著者

尾田 正二

出版者

The Japanese Society of Environmental Toxicology

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.19, no.1, pp.9-17, 2016-06-30 (Released:2018-09-04)

参考文献数

26

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The 4 morphological criteria for a new species of Japanese medaka, “Oryzias sakaizumii” proposed by Asai et al.(2011) were examined in males of 75 closed colonies derived from wild populations caught in the Japan islands and maintained for longer than 30 years in laboratory. Males of 14 colonies from the Northern population medaka (“O. sakaizumii” ) were identified only by one criterion: “dense network of melanophores along each scale margin on body side” , and it was impossible to distinguish the males of the Northern populations from those of the Southern population(O. latipes) by the other 3 criteria. In addition, it has been known that hybrid populations between the Southern and the Northern populations are present in Tajima-Tango area in wild, providing the evidence for crossing of the two medaka populations in Japan in this area. In this report, the author concludes that the Southern and the Northern populations of Japanese medaka are the same species and the Northern population is a geographical subspecies of O. latipes), since both populations have crossed naturally and the confirmed morphological difference between them is slight, not giving a clear implication that these populations have differentiated into separate species.

著者

Naomasa Kobayashi Chisato Kataoka Shosaku Kashiwada

出版者

The Japanese Society of Environmental Toxicology

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.23, no.2, pp.38-46, 2020-07-22 (Released:2020-07-21)

参考文献数

12

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We compared stage-dependent sensitivities of the sea urchin Anthocidaris crassispina to silver nitrate (AgNO3) and silver nanocolloids (SNCs). Our experimental design included three different exposure experiments: (1) pre-fertilization exposures (to assess effects on first cleavage and embryogenesis); (2) exposures of fertilized eggs (to assess effects on cleavage and embryogenesis); and (3) exposures of gastrulae (to assess effects on the gastrula stage and embryogenesis). In the case of the pre-fertilization exposures, exposure of sperm to SNCs induced higher rates of abnormal development than did exposure to AgNO3, and SNCs had higher teratogenicity on pluteus formation than did AgNO3. In the case of the fertilized egg exposures, exposed embryos experienced high rates of cytolysis. These rates exceeded those observed in pre-fertilization exposures of eggs and sperm and were similar to those observed in exposures of sperm alone. In the case of the gastrula exposures, rates of cytolysis were higher than those observed in pre-fertilization exposures of eggs and sperm and lower than those observed in exposures of fertilized eggs and of sperm alone. Sperm exposures showed the highest chemical sensitivity, followed by exposures of gastrulae and of unfertilized eggs and sperm.

著者

Yuki Takai Takumi Takamura Shintaro Enoki Moeko Sato Yoko Kato-Unoki Xuchun Qiu Yohei Shimasaki Yuji Oshima

出版者

The Japanese Society of Environmental Toxicology

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.23, no.1, pp.10-21, 2020-07-21 (Released:2020-07-21)

参考文献数

48

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Tributyltin (TBT) is an organotin compound that disrupts the endocrine system of aquatic organisms, and its obesogenic toxicity to various species is well known. However, the mechanism by which TBT disrupts the endocrine system has not been clarified. Therefore, to investigate the effects of TBT in fish, we exposed juvenile medaka (Oryzias latipes) to TBT and analyzed the gene expression changes using mRNA-Seq. As a result of this analysis, it was clear that toxicity-related genes, such as cytochrome P450 superfamily genes connected to hormonal metabolism, and peroxisomeproliferator-activated receptor signaling pathway genes related to obesity, were significantly affected by TBT. Thus, our mRNA-Seq results identified candidate genes for involvement in the mechanisms of TBT toxicity in TBT-exposed medaka. mRNA-Seq could be a strong tool to investigate and further understand the toxic effects caused by pollutants.

著者

Nana Ushine Shouta MM Nakayama Mayumi Ishizuka Takuya Kato Shin-ichi Hayama

出版者

The Japanese Society of Environmental Toxicology

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.26, pp.25-37, 2023-06-22 (Released:2023-06-22)

参考文献数

83

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Lead (Pb) is extensively used in industries and often inadvertently discharged into the environment. Despite some studies examining the effects of Pb pollution on raptors and waterfowl, its effects on other avian species have not been investigated. This study investigated the feeding selectivity of a black-headed gull (Chroicocephalus ridibundus) population using stable isotope ratios to determine the source of Pb pollution. Gulls in Tokyo and Mikawa Bay were captured from December 2016 to February 2017 and from December 2020 to March 2021, respectively. These gulls were measured 13C/12C carbon ratio (δ13C), and 15N/14N nitrogen ratio (δ15N). Blood Pb level (BLL) was measured gulls in Mikawa Bay. Based on the measurement values of δ15N, gulls were classified into two groups: primary and higher predator groups. No differences in stable isotope ratios were found between the two groups. The secondary consumers showed significantly high BLLs (P=0.002). BLLs during the wintering period were significantly higher in the primary consumer group. Our findings suggest that reducing Pb emissions, along with biological and chemical remediation of water sediment is required to prevent further Pb pollution and bioaccumulation in wild animals.

