[Show abstract][Hide abstract] ABSTRACT: Increase in the use of manufactured nanomaterials (NMs) has led to concerns about the environmental impacts. Especially, hazard of metal-based NMs is more severe due to ions released from surface by water quality parameters and physicochemical properties after entering into the water environment. However, little is known about the effects of ionization on the toxicity of metal-based NMs in the water environment. To address this question, we prepared the suspensions of silver nanoparticles (AgNP) at 25 μg L(-1) containing different concentrations of Ag(+) (5, 10, 20, 45, and 75% Ag(+) to total Ag), and evaluated their toxicity to Japanese medaka (Oryzias latipes) embryos. Higher Ag(+) ratios in the AgNP suspension, suggesting the lower number of particles, led to the higher adverse effects on embryos and sac-fries. In addition, histopathology analysis revealed that AgNPs penetrated through chorion of eggs and skin membrane, and were distributed into the tissues. The results imply that the ionization could decrease the toxicity of metal-based NMs in the water environment.
Journal of Environmental Science and Health Part A Toxic/Hazardous Substances & Environmental Engineering 01/2014; 49(3):287-93.
[Show abstract][Hide abstract] ABSTRACT: Combined repeated-dose toxicity study of citrate-capped silver nanoparticles (7.9 ± 0.95 nm) with reproduction/developmental toxicity was investigated in rats orally treated with 62.5, 125 and 250 mg/kg, once a day for 42 days for males and up to 52 days for females. The test was performed based on the Organization for Economic Cooperation and Development test guideline 422 and Good Laboratory Practice principles. No death was observed in any of the groups. Alopecia, salivation and yellow discolouration of the lung were observed in a few rats but the symptoms were not dose-dependent. Haematology, serum biochemical investigation and histopathological analysis revealed no statistically significant differences between control group and the treated groups. Toxicity endpoints of reproduction/developmental screening test including mating, fertility, implantation, delivery and foetus were measured. There was no evidence of toxicity.
[Show abstract][Hide abstract] ABSTRACT: This study evaluated the cytotoxicity of mixtures of citral (CTR) and either benzisothiazolinone (BIT, Mix-CTR-BIT) or triclosan (TCS, Mix-CTR-TCS) in human A549 lung epithelial cells. We investigated the effects of various mix ratios of these common air freshener ingredients on cell viability, cell proliferation, reactive oxygen species (ROS) generation, and DNA damage. Mix-CTR-BIT and Mix-CTR-TCS significantly decreased the viability of lung epithelial cells and inhibited cell growth in a dose-dependent manner. In addition, both mixtures increased ROS generation, compared to that observed in control cells. In particular, cell viability, growth, and morphology were affected upon increase in the proportion of BIT or TCS in the mixture. However, comet analysis showed that treatment of cells with Mix-CTR-BIT or Mix-CTR-TCS did not increase DNA damage. Taken together, these data suggested that increasing the content of biocides in air fresheners might induce cytotoxicity, and that screening these compounds using lung epithelial cells may contribute to hazard assessment.
[Show abstract][Hide abstract] ABSTRACT: Aluminum nanoparticles (Al-NPs) are one of the most widely used nanomaterial in cosmetics and medical materials. For this reason, Al-NP exposure is very likely to occur via inhalation in the environment and the workplace. Nevertheless, little is known about the mechanism of Al-NP neurotoxicity via inhalation exposure. In this study, we investigated the effect AL-NPs on the brain. Rats were exposed to Al-NPs by nasal instillation at 1 mg/kg body weight (low exposure group), 20 mg/kg body weight (moderate exposure group), and 40 mg/kg body weight (high exposure group), for a total of 3 times, with a 24-hr interval after each exposure. Inductively coupled plasma mass spectrometry (ICP-MS) analysis indicated that the presence of aluminum was increased in a dose-dependent manner in the olfactory bulb (OFB) and the brain. In microarray analysis, the regulation of mitogen-activated protein kinases (MAPK) activity (GO: 0043405), including Ptprc, P2rx7, Map2k4, Trib3, Trib1, and Fgd4 was significantly over-expressed in the treated mice than in the controls (p = 0.0027). Moreover, Al-NPs induced the activation of ERK1 and p38 MAPK protein expression in the brain, but did not alter the protein expression of JNK, when compared to the control. These data demonstrate that the nasal exposure of Al-NPs can permeate the brain via the olfactory bulb and modulate the gene and protein expression of MAPK and its activity.
