Objectives: Because the amount of medical waste (i.e., health-care waste) generated in Korea is rapidly increasing and social concern against its safety is widespread, a number of issues related with medical wastes are being discussed. The purpose of this study is to compare diverse medical waste management systems worldwide and propose future directions of a medical waste management system in Korea. Methods: Literature review was conducted mainly on the WHO, and developed countries such as the European Union (Germany, Belgium and UK), Japan and the United States. For these countries, the data with respect to their systems for medical waste management ranging from the definition of medical waste to the whole processes of collection, transportation and disposal were summarized and compared. Results: The terminology and classification of medical wastes were not consistent for WHO recommendation, EU, Japan, US and Korea. Comparison of the collection, storage, transportation and disposal of medical waste showed that Korea had rather stronger regulations for medical waste management compared to developed countries including Belgium (Flanders region), Germany, Japan and the US. Considering that developed countries adopt rather flexible disposal system especially for general medical wastes which pose lower possibility of infection, Korean government could consider diversifying disposal methods other than incineration. It may also be very important to try to reduce the amount of medical wastes and enough capacity for off-site incineration are secured. Conclusion: Our study of international comparisons suggests that it is necessary to continue to identify advantages and disadvantages of the current medical waste management systems and establish more effective one in Korea.

The objective of this study was to verify a change in the longitudinal trend of blood lead levels for the Korean population, before and after the regulation of leaded gasoline— which occurred between 1987 and 1993 in Korea. A total of 77 reports on blood lead levels among general Korean population between 1981 and 2014 were selected, and the results were summarized to have the variables of year, number of subjects, the subjects’ range in age, gender, and blood lead concentrations (arithmetic mean). The annual average atmospheric lead levels for four major cities (i.e., Seoul, Busan, Daegu and Gwangju) were collected from the Air Pollution Monitoring Database from 1991, and pilot studies from 1985 to 1990 before the national air quality monitoring system was launched in 1991. Blood lead levels were visualized in a bubble plot in which the size of each bubble represented the sample size of each study, and the annual average concentrations in ambient air were depicted on line graphs. Blood lead levels in the Korean population tended to gradually increase from the early 1980s (approximately 15-20 μg/dL) until 1990-1992 (20-25 μg/dL). Blood lead levels then began to rapidly decrease until 2014 (<2 μg/dL). Similar patterns were observed for both adults (≥20 years) and younger children/adolescents. The same longitudinal trend was observed in annual average atmospheric lead concentration, which suggests a significant correlation between air lead concentration and blood lead concentration in the general population. In conclusion, the regulation of leaded gasoline has significantly contributed to the rapid change in blood lead concentrations. And, the regulation of other sources of lead exposure should be considered to further decrease blood lead levels in the Korean population.

Objectives: The purpose of this study was to investigate whether chemical exposure among workers has relevance to dyspnea using data from the $3^{rd}$ Korea Working Conditions Survey. Methods: The research subjects were 29,711 wage workers. Chemical exposures consist of four factors, (1) breathing in vapors, fumes, dust and dirt, (2) breathing in organic solvent vapors, (3) handling or touching chemicals, and (4) secondhand smoke. Multiple logistic regression analysis was performed to examine the association between chemical exposure and dyspnea in the last 12months using proc surveylogistic in SAS 9.3 statistical software excluding people who had received a diagnosis of hypertension or obesity that can affect the respiratory distress symptoms(n=27,842). Results: Chemical exposure among workers was associated with dyspnea after adjustment for demographics and job characteristics. Prevalence of dyspnea was 4.9 per 1,000 among men and 5.8 per 1,000. Compared to a total score of 0 points of chemical exposure among workers, a total score of 1, 2-3, and 4 points tended to have increased risk of dyspnea in a dose-response manner for both men (OR=1.43, 1.93, and 4.26; P-for trend=0.002) and women(OR=1.10, 2.81, and 7.70; P-for trend=0.002). Stratified analysis by duration of current job showed that the association between chemical exposure and dyspnea tended to get stronger until 15 years and then disappeared afterwards, which reflects healthy worker survivor effect. Conclusions: We observed significant association between chemical exposure and dyspnea using the data of the $3^{rd}$ Korea Working Conditions Survey. Our results warrants providing knowledge related to chemical exposure, performing prevention activities, and creating various health policies to protect workers.

Objectives: Exposure assessment using questionnaires is effective in large-scale epidemiological studies. However, a limited number of studies have evaluated the questionnaires used in epidemiologic studies in terms of occupational and environmental exposure. The purpose of this study was to summarize and evaluate questionnaire items included in major epidemiological studies conducted in Korea with regard to occupational and environmental exposure. Methods: A total of 12 studies (four cohort studies, six large-scale cross-sectional surveys, and two panel studies) were selected for this study. Various questionnaire items related with occupational and environmental items were collected and summarized into tables. Results: Although job type and address were included in almost all of the studies, the information on occupational or environmental exposure to specific risk factors was collected in a limited number of studies. Moreover, questionnaire items were not standardized, warranting a continuous effort to develop questionnaires and evaluate their validity. Conclusion: Our results suggest that validated questionnaire items focusing on occupational and environmental exposure need to be developed in order to enhance the availability of the information collected from questions in epidemiological studies.

Objectives: In Korea, the system of management of medical waste largely relies on the incineration method. Our study aimed to identify any regional imbalances between the generation and treatment of medical waste, and provide reference data for future policy in Korea. Methods: We analyzed data on the amount of medical waste from 2,000 hospitals in 2012, 2013, and 2014 obtained from the Korea Environment Corporation. In the Arc GIS program (version 10.2.3), the addresses of hospitals and incinerators were transformed into map coordinates. The amount of waste generated by each hospital and the amount incinerated were represented by density and size of a triangle symbol, respectively. Results: As of 2014, the total amount of medical waste from the top 2,000 hospitals was 136,073 tons, out of which about half (49%) was generated in the capital area. Eleven incineration companies (three in the capital area, two in the Chungcheong Provinces area, one in the Jeolla Provinces area, and five in the Gyeongsang Provinces area) treated this waste. For the years 2012, 2013, and 2014, about 60% of the medical waste generated from the hospitals in the capital area was treated within the capital area and about 40% was transported to other areas, especially the Gyeongsang Provinces area, for treatment. On the other hand, about 90% of the medical waste incinerated in the capital area originated from the capital area. Conclusion: Our results suggest a spatial imbalance between the generation and treatment of medical waste in Korea and warrants multilateral policies, including the expansion of on-site treatment, strengthening regulation of the containment of medical wastes, promoting reductions in medical waste and more.