OBJECTIVES: 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. METHODS: 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. RESULTS: 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 (LC50) was >100 (measured:>2.14) mg/L and >100 (measured: >13.5) mg/L, respectively. In the Daphnia test, 48 hr 50% effective concentration (EC50) 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 EC50 was >100 (measured: >1.56) mg/L and >100 (measured: >4.4) mg/L, respectively. CONCLUSIONS: Based on the results of the ecotoxicity test of phosphate using fish, Daphnia, and algae, L(E)C50 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.
Calcium ; Daphnia ; Disinfectants ; Ecosystem ; Eutrophication ; Lakes ; Lubricants ; Oryzias ; Phosphorus ; Resins, Synthetic ; Risk Assessment ; Rivers ; Toxicity Tests ; Toxicity Tests, Acute

OBJECTIVES: We investigated the genotoxic effects of 40-59 nm silver nanoparticles (Ag-NPs) by bacterial reverse mutation assay (Ames test), in vitro comet assay and micronucleus (MN) assay. In particular, we directly compared the effect of cytochalasin B (cytoB) and rat liver homogenate (S9 mix) in the formation of MN by Ag-NPs. METHODS: Before testing, we confirmed that Ag-NPs were completely dispersed in the experimental medium by sonication (three times in 1 minute) and filtration (0.2 microm pore size filter), and then we measured their size in a zeta potential analyzer. After that the genotoxicity were measured and especially, S9 mix and with and without cytoB were compared one another in MN assay. RESULTS: Ames test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains revealed that Ag-NPs with or without S9 mix did not display a mutagenic effect. The genotoxicity of Ag-NPs was also evaluated in a mammalian cell system using Chinese hamster ovary cells. The results revealed that Ag-NPs stimulated DNA breakage and MN formation with or without S9 mix in a dose-dependent manner (from 0.01 microg/mL to 10 microg/mL). In particular, MN induction was affected by cytoB. CONCLUSIONS: All of our findings, with the exception of the Ames test results, indicate that Ag-NPs show genotoxic effects in mammalian cell system. In addition, present study suggests the potential error due to use of cytoB in genotoxic test of nanoparticles.
Animals ; Comet Assay ; Cricetinae ; Cricetulus ; Cytochalasin B ; DNA ; Female ; Filtration ; Liver ; Micronucleus Tests ; Mutagenicity Tests* ; Nanoparticles* ; Ovary ; Rats ; Salmonella typhimurium ; Silver* ; Sonication

OBJECTIVES: Despite increasing availability of global positioning system (GPS), no research has been conducted to analyze GPS data for exposure opportunities associated with time at indoor and outdoor microenvironments. We developed location-based and time-weighted spatial measures that incorporate indoor and outdoor time-location data collected by GPS. METHODS: Time-location data were drawn from 38 female subjects in California who wore a GPS device for seven days. Ambient standard deviational ellipse was determined based on outdoor locations and time duration, while indoor time weighted standard deviational ellipse (SDE) was developed to incorporate indoor and outdoor times and locations data into the ellipse measure. RESULTS: Our findings indicated that there was considerable difference in the sizes of exposure potential measures when indoor time was taken into consideration, and that they were associated with day type (weekday/weekend) and employment status. CONCLUSIONS: This study provides evidence that time-location weighted measure may provide better accuracy in assessing exposure opportunities at different microenvironments. The use of GPS likely improves the geographical details and accuracy of time-location data, and further development of such location-time weighted spatial measure is encouraged.
California ; Employment ; Female ; Geographic Information Systems* ; Humans

Cancer has been the leading cause of death in Korea for the last 30 years. Cancer patients' 5-year survival rate between 2005 and 2009 was 62.0%, representing a highly advanced standard of care, as much as developed countries in the EU and the US. The Korean government formulated its first 10-year plan for cancer control in 1996 and has been carrying out a second 10-year plan for cancer control since 2006. But despite the Korean government's efforts, the cancer burden in Korea continues to increase. Many separate laws have gone into effect concerning the management of carcinogen exposure. However, there are no integrated regulatory laws or management systems against carcinogen exposure in Korea. Dead zones remain where carcinogen exposure cannot be controlled properly in Korea. In this paper, we suggest the need to establish a national carcinogen list based on international harmonization as a prerequisite for a paradigm shift in cancer control policy from treatment to primary prevention.
Cause of Death ; Developed Countries ; Jurisprudence ; Korea* ; Primary Prevention ; Standard of Care ; Survival Rate

OBJECTIVES: Children are one of the most vulnerable populations to the impact of disasters. We aimed to examine children's mental health in the area affected by the Hebei Spirit oil spill accident on December 7, 2007. METHODS: A cross-sectional questionnaire survey was conducted using the Korean versions of the Children's Depression Inventory and State Anxiety Inventory for Children on 1,362 children attending elementary schools in the affected area. The information on distances between the nearest contaminated coastline to the child's residential house or attending school were obtained using a web-based map by inputting two address points. The symptom risks of depression and state anxiety were estimated by multiple logistic regression analyses adjusted for age, gender, and other covariates. RESULTS: Children with the closest distance (in the fourth quartile) to the school from the contaminated coastline showed a significantly higher symptom risk of depression compared to those with the farthest distance (first quartile)(odds ratio, 2.73; 95% confidence interval, 1.40-5.33), while there was no significant association between anxiety symptoms and distance. CONCLUSIONS: Children, a vulnerable population for mental health impact by the oil spill accident, should be included in mental health programs in the community along with their family as victims of the disaster.
Anxiety ; Child ; Depression ; Disasters ; Humans ; Logistic Models ; Mental Health* ; Petroleum Pollution* ; Vulnerable Populations ; Surveys and Questionnaires

This article was initially published on the Environmental Health and Toxicology 2013;28:e2013008, with a misspelled name of the 7th coauthor.

