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1.
Ann Occup Environ Med ; 27: 20, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26306202

RESUMEN

OBJECTIVE: The aim of this study was to determine the association between urinary cadmium (U-cd) concentration and diabetes in middle-aged Korean residents of abandoned mines using the first Health Effect Surveillance for Residents in Abandoned Metal mines (HESRAM). METHODS: This study was cross-sectional study conducted on 719 residents between 40-70 years in 38 abandoned metal mines in Korea. Data was collected by HESRAM from 2008 to 2011. The correlation coefficient of U-cd and fasting blood glucose, odds ratio in urinary cadmium tertiles and diabetes prevalence was analyzed according to the sex category. RESULTS: The correlation coefficient U-cd concentration and fasting blood glucose was 0.182 in male. Logistic regression analysis in male revealed a third tertile odds ratio of U-cd (2 µg/g creatinine < U-cd) while diabetes prevalence was 1.81 (95 % CI 1.05-3.12) with adjusted age, BMI, smoking and alcohol consumption, region, family income. On the other hand, the odds ratio for third tertile of U-cd (3 µg/g creatinine < U-cd) between diabetes prevalence in female was 1.39 (95 % CI 0.52-3.72) in addition to adjusted menopausal status. CONCLUSIONS: Environmental exposure to cadmium in abandoned mine residents was associated with diabetes in male. Closed monitoring and periodic evaluation of the health effects of chronic environmental exposure on abandoned mines residents will be needed.

2.
Int J Biometeorol ; 59(7): 791-8, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25234750

RESUMEN

The objective of this study is to examine the association between ambient temperature and children's lung function in Baotou, China. We recruited 315 children (8-12 years) from Baotou, China in the spring of 2004, 2005, and 2006. They performed three successive forced expiratory measurements three times daily (morning, noon, and evening) for about 5 weeks. The highest peak expiratory flow (PEF) was recorded for each session. Daily data on ambient temperature, relative humidity, and air pollution were monitored during the same period. Mixed models with a distributed lag structure were used to examine the effects of temperature on lung function while adjusting for individual characteristics and environmental factors. Low temperatures were significantly associated with decreases in PEF. The effects lasted for lag 0-2 days. For all participants, the cumulative effect estimates (lag 0-2 days) were -1.44 (-1.93, -0.94) L/min, -1.39 (-1.92, -0.86) L/min, -1.40 (-1.97, -0.82) L/min, and -1.28 (-1.69, -0.88) L/min for morning, noon, evening, and daily mean PEF, respectively, associated with 1 °C decrease in daily mean temperature. Generally, the effects of temperature were slightly stronger in boys than in girls for noon, evening, and daily mean PEF, while the effects were stronger in girls for morning PEF. PM2.5 had joint effects with temperature on children's PEF. Higher PM2.5 increased the impacts of low temperature. Low ambient temperatures are associated with lower lung function in children in Baotou, China. Preventive health policies will be required for protecting children from the cold weather.


Asunto(s)
Contaminantes Atmosféricos/análisis , Pulmón/fisiopatología , Material Particulado/análisis , Temperatura , Contaminación del Aire/análisis , Niño , China/epidemiología , Monitoreo del Ambiente , Femenino , Humanos , Masculino , Dióxido de Nitrógeno/análisis , Ápice del Flujo Espiratorio , Dióxido de Azufre/análisis
3.
J Korean Med Sci ; 29(5): 633-9, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24851017

RESUMEN

The purpose of this study was to investigate demographic and lifestyle variables and blood cadmium concentrations in residents living near abandoned metal mines in Korea. Blood cadmium concentrations were measured in 15,161 subjects living around abandoned metal mines (exposed group, n = 14,464) and compared with those living in designated control areas (control group, n = 697). A questionnaire was provided to all subjects to determine age, gender, mine working history, times of residence, smoking habits and dietary water type. The geometric mean (95% confidence intervals) of blood cadmium concentration (1.25 [1.24-1.27] µg/L) in the exposed group was significantly higher than in the control group (1.17 [1.13-1.22] µg/L). Mean residence time and mine working history in the exposed group were significantly higher than in the control group. Blood cadmium concentrations increased with increasing age, and residence time in both groups, and blood cadmium concentrations were higher in current-smokers than in non-smokers in both groups. This study shows the geometric mean of blood cadmium concentration in abandoned mining areas are higher than in non-mining areas in the general adult Korean population.


