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PubMed2006

Studies on the coupling product between oxidation products derived from pentachlorophenol and cyclodextrins.

The coupling products (CPs), which were formed via the peroxosulfate catalyzed oxidation of pentachlorophenol (PCP) with iron(III)-tetrakis(sulfonatophenyl)porphyrin (Fe(III)-TPPS) in the presence of hydroxypropyl-beta -cyclodextrin (HP-beta -CD) or HP-gamma -CD, were separated by ultrafiltration from the reaction mixture. When the percentages of chlorine species in the reaction mixture were calculated from the concentrations of organic chlorine in the reaction mixture and CPs, 10-25% of chlorine species in the reaction mixture was organic chlorine that was incorporated into CDs. Analyses of the CPs by pyrolysis-GC/MS (Py-GC/MS) and 13C NMR showed that the PCP-derived products were covalently incorporated into the CDs. To evaluate the acute toxicity of the CPs, a Microtox test was examined. Toxicities of the CPs were reduced slightly, compared to the controls (PCP alone and PCP + reaction blanks). In the reaction blanks, mesaconic acid (MA) moieties were detected as a result of the oxidation of CDs in the absence of PCP. Thus, factors in the toxicities, detected in the CPs, can be attributed to the oxidation products derived from CDs, such as MA, as well as the PCP-derived products incorporated into the CDs.

Catalysis↗
PubMed2006

Enhanced photocatalysis of pentachlorophenol by metal-modified titanium (IV) oxide.

The effects of four metals (Ag, Au, Pt, and Cu) doped on TiO2 on the photocatalysis of pentachlorophenol (PCP) were investigated. The results of this study indicated that all four metals-doped TiO2 catalysts were able to enhance the efficiency of PCP photocatalysis with an optimum metallic content of 0.1 wt%. For the metal-doped TiO2 samples (Au, Pt, and Cu), the patterns of light absorption were significantly extended toward visible light spectra in the wavelengths between 400 and 800 nm. The photocatalysis of PCP was pH dependent with the maximum degradation rate achieved in the solution at pH 3. The formation of chloride ion corresponded with the concentration of PCP degraded which confirmed that dechlorination was the major pathway of PCP photocatalysis. The overall toxicities of PCP samples were reduced with the extension of light exposure using the microtox test. The results of PCP photocatalysis are also discussed based on the characteristics of metal/TiO2 including X-ray differential (XRD) patterns, Brunquer Emmett Teller (BET) specific area analysis, and Ultra Violet (UV)-Vis absorption spectra.

Catalysis↗
PubMed1977

Metabolism of pentachlorophenol by a soil microbe.

Metabolism of pentachlorophenol (PCP)-ring-14C(U) by a microorganism (Pseudomonas sp.) isolated from soil was examined. The microorganism degraded PCP-14C rapidly, and released 14CO2 equivalent to approximately 50% of the PCP-14c added to the bacterial cell suspension in 1 hour of incubation. The results of amino acid analysis of the bacterial cells incubated with PCP-14C showed that radioactive carbon derived from PCP-14C was incorporated rapidly into the cell constituents, and that the pattern of 14C-amino acids in the cell constituents was not much different between the 15 minute and 24 hour incubation periods. Intermediate metabolities of PCP isolated from the incubation medium were identified as tetrachlorocatechol and tetrachlorohydroquinone by spectral analyses.

Biodegradation, Environmental↗
PubMed1979

Degradation of pentachlorophenol (PCP) in aerobic and anaerobic soil.

Aerobic and anaerobic degradation of 14C-labeled pentachlorophenol (PCP) was examined in nitrogen aerated, moist Hagerstown silty clay loam with or without cellulose amendments. In anaerobic soil, PCP reduced soil respiration in the presence of cellulose; volatilization losses accounted for only 0.5% of the PCP added to soil; no 14CO2 was detected; and organic solvent extractable radioactivity was the same from all treatments. Gas and thin-layer chromatographic analysis of the soil extracts showed the presence of pentachloroanisole in both aerobic and anaerobic soils. 2,3,5,6- and 2,3,4,5-tetrachlorophenols and 2,3,6-trichlorophenol were also detected as degradation products by gas chromatography after methylation. Further degradation of pentachloroanisole was examined in both aerobic and anaerobic soils.

Aerobiosis↗
PubMed1984

Detection and occurrence of pentachlorophenol residues in chicken liver and fat.

A method for the detection of pentachlorophenol (PCP) residues in chicken liver and fat is presented. A detection limit of 0.002 mg/kg was achieved. Recoveries from liver and fat were in the range 82-88% and 95-97%, respectively. Low level residues of PCP were found in all 1072 liver and 723 fat samples. These levels were less than 0.010 mg/kg in 92.7% of the fat and 75.6% of the livers. Only 0.75% of the liver samples had PCP levels greater than 0.1 mg/kg. None of the more toxic impurities of PCP were detected in the chicken tissues.

Adipose Tissue↗
PubMed1988

Detection of pentachlorophenol and its glucuronide and sulfate conjugates in fish bile and exposure water.

The glucuronide and sulfate conjugates of pentachlorophenol (PCP) that were present in the bile and exposure water of goldfish (Carassius auratus) were used to develop methodology to quantify PCP and its metabolites. Reverse phase HPLC with radioactivity detection separated PCP and its metabolites, and was used to verify a method of quantification that used differential extraction and scintillation counting. Extractions of aqueous phase at pH 2 or 8, with butanol, ethyl acetate, or ether indicated that ether at pH 8 best separated PCP from its metabolites. The sulfate conjugate of PCP was the major metabolite produced when goldfish were exposed to 125 micrograms 14C-PCP/l. It was present primarily in the exposure water, but also appeared in the bile.