[Show abstract][Hide abstract] ABSTRACT: The aggregate risk assessment on xylene and ethylbenzene was carried out according to the guidance established newly in 2010 with the purpose of providing information for risk management. In human exposure assessment, the results indicated that lower ages were exposed more and that, in the interior space at home, the highest level of human exposure occurred via inhalation. At outdoor spaces, exposures via inhalation and drinking were less than 1%. In human health risk characterization, xylene showed HI(Hazard Index) < 1 in all ages. When reasonable maximum exposure(RME) was applied, HI for young children was 0.64. The HI of ethylbenzene was also below 1(0.02~0.04) in all ages, indicating no potential risk. From this study, it is considered that xylene need to be continous monitoring with interest because this substance may be more sensitive on young age group. In additon, to reduce the uncertainty of the risk assessment, the korean exposure factors on young age group such as infant, children had to be established as soon as possible.
Journal of Environmental Science International. 01/2013; 22(2).
[Show abstract][Hide abstract] ABSTRACT: Tricalcium phosphate and calcium hydrogenorthophosphate are high production volume chemicals, mainly used as foodstuff additives, pharmaceuticals, lubricants, synthetic resin, and disinfectants. Phosphate has the potential to cause increased algal growth leading to eutrophication in the aquatic environment. However, there is no adequate information available on risk assessment or acute and chronic toxicity. The aim of this research is to evaluate the toxic potential of phosphate compounds in the aquatic environment.
An aquatic toxicity test of phosphate was conducted, and its physico-chemical properties were obtained from a database recommended in the Organization for Economic Cooperation and Development (OECD) guidance manual. An ecotoxicity test using fish, Daphnia, and algae was conducted by the good laboratory practice facility according to the OECD TG guidelines for testing of chemicals, to secure reliable data.
THE RESULTS OF THE ECOTOXICITY TESTS OF TRICALCIUM PHOSPHATE AND CALCIUM HYDROGENORTHOPHOSPHATE ARE AS FOLLOWS: In an acute toxicity test with Oryzias latipes, 96 hr 50% lethal concentration (LC(50)) was >100 (measured:>2.14) mg/L and >100 (measured: >13.5) mg/L, respectively. In the Daphnia test, 48 hr 50% effective concentration (EC(50)) was >100 (measured: >5.35) mg/L and >100 (measured: >2.9) mg/L, respectively. In a growth inhibition test with Pseudokirchneriella subcapitata, 72 hr EC(50) was >100 (measured: >1.56) mg/L and >100 (measured: >4.4) mg/L, respectively.
Based on the results of the ecotoxicity test of phosphate using fish, Daphnia, and algae, L(E)C(50) was above 100 mg/L (nominal), indicating no toxicity. In general, the total phosphorus concentration including phosphate in rivers and lakes reaches levels of several ppm, suggesting that phosphate has no toxic effects. However, excessive inflow of phosphate into aquatic ecosystems has the potential to cause eutrophication due to algal growth.
Environmental health and toxicology. 01/2013; 28:e2013002.
[Show abstract][Hide abstract] ABSTRACT: Triclosan (TCS) is a chemical compound used in household products as biocide. However, their pulmonary toxicity has been unclear. Thus, the purpose of this study was to investigate the possibility of injury to the lung by inhalation of TCS. Rats were exposed to TCS by single intratracheal instillation of 10 µg/B.W. kg for the low-dose group and 1,000 µg/B.W. kg for the high-dose group, respectively. TCS induced increase in the level of total cell (TC) count, polymorphonuclear leukocytes (PMNs), total protein (TP), lactate acid dehydrogenase (LDH), tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in bronchoalveolar lavage fluid (BALF) at 1 day after instillation. However, most pulmonary toxicity marker levels except TP in BALF were restored 14 days after instillation. In addition, TCS led to reduction of cell viability with morphological change in lung eptiehelial cells (L2 cell). Therefore, TCS may affect responses of acute inflammation and permeability in the lung.
