As a fundamental study for chronic test (definitive test), the range finding test must have been done prior to conducting chronic test. The aims of this study were 1) to search the effective concentration range of two different heavy metals (cadmium and nickel) to indigenous collembolan species (Paranura rosea) 2) to compare the toxicity of cadmium and nickel depending on exposure durations. Toxicity tests were conducted in accordance with the standardized toxicity test proposed by OECD. In this study, there were no mortality occurred at all test concentrations for 7-days exposure. In contrast to 7-days exposure, there were slight increases in mortalities were observed at the concentration higher than 400 mg/kg for both heavy metals for 14-days exposure. The estimated LC50s for cadmium and nickel were 3980.65 (2036.08-64668.61) and 1597.85 (1087.87-3817.61) mg/kg, respectively. The results of this study may be used as a fundamental toxicity data for two heavy metals to proceed in chronic test in the future study.

실내에서 사육된 C. riparius를 대상으로 내분비계 교란물질인 DEHP를 처리하여 노출시간에 따른 기형발생률과 발생한 기형의 유형을 세분화하였다. 하순기절 구조별 기형발생률은 MLT (medial lateral tooth)에서 가장 높았고 그 다음이 LT (lateral tooth), MIX 순으로 높게 나타났다. 비처리군과 처리군 모두 MLT 단독의 기형이 가장 많았다. 하순기절의 기형유형은 여섯 가지로 세분화하였다. 발생빈도가 높은 기형유형은

The aim of present experiment was to examine hatching rate as in vitro indicator of viability of porcine embryos before early stage embryo transfer such as zygotes or 2-cell stage embryos. Cumulus-oocyte complexes (COCs) collected from ovaries were matured in North Carolina State University 23 (NCSU-23) containing 10% porcine follicular fluid (pFF), 10 ng/ml epidermal growth factor (EGF), follicle stimulating hormone (FSH), luteinizing hormone (LH), and 1mg/ml cysteine. After 24 hours, the COCs were transferred to the same medium without hormones. After 65h of maturation, oocytes were exposed to phosphate buffered saline (PBS) with 7% ethanol (v/v) for 7 minutes, and then the oocytes were washed and cultured in tissue culture medium (TCM) 199 containing 5 ug/ml cytochalasin B for 5h at in an atmosphere of 5% and 95% air with high humidity. After cytochalasin B treatment, the presumptive parthenotes were cultured in porcine zygote medium (PZM)-5 and cleavage of the parthenotes was assessed at 72h of activation, Normally cleaved parthenotes were cultured for an additional 8 days to evaluate their ability to develop to blastocyst and hatching stages. The fetal bovine serum (FBS) were added at Day 4 or 5 with concentrations of 2.5, 5 or 10%. The blastocyst rates were ranged within in each treatment. However hatching rate was dramatically decreased in non-addition group. In this experiment, embryo viability in female reproductive tract may be estimated before embryo transfer with in vitro culture adding FBS by hatching ability.

실내에서 사육된 C. riparius를 대상으로 내분비계 교란물질인 BPA와 4-nonylphenol을 처리하여 형태적인 변화를 살펴보았다. 약제에 노출된 개체의 하순기절은 부드러워지거나(smooth) 손실(loss)이 가장 많았다. 처리물질에 따른 기형의 정도를 살펴보면, BPA는 31~90%, 4-nonlyphenol은 40~80%의 범위를 보였다. BPA는 처리 농도가 증가할수록 기형도 증가하였으나 4-nonylphenol

Our previous research has identified granulin (grn) and p130 genes as sex steroidinducible genes in the rat hypothalamus, which might be involved in sexual differentiation of the brain. Phthalate esters that are used as plasticizers and also found at low levels in foods such as dairy products are often mentioned as suspected endocrine disrupters. The purpose of the present study is to elucidate whether perinatal exposure to dinbutyl phthalate (DBP), diisononyl phthalate (DINP) and di2ethylhexyl adipate (DEHA) affects hypothalamic sex steroidinducible genes. The present study assessed the effects of perinatal exposure to DBP, DINP and DEHA on sex steroid hormones levels and hypothalamic grn and p130 mRNA expressions at postnatal day (PND) 3 and 7. Pregnant rats were fed a soyfree diet containing 20, 200, 2,000 and 10,000 ppm of DBP, 40, 400, 4,000 and 20,000 ppm of DINP, or 480, 2,400 and 12,000 ppm of DEHA from gestational day (GD) 15 to GD 3 or 7. At PND 3 and 7, perinatal exposure to these chemicals did not substantially affect serum concentrations of testosterone and estradiol. At PND 3, the expression of grn mRNA levels in males was decreased by DEHA, and that of p130 was decreased by DBP, DINP and DEHA, though the effects were not dosedependent. At PND 7, the expression of grn gene in female pups was increased by higher doses of DBP and all the doses, except for 4,000 ppm, of DINP, while that in male pups decreased by 480 and 12,000 ppm of DEHA. Hypothalamic expression of p130 mRNA in males was increased by lower doses of DBP and all the doses of DINP, whereas that of females was decreased by 480 and 2,400 ppm of DEHA. These results suggest that these chemicals may affect the expression of grn and p130 genes by directly acting on the hypothalamus, thus leading to inappropriate expression of these genes.

