Reliability and Validity of a Nationwide Survey (the Korean Radiation Workers Study)

Background@#This study aimed to evaluate the reliability and validity of the self-administered questionnaire for Korean radiation workers. @*Methods@#From May 24, 2016, to June 30, 2017, 20,608 participants completed the questionnaire, providing information on sociodemographics, lifestyle, work history and practices, medical radiation exposure, and medical history, which was linked to the National Dose Registry and the National Cancer Registry. The validity of the questionnaire was evaluated using the responses of 20,608 workers, and reliability was evaluated using the responses of 3043 workers who responded to the survey twice. @*Results@#Responses concerning demographic characteristics and lifestyle showed reliability with a moderate-to-high agreement (kappa: 0.43–0.99), whereas responses concerning occupation and medical radiation exposure had a wide range of agreement (kappa: 0.05–0.95), possibly owing to temporal variability during employment. Regarding validity, responses to the question about the first year of employment had an excellent agreement with the national registry (intraclass correlation coefficient = 0.9); however, responses on cancer history had a wide range of agreement (kappa: 0.22–0.85). @*Conclusion@#Although the reliability and validity of the questionnaire were not distinguished by demographic characteristics, they tended to be low among participants whose occupational radiation exposure was minimal. Overall, the information collected can be reliable for epidemiological studies; however, caution must be exercised when using information such as medical exposure and work practices, which are prone to temporal variability.

Projected lifetime cancer risk from cone-beam computed tomography for orthodontic treatment / 대한치과교정학회지

Objective@#To estimate the projected cancer risk attributable to diagnostic cone-beam computed tomography (CBCT) performed under different exposure settings for orthodontic purposes in children and adults. @*Methods@#We collected a list of CBCT machines and their specifications from 38 orthodontists. Organ doses were estimated using median and maximum exposure settings of 105 kVp/156.8 mAs and 130 kVp/200 mAs, respectively. The projected cancer risk attributable to CBCT procedures performed 1–3 times within 2 years was calculated for children (aged 5 and 10 years) and adult (aged 20, 30, and 40 years) male and female patients. @*Results@#For maximum exposure settings, the mean lifetime fractional ratio (LFR) was 14.28% for children and 0.91% for adults; this indicated that the risk to children was 16 times the risk to adults. For median exposure settings, the mean LFR was 5.25% and 0.58% for children and adults, respectively. The risk of cancer decreased with increasing age. For both median and maximum exposure settings, females showed a higher risk of cancer than did males in all age groups. Cancer risk increased with an increase in the frequency of CBCT procedures within a given period. @*Conclusions@#The projected dental CBCT-associated cancer risk spans over a wide range depending on the machine parameters and image acquisition settings. Children and female patients are at a higher risk of developing cancer associated with diagnostic CBCT. Therefore, the use of diagnostic CBCT should be justified, and protective measures should be taken to minimize the harmful biological effects of radiation.

Projected lifetime cancer risk from cone-beam computed tomography for orthodontic treatment / 대한치과교정학회지

Objective@#To estimate the projected cancer risk attributable to diagnostic cone-beam computed tomography (CBCT) performed under different exposure settings for orthodontic purposes in children and adults. @*Methods@#We collected a list of CBCT machines and their specifications from 38 orthodontists. Organ doses were estimated using median and maximum exposure settings of 105 kVp/156.8 mAs and 130 kVp/200 mAs, respectively. The projected cancer risk attributable to CBCT procedures performed 1–3 times within 2 years was calculated for children (aged 5 and 10 years) and adult (aged 20, 30, and 40 years) male and female patients. @*Results@#For maximum exposure settings, the mean lifetime fractional ratio (LFR) was 14.28% for children and 0.91% for adults; this indicated that the risk to children was 16 times the risk to adults. For median exposure settings, the mean LFR was 5.25% and 0.58% for children and adults, respectively. The risk of cancer decreased with increasing age. For both median and maximum exposure settings, females showed a higher risk of cancer than did males in all age groups. Cancer risk increased with an increase in the frequency of CBCT procedures within a given period. @*Conclusions@#The projected dental CBCT-associated cancer risk spans over a wide range depending on the machine parameters and image acquisition settings. Children and female patients are at a higher risk of developing cancer associated with diagnostic CBCT. Therefore, the use of diagnostic CBCT should be justified, and protective measures should be taken to minimize the harmful biological effects of radiation.