The Journal of Toxicological Sciences 01/2013; 38(3):471-475. · 1.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chloramine T has been widely used as a disinfectant in many areas such as kitchens, laboratories and hospitals. It has been also used as a biocide in air fresheners and deodorants which are consumer products; however, little is known about its toxic effects by inhalation route. This study was performed to identify the subacute inhalation toxicity of chloramine T under whole-body inhalation exposure conditions. Male and female groups of rats were exposed to chloramine T at concentrations of 0.2, 0.9 and 4.0 mg/m(3) for 6 hr/day, 5 days/week during 4 weeks. After 28-day repeated inhalation of chloramine T, there were dose-dependently significant DNA damage in the rat tissues evaluated and inflammation was histopathologically noted around the terminal airways of the lung in both genders. As a result of the expression of three types of antioxidant enzymes (SOD-2, GPx-1, PRX-1) in rat's lung after exposure, there was no significant change of all antioxidant enzymes in the male and female rats. The results showed that no observed adverse effect level (NOAEL) was 0.2 mg/m(3) in male rats and 0.9 mg/m(3) in female rats under the present experimental condition.
The Journal of Toxicological Sciences 01/2013; 38(6):937-46. · 1.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The developmental toxicity of silver nanoparticles (AgNPs) was investigated following exposure of Oryzias latipes (medaka) embryos to 0.1-1 mg/L of homogeneously dispersed AgNPs for 14 days. During this period, developmental endpoints, including lethality, heart rate, and hatching rate, were evaluated by microscopy for different stages of medaka embryonic development. To compare toxic sensitivity, acute adult toxicity was assessed. There was no difference in acute lethal toxicity between embryo and adult medaka. Interestingly, we found that the increase in stepwise toxicity was dependent on the developmental stage of the embryo. Lethal embryonic toxicity increased from exposure days 1 to 3 and exposure days 5 to 8, whereas there was no change from exposure days 3 to 5. In addition, 7 d exposure to 0.8 mg/L AgNPs resulted in significant heart beat retardation in medaka embryos. AgNPs also caused a dose-dependent decrease in the hatching rate and body length of larvae. These results indicate that AgNP exposure causes severe developmental toxicity to medaka embryos and that toxicity levels are enhanced at certain developmental stages, which should be taken into consideration in assessments of metallic NPs toxicity to embryos.
BioMed research international. 01/2013; 2013:494671.
[Show abstract][Hide abstract] ABSTRACT: In this study, physico-chemical properties and environmental fate were investigated and ecotoxicity tests using fish, daphnia and algae were conducted for an initial ecological risk assessment of 1,2-Benzisothiazol-3-one. Due to low volatility of the test substance under environmental conditions, it is likely to distributed in soil and water environment. The compound has low adsorption in the soil, with low bioconcentration potential. Acute toxicity results showed that 96 h- for Oryzias laties was 4.7 mg/L (measured) and 48h- for Daphnia magna was 3.3 mg/L (measured). In a growth inhibition test with Pseudokirchneriella subcapitata, 72 h- was 0.456 mg/L (growth rate, nominal) and 0.262 mg/L (yield, nominal). Using the acute toxicity value of algae, predicted no-effect concentration (PNEC) in the aquatic environment was determined to be 2.62 using an factor of 100. According to globally harmonized system (GHS), the compound was categorized as aquatic acute 1 for algae, while it was categorized as aquatic acute 2 for fish and daphnia. This screening assessment suggests that the test substance may pose ecological risks in the aquatic environment.
Journal of Korean Society of Environmental Engineers. 01/2013; 35(3).