Di-n-butyl phthalate (DBP), diisononyl phthalate (DINP) and di-(2-ethylhexyl) adipate (DEHA) are ubiquitously distributed chemicals that are widely used as plasticizers and also found at low levels in foods. The aims of this study were to determine whether perinatal exposure to DBP, DINP and DEHA could alter normal patterns of neonatal development. Dams were provided with pulverized soy-free diet containing 20, 200, 2,000 and 10,000 ppm of DBP, 40, 400, 4,000 and 20,000 ppm of DINP, or 480, 2,400 and 12,000 ppm of DEHA from gestational day 15 to postnatal day 21. Exposure to the high doses of DBP, DINP and DEHA during gestational period significantly decreased food consumption and body weight gain of dams. These chemicals reduced neonatal body weight as well as that of the after maturation. Also, exposure to DINP of all the doses used and the higher doses (2,400 and 12,000 ppm) of DEHA decreased AGD at PND 1 in male neonates, though that to DBP did not affect AGD in males. In female neonates, an increase in AGD was observed in DBP- and DINP-exposed animals at the highest doses. Moreover, these chemicals affected survival rate of pups at PND 5, and delayed onset of eye opening in all chemical-exposed groups at PND 17. These results suggest that perinatal exposure to these chemicals may affect the normal development and / or growth of offspring.

Effects of three packing materials and exposure time on the mortality of Plodia interpunctella and Tribolium castaneum were studied using CO₂-modified atmosphere control. Materials used were triple layered craft paper (KKK), triple layered craft paper with one laminate coating layer (KLK), and triple layered craft paper with one HD film coating layer (KHK). In the test balls (ø 1.2 m) containing 85% CO₂-modified atmosphere, concentration of CO₂ in small packing envelopes (9.8×9.8 ㎝) made of the materials after one day was higher in KKK (26.67±0.58%) than KLK (23.33±0.58%) or KHK (20.67±0.58%). Both P. interpunctella and T. castaneum showed higher mortality in KKK than in either KLK or KHK. Similar results were obtained by larger space (9×4×3 m) and packing volume (20 ㎏) studies. The effect of the packing materials was clearer on T. castaneum more tolerant to CO₂ than P. interpunctella. Regression of the insect mortality on cumulative concentration time (∫<SUP>t</SUP>₀c × tdc ≈ ∑concentration × time) was highly significant. Control of P. interpunctella and T. castaneum by CO₂-modified atmosphere were discussed in relation to packing materials, cumulative concentration time of CO₂ and food products.

This study performed and re-analysed the articles of exposure assessment for the indoor environment of houses in many environment-related journals published. in Korea since 1990. Based on this comparative study, we estimated the unit health risk on indoor environment. The objective of this study was to offer scientific data for decision-making policy for improvement and management of indoor air quality on Korean house in. The pooled concentrations for the critical air pollutants in the house were 13.93±13.91㎍/m3 (PM10), 680±226 ppm for (CO2), 1.9±1.6 ppm (CO), 419±158 CFU/m3 (bacteria), 0.036 ± 0.002 ppm (NO2), and 104.935 ± 16.424 Bq/m3 (Rn), The pooled concentrations for the volatile organic compounds were 6.9±6.7㎍ /m3 (benzene), 39.3±55.1㎍/m3 (toluene), 4.2±4.0㎍/m3 (ethylbenzene), 11.4±8.3㎍/m3 (m, p-xylene), 4.2 ±1.5㎍/m3 (styrene) and 6.3±4.5㎍/m3 (o-xylene). The unit cancer risk for men and women by inhalation of benzene was 3.7 × 10-5 and 4.8 × 10-6, respectively. In additio

Indoor air quality tends to be the dominant contributor to personal exposure, because most people spend over 80% of their time indoors. In this study, indoor and outdoor NO2 concentrations were measured simultaneously with personal exposures of 30 university students in weekday and weekend in Daegu, Korea. House characteristics and subject's activity pattern were used to determine the effects on personal exposure. Since university students spent most of their times indoor, their NO2 exposure was associated with indoor NO2 level during both weekday and weekend in spite of different time activity. Using a time-weighted average model, NO2 exposures of university students were estimated by NO2 measurements in indoor home, indoor school, and outdoor home. In conclusion, major personal exposure to NO2 resulted from air quality of indoor environment at house.

The exposed strain of C. riparius treated with di (ethyl- hexyl)-phthalate (DEHP) did not result in a consistent relationship between mortality or sex ratio and chemical concentrations. And after treating with DEHP, the emergent female from the exposed st