Octachlorodipropyl Ether Research Articles

Migration and Accumulation of Octachlorodipropyl Ether in Soil-Tea Systems in Young and Old Tea Gardens.

The migration and accumulation of octachlorodipropyl ether (OCDPE) in soil-tea systems were investigated using a gas chromatography-electron capture detector (GC-ECD) method in young and old tea gardens. When the residual concentration of OCDPE was 100 g a.i. hm−2 in soils, the peak concentrations of OCDPE in fresh leaves of young and old tea plants were 0.365 mg/kg and 0.144 mg/kg, taking 45 days and 55 days, respectively. Equations for the accumulation curves of OCDPE in fresh leaves of young and old tea plants were Ct = 0.0227e0.0566t (R2 = 0.9154) and Ct = 0.0298e−0.0306t (R2 = 0.7156), and were Ct = 3.8435e0.055t (R2 = 0.9698) and Ct = 1.5627e−0.048t (R2 = 0.9634) for dissipation curves, with a half-life of 14.4 days and 12.6 days, respectively. These results have practical guiding significance for controlling tea food safety.

Evidence of exposure to chemicals and heavy metals during pregnancy in Japanese women.

PurposePrenatal exposure to environmental chemicals is a growing concern, because such exposures have been shown to be associated with various diseases. The levels of chemicals and heavy metals in maternal blood, cord blood, maternal urine and amniotic fluid in Japanese pregnant women were investigated.MethodsA total of 145 women, including 14 fetal growth restriction cases, were included in the present study. The levels of phthalates (di[2‐ethylhexyl]phthalate and mono[2‐ethylhexyl]phthalate), perfluorinated compounds (perfluorooctane sulfonate, perfluorohexanoic acid, perfluorooctanoic acid, and perfluorononanoic acid), pesticides (dimethylphosphate, dimethylthiophosphate, diethylphosphate, diethylthiophosphate, 3‐phenoxybenzoic acid, and octachlorodipropyl ether), bisphenol A, nicotine (nicotine, nornicotine, cotinine, norcotinine, and trans‐3’‐hydroxycotinine), polybrominated diphenyl ethers, and heavy metals were measured. The relationship between fetal growth and the levels of chemicals and heavy metals were investigated.ResultsPhthalates, perfluorinated compounds, pesticides, polybrominated diphenyl ethers, and heavy metals were detected in high frequency, whereas nicotine and bisphenol A were almost negative. Phthalates, perfluorinated compounds, and several heavy metals were transferred to the fetus. High perfluorononanoic acid levels in the maternal blood and cord blood, and low perfluorooctanoic acid level in the cord blood were significantly and negatively associated with fetal growth.ConclusionsThe present study showed that pregnant women in Japan and their fetuses are exposed to a variety of chemicals and heavy metals.

Dissipation behavior of octachlorodipropyl ether residues during tea planting and brewing process.

The dissipation behavior of octachlorodipropyl ether (OCDPE) residues in fresh tea shoots and in tea prepared under field conditions was investigated, and the transfer of residues from brewed tea to tea infusion was determined. OCDPE levels in tea shoots, prepared tea, tea infusion, and spent tea leaves were determined using a sensitive and simple method. The dissipation of OCDPE is fairly slow in tea shoots and prepared tea, with half-life values of 5.10 and 5.46 days, respectively. The degradation rates of OCDPE residues in tea processing were 23.9–43.1 %. The terminal residues of OCDPE in tea shoots and prepared tea samples after 20 and 30 days of OCDPE application were higher than 0.01 mg/kg. However, OCDPE’s transfer rates from brewed tea to tea infusion were only 6.0–14.8 %. Further studies on risk assessment of OCDPE residue in tea on the basis of the relationship of OCDPE in prepared tea and infusion are warranted.

