Chang Sun Sim

A Case of Acute Organotin Poisoning

Alkyl compounds of tin chlorides are widely used for the production of plastics in the chemical industry. They inhibit the dissociation of hydrochloric acid from polyvinyl chloride (PVC) and in combination with PVC they are not toxic. However, as free molecules, organic tin compounds are highly toxic in contrast to inorganic tin compounds . The toxic components are dimethyltin chloride and trimethyltin chloride. Previous studies have reported that dimethyltin chloride is toxic to the liver and kidneys, whereas trimethyltin chloride damages the central nervous system . The neurotoxicity of dialkyltin or trialkyltin compounds has been recognized in animal studies, but only a few descriptions of their human toxicity have been reported 1, . Especially, reports of human dimethyltin intoxication are very rare . We report here a case with neurological manifestations similar to trialkyltin encephalopathy from the exposure to dimethyltin compounds.

The Effects of Different Noise Types on Heart Rate Variability in Men

Purpose To determine the impact of noise on heart rate variability (HRV) in men, with a focus on the noise type rather than on noise intensity. Materials and Methods Forty college-going male volunteers were enrolled in this study and were randomly divided into four groups according to the type of noise they were exposed to: background, traffic, speech, or mixed (traffic and speech) noise. All groups except the background group (35 dB) were exposed to 45 dB sound pressure levels. We collected data on age, smoking status, alcohol consumption, and disease status from responses to self-reported questionnaires and medical examinations. We also measured HRV parameters and blood pressure levels before and after exposure to noise. The HRV parameters were evaluated while patients remained seated for 5 minutes, and frequency and time domain analyses were then performed. Results After noise exposure, only the speech noise group showed a reduced low frequency (LF) value, reflecting the activity of both the sympathetic and parasympathetic nervous systems. The low-to-high frequency (LF/HF) ratio, which reflected the activity of the autonomic nervous system (ANS), became more stable, decreasing from 5.21 to 1.37; however, this change was not statistically significant. Conclusion These results indicate that 45 dB(A) of noise, 10 dB(A) higher than background noise, affects the ANS. Additionally, the impact on HRV activity might differ according to the noise quality. Further studies will be required to ascertain the role of noise type.

Impact of adenotonsillectomy on nocturnal enuresis in children with sleep-disordered breathing: A prospective study.

To investigate the relationship between sleep‐disordered breathing (SDB) and nocturnal enuresis (NE) in children and to prospectively evaluate the effectiveness of adenotonsillectomy on resolving enuresis in indicated SDB patients with NE.

Influence of Transportation Noise and Noise Sensitivity on Annoyance: A Cross-Sectional Study in South Korea

Environmental noise is known to cause noise annoyance. Since noise annoyance is a subjective indicator, other mediators—such as noise sensitivity—may influence its perception. However, few studies have thus far been conducted on noise annoyance in South Korea that consider noise sensitivity and noise level simultaneously. The aim of this study was to evaluate the correlations between noise sensitivity or noise level and noise annoyance on a large scale in South Korea. This study estimated the level of noise exposure based on a noise map created in 2014; identified and surveyed 1836 subjects using a questionnaire; and assessed the impact of transportation noise and noise sensitivity on noise annoyance. The result showed that noise exposure level and noise sensitivity simultaneously affect noise annoyance, and noise sensitivity has a relatively larger impact on noise annoyance. In conclusion, when study subjects were exposed to a similar level of noise, the level of noise annoyance differed depending on the noise sensitivity of the individual.

