farmacológico, quirúrgico y especialmente con radioyodo. La terapia con radioyodo se emplea desde 1941. Está indicada en pacientes adultos de cualqier edad, aunque en los últimos años se aplica en niños y adolescentes, en portadores de bocio difuso pequeños o moderados, en hipertiroidismo recurrente y en los que rechazan la cirugía. Contraindicada en embarazo y mujeres en período de lactancia. La dosimetría adecuada depende, entre otros factores, de la captación de I131 por la glándula, volumen tiroideo, desintegración efectiva del isótopo y sensibilidad relativa de la glándula al radioyodo. La complicación inevitable es el hipotiroidismo permanente, que ocurre entre 5 por ciento y 25 por ciento dentro del primer año y aproximadamente 3 por ciento cada año siguiente. En la actualidad, se considera al yodo radioactivo como la primera opción para el tratamiento de la enfermedad del Graves Basedow.

Análise de radioelementos, a níveis de traços, utilizando espectrometria de massa de íons secundários / Analysis of radioelements by levels of traits using mass spectrometry of secundary ions

A espectrometria de massa de íons secundários (SIMS) permite a detecção rápida de elementos estáveis ou radioativos, bem como o cálculo de seu percentual isotópico. Ademais, essa técnica possibilita a localização de radioisótipos, à níveis de traços, em amostras biológicas. Neste trabalho procurou-se estudar a utilização dessa metodologia na detecção de urânio natural à baixa concentração. Estudos sobre a preparação de amostras e limites de detecção foram também realizados.