Influence of Facial Flushing on Pre- or Type 2 Diabetes Risk according to Alcohol Consumption in Korean Male / 가정의학회지

Background@#This study aims to examine the association between alcohol consumption and the risk of pre- or type 2 diabetes mellitus (T2DM) by alcohol-induced flushing response in Korean male adults, particularly based on their body mass index (BMI). @*Methods@#This study selected 1,030 (158 non-drinkers, 364 flushers, and 508 non-flushers) male adults who had medical checkups. A logistic regression analysis was used to compare the association between alcohol consumption and the risk of pre- or T2DM. @*Results@#In both the normal-weight group (BMI 4 and ≤8 drinks: 2.64, 1.10–6.36; >8 drinks: 2.42, 1.11–5.27). However, obese non-flushers had only a significant higher risk of pre- or T2DM when consuming more than 8 drinks of alcohol per week than the non-drinkers (2.72, 1.39–5.30) @*Conclusion@#These results suggest that obese flushers have an increased risk of developing pre- or T2DM even with less alcohol consumption.

Cesium-137 Contaminated Roads and Health Problems in Residents: an Epidemiological Investigation in Seoul, 2011

BACKGROUND: In 2011, two roads in a residential area in Seoul were found to be contaminated with the radionuclide cesium-137 (137Cs). In response to public concerns, an epidemiological study was conducted. METHODS: The standardized cancer incidence ratios in the affected and neighboring regions were calculated based on the central cancer registry. Households in the region were sampled using the random stratified sampling technique, and questionnaires were administered to family members, via home visit and via students in elementary to high schools. Information on duration of residency and frequency of use of the roads was applied to calculate cumulative radiation exposure dose from the roads, alongside with the reported 137Cs contamination amounts. Information on past medical history, perceived risk, anxiety and psychological stress was also obtained. Of the 31,053 residents, 8,875 were analyzed. To examine possible associations between radiation exposure and health problems, logistic regression adjusted for covariates were performed with consideration of the sampling design, population weight and stratification. RESULTS: No significant association was found between self-informed diseases, including cancers, and estimated radiation exposure dose. According to an increase of radiation level, a significant increase in anxiety in all and a decline in the psychosocial wellbeing of the adults was noted. The risk perception level was higher in the elderly, females, the less educated, and the highest exposed individuals. CONCLUSION: This study provides a basis for risk communication with residents and community environmental health policy.

Thyroid cancer among female workers in Korea, 2007–2015

BACKGROUND: Prevalence of thyroid cancer has been increasing rapidly worldwide, especially among women. There has been a debate as to whether such an increase represents consequences of over-diagnosis or a true increase. To find the occupational risk of Korean female workers in different industry sectors, we analyzed the data of Korean female workers. METHODS: National Female Worker Cohort data that contain information on total female workers were used for our analysis of prevalence of thyroid cancer (C73 according to KCD-5, 6 code) derived from National Health Insurance data. By combining industrial codes from National Health Insurance Service and those from Korea Workers’ Compensation and Welfare Service, the classification of industrial codes became to consist of the total of thirty three representing both non-office (NO) and office (O) categories. Both an internal comparison among female workers within the cohort and an external comparison to compare female workers with Korean general female population were carried out. RESULTS: Among 149,258 female workers, 2,641 cases of thyroid cancers were identified. Differences in prevalence of thyroid cancer between female workers (40.5%) and general Korean female population (32.6%) were observed; however, the differences in prevalence of thyroid cancer between NO workers and O workers were not apparent. An analysis involving workers in Financial and insurance activities sector revealed that, standardized prevalence rate (SPR) of both NO (2.96, 95% CI = 2.01–4.20) and O workers (3.68, 95% CI = 3.10–4.33) increased significantly and that an AOR (adjusted odds ratio) increased marginally (1.38, 95% CI = 0.97–1.96). Further, when stratified in respect to the duration of employment, an AOR of female workers having been employed for more than 8 years showed a significant increase (1.63, 95% CI = 1.07–2.49). CONCLUSIONS: Female workers had a higher risk of thyroid cancer than general female population but the difference between NO workers and O workers was not found to be significant in most industrial sectors. Further studies using data with information regarding specific occupational exposures are needed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s40557-018-0259-3) contains supplementary material, which is available to authorized users.

Towards More Influential Research in Acute Poisoning from Toxic Materials

No abstract available.

The Burden of Acute Pesticide Poisoning and Pesticide Regulation in Korea

BACKGROUND: This study aimed to estimate the burden of acute pesticide poisoning and to determine its trend with recently implemented pesticide regulations. METHODS: Disability-adjusted life-years (DALYs) were calculated as the sum of years of life lost (YLLs) and years lived with disability (YLDs) due to acute pesticide poisoning using the methods of the Global Burden of Disease Study 2013. The values of YLLs, YLDs, and DALYs were stratified by sex, age groups, intentionality of poisoning, and causative agents. RESULTS: From 2006 to 2014, DALYs decreased by 69% (from 69,550 to 21,742). The decreasing tendency of DALYs was especially marked from 2011. The total burden of acute pesticide poisoning was mainly caused by YLLs and intentional pesticide poisoning. The highest DALYs due to acute pesticide poisoning occurred in those in their 40s and 50s; however, the decreased rates of DALYs were higher in those aged 10–49 years than in those aged more than 50 years. Herbicides including paraquat contributed to the largest proportion of total DALYs. CONCLUSION: As this is the first study to quantify the burden of acute pesticide poisoning using DALYs, our results provide comprehensive evidence of the importance of using strict regulations to prevent public health hazards due to acute pesticide poisoning.