Prevalence of Children's Allergic Diseases in Ulsan: Local Differences and Environmental Risk Factors

Objectives: This study aims to investigate the AD (allergic diseases: asthma, allergic rhinitis and atopic dermatitis) prevalence among elementary schoolchildren in an industrial city, Ulsan, and identify major environmental risk factors associated with AD prevalence. Methods: Data on the physician-diagnosed prevalence over the past 12 months and potential risk factors of AD were collected through a questionnaire from a 2009-2010 survey of 4,067 schoolchildren living in different urban environments. The logistic regression analysis was performed to assess differences in AD prevalence among the areas and to determine which environmental factors impacted AD. Results: Our survey results showed that the AD prevalence rate ranged between 26.2% and 35.9%. Children living in polluted areas (near industrial and central urban areas) had about a 10% higher prevalence of AD than did those living in coastal or suburban residences. The Chi-Square test demonstrated that this local difference was statistically significant before and after adjustment of major confounders such as parental AD history and parental education. The results of the logistic regression analysis showed a statistically significant association between several environmental factors (ventilation in winter, odor conditions and exposure to traffic smoke, and outdoor pollution) and the prevalence of AD found by multivariate model after adjusting confounders. Conclusion: These results suggest that local differences in AD prevalence are significantly associated with outdoor environmental factors. Although there are likely to be other risk factors for AD, living in a polluted area and exposure to high levels of air pollutants can contribute to an increased risk of childhood AD.

Association between particulate matter concentration and symptoms of atopic dermatitis in children living in an industrial urban area of South Korea

Introduction Increased exposure to particulate matter (PM) appears to increase the development of atopic diseases and allergic sensitization. This study evaluated the association between daily levels of PM with diameters less than 10 &mgr;m (PM10) and PM2.5 and symptoms of atopic dermatitis (AD) in children living in an industrial urban area. Methods Indoor PM10 and PM2.5 concentrations were measured with an optical particle counter in two preschools near large industrial complexes in Ulsan, South Korea during two 6‐month periods (May–October of 2012 and 2013). Twenty‐one children with AD from these preschools were enrolled and observed daily for AD symptoms during the same periods. Indoor and outdoor PM concentrations were used to estimate PM exposure based on time activity patterns. Results Analysis of PM10 and PM2.5 concentrations showed that indoor and outdoor PM10 levels varied similarly throughout each 6‐month period. In addition, indoor concentration of PM2.5 had high correlation with ambient outdoor concentration of PM10. Correlation analysis also indicated a significant positive correlation between the exacerbation of AD symptoms and daily mean exposure to PM10 and PM2.5. Based on a generalized linear mixed model (GLMM), PM exposure was significantly associated with the exacerbation of AD symptoms, with a maximum adjusted odds ratio (aOR) of 1.399 for a 10 &mgr;g/m3 increase of PM2.5 (95% CI: 1.216–1.610). Discussion Our findings suggest that short‐term exposure to PM can exacerbate AD in young children living in an industrial urban area. PM2.5 had a stronger effect than PM10 on exacerbation of AD symptoms. HighlightsTwenty‐one children were observed daily for atopic dermatitis (AD) symptoms with PM measurement.PM exposure was significantly associated with the exacerbation of AD symptoms.PM2.5 had a stronger effect than PM10 on exacerbation of AD symptoms.

The association between cadmium and lead exposure and blood pressure among workers of a smelting industry: a cross-sectional study

BackgroundLead and cadmium are harmful heavy metals that are used for a variety of occupational purposes. Considering their potentially hazardous effects on health, studies on the association between exposure to these two heavy metals and health disorders have been actively conducted. This study aimed to determine the association between blood lead and cadmium levels and blood pressure in workers exposed to lead and cadmium in a smelter.MethodsNine hundred and sixty-three male workers who worked in a smelter, and underwent medical examinations at the Ulsan University Hospital between January 1 and December 31, 2014, were selected as participants. Among them, 310 subjects whose data on height, weight, blood pressure, fasting blood glucose, lipid profile, and blood lead and cadmium levels were available and who answered the questionnaire were selected as the final participants. We investigated the drinking habit, smoking status, exercise adequacy, and family history of hypertension of these workers using formal questionnaires. A statistical analysis was conducted using Student’s t-test, analysis of variance, and linear or logistic regression.ResultsThe association between blood lead and cadmium levels and blood pressure was analyzed through statistical adjustment of the risk factors of hypertension. Results showed an association between blood cadmium level and blood pressure elevation. However, blood lead level was found to be not correlated with blood pressure elevation.ConclusionsThis study shows the association between blood cadmium level and systolic blood pressure (SBP) and diastolic blood pressure (DBP) elevation.Trial registrationIRB No. 2017–03-037. Retrospectively Registered 30 March 2017.

