• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1691-1695
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• 2013

Objective: To evaluate the association between tea consumption and the risk of renal cell carcinoma. Methods: We searched PubMed, Web of Science and Scopus between 1970 and November 2012. Two evaluators independently reviewed and selected articles based on predetermined selection criteria. Results: Twelve epidemiological studies (ten case-control studies and two cohort studies) were included in the final analysis. In a meta-analysis of all included studies, when compared with the lowest level of tea consumption, the overall relative risk (RR) of renal cell carcinoma for the highest level of tea consumption was 1.03 (95% confidence interval [CI] 0.89-1.21). In subgroup meta-analyses by study design, there was no significant association between tea consumption and renal cell carcinoma risk in ten case-control studies using adjusted data (RR=1.08, 95% CI 0.84-1.40). Furthermore, there was no significant association in two cohort studies using adjusted data (RR=0.95, 95% CI 0.81-1.12). Conclusion: Our findings do not support the conclusion that tea consumption is related to decreased risk of renal cell carcinoma. Further prospective cohort studies are required.

• Journal of Radiation Protection and Research
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• v.31 no.2
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• pp.69-89
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• 2006

Biological mechanisms for ionizing radiation effects are different at low doses than at high doses. Radiation hormesis involves low-dose-induced protection and high-dose-induced harm. The protective component is associated with a reduction in the incidence of cancer below the spontaneous frequency, brought about by activation of defensive and repair processes. The Linear No-Threshold (LNT) hypothesis advocated by the International Commission on Radiological Protection (ICRP) and the Biological Effects of ionizing Radiation (BEIR) Report VII for cancer risk estimations Ignores hormesis and the presence of a threshold. Cancer incidences significantly less than expected have been found in a large number of epidemiological studies including, airline flight personnel, inhabitants of high radiation backgrounds, shipyard workers, nuclear site workers in scores of locations throughout the world, nuclear power utility workers, plutonium workers, military nuclear test site Participants, Japanese A-bomb survivors, residents contaminated by major nuclear accidents, residents of Taiwan living in $^{60}Co$ contaminated buildings, fluoroscopy and mammography patients, radium dial painters, and those exposed to indoor radon. Significantly increased cancer was not found at doses <200 $mSv^*$. Evidence for radiation hormesis was seen in both sexes for acute or chronic exposures, low or high LET radiations, external whole- or partial body exposures, and for internal radionuclides. The ubiquitous nature of the Healthy Worker Effect (HWE)-like responses in cellular, animal and epidemiological studies negates the HWE as an explanation for radiation hormesis. The LNT hypothesis is wrong and does not represent the true nature of the dose-response relationship, since low doses or dose-rates commonly result in thresholds and reduce cancer incidences below the spontaneous rate. Radiation protection organizations should seriously consider the cost and health implications of radiation hormesis.

• Journal of Environmental Health Sciences
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• v.49 no.1
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• pp.1-10
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• 2023

Low-dose radiation exposure has received considerable attention because it reflects the general public's type and level of exposure. Still, controversy remains due to the relatively unclear results and uncertainty in risk estimation compared to high-dose radiation. However, recent epidemiological studies report direct evidence of health effects for various types of low-dose radiation exposure. In particular, international nuclear workers' studies, CT exposure studies, and children's cancer studies on natural radiation showed significantly increased cancer risk among the study populations despite their low-dose radiation exposure. These studies showed similar results even when the cumulative radiation dose was limited to an exposure group of less than 100 mGy, demonstrating that the observed excess risk was not affected by high exposure. A linear dose-response relationship between radiation exposure and cancer incidence has been observed, even at the low-dose interval. These recent epidemiological studies include relatively large populations, and findings are broadly consistent with previous studies on Japanese atomic bomb survivors. However, the health effects of low-dose radiation are assumed to be small compared to the risks that may arise from other lifestyle factors; therefore, the benefits of radiation use should be considered at the individual level through a balanced interpretation. Further low-dose radiation studies are essential to accurately determining the benefits and risks of radiation.