Acaricidal activity of commercialized insecticides against Haemaphysalis longicornis (Acari: Ixodidae) nymphs

The acaricial activity of 13 commercialized insecticides in Korea against the hard tick nymphs Haemaphysalis longicornis collected in a field was tested using nymph dipping and folded filter paper methods and a spraying-residual assay. In a nymph dipping bioassay, 100% mortality at all tested doses was observed in insecticides containing active ingredients such as phthalthrin 8%+d-phenothrin 2%+piperonyl butoxide 20%, deltamethrin 1.5%, pyrethrum 0.5%, lambda-cyhalothrin 5.5%, alpha-cypermethrin 10% and teflubenzuron 50%, whereas the insecticide containing etofenprox 5%+octachlorodipropyl ether 11% at recommended dose (RD) and 0.5 times RD showed 97 and 90% activity, respectively. Other insecticides containing alpha-cypermethrin 5%, polyoxyethylene isostearylether 10%, etofenprox 5%, bistrifluron 10% and Bti did not show any significant activity. In the folded filter paper contact test with nymph H. longicornis at RD, polyoxyethylene isostearylether 10%, deltamethrin 1.5% and alpha-cypermethrin 10% showed 100% mortality at 1day after treatment (DAT). At 7 DAT, polyoxyethylene isostearylether 10%, deltamethrin 1.5% and lambda-cyhalothrin 5.5% exhibited 100, 93 and 87% mortality. Although the selected 5 insecticides showed strong mortality under laboratory conditions, their residual effect sprayed on field grown lawn leaves significantly decreased depending on DAT. Etofenprox 5% mixture (+octachlorodipropyl ether 11%) only showed 93 and 80% mortality at 1 and 2 DAT, respectively. Polyoxyethylene isostearylether 10% gave 0% mortality at even 1 DAT and the other insecticides also showed 60–70% mortality at 1 DAT. These results indicate that pyrethroid insecticides gave good activity against the H. longicornis nymphs but their residual effect is within 1 DAT under field conditions.

Mosquito coil exposure associated with small cell lung cancer: A report of three cases.

Mosquito coils, which are commonly used as residential insecticides in Asia, contain different concentrations of octachlorodipropyl ether (S-2) as a synergist or an active ingredient. As bis(chloromethyl) ether (BCME) is an extremely potent lung carcinogen that can be produced by the thermolytic degradation of S-2, contact with mosquito coils is likely to expose individuals to a certain level of BCME, and therefore increase the risk of lung cancer. However, the significance of exposure is uncertain, as clinical and epidemiological studies concerning mosquito coil users and workers are lacking. The present study describes three cases of small cell lung cancer treated at the Shanghai Pulmonary Hospital that were likely to be the result of exposure to mosquito coils. All patients had worked in the mosquito coil manufacturing industry, with an mean occupational duration of 9.1 years, and presented with similar respiratory symptoms, such as cough and dyspnea. Upon diagnosis, no metastasis to other organs was identified in any of the cases. Subsequently, the three patients were treated with chemotherapy as well as radiotherapy in one case, however, all patients succumbed to the disease, with a mean overall survival time of 10.7 months. We conclude that contact with mosquito coils is likely to expose individuals to a level of S-2 that may increase the risk of SCLC.

Putative Epimutagens in Maternal Peripheral and Cord Blood Samples Identified Using Human Induced Pluripotent Stem Cells.

The regulation of transcription and genome stability by epigenetic systems are crucial for the proper development of mammalian embryos. Chemicals that disturb epigenetic systems are termed epimutagens. We previously performed chemical screening that focused on heterochromatin formation and DNA methylation status in mouse embryonic stem cells and identified five epimutagens: diethyl phosphate (DEP), mercury (Hg), cotinine, selenium (Se), and octachlorodipropyl ether (S-421). Here, we used human induced pluripotent stem cells (hiPSCs) to confirm the effects of 20 chemicals, including the five epimutagens, detected at low concentrations in maternal peripheral and cord blood samples. Of note, these individual chemicals did not exhibit epimutagenic activity in hiPSCs. However, because the fetal environment contains various chemicals, we evaluated the effects of combined exposure to chemicals (DEP, Hg, cotinine, Se, and S-421) on hiPSCs. The combined exposure caused a decrease in the number of heterochromatin signals and aberrant DNA methylation status at multiple gene loci in hiPSCs. The combined exposure also affected embryoid body formation and neural differentiation from hiPSCs. Therefore, DEP, Hg, cotinine, Se, and S-421 were defined as an “epimutagen combination” that is effective at low concentrations as detected in maternal peripheral and cord blood.