Asunto(s)
Cadmio/sangre , Exposición a Riesgos Ambientales , Características de la Residencia , Contaminantes del Suelo/sangre , Contaminantes del Agua/sangre , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento , Monitoreo del Ambiente , Femenino , Humanos , Masculino , Persona de Mediana Edad , Minería , República de Corea , Fumar , Encuestas y Cuestionarios
4.
Environ Monit Assess ; 186(8): 5209-20, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24744211

RESUMEN

We analyzed national data on blood lead levels (BLL) and blood cadmium levels (BCL) in residents living near 38 abandoned metal mining areas (n = 5,682, 18-96 years old) in Korea that were collected by the first Health Effect Surveillance for Residents in Abandoned Metal mines (HESRAM) from 2008 to 2011. The geometric mean BCL and BLL were 1.60 µg/L (95 % CI = 1.57-1.62 µg/L) and 2.87 µg/dL (95 % CI = 2.84-2.90 µg/dL), respectively, notably higher than levels in the general population in Korea and other countries. We found significantly higher BLL and BCL levels in people living within 2 km of an abandoned metal mine (n = 3,165, BCL = 1.87 µg/L, BLL = 2.91 µg/dL) compared to people living more than 2 km away (n = 2,517, BCL = 1.31 µg/L, BLL = 2.82 µg/dL; P < 0.0001) and to the general population values reported in the literature.


Asunto(s)
Cadmio/sangre , Exposición a Riesgos Ambientales/estadística & datos numéricos , Contaminantes Ambientales/sangre , Plomo/sangre , Minería , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Monitoreo del Ambiente , Femenino , Humanos , Masculino , Metales/sangre , Persona de Mediana Edad , República de Corea , Adulto Joven
5.
Environ Health Toxicol ; 28: e2013015, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24303351

RESUMEN

OBJECTIVES: The aim of this study was to determine the association between low-level mercury exposure and neurobehavioral functions in adults living in coastal regions of Korea. METHODS: We selected 172 adults aged 20-65 years living in a city in the coastal region of Korea. A sociodemographic survey was conducted, mercury levels in the blood, urine, and hair were measured, and the associations according to computerized neurobehavioral tests were determined using univariate analysis. After adjustment for associated variables, a multivariate linear regression analysis was performed. RESULTS: The geometric mean mercury levels in the blood, urine, and hair were 5.41 µg/L (range, 0.00-15.84 µg/L), 1.17 µg/g-creatinine (range, 0.00-32.86 µg/g-creatinine), and 1.37 mg/kg (range, 0.42-6.56 mg/kg), respectively. Variables that were associated with simple reaction time according to the neurobehavioral test results were age and urine mercury level. Variables associated with choice reaction time were the recent use of Korean traditional medicine and urine mercury level. Variables associated with the right-hand finger tapping speed test were age, gender, smoking behavior, education level, monthly household income, and urine mercury level. Variables associated with the left-hand finger tapping speed test were age, gender, education level, and urine mercury level. After adjustment for associated variables, there was no significant association between urine mercury level and simple reaction time (ß=25.96; p=0.47), choice reaction time (ß=50.37; p=0.32), or the number of left-hand finger taps (ß=-1.54; p=0.21). However, urine mercury level was significantly associated with the number of right-hand finger taps (ß=-3.86; p=0.01). CONCLUSIONS: We found no evidence that low-level mercury exposure in adults is associated with deficits in neurobehavioral functions. A longer follow-up study is required to confirm this conclusion.

6.
Environ Pollut ; 182: 184-9, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23920315

RESUMEN

We determined the levels of prenatal Hg exposure in Wujiang City, located in the southeast of Taihu Lake in China's Jiangsu Province, and analyze the relationship between prenatal exposure to Hg and neonatal anthropometry, including birth weight, body length, and head circumference. From June 2009 to July 2010, a total of 213 mother-infant pairs were enrolled. The geometric means of Hg levels in maternal hair, fetal hair, placentas, and cord blood were 496.76 µg/kg, 233.94 µg/kg, 3.58 µg/kg, and 1.54 µg/L, respectively. The Hg levels detected in our study were significantly lower than those reported by previous studies. In addition, no significant correlations were found between Hg levels in maternal hair, fetal hair, placenta, or cord blood and neonatal anthropometrics. Together, our findings may be important for understanding the effects of prenatal exposure to Hg on newborns' development and have implications concerning the recommended dose for Hg.


