BACKGROUNDOur previous studies revealed cyclicity in the incidence rate of skin malignant melanoma (SMM; ICD9, Dx:172) in the Czech Republic (period T=7.50-7.63 years), UK (T=11.00 years) and Bulgaria (T=12.20 years). Incidences compared with the sunspot index Rz (lag-period dT=+2, +4, +6, +10 or +12 years) have indicated that maximal rates are most likely to appear on descending slopes of the 11-year solar cycle, i.e., out of phase. We summarized and explored more deeply these cyclic variations and discussed their possible associations with heliogeophysical activity (HGA) components exhibiting similar cyclicity.

METHODSAnnual incidences of SMM from 5 countries (Czech Republic, UK, Bulgaria, USA and Canada) over various time spans during the years 1964-1992 were analyzed and their correlations with cyclic Rz (sunspot number) and aa (planetary geomagnetic activity) indices were summarized. Periodogram regression analysis with trigonometric approximation and phase-correlation analysis were applied.

RESULTSPrevious findings on SMM for the Czech Republic, UK and Bulgaria have been validated, and cyclic patterns have been revealed for USA (T=8.63 years, P<0.05) and Canada (Ontario, T=9.91 years, P<0.10). Also, various 'hypercycles' were established (T=45.5, 42.0, 48.25, 34.5 and 26.5 years, respectively) describing long-term cyclic incidence patterns. The association of SMM for USA and Canada with Rz (dT=+6 and +7 years, respectively) and aa (dT=-10 and +9 years, respectively) was described. Possible interactions of cyclic non-photic influences (UV irradiation, Schumann resonance signal, low-frequency geomagnetic fluctuations) with brain waves absorbance, neuronal calcium dynamics, neuro-endocrine axis modulation, melatonin/serotonin disbalance and skin neuro-immunity impairment as likely causal pathways in melanoma appearance, were also discussed.

CONCLUSIONThe above findings on cyclicity and temporal association of SMM with cyclic environmental factors could not only allow for better forecasting models but also lead to a better understanding of melanoma aetiology.

Cosmic Radiation ; adverse effects ; Female ; Forecasting ; Humans ; Male ; Melanoma ; epidemiology ; etiology ; Models, Biological ; Neoplasms, Radiation-Induced ; epidemiology ; etiology ; Periodicity ; Regression Analysis ; Skin Neoplasms ; epidemiology ; etiology ; Solar Activity

Inevitable human exposure to ionizing radiation from man-made sources has been increased with the proceeding of human civilization and consequently public concerns focus on the possible risk to human health. Moreover, Fukushima nuclear power plant accidents after the 2011 East-Japan earthquake and tsunami has brought the great fear and anxiety for the exposure of radiation at low levels, even much lower levels similar to natural background. Health effects of low dose radiation less than 100 mSv have been debated whether they are beneficial or detrimental because sample sizes were not large enough to allow epidemiological detection of excess effects and there was lack of consistency among the available experimental data. We have reviewed an extensive literature on the low dose radiation effects in both radiation biology and epidemiology, and highlighted some of the controversies therein. This article could provide a reasonable view of utilizing radiation for human life and responding to the public questions about radiation risk. In addition, it suggests the necessity of integrated studies of radiobiology and epidemiology at the national level in order to collect more systematic and profound information about health effects of low dose radiation.
DNA Damage/drug effects ; Environmental Exposure ; Humans ; Leukemia/epidemiology/etiology ; Neoplasms, Radiation-Induced/epidemiology ; *Radiation Dosage ; Radiation Tolerance ; *Radiation, Ionizing ; Radioactive Hazard Release ; Risk

Chernobyl Nuclear Accident ; Humans ; Japan ; epidemiology ; Neoplasms, Radiation-Induced ; etiology ; mortality ; Nuclear Warfare ; Radiation Dosage ; Radiation Injuries ; etiology ; mortality ; Radioactive Hazard Release ; Risk ; Ukraine ; epidemiology

No abstract available.
Adult ; Carcinogens/toxicity ; Environmental Exposure ; Genome, Human/radiation effects ; Humans ; Neoplasms, Radiation-Induced/epidemiology/etiology/*genetics ; *Nuclear Power Plants ; Republic of Korea/epidemiology ; Thyroid Neoplasms/epidemiology/etiology/*genetics