OBJECTIVES: The role of genetic polymorphisms of tumor necrosis factor-alpha (TNF-alpha) for lung cancer development was evaluated. METHODS: Genotypes of the TNF-alpha polymorphisms, -1210C>T, -487A>G, -417A>G, IVS1+123G>A, and IVS3+51A>G, were determined in 616 lung cancer cases and 616 lung cancer-free controls. RESULTS: After adjusting for body mass index and smoking, each TNF-alpha genotype or haplotype composed of five TNF-alpha single nucleotide polymorphisms did not show an association with lung cancer risk (p>0.05). The statistical power was found to be 88.4%, 89.3%, 93.3%, 69.7%, and 93.9% for 1210C>T, -487A>G, -417A>G, IVS1+123G>A, and IVS3+51A>G, respectively. Furthermore, the effects of each SNP or haplotype on lung cancer risk were not found to be different according to the cell type of lung cancer (p>0.05). In the repeated analysis with only subjects without other diseases related to inflammation, there was also no association between polymorphisms or haplotypes of the TNF-alpha gene and lung cancer risk (p>0.05). CONCLUSIONS: This study found no association between common variants of the TNF-alpha gene and lung cancer risk.
Body Mass Index ; Genotype ; Haplotypes ; Inflammation ; Lung Neoplasms* ; Lung* ; Polymorphism, Genetic ; Polymorphism, Single Nucleotide ; Smoke ; Smoking ; Tumor Necrosis Factor-alpha*

OBJECTIVES: Potential environmental risks caused by chemicals that could be released from a recycled plastic product were assessed using a screening risk assessment procedure for chemicals in recycled products. METHODS: Plastic slope protection blocks manufactured from recycled plastics were chosen as model recycled products. Ecological risks caused by four model chemicals -di-(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), cadmium (Cd), and lead (Pb)- were assessed. Two exposure models were built for soil below the block and a hypothetic stream receiving runoff water. Based on the predicted no-effect concentrations for the selected chemicals and exposure scenarios, the allowable leaching rates from and the allowable contents in the recycled plastic blocks were also derived. RESULTS: Environmental risks posed by slope protection blocks were much higher in the soil compartment than in the hypothetic stream. The allowable concentrations in leachate were 1.0x10(-4), 1.2x10(-5), 9.5x10(-3), and 5.3x10(-3) mg/L for DEHP, DINP, Cd, and Pb, respectively. The allowable contents in the recycled products were 5.2x10(-3), 6.0x10(-4), 5.0x10(-1), and 2.7x10(-1) mg/kg for DEHP, DINP, Cd, and Pb, respectively. CONCLUSIONS: A systematic ecological risk assessment approach for slope protection blocks would be useful for regulatory decisions for setting the allowable emission rates of chemical contaminants, although the method needs refinement.
Cadmium ; Diethylhexyl Phthalate ; Mass Screening ; Plastics* ; Risk Assessment* ; Rivers ; Soil ; Water

OBJECTIVES: This study was conducted to determine whether nano-sized carbon black exposure results in greater damage in high fat diet-induced overweight rats than normal weight ones and to identify the possible causes of any differences. METHODS: Two groups of Sprague-Dawley rats allocated by body weight (normal and overweight) were exposed to aerosolized nano-sized carbon black for 6 hours a day, 5 days per week over a 4-week period. Differential cell counts, lactate dehydrogenase (LDH) activities and albumin concentrations were measured in bronchoalveolar lavage (BAL) fluid, and histopathological findings in the lungs were evaluated. Tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6 were measured in BAL fluid and supernatants of lipopolysaccharide(LPS)-stimulated lymphocyte culture. RESULTS: Rats exposed to high concentrations of nano-sized carbon black showed significantly increased (p<0.05) polymorphonuclear leukocyte number and LDH activity in the BAL fluid from both overweight and normal rats. Mild histopathological changes were observed in normal rats irrespective of carbon black concentrations. However, severe histological scores were found in overweight rats (1.75+/-0.46, 2.25+/-0.46, and 2.88+/-0.35 after low, medium, and high concentration exposures). Proinflammatory cytokine levels of TNF-alpha and IL-6 were significantly higher in the supernatant of LPS-stimulated lymphocytes of overweight rats, whereas there was no significant difference in the BAL fluid between normal and overweight rats. CONCLUSIONS: Inflammation and damage to lungs exposed to nano-sized carbon black was more severe in high fat diet-induced overweight rats compared to normal rats.
Animals ; Body Weight ; Bronchoalveolar Lavage ; Carbon* ; Cell Count ; Inflammation ; Inhalation ; Interleukin-6 ; Interleukins ; L-Lactate Dehydrogenase ; Lung* ; Lymphocytes ; Neutrophils ; Obesity ; Overweight* ; Rats* ; Rats, Sprague-Dawley ; Soot* ; Tumor Necrosis Factor-alpha

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 microg/L (range, 0.00-15.84 microg/L), 1.17 microg/g-creatinine (range, 0.00-32.86 microg/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 (beta=25.96; p=0.47), choice reaction time (beta=50.37; p=0.32), or the number of left-hand finger taps (beta=-1.54; p=0.21). However, urine mercury level was significantly associated with the number of right-hand finger taps (beta=-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.
Adult* ; Education ; Family Characteristics ; Fingers ; Hair ; Humans ; Korea ; Linear Models ; Medicine, Korean Traditional ; Reaction Time ; Smoke ; Smoking