• Toxicological Research
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• v.24 no.1
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• pp.37-44
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• 2008

The in vitro cell transformation assays (CTA) were performed using BALB/3T3 murine fibroblasts and HaCaT human keratinocytes in order to evaluate concordance between both in vitro CTAs and carcinogenicity with compounds differing in their genotoxic and carcinogenic potential. Six test articles were evaluated, two each from three classes of compounds: genotoxic carcinogens (2-amino-5-nitrophenol and 4-nitroquinoline-N-oxide), genotoxic noncarcinogens (8-hydroxyquinoline and benzyl alcohol), and nongenotoxic carcinogens (methyl carbamate and N-nitrosodiphenylamine). Any foci of size $\geq$2 mm regardless of invasiveness and piling was scored as positive in CTA with BALB/3T3. As expected, four carcinogens regardless of their genotoxicity had positive outcomes in two-stage CTA using BALB/3T3 cells. However, of the two genotoxic noncarcinogens, benzyl alcohol was positive CTA finding. We concluded that, of the 6 chemicals tested, the sensitivity for BALB/3T3 system was reasonably high, being 100%. The respective specificity for BALB/3T3 assay was 50%. We also investigated the correlation between results of BALB/3T3 assay and results from HaCaT assay in order to develop a reliable human cell transformation assay. However, evaluation of staining at later time points beyond the confluency stage did not yield further assessable data because most of HaCaT cells were detached after $2{\sim}3$ days of confluency. Thus, after test article treatment, HaCaT cells were split before massive cell death began. In this modified protocol for this HaCaT system, growing attached colonies were counted instead of transformed foci 3 weeks since last subculture. Compared to BALB/3T3 assay, HaCaT assay showed moderate low sensitivity and high specificity. Despite these differences in specificity and sensitivity, both cell systems did exhibit same good concordance between in vitro CTA and rodent carcinogenicity findings (overall 83% concordant results). At present the major weakness of these in vitro CTA is lack of validation for regulatory acceptance and use. Thus, more controlled studies will be needed in order to be better able to assess and quantitatively estimate in vitro CTA data.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.3
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• pp.203-215
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• 2010

This study is an overview of toxicities and measurement techniques of ultrafine particles (UFPs), and their exposure controls. UFPs are ubiquitous in many working situations. Exposure to UFPs is possibly causing adverse health symptoms including cardio-respiratory disease to humans. In order to measure exposure levels of airborne UFPs, there are current available measurement guidelines, instruments and other techniques (i.e. contour mapping, control banding). However, these risk assessment techniques including measurement techniques, controls and guidelines are dependent on background levels, metrics (e.g. size, mass, number, surface area, composition), environmental conditions and controls. There are no standardized measurement methods available and no generic and specific occupational exposure standards for UFPs. It is thought that there needs to be more effort to develop Regulations and Exposure Standards for generic UFPs should be based on more exposure data, health surveys, toxicological data and epidemiological data. A carefully considered hierarchy of controls can also reduce the maximum amount of airborne UFPs being emitted from diverse sources in industries.

• Toxicological Research
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• v.18 no.2
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• pp.167-174
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• 2002

Historical control data have been shown to be valuable in the proper interpretation and validation of reproductive toxicology studies. The present data were compiled from rat fertility and early embryonic development studies conducted at Korea Institute of Toxicology during the 1994∼2001 period. These data were assembled in order to provide background information for the general and reproductive data collected in 11 fertility and early embryonic development studies using Sprague-Dawley rats obtain-ing from the Breeding Facility, Korea Institute of Toxicology, Korea. A total of 274 males and 274 females were used in these studies during the eight-year period. Parameters of fertility and early embryonic development included clinical sign, body weights, food consumption, organ weights, estrus cycle, copulation index, precoital time, fertility index, pregnancy index, sperm parameters, and early embryonic development parameters. Most of the values were comparable to the previous historical control data reported by other investigators. These data can be wed not only as a historical data base for the meaningful interpretation of data from reproductive and developmental toxicity studies, but also as a contribution to biological characterization of Sprague-Dawley rats.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2002.10a
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• pp.107-116
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• 2002