• Proceedings of the KSCN Conference
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• 2001.12a
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• pp.941-944
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• 2001

• Genomics & Informatics
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• v.12 no.4
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• pp.203-207
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• 2014

Hepatitis is a common and serious disease for the Korean population. It is caused by a virus, the A and B types of which are plentiful in Koreans. In this study, we tried to find genetic factors for hepatitis through genome-wide association studies. We took 368 cases and 1,500 controls from Anseong and Ansan cohort data. About 300,000 single-nucleotide polymorphisms and 20 epidemiological variables were analyzed. We did not find any meaningful significant single nucleotide polymorphisms, but we confirmed the influence of major epidemiological variables on hepatitis.

• The Korean Journal of Pain
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• v.35 no.1
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• pp.4-13
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• 2022

Changes in diagnostic criteria, for example, the various International Classification of Headache Disorders criteria, would lead to changes in the outcomes of epidemiological studies. International Classification of Headache Disorders-1 was based mainly on expert opinion, yet most of the diagnostic criteria were reliable and valid, but it did not include chronic migraine. In its second version, the classification introduced chronic migraine, but this diagnosis resembled more a high-frequency migraine rather than the actual migraine transformation process. It also introduced medication overuse headache, but it necessitated analgesic withdrawal and subsequent headache improvement to be diagnosed as such. Hence patients having medication overuse headache could only be diagnosed in retrospect, which was an awkward situation. Such restrictive criteria for chronic migraine and medication overuse headache omitted a high proportion of patients. International Classification of Headache Disorders-3 allows a diagnosis of medication overuse headache due to combination analgesics if taken for at least 10 days per month for more than three months. Hence the prevalence rate of medication overuse headache and chronic migraine can increase compared to the previous version of the headache classification. Different criteria have been used across studies to identify chronic migraine and medication overuse headache, and therefore the information acquired from previous studies using earlier criteria becomes uncertain. Hence much epidemiological research would need to be interpreted cautiously or repeated with the most updated criteria, since the subjects in studies that apply the latest criteria may be phenotypically different from those in older studies.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.3
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• pp.270-279
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• 2020

Objective: The aim of this study was to propose revision of the occupational exposure limit(OEL) for 1-Bromopropane(1-BP) following a review of the appropriateness of the standard in light of increasing epidemiological data and handling risk. Materials and Methods: The results of toxicity and epidemiologic investigations for 1-BP and agencies' OELs were compared and reviewed through a literature review. In order to investigate the status of 1-BP handling in South Korea, data from work environment actual condition survey results and work environment measurement results were used. Results: The toxicity of 1-BP, such as central nervous system(CNS) damage, peripheral neuropathy, hematological adverse effects, and developmental and reproductive toxicity(male and female) has been reported. ACGIH recommends 0.1 ppm as a TLV-TWA value, but the OEL of South Korea stands at 25 ppm, which is 250 times higher than the TLV-TWA. Although 1-BP is a specially managed substance under the Industrial Safety and Health Law, the currently applied OEL cannot be said to be a safe level based on the results of epidemiological studies to date. In a work environment measurement in 2017, the total number of samples was 626, which were derived from 78 industries, and the average concentration was 1.173 ppm(standard deviation 2.88). Conclusions: To protect the health of workers handling 1-BP, estimated to be 780 in South Korea, it is necessary to strengthen the OEL(TWA) to a level of 0.3 ppm(lower than the 0.34 ppm with known toxic effects), which is believed to be safe as a result of epidemiological investigation. "Skin" notation should be recommended.

• Journal of Preventive Medicine and Public Health
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• v.41 no.3
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• pp.195-199
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• 2008