Occupational Radiation Exposure and Health Effects among Medical Workers / 대한내과학회지

Medical radiation workers occupy the largest group of radiation workers and is rapidly increasing worldwide. They expose to protracted low-dose radiation and include a large proportion of women. The purpose of this article is to provide an overview of occupational radiation exposure and health effects among medical radiation workers through literature review and from the findings of Korean medical radiation workers' studies. Occupational radiation exposure increases the risk of many chronic diseases including cancer, cataract, cardiovascular diseases, thyroid diseases, and others. Although Korean medical radiation workers had a more favorable mortality than in general population, male workers experienced higher mortality from all cancers, leukemia, cancers of the stomach and the colon, and diseases of circulatory system after adjusting for the lower overall mortality. The potential adverse health risks from occupational radiation exposure are not negligible in medical radiation workers if current working level remains. Therefore, effective prevention efforts are needed to reduce the risks of diseases from occupational radiation exposures.

Study on application to the field of dentistry using optical coherence tomography (OCT) / 대한치과보철학회지

PURPOSE: This paper describes the basic principles and the feasibility of the field of dental diagnosis of optical coherence tomography (OCT) used in diverse field of medical diagnosis. MATERIALS AND METHODS: In this review, the research data of OCT were searched from PubMed, medical journal and related papers. RESULTS: Generally, OCT is non-invasive and is possible to secure an excellent spatial resolution and real-time images of biological microstructure. CONCLUSION: This review discusses not only the basic principles of operation, types, advantages, disadvantages of OCT but also the future applications of OCT technology and their potential in the field of dental diagnosis.

Reconstruction of Radiation Dose Received by Diagnostic Radiologic Technologists in Korea / 예방의학회지

OBJECTIVES: Diagnostic medical radiation workers in Korea have been officially monitored for their occupational radiation doses since 1996. The purpose of this study was to design models for reconstructing unknown individual radiation doses to which diagnostic radiation technologists were exposed before 1996. METHODS: Radiation dose reconstruction models were developed by using cross-sectional survey data and the personal badge doses of 8167 radiologic technologists. The models included calendar year and age as predictors, and the participants were grouped into six categories according to their sex and facility type. The annual doses between 1971 and 1995 for those who were employed before 1996 were estimated using these models. RESULTS: The calendar year and age were inversely related to the estimated radiation doses in the models of all six groups. The annual median estimated doses decreased from 9.45 mSv in 1971 to 1.26 mSv in 1995, and the associated dose variation also decreased with time. The estimated median badge doses from 1996 (1.22 mSv) to 2011 (0.30 mSv) were similar to the measured doses (1.68 mSv to 0.21 mSv) for the same years. Similar results were observed for all six groups. CONCLUSIONS: The reconstruction models developed in this study may be useful for estimating historical occupational radiation doses received by medical radiologic technologists in Korea.

Estimates of Radiation Doses and Cancer Risk from Food Intake in Korea

The aim of this study was to estimate internal radiation doses and lifetime cancer risk from food ingestion. Radiation doses from food intake were calculated using the Korea National Health and Nutrition Examination Survey and the measured radioactivity of 134Cs, 137Cs, and 131I from the Ministry of Food and Drug Safety in Korea. Total number of measured data was 8,496 (3,643 for agricultural products, 644 for livestock products, 43 for milk products, 3,193 for marine products, and 973 for processed food). Cancer risk was calculated by multiplying the estimated committed effective dose and the detriment adjusted nominal risk coefficients recommended by the International Commission on Radiation Protection. The lifetime committed effective doses from the daily diet are ranged 2.957-3.710 mSv. Excess lifetime cancer risks are 14.4-18.1, 0.4-0.5, and 1.8-2.3 per 100,000 for all solid cancers combined, thyroid cancer, and leukemia, respectively.

Cancer Risk among Population near Nuclear Power Plants in Korea

No abstract available.

Can screening effects explain increased risk of thyroid cancer among population living near nuclear power plants in Korea?

No abstract available.

Can screening effects explain increased risk of thyroid cancer among population living near nuclear power plants in Korea?

No abstract available.

