Time series of hexabromocyclododecane transfers from flame-retarded curtains to attached dust.

While the production and new use of hexabromocyclododecane (HBCD) mostly ceased after being listed as a persistent organic pollutant under the Stockholm Convention in 2013, its emission from treated products in use to indoor environments still deserves attention. To examine the transfer of HBCD diastereomers to dust on the surface of flame-retarded curtains and to better characterize the potential of treated fabrics to be sources of HBCD in dust, we carried out a series of 196-day experiments using two types of curtains and attached dusts. Concurrently, the physicochemical properties (vapor pressure, water solubility, and octanol-water partition coefficient) of the HBCD diastereomers were measured. HBCD diastereomers migrated from curtains to dust with half-saturation times of about 20-50 days. By day 196, mean HBCD concentrations in dust had reached 13-290 µg/g, depending on the types of curtains and dusts. The composition of HBCD, dominated by γ-HBCD in the curtains, was dominated by α-HBCD in the post-experiment dusts, probably because of the higher vapor pressure of α-HBCD compared to γ-HBCD. The initial HBCD contents of the two curtains were comparable, but the concentrations and profiles of HBCD diastereomers in the post-experiment dusts differed markedly, probably because differences between the texture and/or surface finishing of the treated fabrics affected HBCD transfer to the attached dust.

Proposal of a flow scheme for the chemical-form-based quantitative analysis of chlorine compounds in pulp for sanitary products and verification of safety.

To determine the amounts and chemical forms of chlorine compounds in elemental chlorine-free (ECF) bleached pulp for sanitary products, a chemical-form-based quantitative analysis flow scheme was created. The scheme involves quantitative determination of compounds eluted in elution tests assuming dermal exposure. The results indicated that most of the chlorine compounds in pulp used for sanitary products were insoluble organically bound chlorine and water-soluble chlorides consisting of chloride ions. The total amount of chlorine obtained by analysis of the total chlorine in the pulp products was close to the sum of the amounts of water-soluble chlorides, residual chlorine, chloroacetic acids, and insoluble organically bound chlorine. Therefore, the balance of chlorine measured by the flow scheme was acceptable. Little residual chlorine was detected in the pulp products, suggesting that the chlorine dioxide used for bleaching was almost completely converted into inactive inorganic chlorides and organic chlorine compounds and that these substances do not affect the health risk posed by pulp products. A risk assessment of the detected chloroacetic acid and dichloroacetic acid revealed that there is no concern about the health risk posed by use of these products.

Identification of a novel component leading to anti-tumor activity besides the major ingredient cordycepin in Cordyceps militaris extract.

In accordance with our previous study that was carried out to identify novel anti-tumor ingredients, chromatographic separation in combination with an anti-tumor activity assay was used for analysis of Cordyceps militaris extract in this study. Various modes of chromatography including reversed-phase, cation-exchange and anion-exchange were used to separate components of Cordyceps militaris, which showed various chemical properties. Anti-tumor activity of each fraction was assessed by a Hoechst staining-based apoptosis assay using malignant melanoma MeWo cells. By these repeated approaches through chromatographic segregation and cell biological assay, we finally succeeded in identifying the target substance from a certain fraction that included neutral hydrophilic components using a pre-column and post-column chlorine adduct ionization LC-APCI-MS method. The target substance was a mono-carbohydrate, xylitol, that induced apoptotic cell death in MeWo cells but not in normal human OUMS-24 fibroblasts. This is the first study showing that Cordyceps militaris extract contains a large amount of xylitol. Thus, our results will contribute greatly to uncovering the mysterious multifunctional herbal drug Cordyceps militaris as an anti-tumor agent.

Direct contact between dust and HBCD-treated fabrics is an important pathway of source-to-dust transfer.

Hexabromocyclododecanes (HBCDs) are a class of brominated flame retardant that have found extensive application in consumer products used widely in indoor environments. Although uncertainty remains about the human health impacts of HBCDs, ingestion of HBCD-contaminated indoor dust has been shown to be a particularly significant exposure pathway for young children. Despite this, understanding of the mechanisms via which HBCD transfer from products to indoor dust remains incomplete. In this study, an in-house test chamber was used to investigate transfer of HBCDs from a treated textile sample to indoor dust via direct textile:dust contact. Results were compared with previous data using the same test chamber to examine other pathways via which HBCDs transfer from products to dust, and highlighted HBCD transfer via direct source:dust contact as being particularly important. This novel finding was corroborated by complementary experiments that examined HBCD transfer via direct contact, from other treated textiles to three major components of indoor dust: artificial indoor dust, soil particles, and cotton linters.