Indoor Air Quality in Elementary School Children`s Homes in Ulsan: Comparison between Groups with and without Allergic Rhinitis

This study compared indoor air quality of homes in which elementary school children with and without (case and control) allergic rhinitis live in the Ulsan metropolitan region (UMR). A total of 58 homes (case and control: 29, respectively; children aged 7 to 12 years) was selected for indoor air quality measurements. The concentrations of all general indoor air pollutants, except , in the case group were much higher than those in the control group. In particular, the average concentrations of and in the case group were statistically significantly (p in the case and control groups and in the case group exceeded the standard level. Some components of aldehydes and ketones and VOCs indicated large difference of average concentrations between two groups, but there were no statistically significant differences.

Effects of self-reported sensitivity and road-traffic noise levels on the immune system

Sensitivity to noise, particularly road traffic noise, can increase cortisol levels and result in changes in immune system biomarkers. Therefore, continuous exposure to noise can have an effect on immune function, hormonal levels, and cardiovascular function, leading to hypertension and stress. The purpose of this study was to investigate the changes in stress-and immune system-related biomarkers according to the self-reported sensitivity to noise and exposure to road traffic noise, to ultimately determine the potential effects of noise on health. A survey was conducted through questionnaire (ISO/TS 15666) sent to 172 female subjects in Korea, including 128 from Ulsan and 44 from Seoul. The average noise level was calculated, and blood samples were collected for measurements of cortisol levels, Natural killer (NK) / Natural killer T (NKT) cell populations, and NK cell activity (through measurements of interleukin-12 (IL-12) and interferon-gamma (INF-γ) concentrations). Multivariate linear regression analysis of the measured biomarkers according to the road traffic noise level and self-reported noise sensitivity was conducted adjusting for the effects of age, alcohol status, smoking status, regular exercise, and residence period. IL-12 levels increased, whereas the NKT cell population decreased with increasing noise levels. The results further suggested that cortisol levels are more influenced by the subject’s sensitivity to noise than to the level of chronic road traffic noise. Therefore, noise appears to have the largest effect on IL-12 levels as well as the population and activity of NKT cells. In conclusion, our results suggest that low-level road traffic noise and sensitivity to noise can affect health by causing changes in the immune response through mechanisms other than increased cortisol.

Relationship of Transportation Noise and Annoyance for Two Metropolitan Cities in Korea: Population Based Study

Transportation noise is known to have negative impact on both public health and life quality. This study evaluated the relationship between transportation noise and annoyance levels, and also the difference of annoyance levels in two metropolitan cities based on epidemiologic surveys. Two thousand adult subjects living in Seoul and Ulsan were enrolled by stratified random sampling on the basis of noise maps from July 2015 to January 2016. Individual annoyance in accordance with transportation noise levels in two metropolitan cities were surveyed using an 11-point visual analog scale questionnaire. The results show that transportation noise level was significantly correlated with annoyance in both cities. Logistic regression analysis revealed that the risk of being ‘highly annoyed’ increased with noise level (Ldn, day-night average sound level) in both cities. After adjusting for age, residence period, sociodemographic factors (sex, education, marriage, income, alcohol, smoking, and exercise) and noise sensitivity, the risk of being ‘highly annoyed’ was increased with noise levels in both cities. In comparison to those of areas with noise levels below 55 dBA, the adjusted odds ratios of ‘highly annoyed’ for areas with 55–65 dBA and over 65 dBA were 2.056 (95% confidence interval [CI] 1.225–3.450), 3.519 (95% CI 1.982–6.246) in Seoul and 1.022 (95% CI 0.585–1.785), 1.704 (95% CI 1.005–2.889) in Ulsan, respectively. Based on the results of a population study, we showed that transportation noise levels were significantly associated with annoyance in adults. However, there were some differences between the two cities. In this study, there were differences in transportation noise between the two cities. Seoul has complex noise (traffic and aircraft), compared to single road traffic noise in Ulsan. Therefore, single and complex transportation noise may have different effects on annoyance levels.