GLP regulations were initially “promulgated to address assuring the validity of data in the wake of investigations by EPA and FDA during the mid -1970's which revealed that some studies submitted to the agencies had not been conducted in accordance with acceptable laboratory practices.” [1] In the early 1970s, results of an investigation by the FDA in about 40 laboratories revealed many cases of badly managed studies, poor training of personnel and some cases of deliberate fraud. The general findings were that there were poorly trained study directors and study personnel, poorly designed protocols, protocols not followed, procedures not conducted as described, raw data badly collected, data not correctly identified, data without traceability, data not verified and approved by responsible persons, lack of standardised procedures, poor animal husbandry, inadequate characterisation of test items and test systems, inadequate resources, equipment poorly calibrated or otherwise qualified, reports not sufficiently verified, not an accurate account of the actual study, not a proper reflection of raw data and inadequate archiving of data. These problems are not just past history, since they resurface time and time again, even in quite recent times as the experience of GLP inspectors shows [1]. The GLPs specify minimum practices and procedures in order to ensure the quality and integrity of data submitted in accordance with a regulatory requirement

• Toxicological Research
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• v.23 no.2
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• pp.173-177
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• 2007

The GLP contains specific language concerning characterization of the test, control and reference substances used in toxicity studies. This paper will describe and discuss what types of documents are required to support test/reference substance characterization under GLP system. The purpose of this article is to present an overview of data needed in the characterization package that will adequately define the substance. Most sponsors use a certificate of analysis (COA) to communicate the test sub-stance characterization status information to the contracting research organizations. The COA should provide the test $material^{\circ}{\phi}s$ characterization results, substance storage requirements, expiration dates, verification of the collection of the retention sample, archival location of the data to support the characterization and GLP compliance status of the characterization.

• Journal of Food Hygiene and Safety
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• v.2 no.3
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• pp.137-148
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• 1987

The wholesomeness studies on irradiated foods and the evaluation of the data obtained have been conducted at both national and international levels. The conclusion of the FAO/IAEA/WHO Expert Committee on Wholesomeness of Irradiated Food in 1980 that irradiated foods treated with doses up to 10 kGy are safe for human consumption are being significantly influencing on the regulatory circumstances, in individual countries as well as a regional economic community. Principles of the wholesomeness evaluation, importance of radiation chemical considerations, methodology of toxicological testing and the interpretation of in vitro and in vivo toxicity studies are discussed. Emphasis is placed on the progress of methods for wholesomeness studies and data evaluations and also on the importance e of comparative assessments together with safety problems concerning other food treatments and environmental factors.

• The Korean Journal of Applied Statistics
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• v.8 no.2
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• pp.147-161
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• 1995

The primary objective of this paper is to review parametric models and test statistics related to overdspersion of count data. Poisson or binomial assumption often fails to explain overdispersion. We reviewed real examples of overdispersion in count data that occurred in toxicological or teratological experiments. We also reviewed several models that were suggested for implementing experiments. We also reviewed several models that were suggested for implementing the extra-binomial variation or hyper-Poisson variability, and we noted how these models were generalized and further developed. The approaches that have been suggested for the overdispersion fall into two broad categories. The one is to develop a parametric model for it, and the other is to assume a particular relationship between the variance and the mean of the response variable and to derive a score test staistics for detecting the overdispersion. Recently, Dean(1992) derived a general score test statistics for detecting overdispersion from the exponential family.