Objectives : Malondialdehyde (MDA), a lipid peroxidation by-product, has been widely used as an indicator of oxidative stress. Urinary 2-naphthol, a urinary PAH metabolite, is used as a marker of ambient particulate exposure and is associated with lung cancer and chronic obstructive pulmonary disease. However, the stability and intra-individual variation associated with urinary MDA and 2-naphthol have not been thoroughly addressed. The objective of this study was to assess the stability and intra-individual variation associated with urinary MDA and 2-naphthol. Methods : Urine samples were collected from 10 healthy volunteers (mean age 34, range $27{\sim}42$ years old). Each sample was divided into three aliquots and stored under three different conditions. The levels of urinary MDA and 2-naphthol were analyzed 1) just after sampling, 2) after storage at room temperature ($21^{\circ}C$) for 16 hours, and 3) after storage in a $-20^{\circ}C$ freezer for 16 hours. In addition, an epidemiological study was conducted in 44 Chinese subjects over a period of 3 weeks. The urinary MDA and 2-naphthol were measured by HPLC three times. Results : There was no difference in the levels of urinary MDA and 2-naphthol between the triplicate measurements (n=10, p=0.84 and p=0.83, respectively). The intra-class correlation coefficients (ICC) for urinary MDA and 2-naphthol were 0.74 and 0.42, respectively. However, the levels of PM2.5 in the air were well correlated with the levels of both MDA and 2-naphthol in the epidemiological study. Conclusions : These results suggest that urinary MDA and 2-naphthol remain stable under variable storage conditions, even at room temperature for 16 hours, and indicate that these markers can be used in epidemiological studies involving various sample storage conditions. The intra-CC of urinary 2-naphthol and MDA were acceptable for application to epidemiological studies.

• Safety and Health at Work
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• v.4 no.3
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• pp.123-135
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• 2013

Exposure to manganese (Mn) is associated with neurobehavioral effects. There is disagreement on whether commonly occurring exposures in welding, ferroalloy, and other industrial processes produce neurologically significant neurobehavioral changes representing parkinsonism. A reviewof methodological issues in the human epidemiological literature onMnidentified: (1) studies focused on idiopathic Parkinson disease without considering manganism, a parkinsonian syndrome; (2) studies with healthy worker effect bias; (3) studies with problematic statistical modeling; and (4) studies arising from case series derived from litigation. Investigations with adequate study design and exposure assessment revealed consistent neurobehavioral effects and attributable subclinical and clinical signs and symptoms of impairment. Twenty-eight studies show an exposure-response relationship between Mn and neurobehavioral effects, including 11 with continuous exposure metrics and six with three or four levels of contrasted exposure. The effects of sustained low-concentration exposures to Mn are consistent with the manifestations of early manganism, i.e., consistent with parkinsonism. This is compelling evidence thatMnis a neurotoxic chemical and there is good evidence that Mn exposures far below the current US standard of $5.0mg/m^3$ are causing impairment.

• Journal of Ginseng Research
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• v.20 no.4
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• pp.520-539
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• 1996

Based upon Shennong's Ancient Chinese Medical Textbook and Tsorngji Mingyi Byelu. Ginseng has been widely used for over 2,000 years in oriental countries. Scientific basic medical study or clinical study on ginseng was seal·toed 1910's in Eastern countries and from the 1950's in Western countries To obtain kotvledge of clinical studies on Korean ginseng. I investigated the following items 1) Oriental pharmacological documents. 2) the start and corrent state of ginseng research. 3) Clinical studies, 4) epidemiological studies. 5) non-medical human studies. 6) Foreign evaluation in published papers, and 7) future perspectives of clinical study. Although wide and profound research has been carried on the effect of ginseng (diabetes cardiovascular diseases, hypertension, liver diseases. gastrointestinal disorders soress, bram function. aging, antiradiation effect. anemia. hemopoiesis. immuomodulating effect. and tonic effect). Systemic clinical study to determine the therapeutic effects of speciblc disease have hardly been done even in other countries Clinical study or researches with human as the target. on ginseng has been performed in the field of body tenperazure. Pulse, clinical symptoms and hematological findings . fatigue, porformances. anemia. essential hypertension. blood sugar. serum cholesterol. lipid and prolactin. adrenocortical function. impotence. hypospermia. male sterility, climacteric disorder. anticancer effects. cancer preventive effects. and viral hepatitis. adverse effects. and prefered type of ginseng. At the same time as trying preventives or therapeutics from dietary oi natural products scientific research to support that ginseng is not a mystery. should be porformad to prove the effectiveness of Korean ginseng in the treatment of certain diseases using scientific methods or epidemiological approach.