• Communications for Statistical Applications and Methods
• /
• v.29 no.3
• /
• pp.353-371
• /
• 2022

This paper analyzes death counts after World War II of several countries to identify and to compare their stochastic structures. The stochastic structures that this paper entertains are three structural time series models, a local level with a random walk model, a fixed local linear trend model and a local linear trend model. The structural time series models assume that a time series can be formulated directly with the unobserved components such as trend, slope, seasonal, cycle and daily effect. Random effect of each unobserved component is characterized by its own stochastic structure and a distribution of its irregular component. The structural time series models use the Kalman filter to estimate unknown parameters of a stochastic model, to predict future data, and to do filtering data. This paper identifies the best-fitted stochastic model for three types of death counts (Female, Male and Total) of each country. Two diagnostic procedures are used to check the validity of fitted models. Three criteria, AIC, BIC and SSPE are used to select the best-fitted valid stochastic model for each type of death counts of each country.

• Journal of Environmental Impact Assessment
• /
• v.13 no.1
• /
• pp.9-19
• /
• 2004

This study is performed to examine the relationship between air pollution exposure and mortality in Daejeon for the years of 1998 - 2001. Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of seasonal trend, air temperature, humidity, and day of the week as confounders in a nonparametric approach. Daily death counts were associated with CO(4 day before), $O_3$(current day), $PM_10$(4 day before), $NO_2$(6 day before), $SO_2$(2 day before). Increase of $31.07{\mu}g/m^3$(interquartile range) in $PM_10$ was associated with 2.0 % (95% CI = 0.5 % - 3.5 %)) increase in the daily number of death. This effect was greater in children(less than 15 aged) and elderly(more than 65 aged). We concluded that Daejeon had 2 - 4 % increase in mortality in association with IQR in air pollutants. Daily variations in air pollution within the range currently occurring in Daejeon might have an adverse effect on daily mortality. These findings also support the hypothesis that air pollution at levels below the current ambient air quality standards of Korea except PM10, is harmful to sensitive subjects, such as children or elderly.

• Journal of environmental and Sanitary engineering
• /
• v.18 no.3 s.49
• /
• pp.89-99
• /
• 2003

This study is peformed to examine the relationship between air pollution exposure and mortality in Incheon for the years of 1998 - 2001. Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of seasonal trend, air temperature, humidity, and day of the week as confounders in a nonparametric approach. Daily death counts were associated with CO(1 day before), O$_3$(2 day before), PM$_{10}$(1 day before), NO$_2$(1day before), SO$_2$(1 day before). Increase of 32.21 ${\mu}$g/m$^3$(interquartile range) in PM$_{10}$ was associated with 1.9 % (95% CI = 0.8 % - 2.9 %) increase in the daily number of death. This effect was greater in children(less than 15 aged) and elderly(more than 65 aged). We concluded that Incheon had 2 - 4 % increase in mortality in association with IQR in air pollutants. Daily variations in air pollution within the range currently occurring in Incheon might have an adverse effect on daily mortality. These findings also support the hypothesis that air pollution, at levels below the current ambient air quality standards of Korea, is harmful to sensitive subjects, such as children or elderly.

• Journal of Environmental Impact Assessment
• /
• v.20 no.5
• /
• pp.747-755
• /
• 2011

This study was investigated the relationship between the temperature and the mortality of aged (${\geq}65$ yr) during the winter seasons from 1992 to 2007 in Seoul, Korea by utilizing climate data and death records. The study also estimated the future risks by employing the projections of the population in Seoul, Korea and climate change scenario of Korea from 2011 to 2030. The limitation of this study was the impossibility in the prediction of daily mortality counts. Therefore, daily death numbers could be predicted based on the future population projection for Korea and the death records of 2005. The result indicated that risks increased by 0.27%, 0.52%, 0.32% and 0.41% in association with the $1^{\circ}C$ decrease in daily minimum temperature from the mortality counts of total, respiratory, cardiovascular, and cardiorespiratory in the past date while 0.31%, 0.42%, 0.59% and 0.66% in the future. Based on the results obtained from this study, it is concluded that the risk in the future will be higher than the past date although there is an uncertainty in estimating death counts in the future.

