Taksoo Kim

Survey of Exposure Factors for Risk Assessment of Hazardous Materials in Child-Specific Products

Background: Despite children’s unique characteristics that distinguish them from adults, relatively few attempts have been made to measure exposure factors for characterization of children’s exposure to hazardous chemicals in child-specific products (CSP). This study was conducted to establish the child-specific exposure factors for exposure and risk assessment of hazardous substances in CSP. Methods: We investigated the exposure factors (e.g., time use of child-products, time and frequency of objectto-body contact, time and frequency of object-to-mouth contact) influencing children’s exposure to CSP (e.g., toys, playmats, oil pastels, etc.) in 650 children through a parent-completed questionnaire using a web-based survey. Participants were recruited in five age groups, <1, 1-2, 2-3, 3-6, and 6-12 years of age. Results: The child-specific exposure factors were presented as the mean, median, 95 percentile, minimum, and maximum values. Time activity for play mats was the longest among CSP and infants spent more time on them than did elder age groups (189.3-224.7 min/day for <1-2 years vs. 91.2 min/day for 6-12 years). It is apparent that time and frequency of toy blockand plastic toy-to-mouth contact significantly decreased as a function of age. When the variation of CSP use patterns was compared by gender, the only variable that was statistically different between genders was time activity in child-products exposure space. Conclusion: We believe the five child-specific exposure factors suggested in the present study will be valuable for reducing uncertainty in the estimation of chemical exposure during risk assessment of CSP and furthermore, in the appropriate regulations to protect children’s health.

Determining Exposure Factors of Anti-Fogging, Dye, Disinfectant, Repellent, and Preservative Products in Korea

Reliable exposure factors are essential to determine health risks posed by chemicals in consumer products. We analyzed five risk-concerned product categories (anti-fogging, dye, disinfectant, repellent, and preservative products) for 13 products (three car anti-fogging products, a lens anti-fogging product, two car dye products, two drain disinfectants, an air conditioner disinfectant, a chlorine-based disinfectant, a fabric repellent, an insect repellent for food, and a wood preservative) considered to be of high risk in order to determine exposure factors via web surveys and estimation of amount of product. Among the 3000 participants (1482 (49%) men) aged ≥19 years, drain disinfectants were used most frequently (38.2%); the rate of usage of the other products ranged between 1.1–24.0%. The usage rates for the consumer products differed by sex, age, income, and education. Some consumer products such as car and lens anti-fogging products, chlorine-based disinfectants, fabric repellents, and drain disinfectants were regularly used more than once a month, while car dye products, air conditioner disinfectants, insect repellents for food, and wood preservatives were not regularly used owing to the specific product purposes and seasonal needs. Our results could be used for managing or controlling chemical substances in consumer products and conducting accurate exposure assessments.

Accumulation of Microcystins in Fish and Evaluation of Potential Human Health Risks: A Case Study on a Eutrophic Reservoir in Korea

【Objectives: Microcystin (MC) produced during cyanobacterial blooms is a worldwide problem presenting a serious health threats to humans and ecosystems. During July through October of 2013, the Ilwol Reservoir experienced a high biomass of phytoplankton (maximum

Human Risk Assessment of Perchloroethylene Considering Multi-media Exposure

211.7mg/m^3

Future Challenges for Risk-Based Management of 135 Environmental Hazardous Substances in Children's Products

of Chlorophyll-a) containing the toxigenic cyanobacterium Oscillatoria sp. The aim of this study is to analyze MC concentration in the reservoir water, as well as in representative fish species (Carassius cuvieri, Carassius auratus, Channa argus). We also evaluated the human health risk of exposure to MCs accumulated in the fish. Methods: Concentrations of MCs in the water and fish samples were analyzed by liquid chromatography with a triple quadrupole tandem mass spectrometer (LC/MS/MS) and enzyme-linked immunosorbent assay (ELISA). Results: The total levels of four MC variants, including MC-LR, MC-RR, MC-YR and MC-LA were below the WHO drinking water guideline limit (1 ug MC-LR per liter) both for the dissolved and particulate fraction present in the water samples. The mean MC concentrations in the livers of all species were significantly higher than in the gills (p

Degradation mechanism and the toxicity assessment in TiO2 photocatalysis and photolysis of parathion

0.005-0.015{\mu}g/kg{\cdot}day

Estrogen receptor gene polymorphism and craniofacial morphology in female TMJ osteoarthritis patients

, much lower than WHOs provisional tolerable daily intake of

Development of Korean Exposure Factors for Children in Korea

0.04{\mu}g/kg{\cdot}day

Exposure Factor Development of Children's Hand and Mouthing Activities Using Videotaping Methodology and Analysis of Influential Factors

. Conclusion: This study suggests that, owing to the spatial distribution or temporal variation of MC, there is a need for careful monitoring of cyanotoxin in reservoir water and aquatic animals to protect public health.】

Microenvironmental time-activity patterns of weekday and weekend on Korean adults

National Institute of Environmental Research, Incheon, KoreaABSTRACTObjectives: Perchloroethylene (PCE) is a volatile chemical widely used as a solvent in the dry-cleaning andtextile processing industries. It was evaluated as Group 2 “probably carcinogenic to humans” by the IntegratedRisk Information System (IRIS) of the United State Environmental Protection Agency (U.S. EPA) in 2012. Inorder to provide a scientific basis for establishing risk management measures for chemicals on the nationalpriority substances list, aggregate risk assessment was conducted for PCE, included in the top-10 substances.Methods: We conducted the investigation and monitoring of PCE exposure (e.g., exposure scenario, detectionlevels, and exposure factors, etc.) and assessed its multi-media (e.g., outdoor air, indoor air, and ground water)exposure risk with a deterministic and probabilistic approach. Results: In human risk assessment (HRA), the level of human exposure was higher in the younger age group.The exposure level through inhalation at home was the highest among the exposure routes. Outdoor air or uptakeof drinking water represented less than 1% of total contributions to PCE exposure. These findings suggested thatthe level of risk was negligible since the Hazard Index (HI) induced by HRA was below one among all agegroups, with a maximum HI value of 0.17 when reasonable maximum exposure was applied. Conclusion: In conclusion, it was suggested that despite low exposure risk, further studies are neededconsidering main sources, including occupational exposure. Keywords: Monte-carlo method, Perchloroethylene, Risk assessment