Radiation risk has become well known through epidemiological studies of clinically or occupationally exposed populations, animal experiments, and in vitro studies; however, the study of radiation related or induced disease has been limited in Korea. This study is to find the level of occupational radiation exposure for various kinds of accidents, compensated occupational diseases, related studies, and estimations on future occupational disease risks. Research data of related institutions were additionally investigated. About 67% of 62,553 radiation workers had no exposure or less than 1.2 mSv per year. The 5 reported cases on radiation accident patients in Korea occurred during nondestructive testing. According to the recent rapid increase in the number of workers exposed to radiation, a higher social recognition of cancer, and an increasing cancer mortality rate, it is expected that occupational disease compensation will rapidly increase as well. Therefore, it is important to develop scientific and objective decision methods, such as probability of causation and screening dose in the establishment of an exposure and health surveillance system.
Female ; Humans ; Male ; Neoplasms, Radiation-Induced/*epidemiology ; Nuclear Power Plants ; Occupational Diseases/*epidemiology/etiology ; Occupational Exposure ; Radiation Injuries/*epidemiology ; *Radiation, Ionizing ; Radioactive Hazard Release/*statistics & numerical data ; Republic of Korea/epidemiology

To establish an in vivo radiation carcinogenesis model using glutathione S-transferase placental form positive (GST-P+) hepatic foci, newborn rats were irradiated once by 0.5 Gy and 2 Gy of gamma ray or 0.15 Gy and 0.6 Gy of neutron with or without 0.05% phenobarbital (PB). When the rats were sacrificed at the 12th or 21st week, the incidence of GST-P+ foci induction by radiation alone was very low. The neutron was more sensitive than the gamma ray at week 12 and the reverse phenomenon was observed in the groups at week 21. PB combination showed an increased incidence of GST-P+ foci in gamma ray irradiated groups. The neutron irradiation combined with PB did not show any significant difference compared with the corresponding PB untreated groups. We also investigated the combined effect of diethylnitrosamine (DEN) and 0.75 Gy of gamma ray irradiation. Intraperitoneal injection of 0.15 mumol/g body weight of DEN at 1 hour after gamma ray irradiation showed significantly increased the number and area of GST-P+ foci compared with those of DEN alone or DEN at 1 hour before gamma radiation (P < 0.001). From these data, after more defined experiments, an in vivo radiation carcinogenesis model will be established by radiation alone or a combination of radiation and carcinogens.
Animal ; Body Weight ; Diethylnitrosamine/*adverse effects ; Female ; Gamma Rays/adverse effects ; Glutathione Transferase/*drug effects/*radiation effects ; Liver/*drug effects/pathology/*radiation effects ; Liver Neoplasms/epidemiology/*etiology/pathology ; Neoplasms, Radiation-Induced/epidemiology/*etiology/pathology ; Neutrons/adverse effects ; Organ Weight ; Phenobarbital/*adverse effects ; Placenta/drug effects/radiation effects ; Pregnancy ; Radiation Dosage ; Rats ; Rats, Sprague-Dawley ; Time Factors

Radon is likely the second most common cause of lung cancer after smoking. We estimated the lung cancer risk due to radon using common risk models. Based on national radon survey data, we estimated the population-attributable fraction (PAF) and the number of lung cancer deaths attributable to radon. The exposure-age duration (EAD) and exposure-age concentration (EAC) models were used. The regional average indoor radon concentration was 37.5 95 Bq/m3. The PAF for lung cancer was 8.3% (European Pooling Study model), 13.5% in males and 20.4% in females by EAD model, and 19.5% in males and 28.2% in females by EAC model. Due to differences in smoking by gender, the PAF of radon-induced lung cancer deaths was higher in females. In the Republic of Korea, the risk of radon is not widely recognized. Thus, information about radon health risks is important and efforts are needed to decrease the associated health problems.
Adult ; Demography ; *Environmental Exposure ; Female ; Humans ; Lung Neoplasms/*epidemiology/etiology/mortality ; Male ; Models, Theoretical ; Neoplasms, Radiation-Induced/*epidemiology/etiology ; Radon/*toxicity ; Republic of Korea/epidemiology ; Risk Assessment ; Smoking ; Survival Analysis