Urinary concentration of 3-phenoxybenzoic acid in elementary students in South Korea

OBJECTIVES: Pyrethroid pesticides are among the most commonly using insecticides in South Korean households and have been the subject of considerable interest among public health professionals for their potential health effects. The objective of this study is to examine the level of urinary 3-phenoxybenzoic acid (3-PBA) among elementary students in South Korea. METHODS: We conducted a cross-sectional study to evaluate pyrethroid pesticide exposure levels by measuring the urinary metabolites of 3-PBA using a gas chromatography-mass spectrometry method in March 2011. Study participants were 70 Asan-area and Incheon-area elementary students. RESULTS: All respondents had values above the detection limit, and the geometric means of 3-PBA in all children were 1.85 μg/L and 1.46 μg/g creatinine. Children with the top 10% urinary levels of 3-PBA were more likely to be girls, under nine years of age, living in a rural area, and living in a residential type apartment. CONCLUSIONS: South Korean children have a higher concentration of urinary 3-PBA compared with those of other countries. Further research identifying exposure pathways and intervention efforts to reduce environmental pesticide use are needed in South Korea.

Urinary concentration of 3-phenoxybenzoic acid in elementary students in South Korea

OBJECTIVES: Pyrethroid pesticides are among the most commonly using insecticides in South Korean households and have been the subject of considerable interest among public health professionals for their potential health effects. The objective of this study is to examine the level of urinary 3-phenoxybenzoic acid (3-PBA) among elementary students in South Korea. METHODS: We conducted a cross-sectional study to evaluate pyrethroid pesticide exposure levels by measuring the urinary metabolites of 3-PBA using a gas chromatography-mass spectrometry method in March 2011. Study participants were 70 Asan-area and Incheon-area elementary students. RESULTS: All respondents had values above the detection limit, and the geometric means of 3-PBA in all children were 1.85 μg/L and 1.46 μg/g creatinine. Children with the top 10% urinary levels of 3-PBA were more likely to be girls, under nine years of age, living in a rural area, and living in a residential type apartment. CONCLUSIONS: South Korean children have a higher concentration of urinary 3-PBA compared with those of other countries. Further research identifying exposure pathways and intervention efforts to reduce environmental pesticide use are needed in South Korea.

Assessment of radiation exposure from cesium-137 contaminated roads for epidemiological studies in Seoul, Korea

OBJECTIVES: We aimed to assess the radiation exposure for epidemiologic investigation in residents exposed to radiation from roads that were accidentally found to be contaminated with radioactive cesium-137 (137Cs) in Seoul. METHODS: Using information regarding the frequency and duration of passing via the 137Cs contaminated roads or residing/working near the roads from the questionnaires that were obtained from 8875 residents and the measured radiation doses reported by the Nuclear Safety and Security Commission, we calculated the total cumulative dose of radiation exposure for each person. RESULTS: Sixty-three percent of the residents who responded to the questionnaire were considered as ever-exposed and 1% of them had a total cumulative dose of more than 10 mSv. The mean (minimum, maximum) duration of radiation exposure was 4.75 years (0.08, 11.98) and the geometric mean (minimum, maximum) of the total cumulative dose was 0.049 mSv (<0.001, 35.35) in the exposed. CONCLUSIONS: An individual exposure assessment was performed for an epidemiological study to estimate the health risk among residents living in the vicinity of 137Cs contaminated roads. The average exposure dose in the exposed people was less than 5% of the current guideline.

Assessment of radiation exposure from cesium-137 contaminated roads for epidemiological studies in Seoul, Korea

OBJECTIVES: We aimed to assess the radiation exposure for epidemiologic investigation in residents exposed to radiation from roads that were accidentally found to be contaminated with radioactive cesium-137 (137Cs) in Seoul. METHODS: Using information regarding the frequency and duration of passing via the 137Cs contaminated roads or residing/working near the roads from the questionnaires that were obtained from 8875 residents and the measured radiation doses reported by the Nuclear Safety and Security Commission, we calculated the total cumulative dose of radiation exposure for each person. RESULTS: Sixty-three percent of the residents who responded to the questionnaire were considered as ever-exposed and 1% of them had a total cumulative dose of more than 10 mSv. The mean (minimum, maximum) duration of radiation exposure was 4.75 years (0.08, 11.98) and the geometric mean (minimum, maximum) of the total cumulative dose was 0.049 mSv (<0.001, 35.35) in the exposed. CONCLUSIONS: An individual exposure assessment was performed for an epidemiological study to estimate the health risk among residents living in the vicinity of 137Cs contaminated roads. The average exposure dose in the exposed people was less than 5% of the current guideline.

The user-friendly, ergonomic design aspect of recent intraoral scanners: a literature review

Recently, traditional impression has been rapidly replaced by digital impression using intraoral scanning. There are more than 7 types of intraoral scanners available in the dental market. It is difficult to make effective strategic choices due to a lack of standards and guidelines for optimal intraoral scanning devices. So far, little has been reported about evaluating the ergonomic aspect of these scanners. This literature review compares current intraoral scanning systems based on different types of handles and suggests the most comfortable, user-friendly intraoral scanners from an ergonomic standpoint.