[Show abstract][Hide abstract] ABSTRACT: 7.9 ± 0.95 nm, dosage: 250 mg/kg) were orally administered to pregnant rats. At 4 days after parturition, four pups were randomly selected (one pup from one dam) and silver level in liver, kidney, lung and brain was determined by ICP-MS and electron microscope. As results, silver nanoparticles highly accumulated in the tissues of the pups. Silver level in the treated group was 132.4 ± 43.9 ng/g in the kidney (12.3 fold compared to control group), 37.3 ± 11.3 ng/g in the liver (7.9 fold), 42.0 ± 8.6 ng/g in the lung (5.9 fold), and 31.1 ± 4.3 ng/g in the brain (5.4 fold). This result suggested that the possible transfer of silver nanoparticles from pregnant dams to the fetus through mainly placenta.
[Show abstract][Hide abstract] ABSTRACT: Fly ash from industrial waste incinerators has been a significant concern because of their constituent toxic heavy metals and organic compounds. The objective of this study was to identify the subacute inhalation toxicity of fly ash from industrial waste incinerators, using whole body inhalation exposure chambers. Male and female groups of Sprague-Dawley rats were exposed to fly ash by inhalation of concentrations of 0, 50, 100, 200 mg/m(3), for 6 h/day, 5 days/week for 4 weeks. There was no significant difference in body weight, and relative organ weight to body weight, between the exposure groups and the control group. Hematological examinations revealed a significant increase of monocyte counts in fly ash exposed rats and brown pigment laden macrophage was found in the lungs of rats exposed to high concentration of fly ash. A decrease of blood glucose levels and an increase in glutamate oxaloacetate transaminase activity were observed in fly ash treated rats. There was also a significant increase of lactate dehydrogenase levels in rat blood exposed fly ash. A significant dose-dependent increase of DNA damage was found in lymphocytes, spleen, bronchoalveolar lavage, liver, lung, and thymus of rats exposed to fly ash. In addition, the level of lipid peroxidation was increased in the plasma of rats exposed to a high concentration of fly ash. These results suggest that inhalation of fly ash from industrial waste incinerators can induce histopathologic, hematological, and serum biochemical changes and oxidative damage.
[Show abstract][Hide abstract] ABSTRACT: Abstract Serum kinetics, tissue distribution, and excretion of citrate-coated silver nanoparticles (AgNPs) were investigated in rabbits (n = 4) up to 28 days after a single intravenous injection. Following a single injection of AgNPs, the AUC((last)) was reported to be 3.65 ± 0.68 μg·day/ml in 5 mg/kg-treated group and 0.90 ± 0.16 μg·day/ml in 0.5 mg/kg-treated group, respectively. The accumulation of silver was observed in all the tested organs including liver, kidney, spleen, lung, brain, testis, and thymus at 1 day, 7 day, and 28 day of measurement. The liver and spleen seemed to be the major targets because of high accumulation of silver. Excretion via feces and urine was also monitored during the entire experimental period. Unexpectedly, much more excretion of silver occurred via feces than through urine after an intravenous injection, which suggests biliary excretion of AgNPs. General toxicity was analyzed and histopathological changes were also evaluated.
[Show abstract][Hide abstract] ABSTRACT: Although task-based sampling is, theoretically, a plausible approach to the assessment of nanoparticle exposure, few studies using this type of sampling have been published. This study characterized and compared task-based nanoparticle exposure profiles for engineered nanoparticle manufacturing workplaces (ENMW) and workplaces that generated welding fumes containing incidental nanoparticles. Two ENMW and two welding workplaces were selected for exposure assessments. Real-time devices were utilized to characterize the concentration profiles and size distributions of airborne nanoparticles. Filter-based sampling was performed to measure time-weighted average (TWA) concentrations, and off-line analysis was performed using an electron microscope. Workplace tasks were recorded by researchers to determine the concentration profiles associated with particular tasks/events. This study demonstrated that exposure profiles differ greatly in terms of concentrations and size distributions according to the task performed. The size distributions recorded during tasks were different from both those recorded during periods with no activity and from the background. The airborne concentration profiles of the nanoparticles varied according to not only the type of workplace but also the concentration metrics. The concentrations measured by surface area and the number concentrations measured by condensation particle counter, particulate matter 1.0, and TWA mass concentrations all showed a similar pattern, whereas the number concentrations measured by scanning mobility particle sizer indicated that the welding fume concentrations at one of the welding workplaces were unexpectedly higher than were those at workplaces that were engineering nanoparticles. This study suggests that a task-based exposure assessment can provide useful information regarding the exposure profiles of nanoparticles and can therefore be used as an exposure assessment tool.