• Toxicological Research
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• v.18 no.1
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• pp.65-71
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• 2002

A benchmark dose (BMD) approach has been evaluated us a replacement for the traditional NOAEL methodology currently being wed to assess the noncancer effects of toxicants. The endocrine disrupt-ing effect of endosulfan which showed decrement of sperm count and testicular testosterone level in animals, was currently reported. The amount of endosulfan used as pesticide in the country has been continuously increased. The aim of this study was to suggest the permissible intake level (PIL), corresponding to Accept-able Daily Intake (ADI), based on endocrine disrupting effect wing BMD. Various animal data were collected by consideration of critical effect showing endocrine disruption and an animal data for reproductive toxicity was selected. The Power model from BMD software for induction of $BMD_10$ having meaning which is the dose at the 95% lower confidence limit on a 10% response was used due to that the form of selected dose-response animal data was continuous data. The $BMD_10$ was estimated to be 0.393 mg/kg/day based on reproductive toxicity showing decrement of sperm count. The permissible intake level (PIL) was calculated by dividing the $BMD_10$ by the uncertainty factors of 100 with consideration of from animal to human and human variability. The PIL as 0.004 mg/kg/day was compared with traditional ADI as 0.006 mg/kg/day based on the incidence of marked progressive glomerulonephrosis and blood vessel aneurysm in males.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.5
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• pp.359-366
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• 2014

For an efficient and reasonable management scheme for protecting the soil environment, a soil ecological risk assessment (ERA) method should be developed prior to utilization, based on the contemporary uses and situations of each country. The Korean environmental policy focusing on soil protection is currently accelerating the development of the soil ecological risk assessment method. The soil ERA requires toxicological data on various trophic levels in the soil environment, and ultimately uses PNEC (Predicted No Effect Concentration), which is derived from collected toxicological data. Therefore, test species that are used to generate toxicity data are essential for conducting reliable ERA. This study aimed to select domestic test species for potential use in a reliable Korean ERA. Copper (Cu) and Nickel (Ni) were identified as target substances, with toxicity data (Cu, Ni) and standard test methods being collected to determine candidate species. The candidate species were first classified by soil trophic level, and then sorted into final domestic species. Forty out of 166 domestic species were determined as potential standard test species, whereas 17 out of 120 species were determined as potential Cu and Ni test species. Finally, this study presented potential soil test species based on the characteristics of the domestic soil environment, and established a preliminary step toward developing a reliable Korean soil ERA method.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.2
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• pp.156-163
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• 2012

Objectives: The aim of the present study was undertaken to investigate the association between communication for chemical hazard information and characteristics of occupational safety and health managers. Subjects and Methods: We surveyed 78 occupational safety and health managers(64 male and 14 female) in 78 chemical manufacturing plants. Data were obtained using a self-reported questionnaire about size and type of company, products, communication system for chemicals and work-related characteristics of occupational safety and health managers. All analyses in this study were performed using SPSS program 12.0. Results: 64.1% of the study participants were occupational health managers aged 39.3 years on average and were graduated from college and university around 90%. 30.0% and of them were majoring in chemistry (engineering chemistry), 18.0% occupational health, 16% nursing and 30.0% others. Occupational safety managers were aged 39.4 years on average, 42.9% of them were majoring in chemistry (engineering chemistry), 21.4% environmental engineering, 10.7% occupational safety and 25% others. 86% of occupational health managers and 71.4% of occupational safety managers were classified as office job. Over 94% of the hazards information for chemicals were delivered by occupational safety and health managers, but about 28.2% workers preferred outside experts who have a profound knowledge about occupational safety and health and understandable. Occupational safety and health managers and workers had difficulties in understanding toxicological information, hazards identification, stability/reactivity, composition/information on ingredients, physical/chemical properties and ecological information. On multiple logistic regression analysis for the 16 heading of material safety data sheet, content of material safety data sheet was significantly associated with education level (odds ratio=0.286, 95% confidence interval=0.105-0.780). The hazard identification (odds ratio=3.947, 95% confidence interval=1.092-14.271) and toxicological information (odds ratio=0.841, 95% confidence interval=0.705-0.998) were significantly associated with type of occupation. Conclusions: This finding implies that the education level, type of occupation and speciality of occupational safety and health managers may affects hazards information delivery.