Eun Shil Cha

Attributable fraction of tobacco smoking on cancer using population-based nationwide cancer incidence and mortality data in Korea

BackgroundSmoking is by far the most important cause of cancer that can be modified at the individual level. Cancer incidence and mortality rates in Korea are the highest among all Asian countries, and smoking prevalence in Korean men is one of the highest in developed countries. The purpose of the current study was to perform a systematic review and provide an evidence-based assessment of the burden of tobacco smoking-related cancers in the Korean population.MethodsSex- and cancer-specific population-attributable fractions (PAF) were estimated using the prevalence of ever-smoking and second-hand smoking in 1989 among Korean adults, respectively, and the relative risks were estimated from the meta-analysis of studies performed in the Korean population for ever-smoking and in the Asian population for passive smoking. National cancer incidence data from the Korea Central Cancer Registry and national cancer mortality data from Statistics Korea for the year 2009 were used to estimate the cancer cases and deaths attributable to tobacco smoking.ResultsTobacco smoking was responsible for 20,239 (20.9%) cancer incident cases and 14,377 (32.9%) cancer deaths among adult men and 1,930 (2.1%) cancer incident cases and 1,351 (5.2%) cancer deaths among adult women in 2009 in Korea. In men, 71% of lung cancer deaths, 55%–72% of upper aerodigestive tract (oral cavity, pharynx, esophagus and larynx) cancer deaths, 23% of liver, 32% of stomach, 27% of pancreas, 7% of kidney and 45% of bladder cancer deaths were attributable to tobacco smoking. In women the proportion of ever-smoking-attributable lung cancer was 8.1%, while that attributable to second-hand smoking among non-smoking women was 20.5%.ConclusionsApproximately one in three cancer deaths would be potentially preventable through appropriate control of tobacco smoking in Korean men at the population level and individual level. For Korean women, more lung cancer cases and deaths were attributable to second-hand than ever-smoking. Effective control programs against tobacco smoking should be further developed and implemented in Korea to reduce the smoking-related cancer burden.

Impact of paraquat regulation on suicide in South Korea

BACKGROUND Ingestion of pesticides (mainly paraquat) accounted for one-fifth of suicides in South Korea in 2006-10. We investigated the effect on suicide mortality of regulatory action, culminating in a ban on paraquat in South Korea in 2011-12. METHODS We calculated age-standardized method-specific suicide mortality rates among people aged ≥15 in South Korea (1983-2013) using registered death data. Negative binomial regression was used to estimate changes in the rate and number of pesticide suicides in 2013, compared with those expected based on previous trends (2003-11). RESULTS Pesticide suicide mortality halved from 5.26 to 2.67 per 100 000 population between 2011 and 2013. Compared with the number expected based on previous trends, the regulations were followed by an estimated 847 [95% confidence interval (CI) -1180 to -533] fewer pesticide suicides, a 37% reduction in rates (rate ratio = 0.63, 95% CI 0.55 to 0.73) in 2013. The decline in pesticide suicides after the regulations was seen in all age/sex/geographical groups. The absolute reduction in the number of suicides was greatest among men, the elderly and in rural areas. The reduction in pesticide suicides contributed to 56% of the decline in overall suicides that occurred between 2011 and 2013. There was no impact of the regulations on crop yield. CONCLUSIONS The regulation of paraquat in South Korea in 2011-12 was associated with a reduction in pesticide suicide. Further legislative interventions to prevent the easy availability of highly lethal suicide methods are recommended for reducing the number of suicides worldwide.

Mortality from and incidence of pesticide poisoning in South Korea: findings from National Death and Health Utilization Data between 2006 and 2010

Pesticide poisoning has been recognized as an important public health issue around the world. The objectives of this study were to report nationally representative figures on mortality from and the incidence of pesticide poisoning in South Korea and to describe their epidemiologic characteristics. We calculated the age-standardized rates of mortality from and the incidence of pesticide poisoning in South Korea by gender and region from 2006 through 2010 using registered death data obtained from Statistics Korea and national healthcare utilization data obtained from the National Health Insurance Review and Assessment Service of South Korea. During the study period of 2006 through 2010, a total of 16,161 deaths and 45,291 patients related to pesticide poisoning were identified, marking respective mortality and incidence rates of 5.35 and 15.37 per 100,000 population. Intentional self-poisoning was identified as the major cause of death due to pesticides (85.9%) and accounted for 20.8% of all recorded suicides. The rates of mortality due to and incidence of pesticide poisoning were higher in rural than in urban areas, and this rural-urban discrepancy was more pronounced for mortality than for incidence. Both the rate of mortality due to pesticide poisoning and its incidence rate increased with age and were higher among men than women. This study provides the magnitude and epidemiologic characteristics for mortality from and the incidence of pesticide poisoning at the national level, and strongly suggests the need for further efforts to prevent pesticide self-poisonings, especially in rural areas in South Korea.

