Publications by authors named "Jae-Hyuck Sung"

Nano-concrete, which is an admixture of nanomaterials in concrete recipes, has been investigated to overcome the limitations of existing concrete, such as its stability and strength. However, there is no information on the human health effects of broken-down dust released during the construction and demolition efforts. In this study, we prepared an inhalable fraction of multi-walled carbon nanotube-containing nano-concrete dust and performed comparative toxicity studies with conventional concrete dust and DQ12 using a rat intratracheal instillation model.

View Article and Find Full Text PDF

Recently, there have been reports that many microplastics are found in the air, which has raised concerns about their toxicity. To date, however, only limited research has investigated the effects of micro(nano)plastics on human health, and even less the potential for inhalation toxicity. To fill this research gap, we investigated the potential inhalation toxicity of micro(nano)plastics using a modified OECD Guideline for Testing of Chemicals No.

View Article and Find Full Text PDF

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease. Epidemiological studies have demonstrated that cigarette smoke or nicotine is a risk factor for the progression of chronic kidney injury. The present study analyzed the kidney toxicity of cigarette smoke in experimental rats with DKD.

View Article and Find Full Text PDF

Smoking is an acknowledged risk factor for vascular disorders, and vascular complication is a main outcome of diabetes. Hence, we investigated the impact of cigarette smoke on blood vessels in diabetes, postulating that smoking might aggravate diabetic vascular impairment. Sprague-Dawley rats were divided into four groups: control, cigarette smoke-exposed, diabetic, and cigarette smoke-exposed diabetic groups.

View Article and Find Full Text PDF

Although the dried root of (Turcz.) Schischk. (Umbelliferae) is a popular medicinal plant in East Asia, there has been no systemic toxicological evaluation of a water extract of Saposhnikoviae Radix (SRE).

View Article and Find Full Text PDF

In this study, we aimed to provide the recommended occupational exposure limits (OELs) for multi-walled carbon nanotubes (MWCNTs) and graphene nanomaterials based on data from a subchronic inhalation toxicity study using a lung dosimetry model. We used a no observed adverse effect level (NOAEL) of 0.98 mg m and 3.

View Article and Find Full Text PDF

Cigarette smoke (CS) has harmful effects on human fertility, reproduction, and development as well as on patients suffering from metabolic diseases such as diabetes than on healthy individuals. This study was conducted to investigate the relationship between CS exposure and histological alterations of reproductive organs in female diabetic rats. We evaluated the histology of uteruses and ovaries obtained from female rats exposed to smoke from standard cigarettes for 4 weeks (28 hours a week).

View Article and Find Full Text PDF

Gold (AuNPs, 12.8 nm) and silver nanoparticles (AgNPs, 10 nm), mixed or separate, were injected into the caudal vein of male Sprague-Dawley rats for 4 weeks. The rats were allowed to recover for further 4 weeks to examine the differences in AuNP/AgNP tissue distribution and clearance.

View Article and Find Full Text PDF

Cigarette smoke (CS) is well known to be very harmful to human body functions such as fertility, reproduction, and development. CS is considered to more affect patients with hypertension (HT). To estimate the effect of CS associated with female rat's fertility, we examined the histopathological characteristics of the uterus and ovary which were obtained from the female rats exposed to smoke of the standard cigarette (3R4F) for 4 weeks (10h a week) according to the OECD guidelines.

View Article and Find Full Text PDF

Titanium dioxide (TiO2) nanoparticles are widely used in cosmetics, sunscreen, electronics, drug delivery systems, and diverse bio-application fields. In the workplace, the primary exposure route for TiO2 nanoparticles is inhalation through the respiratory system. Because TiO2 nanoparticles have different physiological properties, in terms of size and bioactivity, their toxic effects in the respiratory system must be determined.

View Article and Find Full Text PDF

In our previous studies of nanocalcium carbonate, in which we performed physicochemical analysis, genotoxicity, acute single-dose and repeated-dose 14-day oral toxicity testings in Sprague-Dawley (SD) rats, nanocalcium carbonate did not show a difference in toxicity compared to vehicle control. Here, we provide the first report of a repeated-dose 90-day oral toxicity test of nanocalcium carbonate in Sprague-Dawley rats, with physicochemical comparison of micro and nanocalcium carbonate. We find that the two particles differ in size, hydrodynamic size, and specific surface area, with no differences in components, crystalline structure and radical production.

View Article and Find Full Text PDF

Despite their useful physico-chemical properties, carbon nanotubes (CNTs) continue to cause concern over occupational and human health due to their structural similarity to asbestos. Thus, to evaluate the toxic and genotoxic effect of multi-wall carbon nanotubes (MWCNTs) on lung cells in vivo, eight-week-old rats were divided into four groups (each group = 25 animals), a fresh air control (0 mg/m(3)), low (0.17 mg/m(3)), middle (0.

View Article and Find Full Text PDF

To define the relationship between the brain concentration of manganese and neurological signs, such as locomotion, after prolonged welding-fume exposure, cynomolgus monkeys were acclimated for 1 month and then divided into three concentration groups: unexposed, low concentration (31 mg/m(3) total suspended particulate (TSP), 0.9 mg/m(3) of Mn), and high concentration (62 mg/m(3) TSP, 1.95 mg/m(3) of Mn) of TSP.

