• Proceedings of the Korean Nuclear Society Conference
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• 1996.11b
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• pp.629-635
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• 1996

The lifetime radiation-induced cancer mortality for Korean has been estimated for both single and continuous radiation exposure using the BEIR V method. In case of single exposure, a dominant cancer site for young and old ages was digestive and respiratory cancer, respectively. For Korean population, digestive cancer was the most dominant radiation-induced cancer site. In case of 1 mGy/yr continuous exposure from birth to death, the contribution of total radiation-induced cancer mortality was negligible as within 3% in comparison with total natural cancer mortality.

• Clinical and Experimental Pediatrics
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• v.64 no.1
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• pp.3-11
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• 2021

There is a growing body of literature on the adverse health effects of ambient air pollution. Children are more adversely affected by air pollution due to their biological susceptibility and exposure patterns. This review summarized the accumulated epidemiologic evidence with emphasis on studies conducted in Korea and heterogeneity in the literature. Based on systematic reviews and meta-analyses, there is consistent evidence on the association between exposure to ambient air pollution and children's health, especially respiratory health and adverse birth outcomes, and growing evidence on neurodevelopmental outcomes. Despite these existing studies, the mechanism of the adverse health effects of air pollution and the critical window of susceptibility remain unclear. There is also a need to identify causes of heterogeneity between studies in terms of measurement of exposure/outcome, study design, and the differential characteristics of air pollutants and population.

• 대한예방의학회:학술대회논문집
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• 1999.10a
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• pp.104-105
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• 1999

• Korean Journal of Environmental Biology
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• v.37 no.3
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• pp.335-342
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• 2019

The purpose of this study was to investigate the toxic effects of zinc in collembolan Paronychiurus kimi at the individual (survival and juvenile production) and population (population growth and age structure) levels after 28 days of exposure in artificially spiked soil. These toxic effects were interpreted in conjunction with the internal zinc concentrations in P. kimi. The EC₅₀ value for juvenile production based on the total zinc concentration was 457 mg Zn kg^-1 dry soil, while the LC₅₀ value for adult survival and r_i=0 value for population growth were within the same order of magnitude (2,623 and 1,637 mg Zn kg^-1 dry soil, respectively). Significant differences in adult survival, juvenile production, and population growth compared with the control group were found at concentrations of 1,500, 375, and 375 mg Zn kg^-1 dry or higher, respectively, whereas significant differences in the age structure, determined by the proportion of each age group in the population, were observed in all treatment groups. It appeared that the internal zinc level in P. kimi was regulated to some extent at soil zinc concentrations of ≤375 mg Zn kg^-1 dry soil, but not at high soil zinc concentrations. These results indicate that, despite zinc being regulated by P. kimi, excess zinc exceeding the regulatory capacity of P. kimi can trigger changes in the responses at the individual and population levels. Given that population dynamics are affected not only by individual level but also by population level endpoints, it is concluded that the toxic effects of pollutants should be assessed at various levels.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.23-30
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• 2009

Slow sand filtration (SSF) was the first engineered/mechanical filtration process used in drinking water treatment. In SSF, untreated water slowly percolate through a bed of porous sand. Biological activity within the sand bed have the strongest influence on removal efficiency of pollutants by slow sand filtration. In this study, the microbial population distributions in slow sand filters operated at the various operation conditions was evaluated. The concentrations of $10^4$ to $10^5$ CFU per g dry wt. were observed. No significant differences were seen between the number of filter-covered materials. The data indicate that the temperature has affect on population distribution. Also, the light exposure was influenced on microorganism in slow sand filtration according to the heterotropic plate counts. The role of microorganism within the sand media requires further study.

• Korean Journal of Microbiology
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• v.15 no.2
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• pp.77-84
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• 1977

The yeast population on 14 species of seaweeds and in water estimated by cultural mothods over a 5-month period in south-west in Korea, Nine species of yeasts, comprising unidentified one, and one of yeast-like fungi were identified. Fifty phycase were attributed to the difference of cultural method between the present work and earlier repoeters and, to some exent, the higher number of Rhodotorula glutinis which had a prior adaptation to the release of inhibitory polyphenolic materials. Although, to what extent, all division of algae showed a similar variation in yeast population, correlated with month, the rapid decrease of yeast population in August seems to be the cause of exposure of heat irradiation in this month. The cultural estimate of per se fltration without double filter and one of unidentified species are discussed.

• Journal of Preventive Medicine and Public Health
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• v.33 no.3
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• pp.306-312
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• 2000