Asunto(s)
Peso al Nacer , Contaminantes Ambientales/sangre , Cabello/metabolismo , Exposición Materna/estadística & datos numéricos , Mercurio/sangre , Adulto , China , Ciudades , Dieta/estadística & datos numéricos , Contaminantes Ambientales/metabolismo , Femenino , Sangre Fetal/metabolismo , Humanos , Recién Nacido , Masculino , Mercurio/metabolismo
7.
Opt Express ; 21(7): 8450-9, 2013 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-23571935

RESUMEN

A high aspect ratio conical sub-wavelength structure (SWS) was designed by using rigorous coupled-wave analysis (RCWA) method and was realized on polymethyl methacrylate (PMMA) film using a stamping technique. The silicon template containing a hexagonal array of conical holes with a period of 350 nm and an aspect ratio of 2.8 was fabricated by electron-beam (e-beam) lithography followed by a two-step etching process. The SWS with a high aspect ratio was easily transferred from the fabricated silicon template to PMMA film using the stamping method. The replicated PMMA SWS has an array of cones with nanoscale tips and an aspect ratio higher than 2.8. The average reflectance and transmittance of the PMMA film with the conical SWS in the wavelength ranging from 500 and 1500 nm was improved from 7.1 and 91.1% to 4.3 and 94.2%, respectively, as compared to flat PMMA film.


Asunto(s)
Impresión Molecular/métodos , Nanopartículas/química , Nanopartículas/ultraestructura , Polimetil Metacrilato/química , Refractometría/instrumentación , Resonancia por Plasmón de Superficie/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo
8.
Environ Pollut ; 178: 322-8, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23603469

RESUMEN

Metal contamination from mining activity is of great concern because of potential health risks to the local inhabitants. In the present study, we investigated the levels of Cd, Cu, As, Pb, and Zn in environmental samples and foodstuffs grown in the vicinity of the mines in Goseong, Korea, and evaluated potential health risks among local residents. Soils near the mines exceeded the soil quality standard values of Cu, As, and Zn contamination. The concentrations of Cd, Cu, Pb, and Zn in crop samples collected from the study area were significantly higher than those of the reference area. Some rice samples collected from the study area exceeded the maximum permissible level of 0.2 mg Cd/kg. The intake of rice was identified as a major contributor (≥75%) to the estimated daily intake among the residents. The average estimated daily intakes of metals were, however, below the provisional tolerable daily intake.


Asunto(s)
Exposición a Riesgos Ambientales/estadística & datos numéricos , Metales Pesados/análisis , Minería , Contaminantes del Suelo/análisis , Contaminación de Alimentos/estadística & datos numéricos , Estado de Salud , Indicadores de Salud , República de Corea , Medición de Riesgo
9.
Environ Toxicol ; 28(10): 563-70, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21786387

RESUMEN

Cadmium (Cd) is a nonessential toxic metal which is widely distributed in the environment. The general population is exposed to low levels of Cd and the kidney is the organ most sensitive to Cd toxicity. This study was performed to simultaneously evaluate Cd exposure, kidney function, and oxidative stress biomarkers in the general population. A total of 643 adults were interviewed to document demographic characteristics, lifestyles, past-medical history, and diet during the last 24 h. We estimated daily Cd intake based on the diet of study subjects who had not been exposed to Cd occupationally. Whole blood and urine samples were collected and analyzed to determine Cd concentrations and kidney function indices (ß2 -microglobulin [ß2-MG], N-acetyl-ß-D-glucosaminidase [NAG], metallothionein [MT]). The oxidative stress index (malondialdehyde [MDA]) was determined from the urine. The daily Cd intake from diet was established as 7.07 µg/day. The mean concentration of Cd measured in the blood was 1.22 µg/L and urine was 0.95 µg/g creatinine. The concentrations of Cd in blood and urine were higher in females than in males. The blood levels of Cd were affected by sex, age, and smoking, and urine Cd was influenced by sex, age, and blood Cd. The urine Cd was positively correlated with MT, NAG activity, and MDA in females, but with NAG only in males. The blood Cd was associated with MT in males. Increased NAG activity was observed when Cd in urine reached 1.0 µg Cd/g creatinine and was also affected by age, hypertension, and diabetes mellitus. Urinary MT only responded to Cd in urine or blood. In summary, exposure to Cd in the general population was influenced by various factors including sex, age, and smoking habits. Such exposure might eventually cause tubular damage in the kidneys through the oxidative stress mechanism, and females might be more susceptible than males to Cd exposure under the environment.