水溶液中でのオクタクロロプロピルエーテルの光分解に関する速度論的解析

水溶液中でのオクタクロロプロピルエーテルの光分解に関する速度論的解析

Photodegradation kinetics of octachlorodipropyl ether in organic solvents using an HPTLC method

Octachlorodipropyl ether (OCDPE) is a chloroalkyl ether widely used as an insecticide synergist, which was considered as a widespread persistent pollutant. Photodegradation kinetics of OCDPE in selected organic solvents was studied using the high-performance thin-layer chromatography (HPTLC) method in this paper. The results showed that photochemical reaction of OCDPE in organic solvents such as n-hexane, methanol, acetonitrile, and acetone under the irradiation of ultraviolet light could well be described by the first-order kinetic equation. The photodegradation rate constants of OCDPE in methanol, acetone, acetonitrile, and n-hexane were 0.3310, 0.2382, 0.0287, and 0.0276 h−1, and the corresponding half-lives were 2.09, 2.91, 24.1, and 25.1 h, respectively. Photodegradation kinetics of OCDPE under sunlight was slower than UV light, the half-lives of which were 8.87 and 2.09 h, respectively. The main photodegradation products of OCDPE in acetone and methanol under UV light were detected by HPTLC, which i...

Epigenetic Assessment of Environmental Chemicals Detected in Maternal Peripheral and Cord Blood Samples

Epigenetic alteration is an emerging paradigm underlying the long-term effects of chemicals on gene functions. Various chemicals, including organophosphate insecticides and heavy metals, have been detected in the human fetal environment. Epigenetics by DNA methylation and histone modifications, through dynamic chromatin remodeling, is a mechanism for genome stability and gene functions. To investigate whether such environmental chemicals may cause epigenetic alterations, we studied the effects of selected chemicals on morphological changes in heterochromatin and DNA methylation status in mouse ES cells (ESCs). Twenty-five chemicals, including organophosphate insecticides, heavy metals and their metabolites, were assessed for their effect on the epigenetic status of mouse ESCs by monitoring heterochromatin stained with 4¢,6-diamino-2-phenylindole (DAPI). The cells were surveyed after 48 or 96 h of exposure to the chemicals at the serum concentrations of cord blood. The candidates for epigenetic mutagens were examined for the effect on DNA methylation at genic regions. Of the 25 chemicals, five chemicals (diethyl phosphate (DEP), mercury (Hg), cotinine, selenium (Se) and octachlorodipropyl ether (S-421)) caused alterations in nuclear staining, suggesting that they affected heterochromatin conditions. Hg and Se caused aberrant DNA methylation at gene loci. Furthermore, DEP at 0.1 ppb caused irreversible heterochromatin changes in ESCs, and DEP-, Hg- and S-421-exposed cells also exhibited impaired formation of the embryoid body (EB), which is an in vitro model for early embryos. We established a system for assessment of epigenetic mutagens. We identified environmental chemicals that could have effects on the human fetus epigenetic status.

HPTLC analysis of octachlorodipropyl ether in insecticide formulations

A simple, rapid, and sensitive high-performance thin-layer chromatographic method for analysis of octachlorodipropyl ether (OCDPE) in insecticide formulations has been established and validated. Known amounts of analytical grade OCDPE and its emulsifiable concentrate (EC) or wettable powder (WP) formulations were characterized by HPTLC on silica gel with toluene-acetic acidwater 20:20:1 ( v/v ) as mobile phase; detection was by spraying with silver nitrate-2 m alcoholic potassium hydroxide as chromogenic reagent and exposure to UV light. The plates were evaluated densitometrically at 399 nm. The results indicated that the calibration plot for OCDPE was logarithmic in the range 0.2–5.0 μg per band, and the correlation coefficient for the calibration equation in this range was 0.99. Recoveries from laboratory-prepared test EC and WP formulations using this method were 98.5–103.9% and 95.3–104.3%, respectively, and the respective RSDs were 3.39–4.89% and 2.92–5.33%. The accuracy and precision of the method w...

Octachlorodipropyl ether (s-2) mosquito coils are inadequately studied for residential use in Asia and illegal in the United States.