• Journal of Preventive Medicine and Public Health
• /
• v.32 no.2
• /
• pp.191-199
• /
• 1999

Objectives: To examine the relationship between air pollution exposure and mortality in Seoul for the years of 1991-1995, Methods: Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of secular trend, seasonal factor, day of the week, heat wave, temperature, and humidity. Pollution variables were ozone, nitrogen dioxide, total suspended particles(TSP), and sulfur dioxide. Results: Daily death counts were associated with ozone(1 day before), nitrogen dioxide(1 day before), TSP(2 days before), sulfur dioxide(2 days before). The association with ozone was most statisfically significant and independent of other air pollutants. Increase of 100 ppb in ozone was associated with 0%(95% Cl= 2%-10%) increase in the daily number of death, This effect was greater in persons aged 65 and older. The relative risks of death from respiratory disease and cardiovascular disease were greater than for all-cause mortality in each pollutant. After ozone level exceeds 25 ppb, the dose-response relationship between mortality and ozone was almost linear. However, the effect of TSP, sulfur dioxide, and nitrogen dioxide on mortality might be confounded with each other. Conclusion: Daily variations in air pollution within the range currently occurring in Seoul might have an adverse effect on daily mortality.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.6
• /
• pp.625-637
• /
• 2003

This study was performed to examine the relationship between air pollution exposure and mortality in Seoul for the years of 1998∼2001. Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of seasonal trend, air temperature, humidity, and day of the week as confounders in a nonparametric approach. Daily death counts were associated with CO (current day),O$_3$ (current day), PM$_{10}$ (current day), NO$_2$ (1 day before), SO$_2$ (1 day before). Increase of 41.71 $\mu\textrm{g}$/㎥ (interquartile range) in PM$_{10}$ was associated with 1.3% (95% CI = 0.7∼1.9％) increase in the daily number of death. $O_3$ concentrations resulted in an increased risk of 1.3% for 23.86 ppb in all-aged mortality [RR = 1.013 (1.004-1.023)1. This effect was greater in children (less than 15 aged) and elderly (more than 65 aged). After ozone level exceeds 25 ppb, the dose-response relationship between mortality and ozone was almost linear. We concluded that Seoul had 1∼5％ increase in mortality in association with IQR (interquartile range) in air pollutants. Daily variations in air pollution within the range currently occurring in Seoul might have an adverse effect on daily mortality. These findings also support the hypothesis that air pollution, at levels below the current ambient air quality standards of Korea, is harmful to sensitive subjects, such as children or elderly.rly.

• Journal of Korean Society for Atmospheric Environment
• /
• v.29 no.3
• /
• pp.275-286
• /
• 2013

It is well known that exposure to high level of PM (particulate matter) can adversely affect human health. However, little is known about health burden of PM considering the relationship, exposed level of PM, and health level in local communities. And, there is scarcely methodical assessment of uncertainty for application to policies of these assessment results. The scope of this study is divided into two parts: firstly to estimate the death burden of PM10 (particulate matter less then $10{\mu}m$ in diameter) in Seoul metropolitan region, and secondly to evaluate potential uncertainties in these estimates. To estimate the death burden of PM10 in Seoul metropolitan region from 2005~2010, we firstly assessed the relationship between daily mean PM10 and daily death counts in Seoul from 2000~2010, and calculated the death burden of PM10 using BenMAP (Environmental Benefits Mapping and Analysis Program). After that, we identified and characterized uncertainties to substantially influence the results of death burden. The daily mortality risk was increased 1.000227 times (p-value/0.001) associated with $1{\mu}g/m^3$ increase of daily mean PM10 for all ages population, Seoul. And, death burdens of PM10 in Seoul metropolitan region were estimated from 5.51 in 2005 to 5.12 in 2010 per 100,000 people. Finally, we categorized context, model, and input uncertainty and characterized these uncertainties in three dimensions (i.e. location, level, and nature) using uncertainty typology. In our study, we argue that uncertainties need to be identified, assessed, reported and interpreted in order for assessment results to adequately support decision making, such as the establishment of air quality standards based on health burden of air quality.