Asunto(s)
Cadmio/toxicidad , Riñón/efectos de los fármacos , Acetilglucosaminidasa/sangre , Acetilglucosaminidasa/orina , Adulto , Factores de Edad , Anciano , Biomarcadores/sangre , Biomarcadores/orina , Cadmio/sangre , Cadmio/orina , Creatinina/orina , Femenino , Humanos , Riñón/fisiopatología , Pruebas de Función Renal , Masculino , Malondialdehído/orina , Metalotioneína/sangre , Metalotioneína/orina , Persona de Mediana Edad , Estrés Oxidativo , Factores Sexuales , Microglobulina beta-2/sangre , Microglobulina beta-2/orina
10.
Ann Occup Environ Med ; 25(1): 18, 2013 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-24472601

RESUMEN

BACKGROUND: Methylmercury (MeHg) easily crosses the blood-brain barrier and accumulates in the brain. Accumulated MeHg will cause neurological symptoms. We report four pediatric cases of neuropsychological findings with high blood MeHg concentrations. CASE PRESENTATION: Four children were admitted for follow-up study because their total mercury (THg) concentration in the blood was found to be high during a national survey. Case 1 was a 9-year-old female with a 16.6 µg/ℓ blood THg concentration in the survey. During admission, the blood THg, hair THg, and blood MeHg concentration(mercury indices) were 21.4 µg/ℓ, 7.2 µg/g, and 20.1 µg/ℓ, respectively. In our neuropsychological examination, cognitive impairment and attention deficit were observed. Her diet included fish intake 2-3 times per week, and she had been diagnosed with epilepsy at 3 years of age. Case 2 was a 12-year-old male with blood THg of 15.4 µg/ℓ in the survey and the mercury indices were 12.7 µg/ℓ, 5.7 µg/g, and 11.8 µg/ℓ, respectively, on admission. He was also observed to have attention-deficit/hyperactivity disorder. Case 3 was a 10-year-old male child with blood THg of 17.4 µg/ℓ in the survey, and the mercury indices on admission were 21.6 µg/ℓ, 7.5 µg/g and 21.5 µg/ℓ, respectively. In his case, mild attention deficit was observed. Case 4 was a 9-year-old male with blood THg of 20.6 µg/ℓ in the survey and the mercury indices were 18.9 µg/ℓ, 8.3 µg/g, and 14.4 µg/ℓ, respectively, on admission. Mild attention difficulty was observed. CONCLUSION: We suggest that fish consumption may be the main source of MeHg exposure, and that MeHg may have been the cause of the neuropsychological deficits in these cases.

11.
J Prev Med Public Health ; 45(6): 364-73, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23230466

RESUMEN

The United Nations Environmental Program Governing Council has regulated mercury as a global pollutant since 2001 and has been preparing the mercury convention, which will have a strongly binding force through Global Mercury Assessment, Global Mercury Partnership Activities, and establishment of the Open-Ended Working Group on Mercury. The European Union maintains an inclusive strategy on risks and contamination of mercury, and has executed the Mercury Export Ban Act since December in 2010. The US Environmental Protection Agency established the Mercury Action Plan (1998) and the Mercury Roadmap (2006) and has proposed systematic mercury management methods to reduce the health risks posed by mercury exposure. Japan, which experienced Minamata disease, aims vigorously at perfection in mercury management in several ways. In Korea, the Ministry of Environment established the Comprehensive Plan and Countermeasures for Mercury Management to prepare for the mercury convention and to reduce risks of mercury to protect public health.


Asunto(s)
Contaminación Ambiental/prevención & control , Mercurio , Exposición a Riesgos Ambientales , Monitoreo del Ambiente , Unión Europea , Humanos , Japón , Formulación de Políticas , Salud Pública , Naciones Unidas , Estados Unidos
12.
Opt Lett ; 37(13): 2742-4, 2012 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-22743514

RESUMEN

A hemispherical surface structure was fabricated on a sapphire substrate by utilizing a self-assembly and spin-coating process for a terahertz (THz) antireflection coating. The self-assembled glass spheres and spin-coated material led to a gradual change in the effective refractive index. The aspect ratio of the hemispherical surface structure was controlled easily by adjusting the thickness of the B-staged bisbenzocyclobutene used as a coating. The reflectance of the fabricated hemispherical surface structure, having a period of 140 µm, exhibited low reflectance and low Fabry-Perot resonance in a THz spectral range from 0.1 to 1.9 THz.