Children and their parents in residences are often protected by insecticides from nuisance and disease-bearing mosquitoes. The annual worldwide consumption of the four major types of residential insecticide products--aerosols, mosquito coils, liquid vaporizers, and vaporizing mats--is in the billions of units. Mosquito coils are burned indoors and outdoors in East Asia and to a limited extent in other parts of the world, including the United States. Coils consist of an insecticide/repellant, organic fillers capable of burning with smoldering, binder, and additives such as synergists, dyes, and fungicide. The number of coil users in China is in the millions. In Indonesia alone, an estimated seven billion coils are purchased annually. Coils containing pyrethroid insecticides, particularly d-allethrin, may contain octachlorodipropyl ether (S-2, S-421) as a synergist or active ingredient. Use of those coils likely exposes children and adults to some level of bis(chloromethyl)ether (BCME). BCME is formed from formaldehyde and hydrogen chloride, combustion products formed from the slow smoldering (about 8 hr/coil) of the mosquito coils. Because BCME is an extremely potent lung carcinogen, the nature and extent of prolonged exposures that recur in homes during the mosquito season in tropical regions must be evaluated with respect to health. In a small analytical study, coils purchased in Indonesia and in the United States contained highly variable amounts of S-2. Some coils that contained S-2 were not labeled, making it impossible for consumers to make an informed decision about coil contents. Mosquito coils containing S-2 are unregistered, and their use is illegal in the United States. Indoor air monitoring under conditions that represent conditions of use in tropical settings and epidemiology to assess health impacts of coil use are essential to permit responsible regulatory decisions regarding continuing S-2 use.

Carbamate 系殺虫剤と Octachloro-dipropyl ether の共力作用

Octachlorodipropyl ether, a synergist for pyrethroids, was studied as a synergist for carbamates to the house fly. Octachlorodipropyl ether showed a remarkable synergistic activity, as compared with the activity of PHC (Baygon), MPMC (Meobal). CPMC or NAC (Sevin) alone.

Thin-layer chromatography of rat bile and urine following intravenous administration of the pesticidal synergist octachlorodipropyl ether

Chromatographic differences in rat bile and urine samples resulting from single intravenous administration of octachlorodipropyl ether were elaborated using Silica Gel DF-5 chromatoplates with toluene-acetic acid-water (10:10:1) as developer. Detection was accomplished by 2537 Å and 3660 Å ultraviolet as well as conc. sulfuric acid- n-butanol and silver nitrate-2- N alcoholic potassium hydroxide chromogenic reagents. Ten metabolites were detected in the bile and 5 in the urine. The relative rates of elimination of the major biliary and urinary metabolites were compared.

Laboratory Screening of Insecticides for the Prevention of Reproduction of Boophilus Ticks

Adult engorged females of Boophilus annulatus (Say) and B. annulatus microplus (Conestrini) were dipped in 3 or more concentrations of candidate compounds to determine the effects on reproduction. This laboratory screening procedure was used to establish the approximate comparative toxicity of 100 compounds. In general, B. a. microplus collected in Mexico in Tammaulipas were more susceptible to insecticides than B. anmulatus obtained in Coahuila. At concentrations of 0.001% to 0.01%, General Chemical 4072, 2-chloro-1-(2,4-dichlorophencyl) vinyl diethyl phosphate, was completely efflective in preventing hatching. The following compounds gave the same r esult at 0.01% to 0.1%: Bayer 29952, O -enthyl O -[ p- methylthio) phenyl] methylphonothioate; Bayer 30237, O [ p- (methylthio) methylphosphonothioate; Bayer 37341, O-[4-(methylthio)-3,5-xylyl]phosphorothioate; coumaphos; General Chemical 3582, 2,2-dichloro-1-(2,5-dichlorophenyl) vinyl diethyl phosphate; and lindane. The most promising compounds as inhibitors of oviposition were lindane; Stauffer R-3244, 2-(diethoxyphosphinothioyloxy)-ethyl dimethylcarbamate; and Telodrin®, 1,3,4,5,6,7,8,8-octachloro-1,3,3a,4,7,7a-hexahydro-4,7-methanoisobenzofuran. An attempt to increase the toxicity of Pyrolan,® 3-methyl-1-phenyl-5-pyrazolyl dimethylearbamate, by adding synergists was not successful, but in a single test dimetan waas apparently synergized by octachlorodipropyl ether.

Synergism of Carbamate Insecticides with Octachlorodipropyl Ether1

Octachlorodipropyl ether ( bis -(2,3,3,3-tetrachloropropyl)ether), a pyrethrum synergist, was found to act as synergist of carbamate insecticides against susceptible and carbamate-selected strains of houseflies( Musca domestica L.). Under certain circumstances synergistic effect was evident with ratios of synergist to carbamate as low as 1: 20, and persisted for at least 96 hours following application of the synergist.