Disease Prevalence and Mortality among Agricultural Workers in Korea

The aim of this paper was to provide an overview of mortality and disease prevalence related to occupational diseases among agricultural workers in Korea. We evaluated the age-standardized mortality rates and the prevalence of chronic diseases and compared them with those of other populations using death registration data from 2004 through 2008 and the 2005 Korean National Health and Nutrition Examination Survey. In addition, we conducted a literature review on published articles examining the health status of farmers in Korea. Agricultural workers have a significantly higher mortality of cancer, tuberculosis, chronic respiratory diseases, liver diseases, suicide, motor and non-motor vehicle accidents. Compared to other populations, farmers have higher prevalence rates of arthritis and intervertebral disc disorders. The literature review revealed a number of work-related diseases among farmers, such as musculoskeletal diseases, pesticide poisoning, infections, and respiratory and neurologic diseases. Korean farmers demonstrate a distinct pattern of mortality and disease prevalence compared to other populations. Although lifestyle factors remain important contributors to those deaths and diseases, our study suggests that occupation is a major determinant as well. Intensive programs such as surveillance systems, therefore, should be developed in order to identify and prevent work-related diseases among agricultural workers in Korea.

Incidence of acute occupational pesticide poisoning among male farmers in South Korea.

BACKGROUND Pesticide poisoning from agricultural labor has been recognized as a major public health problem among farmers worldwide. The objective of this study was to examine the incidence of acute occupational pesticide poisoning among male farmers in South Korea. METHODS A nationwide sampling survey of male farmers was conducted in South Korea. This survey used a stratified multistage probability sampling design and adopted the face-to-face interview method. A total of 1,958 male farmers were interviewed in order to estimate the incidence of acute occupational pesticide poisoning in rural areas in 2010. Based on a self-reported definition, the incidence rate in 2010 and the lifetime hospitalization rate due to acute occupational pesticide poisoning among male farmers were estimated. RESULTS The incidence rate of acute occupational pesticide poisoning was 24.7 (95% CI 22.1-27.2) per 100 male farmers, which corresponds to 209,512 cases across South Korea in 2010. About 12% of the pesticide poisoning cases included either visiting a medical doctor or hospitalization. The lifetime rate of hospitalization due to occupational pesticide poisoning was 6.1 (95% CI 4.9-7.3) among male farmers. Poisoning occurred mainly when farmers were applying pesticides during summer. CONCLUSION Our nationwide sampling survey demonstrated that acute occupational pesticide poisonings are highly prevalent among male South Korean farmers. Intensive intervention efforts to reduce occupational pesticide poisoning are urgently needed in South Korea.

Amyotrophic Lateral Sclerosis and Agricultural Environments: A Systematic Review

The aim of this study was to examine the relationship between the risk of amyotrophic lateral sclerosis (ALS) and exposure to rural environments. Studies were identified through OVID MEDLINE and EMBASE search up to September 2013 using as keywords rural residence, farmers, and pesticide exposure. Twenty-two studies were included for this meta-analysis. Summary odds ratios (ORs) were calculated using random effect model by type of exposure index, and subgroup analyses were conducted according to study design, gender, region, case ascertainment, and exposure assessment. The risk of ALS was significantly increased with pesticide exposure (OR, 1.44; 95% CI, 1.22-1.70) and with farmers (OR, 1.42; 95% CI, 1.17-1.73), but was not significant with rural residence (OR, 1.25; 95% CI, 0.84-1.87). The risk estimates for subgroup analysis between pesticide exposure and ALS indicated a significant positive association with men (OR, 1.96), and in studies using El Escorial criteria for ALS definition (OR, 1.63) and expert judgment for pesticide exposure (OR, 2.04) as well. No significant publication bias was observed. Our findings support the association of pesticide exposure and an increased risk for ALS, stressing that the use of more specific exposure information resulted in more significant associations.