Background : Polycyclic aromatic hydrocarbons (PAH) are well known environmental pollutants. The measurement of PAH in ambient air is not commonly used, because it is quite difficult to perform and is unreliable. Using biomarkers of PAH can be an alternative approach to this problem. The PAH in ambient air is absorbed in particulate matter. Total suspended particulate(TSP) or particulate matter of less than $10{\mu}m$ in diameter (PM10) can be easily measured. Therefore, TSP or PM10 can be used as a surrogate measurements of ambient air PAH. Objectives : We investigated whether the urinary concentration of two biomarkers of PAH, 1-hydroxypyrene (1-OHP) and 2-naphthol, could reflect the total suspended particulate in the general population. Methods : In order to exclude the effects of occupational exposure and smoking, first grade middle school students were included in this study. Four middle schools within a one kilometer boundary of ambient air monitoring stations were selected. Total suspended particulate was regarded as the marker of airborne PAH. Diet and smoking data were collected by self administered questionnaires, and spot urine samples were collected. Urinary 1-OHP and 2-naphthol were analyzed by high performance liquid chromatography. Results : The correlation between urinary 1-OHP, 2-naphthol and passive smoking was not statistically significant. The correlation between urinary 1-OHP and TSP indices was not statistically significant. The correlations between urinary 2-naphthol and TSP of two lag days, one lag day, and zero lag days were statistically significant. The statistical significance of two lag days was the strongest (p=0.001), one lag day was the next (p=0.0275), and zero lag days was the weakest (p=0.0349). Conclusion : Our results imply that the urinary concentration of 2-naphthol can be applied as a PAH exposure marker for the general population with low PAH exposure.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.541-548
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• 2010

In this study, contamination levels of 7 N-nitrosamine were investigated in processed meat products (n=51), processed fish products (n=62), salted fish pickles (n=20), and beer and malt beverages (n=21) using a GC/PCI-MS/MS method. The limits of detection (LOD) of the N-nitrosamines ranged from 0.2 to 0.5 ${\mu}g$/kg. In addition, methods were used to estimate the recovery of 7 N-nitrosamines, which ranged from 84 to 112%. N-nitrosamines were detected in 89 (58%) out of 154 samples. The exposure of an entire population group to N-nitrosamines through food intake was estimated using the average body weight of the total population and average daily food consumption, to perform risk assessment based on reports of a national health and nutrition survey. The results indicated that the daily intake of N-nitrosamines over a life time was $4.92{\times}10^{-7}$ mg/kg b.w./day. The margin of exposure (MOE) for the general population, estimated using the benchmark dose lower confidence limit 10 ($BMDL_{10}$) of N-nitrosodimethylamine, was 208,939, which was found to be safe.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.3035-3039
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• 2014

Background: Lung cancer is one of the most prevalent malignancies in the world and both incidence and mortality rates are continuing to rise in Pakistan. However, epidemiological studies to identify common lung cancer determinants in the Pakistani population have been limited. Materials and Methods: In this retrospective case-control study, 400 cases and 800 controls were enrolled from different hospitals of all provinces of Pakistan. Information about socio-demographic, occupational, lifestyle and dietary variables was extracted by questionnaire from all subjects. Odd ratios (ORs) and 95% confidence intervals (CIs) were calculated. and dose-response associations were also assessed for suitable factors. Results: Strong associations were observed for smoking (OR=9.4, 95%CI=6.9-12.8), pesticide exposure (OR=5.1, 95%CI=3.1-8.3), exposure to diesel exhaust (OR=3.1, 95%CI=2.1-4.5), red meat consumption (OR=2.9, 95%CI=1.8-4.7) and chicken consumption (OR=2.8, 95%CI=1.7-49). Other associated factors observed were welding fumes (OR=2.5, 95%CI=1.0-6.5), sedentary living (OR=2.0, 95%CI=1.6-2.6), family history (OR=2.0, 95%CI=0.8-4.9), wood dust (OR=1.9, 95%CI=1.2-3.1), tea consumption (OR=1.8, 95%CI=1.2-2.6), coffee consumption (OR=1.8, 95%CI=1.1-2.8), alcoholism (OR=1.7, 95%CI=1.1-2.5) and asbestos exposure(OR=1.5, 95%CI=0.5-4.4). Consumption of vegetables (OR=0.3, 95%CI=0.2-0.4), juices (OR=0.3, 95%CI=0.3-0.4), fruits (OR=0.7, 95%CI=0.5-0.9) and milk (OR=0.6, 95%CI=0.5-0.8) showed reduction in risk of lung cancer. Strongest dose-response relationships were observed for smoking ($X^2=333.8$, $p{\leq}0.0000001$), pesticide exposure ($X^2=50.9$, $p{\leq}0.0000001$) and exposure to diesel exhaust ($X^2=51.8$, $p{\leq}0.0000001$). Conclusions: Smoking, pesticide exposure, diesel exhaust and meat consumption are main lung cancer determinants in Pakistan. Consuming vegetables, fruits, milk and juices can reduce the risk of lung cancer risk, as in other countries.

• Journal of Environmental Science International
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• v.22 no.2
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• pp.151-161
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• 2013

The assessment of personal exposure is a critical component in population-based epidemiologic studies of air pollution. This study was conducted to apply and compare the four exposure estimation methods of individual-level to air pollution concentration in a cohort including 2,283 subjects in Gwangyang, Korea. Individual-level exposure of air pollution were estimated using multiple approaches, including average across all monitors, nearest monitor, and spatial interpolation by inverse distance weighting and kriging. The mean concentrations of $PM_{10}$, $NO_2$, $SO_2$, CO, $O_3$ by four exposure estimation methods were slightly different but not significantly different from each other. Cross-validation showed that kriging was more accurate than other exposure estimation methods because kriging has probably predicted individual exposure levels equivalent to residential locations after estimating the parameters of a model according to the spatial surface of air pollution concentration. These data support that spatial interpolation methods may provide better estimates than selecting the value from the nearest monitor and averaging across values from all monitors by reflecting spatial attributes of air pollution on personal level.