Asunto(s)
Fenómenos Ópticos , Vidrio/química , Compuestos Policíclicos/química , Propiedades de Superficie
13.
Opt Express ; 20(12): 13566-72, 2012 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-22714384

RESUMEN

A broadband terahertz (THz) absorber consisting of multilayer glass spheres and polydimethylsiloxane (PDMS) was realized. The multilayer glass spheres were deposited by repeating a self-assembly method used to form monolayer glass spheres and by the spin-coating of PDMS to fill the gaps between the glass spheres. The average reflection at the surface of the absorber was 0.8% and the absorbance was higher than 98% in the frequency range between 0.7 to 2.0 THz.

14.
Neurotoxicology ; 33(4): 676-82, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22525937

RESUMEN

The purpose of this study was to evaluate the relationship between fish consumption and blood THg/MeHg concentration in Korean adults by measuring MeHg concentration in blood directly. The study subjects consisted of 400 adults aged 20 or older from 30 subareas in Busan, Ulsan and Gyeongsangnam-do province in Korea from August to October, 2010. We tried to recruit the same number of male and female participants in different age groups (20s, 30s, 40s, 50s and 60s) and allocated 13-16 subjects by district to represent Hg concentration in the research areas. The geometric means of THg and MeHg concentration in blood were 5.27 µg/L (5.00-5.57) and 4.05 µg/L (3.81-4.32), respectively. The proportion of MeHg/THg concentration was 78.53% (77.09-79.97). MeHg concentration was higher in coastal areas (4.26 µg/L) than in inland areas (3.52 µg/L) and was higher in men (4.68 µg/L) than in women (3.52 µg/L). In male participants, blood MeHg concentration increased with increasing annual fish consumption, and the proportion of MeHg/THg concentration showed an upward trend as THg concentration increased. However, none of the measures of the proportion of MeHg/THg showed significant differences. This is the first report in Korea about the relationship between blood MeHg concentration and related factors. Our findings suggest that MeHg concentration is affected by fish consumption as well as by gender difference and drinking status. Since the pathological mechanism has not been clarified, additional studies are needed for explaining the biological and lifestyle differences in the risk of adverse health effects by Hg exposure.


Asunto(s)
Dieta/efectos adversos , Contaminación de Alimentos , Compuestos de Metilmercurio/sangre , Alimentos Marinos/análisis , Contaminantes Químicos del Agua/sangre , Adulto , Anciano , Consumo de Bebidas Alcohólicas/efectos adversos , Biomarcadores/sangre , Carga Corporal (Radioterapia) , Femenino , Humanos , Masculino , Compuestos de Metilmercurio/efectos adversos , Persona de Mediana Edad , Análisis Multivariante , República de Corea , Medición de Riesgo , Factores de Riesgo , Alimentos Marinos/efectos adversos , Factores Sexuales , Encuestas y Cuestionarios , Contaminantes Químicos del Agua/efectos adversos , Adulto Joven
15.
Int J Hyg Environ Health ; 215(4): 449-57, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22341685

RESUMEN

BACKGROUND: Recently, there have been several nationwide episodes involving imported toys contaminated with toxic metals and environmental hormones. In addition, cadmium intoxication has occurred due to soil contamination with cadmium from abandoned metal mines. OBJECTIVES: To investigate the distribution, extent and factors influencing the levels of toxic metals in the blood or urine of the Korean general population over twenty years of age, we studied the blood or urine concentrations of heavy metals in a representative sample of 5087 Koreans in 2008. METHODS: Multiple biological substrates were collected from each participant to determine the most suitable samples for an environmental health survey system. Information regarding exposure conditions of all subjects was collected by questionnaire-based interviews. RESULTS: The geometric means of the blood lead, mercury and manganese levels were 19.1, 3.23 and 10.8 µg/L, respectively. The geometric means of urinary arsenic and cadmium concentrations were 43.5 and 0.65 µg/L, respectively. Blood mercury and urinary arsenic levels in the Korean general population were significantly higher than in European and American populations. CONCLUSIONS: The higher levels of blood mercury and urinary arsenic could be explained by the greater seafood consumption among the Korean population. This biomonitoring study of blood or urine heavy metals in the Korean general population provides important reference data stratified by demographic and lifestyle factors that will be useful for the ongoing surveillance of environmental exposure of Koreans to toxic metals.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/sangre , Contaminantes Ambientales/orina , Metales Pesados/sangre , Metales Pesados/orina , Adulto , Anciano , Exposición a Riesgos Ambientales/estadística & datos numéricos , Femenino , Contaminación de Alimentos , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , República de Corea , Adulto Joven
16.
Ann Lab Med ; 32(1): 31-7, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22259776