Suicide from carbon monoxide poisoning in South Korea: 2006-2012

BACKGROUNDS Suicide from carbon monoxide poisoning by burning coal briquette or barbecue charcoal increased rapidly in some East Asian countries in the recent decade. The purpose of this study was to examine trends in suicides from carbon monoxide poisoning in South Korea and their epidemiologic characteristics. METHODS We presented age-standardized mortality rates of carbon monoxide suicide and compared them with those of suicide by other methods using registered death data from Statistics Korea (South Korea) from 2006 to 2012. Logistic regression analysis was conducted to estimate odds ratios of carbon monoxide suicide by socio-demographic characteristics before and after the marked increase in carbon monoxide suicide in September 2008. RESULTS The number of carbon monoxide suicides in South Korea was only 34 in 2006 but rapidly increased to 267 in 2008 and was 1125 in 2012, with the age-standardized rates of 0.06 (2006), 0.48 (2008), and 1.97 (2012) per 100,000 population respectively (a striking 3,183% increase in 2006-2012). Suicide by carbon monoxide poisoning showed greater odds ratios among men, younger age groups, single or the divorced, and those with high education and non-manual jobs compared with suicides by other methods. LIMITATIONS This study only used data for fatal self-poisoning by carbon monoxide (non-fatal cases not included) and had no information on the sources of carbon monoxide. CONCLUSIONS Carbon monoxide suicides substantially increased in South Korea over the relatively short study period and showed some distinct socio-demographic characteristics compared with suicides by other methods.

The impact of improving suicide death classification in South Korea: a comparison with Japan and Hong Kong.

Introduction The suicide rate of South Korea has increased dramatically during the past decades, as opposed to steadily decreasing trends in Japan and Hong Kong. Although the recent increase of suicide in South Korea may be related to changing socioeconomic conditions and other contextual factors, it may also reflect, in part, a reduction of misidentified suicide cases due to improving classification of manner of death. Method We compared the annual proportional change of suicide, undetermined death, and accidental death from South Korea with those of Japan and Hong Kong from 1992 to 2011; a greater proportional change of the manner-of-death categories during the period is indicative of a relatively less stable registration and hence a greater potential for misclassification bias on reported suicide trends. Subgroup analyses stratifying the deaths by methods were also conducted. To estimate the impact, the age-standardized rates of these three death categories in each site were calculated. Results We found that, during the 20-year observation period, the proportional change of suicide, undetermined death, and accidental death in South Korea was significantly greater than Japan and Hong Kong. Similar observations were made in subgroup analyses. While death rates of the three manners in Japan and Hong Kong generally moved in a parallel fashion, the increase of suicide in South Korea occurred concomitantly with a significant reduction of its accidental death rate. 43% of the increase in suicides could be attributed to the decrease in accidental deaths, while 57% of the increase could be due to fundamental causes. Conclusion Our data suggest that, during the mid-1990s and after, the increasing burden of suicide in South Korea initially was masked, in part, by misclassification. Thus, the later apparently rapid increase of suicides reflected steadily improving classification of manner of death, as well as a more fundamental increase in the suicide rate.

Occupational radiation doses among diagnostic radiation workers in South Korea, 1996–2006

This study details the distribution and trends of doses of occupational radiation among diagnostic radiation workers by using the national dose registry between 1996 and 2006 by the Korea Food and Drug Administration. Dose measurements were collected quarterly by the use of thermoluminescent dosimeter personal monitors. A total of 61 732 workers were monitored, including 18 376 radiologic technologists (30 %), 13 762 physicians (22 %), 9858 dentists (16 %) and 6114 dental hygienists (9.9 %). The average annual effective doses of all monitored workers decreased from 1.75 to 0.80 mSv over the study period. Among all diagnostic radiation workers, radiologic technologists received both the highest effective and collective doses. Male radiologic technologists aged 30-49 y composed the majority of workers receiving more than 5 mSv in a quarter. More intensive monitoring of occupational radiation exposure and investigation into its health effects on diagnostic radiation workers are required in South Korea.

Prevalence and changes in chronic diseases among South Korean farmers: 1998 to 2005

BackgroundEpidemiologic studies have suggested a unique pattern of disease among farmers in Western countries, but limited information is available about the magnitude of disease prevalence and their changes over time in Asian farmers. The aim of this study was to compare the prevalence and changes in chronic diseases among farmers with those of other occupational groups in South Korea.MethodsUsing data from three consecutive cross-sectional national surveys: the Korean National Health and Nutrition Examination Survey 1998 (n = 39,060), 2001 (n = 37,769), and 2005 (n = 34,145), we calculated age and gender-standardized prevalence of chronic diseases by the direct method and compared the prevalence changes from 1998 to 2005.ResultsFemale farmers had significantly higher chronic disease prevalence than other occupational groups in all three surveys. Arthritis was the most prevalent chronic disease among farmers for both men and women. Compared with other populations, farmers demonstrated a higher prevalence of arthritis and intervertebral disc disorders. Farmers showed higher prevalence changes for intervertebral disc disorders than other occupational workers.ConclusionOur findings support that South Korean farmers have a distinct pattern of diseases prevalence from other populations. More detailed studies investigating the risk of musculoskeletal diseases and intensive intervention efforts to reduce the prevalence these diseases, particularly among female farmers, are required.