• Journal of Environmental Science International
• /
• v.30 no.7
• /
• pp.573-584
• /
• 2021

To analyze the effects of PM₁₀ and PM_2.5 on daily mortality cases, the relations of death counts from natural causes, respiratory diseases, and cardiovascular diseases with PM₁₀ and PM_2.5 concentrations were applied to the generalized additive model (GAM) in this study. From the coefficients of the GAM model, the excessive mortality risks due to an increase of 10 ㎍/m³ in daily mean PM₁₀ and PM_2.5 for each cause were calculated. The excessive risks of deaths from natural causes, respiratory diseases, and cardiovascular diseases were 0.64%, 1.69%, and 1.16%, respectively, owing to PM₁₀ increase and 0.42%, 2.80%, and 0.91%, respectively, owing to PM_2.5 increase. Our result showed that particulate matter posed a greater risk of death from respiratory diseases and is consistent with the cases in Europe and China. The regional distribution of excessive risk of death is 0.24%-0.81%, 0.34%-2.6%, and 0.62%-1.94% from natural causes, respiratory diseases, and cardiovascular diseases, respectively, owing to PM₁₀ increase, and 0.14%-1.02%, 1.07%-3.92%, and 0.22%-1.73% from natural causes, respiratory diseases, and cardiovascular diseases, respectively, owing to PM_2.5 increase. Our results represented a different aspect from the regional concentration distributions. Thus, we saw that the concentration distributions of air pollutants differ from the affected areas and identified the need for a policy to reduce damage rather than reduce concentrations.

• Journal of Preventive Medicine and Public Health
• /
• v.31 no.1 s.60
• /
• pp.82-90
• /
• 1998

A large number of studies have indicated associations between particulate air pollution and daily mortality. Daily measurements of total suspended particulates (TSP) by high volume air sampler were matched to daily death counts supplied by the National Statistics Office, Korea. All deaths, except deaths from accidents, occurred at Ulsan from 1 January 1991 to 31 December 1994 were considered in the poisson regression analysis. The multiple regression models were used to investigate a main effects of air particulate pollution controlling for $SO_2$ levels, air temperature, relative humidity, seasonal variation, and calendar year. The results indicated that the effects of TSP, $SO_2$, temperature, and relative humidity were not significantly associated with all cause mortality. It could, however, be emphasized that the size of the parameter estimate of TSP was very similar to that of previous studies. An increase in particulates of $100{\mu}g/m^3$ was associated with a 3% increase in mortality. This relationship was observed at TSP levels well below the current National Ambient Air Quality Standard of $150{\mu}g/m^3$ in Korea as well.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
• /
• 2004.11a
• /
• pp.203-208
• /
• 2004

The Family of Man was a 1955 photographic exhibition that depicted normal people in all walks of life from around the world. The viewer was visually confronted with the similarity of all people. The people of the world are now facing common health challenges as a result of changing lifestyles and increasing healthcare costs. Dietary supplements have the potential to be part of the solution. Dietary supplementation with antioxidant vitamins may be the most effective intervention for preventing the onset of Alzheimer's disease in the rapidly expanding elderly population - and at a very low cost. AIDS is devastating much of the developing world, where few resources are available to treat it victims. Inexpensive multivitamin sup-plements have been demonstrated to slow the progression of AIDS, reduce the death rate, reduce AIDS-related morbidity, improve T cell counts, and reduce viral loads. Careful economic analysis demonstrate that calcium and folic acid supplementation could reduce healthcare costs in the USA by $13.9 billion and $1.3 billion, respectively. Most supplements with therapeutic potential have not been subjected to sufficiently rigorous research to permit unqualified public health recommendations. Carefully directed research is needed to identify the supplements with the greatest potential and to verify their safety and efficacy.