RESUMEN

BACKGROUND: Methylmercury is an organic form of mercury that is highly toxic to humans. Here, we present and establish a novel method to detect methylmercury concentrations in the blood of Koreans. METHODS: Methylmercury concentration was analyzed with an automated methylmercury analytic system (MERX, Brooks Rand Co., USA) using cold vapor atomic fluorescence spectrophotometry (CVAFS). A variety of biological materials were digested in methanolic potassium hydroxide solution. The analysis method was validated by examination of certified reference material (955c, National Institute of Standard and Technology, USA). We randomly selected 30 Korean adults (age 20 yr or older) to analyze total blood mercury and methylmercury concentrations. RESULTS: The detection limit and methylmercury recovery rate using this method were 0.1 pg/L and, 99.19% (range: 89.33-104.89%), respectively. The mean blood concentration of methylmercury was 4.54±2.15 µg/L (N=30). The mean proportion of methylmercury to the total mercury concentration was 78.27% (range: 41.37-98.80%). CONCLUSIONS: This study is the first report to analyze blood methylmercury concentration using CVAFS in Korea. We expect that this method will contribute to the evaluation of mercury exposure and the assessment of the toxicological impact of mercury in future studies.


Asunto(s)
Compuestos de Metilmercurio/sangre , Espectrofotometría Atómica , Adulto , Humanos , Hidróxidos/química , Mercurio/sangre , Compuestos de Potasio/química , Reproducibilidad de los Resultados , República de Corea
17.
J Nanosci Nanotechnol ; 11(8): 7407-11, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22103207

RESUMEN

Subwavelength structures (SWSs) were fabricated on the Indium Phosphide (InP) substrate by utilizing the confined convective self-assembly (CCSA) method followed by reactive ion etching (RIE). The surface condition of the InP substrate was changed by depositing a 30-nm-thick SiO2 layer and subsequently treating the surface with O2 plasma to achieve better surface coverage. The surface coverage of nanoparticle monolayer reached 90% by using O2 plasma-treated SiO2/InP substrate among three kinds of starting substrates such as the bare InP, SiO2/InP and O2 plasma-treated SiO2/InP substrate. A nanoparticle monolayer consisting of polystyrene spheres with diameter of 300 nm was used as an etch mask for transferring a two-dimensional periodic pattern onto the InP substrate. The fabricated conical SWS with an aspect ratio of 1.25 on the O2 plasma-treated SiO2/InP substrate exhibited the lowest reflectance. The average reflectance of the conical SWS was 5.84% in a spectral range between 200 and 900 nm under the normal incident angle.

18.
Environ Res ; 111(3): 348-55, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21256479

RESUMEN

Epidemiologists have tried to establish an association between human health and exposure to particulate matter (PM). In addition, many researchers have investigated the adverse effects of PM as a trigger of cardiovascular and pulmonary diseases. It is known that a number of environmental contaminants are attached to PM and the toxicity of PM may depend on the sources. We investigated the effects of PM collected in a residential area of Seoul on the immunotoxic responses including cytokine production in BAL fluid and in blood after a single intratracheal instillation in mice with the characterization of physico-chemical properties of PM 2.5 samples. As results, pro-inflammatory cytokines (IL-1, TNF-α, and IL-6), Th0-type cytokine (IL-2), and Th1-type cytokines (IL-12 and IFN-γ) were increased by a dose-dependent manner. Cell infiltration in the alveolar area and phagocytosis by macrophage was observed until day 28 after instillation. The expressions of oxidative stress-related genes (HSP 1a, HSP 8, and SOD) and tissue damage-related genes (MMP-15, -19, and Slpi) were time-dependently increased. PM 2.5 also induced an increase of T cell distribution in lymphocyte and decreased the CD4+/CD8+ ratio. Based on the results, we suggest that PM 2.5 collected in a residential area of Seoul may induce Th1 type-inflammatory responses with oxidative stress and trigger adverse effects in human health.