Investigation of the amount of transdermal exposure of newborn babies to phthalates in paper diapers and certification of the safety of paper diapers.

A risk assessment study of seven phthalates in paper diapers for newborn babies produced in Japan was performed. The diapers were purchased and the contents of the seven phthalates were determined and estimated amounts of exposure were calculated based on the eluted rate into artificial medium of urine or sweat, average weight of infants, and frequency of use. Di-2-ethylhexyl phthalate and di-n-butyl phthalate were detected in the topsheets and determined to be 0.6 µg/g and 0.2 µg/g, respectively. The daily estimated exposure volume was calculated to be in the range of 1.86 × 10(-10)-2.98 × 10(-6) mg/kg/day as follows: content of seven phthalates in the topsheet (0.1-1 µg/g) × eluted rate of phthalates into artificial sweat (0.0006-2.4%) × weight of the topsheet of a diaper (1.5 g) × the number of diapers used per day (12 sheets) × skin absorption rate (0.005-0.1)/average body weight (2.9 kg). For hazard assessment, we used 0.2-300 mg/kg/day for the seven phthalates based on the data available at international agencies. The margin of exposure to the seven phthalates was 6.71 × 10(4)-1.99 × 10(11), indicating that the risk of exposure to phthalates from the diapers produced in Japan was negligible.

Determination of mustard and lewisite related compounds in abandoned chemical weapons (Yellow shells) from sources in China and Japan.

Knowledge of the states of the contents in chemical munitions that Japanese Imperial Forces abandoned at the end of World War II in Japan and China is gravely lacking. To unearth and recover these chemical weapons and detoxify the contents safely, it is essential to establish analytical procedures to definitely determine the CWA contents. We established such a procedure and applied it to the analysis of chemicals in the abandoned shells. Yellow shells are known to contain sulfur mustard, lewisite, or a mixture of both. Lewisite was analyzed without thiol derivatization, because it and its decomposition products yield the same substances in the derivatization. Analysis using our new procedure showed that both mustard and lewisite remained as the major components after the long abandonment of nearly 60 years. The content of mustard was 43% and that of lewisite 55%. The viscous material found was suggested to be mostly oligomers of mustard. Comparison of the components in the Yellow agents with mustard recovered in both Japan and China showed a difference in the impurities between the CWAs produced by the former Imperial navy and those by the former Imperial army.

Immature uterotrophic assay of estrogenic compounds in rats given diets of different phytoestrogen content and the ovarian changes with ICI 182,780 or antide.

To investigate the influence of phyotestrogens in the diet, an immature uterotrophic assay of ethinylestradiol, bisphenol A, 4-nonylphenol or genistein was performed in rats given the formula MF diet, modified NIH-07 open formula diet, or modified NIH-07 phytoestrogen-lowered-diet (study 1). The chemicals were administered subcutaneously from 20 days of age for 3 days. Doses of ethinylestradiol, bisphenol A, 4-nonylphenol or genistein were 0.06-0.6 micro g/kg per day, 1-10 mg/kg per day, 10-100 mg/kg per day or 1-20 mg/kg per day, respectively. In another study, an immature uterotrophic assay of genistein and ethinylestradiol together with ICI 182,780 or antide was performed to compare the ovarian changes with these chemicals (study 2). Doses of genistein or ethinylestradiol were 30 mg/kg per day or 0.6 micro g/kg per day, respectively, and these chemicals were injected subcutaneously from 20 days of age for 3 days. In study 1, there were no essential differences in the uterus weights among the various phytoestrogen-content diets. In study 2, the ovary weights in rats given genistein were significantly higher than in the controls, whereas the ovary weights in rats given ethinylestradiol were lower than in the controls. The ovary weights in the ICI 182,780 plus genistein group were significantly higher than in the genistein group, but decrease of the ovary weights was detected in the antide plus genistein group. There was no significant difference in ovary weights between the ICI 182,780 plus ethinylestradiol group and the ethinylestradiol group, but decrease of ovary weights was detected in antide plus ethinylestradiol group. In a histological examination of the ovary, fluid-filled follicles in the genistein group were more numerous than in other groups and increase of granulosa cell fragmentation was seen in the ethinylestradiol and other groups with the exception of the genistein group. The present findings demonstrate that the sensitivity of the immature rat uterotrophic assay is not influenced by the relatively low level of phytoestrogen in diets and that the ovarian changes occurring with genistein and ethinylestradiol are different.