View Article and Find Full Text PDF

Silver nanoparticles are known to be distributed in many tissues after oral or inhalation exposure. Thus, understanding the tissue clearance of such distributed nanoparticles is very important to understand the behavior of silver nanoparticles in vivo. For risk assessment purposes, easy clearance indicates a lower overall cumulative toxicity.

View Article and Find Full Text PDF

The specific properties of silver nanoparticles (AgNPs), such as antimicrobial activity and electrical conductivity, allow them to be used in many fields. However, their expanding application is also raising health, environmental and safety concerns. Previous in vivo AgNP toxicity studies have indicated a gender-different accumulation of silver in the kidneys, with 2-3 times more silver in female kidneys compared to male kidneys.

View Article and Find Full Text PDF

To clarify the health risks related to silver nanoparticles (Ag-NPs), we evaluated the genotoxicity, acute oral and dermal toxicity, eye irritation, dermal irritation and corrosion and skin sensitisation of commercially manufactured Ag-NPs according to the OECD test guidelines and GLP. The Ag-NPs were not found to induce genotoxicity in a bacterial reverse mutation test and chromosomal aberration test, although some cytotoxicity was observed. In acute oral and dermal toxicity tests using rats, none of the rats showed any abnormal signs or mortality at a dose level of ∼ 2000 mg/kg.

View Article and Find Full Text PDF

In a previous study, the lung function, as indicated by the tidal volume, minute volume, and peak inspiration flow, decreased during 90 days of exposure to silver nanoparticles and was accompanied by inflammatory lesions in the lung morphology. Therefore, this study investigated the recovery from such lung function changes in rats following the cessation of 12 weeks of nanoparticle exposure. Male and female rats were exposed to silver nanoparticles (14-15 nm diameter) at concentrations of 0.

View Article and Find Full Text PDF

Background: Gold nanoparticles are widely used in consumer products, including cosmetics, food packaging, beverages, toothpaste, automobiles, and lubricants. With this increase in consumer products containing gold nanoparticles, the potential for worker exposure to gold nanoparticles will also increase. Only a few studies have produced data on the in vivo toxicology of gold nanoparticles, meaning that the absorption, distribution, metabolism, and excretion (ADME) of gold nanoparticles remain unclear.

View Article and Find Full Text PDF

Objectives: The antimicrobial activity of silver nanoparticles has resulted in their widespread use in many consumer products. Yet, despite their many advantages, it is also important to determine whether silver nanoparticles may represent a hazard to the environment and human health.

Methods: Thus, to evaluate the genotoxic potential of silver nanoparticles, in vivo genotoxicity testing (OECD 474, in vivo micronuclei test) was conducted after exposing male and female Sprague-Dawley rats to silver nanoparticles by inhalation for 90 days according to OECD test guideline 413 (Subchronic Inhalation Toxicity: 90 Day Study) with a good laboratory practice system.

View Article and Find Full Text PDF

Objectives: We have investigated the toxic effects of the inhalation of subchronic and acute levels of n-octane.

Methods: The rats were exposed to n-octane of 0, 2.34, 11.

View Article and Find Full Text PDF

The acute inhalation toxicity of silver nanoparticles was studied in Sprague-Dawley rats. Seven-week-old rats, weighing approximately 218 g (males) and 153 g (females), were divided into four groups (five rats in each group): fresh-air control, low-dose (0.94 × 10(6) particle/cm(3), 76 µg/m(3)), middle-dose (1.

View Article and Find Full Text PDF

Seven CNT (carbon nanotube) handling workplaces were investigated for exposure assessment. Personal sampling, area sampling, and real-time monitoring using an SMPS (scanning mobility particle sizer), dust monitor, and aethalometer were performed to characterize the mass exposure, particle size distribution, and particle number exposure. No workplace was found to exceed the current ACGIH (American Conference of Governmental Industrial Hygienists) TLVs (threshold limit values) and OELs (occupational exposure levels) set by the Korean Ministry of Labor for carbon black (3.

View Article and Find Full Text PDF

The toxicity test of ammonium persulfate was conducted to ensure of its potential toxic effects according to the single-dose acute oral toxicity study (OECD Guideline 423) and 90-day repeated dose sub-chronic oral toxicity study guideline (OECD Guideline 408) for establishing national chemical management system, and matching in the Globally Harmonized Classification System (GHS) category. In acute oral toxicity study, pasty stool, perineal contamination and temporary body weight decrease were observed after dosing 1st and 2nd challenge (300 mg/kg body weight). All test animals were dead within 6 hours after dosing at 3rd challenge (2000 mg/kg body weight).

View Article and Find Full Text PDF

Previous studies on welding-fume-induced lung fibrosis have indicated that recovery is possible when the degree of exposure is short-term and moderate. However, this study investigated the recovery after recurrent exposure to welding fumes, as welders are invariably re-exposed to welding fumes after recovering from radiographic pneumoconiosis. Thus, to investigate the disease and recovery processes of welding-fume-induced pneumoconiosis in the case of recurrent welding-fume exposure, rats were exposed to manual metal arc-stainless steel (MMA-SS) welding fumes with a total suspended particulate (TSP) concentration of 51.

View Article and Find Full Text PDF

The subchronic inhalation toxicity of silver nanoparticles was studied in Sprague-Dawley rats. Eight-week-old rats, weighing approximately 253.2 g (males) and 162.

View Article and Find Full Text PDF