Asunto(s)
Enfermedades Pulmonares/inducido químicamente , Estrés Oxidativo/efectos de los fármacos , Material Particulado/toxicidad , Células TH1/efectos de los fármacos , Células TH1/inmunología , Animales , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/citología , Ciclo Celular/efectos de los fármacos , Ciclo Celular/inmunología , Ciudades , Citocinas/inmunología , Citometría de Flujo , Perfilación de la Expresión Génica , Histocitoquímica , Inmunoglobulina E/sangre , Inmunofenotipificación/métodos , Corea (Geográfico) , Enfermedades Pulmonares/inmunología , Enfermedades Pulmonares/metabolismo , Ratones , Ratones Endogámicos ICR , Estrés Oxidativo/genética , Estrés Oxidativo/inmunología , Tamaño de la Partícula , Material Particulado/análisis
19.
Toxicol Res ; 26(1): 21-8, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24278502

RESUMEN

As the frequency and the intensity of so called Asian dust (AD) events have increased, public concerns about the adverse health effects has spiked sharply over the last two decades. Despite the recent reports on the correlation between AD events and the risk for cardiovascular and respiratory disease, the nature of the toxicity and the degree of the risk are yet largely unknown. In the present study, we investigated the effects of the dichloromethane extract of AD (AD-X) and that of urban dust (NAD-X) collected during a non-AD period on gene expression in HL-60 cells using Illumina Sentrix HumanRef-8 Expression BeadChips. Global changes in gene expression were analyzed after 24 h of incubation with 50 or 100 µg/ml AD-X and NAD-X. By one-way analysis of variance (p < 0.05) and Benjamini-Hochberg multiple testing correction for false discovery rate of the results, 573 and 297 genes were identified as AD-X- and NAD-X-responsive, respectively. The genes were classified into three groups by Venn diagram analysis of their expression profile, i.e., 290 AD-X-specific, 14 NAD-X-specific, and 283 overlapping genes. Quantitative realtime PCR confirmed the changes in the expression levels of the selected genes. The expression patterns of five genes, namely SORL1, RABEPK, DDIT4, AZU1, and NUDT1 differed significantly between the two groups. Following rigorous validation process, these genes may provide information in developing biomarker for AD exposure.

20.
Int J Environ Health Res ; 19(1): 31-48, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19241245

RESUMEN

The objective of this study is to investigate the relationship between five air pollutants (PM(10), SO(2), NO(2), O(3), CO) measured on the daily basis, and adverse health symptoms using epidemiological surveillance data. The generalized estimated equation (GEE) model, a logistic regression analysis model, was used to estimate the effects of air pollution on children's daily health symptoms, focusing on the morbidity including both respiratory and allergic symptoms in four different cities. Analysis of the effects of each pollutant on children's respiratory and allergic symptoms demonstrated that CO affected all symptoms in all the study areas. When the concentration of SO(2) and NO(2) was elevated, upper respiratory symptoms increased significantly. In contrast, when the concentration of O(3) rose, the symptoms decreased significantly. The relationship between measured concentrations and health symptoms was site-dependent for each pollutant.


Asunto(s)
Contaminantes Atmosféricos/efectos adversos , Contaminación del Aire/efectos adversos , Hipersensibilidad/etiología , Enfermedades Respiratorias/etiología , Contaminantes Atmosféricos/química , Monóxido de Carbono/química , Monóxido de Carbono/toxicidad , Niño , Exposición a Riesgos Ambientales/efectos adversos , Femenino , Humanos , Hipersensibilidad/epidemiología , Corea (Geográfico)/epidemiología , Modelos Logísticos , Masculino , Dióxido de Nitrógeno/química , Dióxido de Nitrógeno/toxicidad , Ozono/química , Ozono/toxicidad , Material Particulado/química , Material Particulado/toxicidad , Vigilancia de la Población , Enfermedades Respiratorias/epidemiología , Dióxido de Azufre/química , Dióxido de Azufre/toxicidad , Población Urbana/estadística & datos numéricos
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