Journal of Nanoparticle Research 01/2012; 14(9). · 2.18 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Juvenile common carp (Cyprinus carpio) were used as a model to investigate acute toxicity and oxidative stress caused by silver nanoparticles (Ag-NPs). The fish were exposed to different concentrations of Ag-NPs for 48 h and 96 h. After exposure, antioxidant enzyme levels were measured, including glutathione-S-transferase (GST), superoxidase dismutase, and catalase (CAT). Other biochemical parameters and histological abnormalities in different tissues (i.e., the liver, gills, and brain) were also examined. The results showed that Ag-NPs agglomerated in freshwater used during the exposure experiments, with particle size remaining <100 nm. Ag-NPs had no lethal effect on fish after 4 days of exposure. Biochemical analysis showed that enzymatic activities in the brain of the fish exposed to 200 μg/L of Ag-NPs were significantly reduced. Varied antioxidant enzyme activity was recorded in the liver and gills. Varied antioxidant enzyme activity was recorded for CAT in the liver and GST in the gills of the fish. However, the recovery rate of fish exposed to 200 μg/L of Ag-NPs was slower than when lower particle concentrations were used. Other biochemical indices showed no significant difference, except for NH(3) and blood urea nitrogen concentrations in fish exposed to 50 μg/L of Ag-NPs. This study provides new evidence about the effects of nanoparticles on aquatic organisms.
BioMed Research International 01/2012; 2012:262670. · 2.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Consequences of long-term exposure to diclofenac up to 3 months were evaluated using freshwater crustaceans (Daphnia magna and Moina macrocopa) and a fish (Oryzias latipes). Marked decrease of reproduction was observed at 25 mg/L for D. magna, and at 50 mg/L for M. macrocopa. Three-month exposure of fish to 0.001-10 mg/L of diclofenac resulted in significant decreasing trend in hatching success and delay in hatch. The hatching of the eggs produced from the fish exposed to 10 mg/L was completely interfered, while fertility of the parent generation was not affected. Gonadosomatic index (GSI) of female fish was also affected at 10 mg/L. Predicted no effect concentration of diclofenac was estimated at 0.1 mg/L, which is a few orders of magnitude greater than those observed in ambient water. Therefore direct impact of diclofenac exposure is not expected. However its bioaccumulation potential through food web should warrant further evaluation.
Ecotoxicology and Environmental Safety 07/2011; 74(5):1216-25. · 2.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chemicals are widely used in our daily lives for various purposes such as disinfectant, air fresher, paints and hair spray. However, their pulmonary toxicity has less studied compared with oral and dermal toxicity. Therefore, the purpose of this study was to examine comparative cytotoxicity of triclosan (TCS), benzisothiazolinone (BIT), dichlorophene (DCP) and citral (CTR) major using spray-type chemicals used in household products (CHPs) in Korea. TCS, DCP and BIT induced more severe mitochondria injury and cell membrane damage than CTR in lung epithelial cell during 24 hrs exposure. Furthermore, the result of clonogenic assay revealed that exposure of CHPs significantly decreased colony size and that BIT reduced cell growth at most compared with TCS, DCP and CTR. In summary, results of comparative cytotoxicity demonstrated that inhalation of TCS, DCP and BIT may cause pulmonary toxicity. Therefore, our results suggest that TCS, BIT and DCP are requiring inhalation toxicity assessment for maintaining a high quality of life.
Molecular and Cellular Toxicology 9(1). · 0.72 Impact Factor