著者

Mayumi Yoshikawa Kaho Murakami Hitomi Inoue Masanori Seki

出版者

The Japanese Society of Environmental Toxicology

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.26, pp.1-7, 2023-01-31 (Released:2023-01-31)

参考文献数

14

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Styrene is a volatile chemical used as a raw material for production of synthetic resins and synthetic rubbers. A study of inhibition of algal growth was carried out according to OECD test guideline 201 in a completely closed system to clarify the inhibition of growth of the green alga Raphidocelis subcapitata by styrene. The median effective concentration for growth rate (ErC50) and no-observed-effect concentration for growth rate (NOECr) based on the measured concentrations of styrene were 5.99 mg/L and 0.985 mg/L, respectively. Based on these results, the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) classification of hazards to the aquatic environment of styrene was Category 2 for short-term (acute) exposure and Category 3 for long-term (chronic) exposure.

著者

Hideaki Tokusumi Naoto Fujioka Nguyen Minh Tue Akitoshi Goto Go Suzuki Kei Nakayama

出版者

The Japanese Society of Environmental Toxicology

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.24, pp.1-11, 2021-01-15 (Released:2021-01-15)

参考文献数

27

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In order to develop an optimal method for the investigation of relative potencies of dioxin-like compounds using Japanese medaka, the present study conducted five independent early-life stage toxicity tests using 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as the positive control. First, both short- and long-term effects of TCDD were examined to determine sensitive and highly reproducible endpoints. Then, the outcome and threshold of TCDD toxicities under different experimental conditions, e.g., exposure timing and duration, were compared to develop a cost-effective method. Finally, we decided to observe yolk sac/pericardial edema, hatching failure, and mortality of medaka embryos/larvae within a 28-d experimental period, after 6-h exposure to TCDD at 0-d post fertilization. We obtained the LC50 values of TCDD at 28-d post fertilization based on its concentration in water (6.84 ng/L) or in egg (753 pg/g-egg), and the LC50 values were comparable with those reported in the literature. Thus, in our future studies, relative toxic potencies of dioxin-like compounds will be tested using the method established in this study.

著者

Hiroshi Hoshino Shouichi Fujita Yoko Goto Takeomi Isono Tsuyoshi Ishinazaka Yasunori Sakurai Hisato Iwata Akio Kazusaka Mayumi Ishizuka Shinsuke Tanabe

出版者

The Japanese Society of Environmental Toxicology

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.6, no.1, pp.1-10, 2003 (Released:2010-07-01)

参考文献数

23

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o clarify the levels of organochlorine compounds (OCs) and the metabolism of OCs in the body of Steller sea lion Eumetopias jubatus migrating along the coast of Hokkaido, OCs in the sea lion's blubbers for each age, sex and reproductive status were determined by gas chromatography linked to ion trap mass spectrometer. In sea lions, the compounds accumulated in the highest concentrations are DDT and its metabolites (DDTs) suggesting these animals are still exposed to DDTs from the surrounding land. The levels of DDTs and polychlorinated biphenyls (PCBs) in sea lions may cause small effects such as the induction of drug metabolizing enzymes. The concentrations of DDTs, PCBs, hexachlorocyclohexanes and chlordanes in the old female sea lions were lower than those in the males and young females. This is most likely due to the loss of these compounds during nursing. In addition, the concentrations of each compound differed in the degree of difference between the young and the old females. This result may reflect ecological and physiological difference between the young and the old females. The proportions of tetrachlorinated biphenyl concentrations with vicinal hydrogen atoms in para- and meta- positions to total tetrachlorinated biphenyl concentrations were found to be higher in older animals implying low “phenobarbital inducible type” enzyme activity.

著者

江馬 眞 納屋 聖人 吉田 喜久雄 永翁 龍一

出版者

The Japanese Society of Environmental Toxicology

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.12, no.1, pp.1-18, 2009 (Released:2010-07-01)

参考文献数

80

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The present paper summarizes the data available in the literature concerning toxicity of the degradation products of 1,1,1,2-tetrahydrofluoroethane (HFC-134a), which is widely used worldwide as a refrigerant, and 2,3,3,3-tetrafluoropropene (HFO-1234yf), which is developed as a refrigerant for new generation. There are many studies available for toxic effects of carbon dioxide CO2) and carbon monoxide (CO) in humans and animals. General toxicity of excessive CO2 exposure in humans is well reported. However, information on reproductive and developmental toxicity of CO2 in humans and animals is inadequate for risk assessment. As for CO, further studies are required to evaluate the adverse effects of chronic exposure to low and near ambient levels of CO on development of fetuses and newborn infants in marginal condition because of high susceptibility to hypoxic effect in fetuses and newborn infants. There is a lack of information on toxicity of trifluoroacetic acid, carbonyl fluoride, hydrogen fluoride, and formic acid in humans and animals. Animal studies remain necessary for risk assessment of chemicals because it is difficult to find alternative methods to determine the toxic effect of chemicals.