Animals↗
PubMed1997

Degradation of pentachlorophenol in soil by Streptomyces rochei 303.

The fate of pentachlorophenol (PCP) in soil under natural conditions was investigated. It was revealed that the total amount of PCP significantly decreased when soil was inoculated by Streptomyces rochei 303, a strain-destructor of chlorophenols. The products of PCP transformation, such as tetra- and trichlorophenols, pentachlorobenzene, chlorinated dioxins, were identified after the first month of the experiment. Their quantity was less in the variant with the introduced strain compared to control.

Biodegradation, Environmental↗
PubMed2005

Biosorption of pentachlorophenol by fungal biomass from aqueous solutions: a factorial design analysis.

A 2(5-1) fractional factorial design was conducted for the biosorption of pentachlorophenol (PCP) using Aspergillus niger biomass. Effects of several factors on the percentage removal of PCP from aqueous solutions were evaluated. These factors were as follows: type of biomass (autoclaved- chemically modified); pH (3-11); concentration (1-10 mgl(-1)); temperature (6-32 degrees C); and dissolved oxygen (2.5-20 mgl(-1)). Time of shaking (equilibrium time), volume of the solution and mass of biomass were kept constant. The results showed that type of biomass and pH had a larger impact on the removal of PCP. Concentration of PCP in the aqueous solution, temperature, and dissolved oxygen only marginally affected the removal efficiency of PCP.

Aspergillus niger↗
PubMed2000

A kinetic study on oxidation of pentachlorophenol by ozone.

The kinetics of pentachlorophenol (PCP) ozonation in terms of the gaseous O3 and dissolved PCP concentrations has been investigated. When the O3 concentration in the gas phase was in the range of 10 to 40 g O3/m3, the O3 dissolved for a short time period was proportional to the gaseous O3 concentration. In this range, the ozonation reaction was first order for each reactant and the overall reaction was second order. At 25 degrees C, in an aqueous solution, the reaction rate constant was estimated to be 10.048 L/mol.sec. The reaction rate was much greater than the mass-transfer rate, indicating that the reaction of O3 and PCP was an interface reaction on the surface of gaseous O3 bubbles. The final product of the PCP ozonation was oxalic acid, with the carbon yield of the reaction being 59.4%. The ozonation of PCP in the aqueous solution was not a radical reaction but a direct reaction between O3 and PCP molecules under the conditions investigated in this study, since O3 has a high selectivity toward PCP. The reaction rate increased with the reaction temperature up to 35 degrees C but decreased at temperatures greater than 35 degrees C due to the decreased solubility of O3. The addition of H2O2 did not increase the reaction rate significantly.

Air Pollution↗
PubMedDate not supplied

Developmental toxicity study of pentachlorophenol in the rabbit.

The potential for developmental toxicity of pentachlorophenol (penta) was studied in New Zealand white rabbits at doses of 0 (corn oil), 7.5, 15, and 30 mg/kg/day administered by gavage on days 6 to 18 of gestation. The rabbits were sacrificed on day 29 of presumed gestation and necropsied. Measurements included number of corpora lutea, pregnancy, number and distribution of implantations, early and late resorptions, live and dead fetuses, fetal weight, gender, and gross external, soft tissue, and skeletal alterations. The mid and high doses reduced maternal body weight gain; the high dose caused transient weight loss and reduced feed consumption. There were no effects on embryofetal development at any of the doses evaluated. Based on these data, the maternal no-observable-adverse-effect level (NOAEL) is 7.5 mg/kg/day, while the developmental NOAEL is 30 mg/kg/day. Penta is not a developmental toxicant in a nonrodent animal model.

Animals↗
PubMedDate not supplied

A study of the developmental toxicity potential of pentachlorophenol in the rat.

Pentachlorophenol (penta, CAS #87-86-5) is primarily used as a wood preservative. As part of the USEPA pesticide reregistration process, the developmental toxicity (embryo-fetal toxicity and teratogenic potential) of commercially available penta was studied following oral gavage to presumed pregnant female Sprague-Dawley rats (Crl:CD BR VAF/Plus Subdivision F, 83-3). Both study design and penta purity met the requirements of the USEPA. Doses of 0 (corn oil), 10, 30, and 80 mg/kg/day were administered to the rats at concentrations of 0, 2, 6, and 16 mg/ml, respectively from day 6 to day 15 of presumed gestation. The dosage volume was 5 ml/kg, adjusted on each day of dosage based on individual body weights recorded immediately before intubation. The rats were sacrificed on day 20 of presumed gestation and necropsied. The number of corpora lutea in each ovary was recorded. The uterus was examined for pregnancy, number and distribution of implantations, early and late resorptions and live and dead fetuses. Each fetus was weighed, sexed, and examined for gross external, soft tissue and skeletal alterations. The no-observable-adverse-effect-level (NOAEL) for maternal toxicity in rats was determined to be 30 mg/kg/day of penta. The developmental NOAEL for penta in rats was also found to be 30 mg/kg/day. The lowest-observable-adverse-effect-level (LOAEL) for penta developmental toxicity (80 mg/kg/day) was associated with increased resorptions, reduced live litter size and fetal body weights, and caused increased malformations and variations. These NOAELs, derived using USEPA approved study designs, are higher than those previously reported using penta that is no longer commercially available in studies with non-approved experimental designs. Penta should not be identified as a selective developmental toxicant in the rat because adverse effects on development of rat conceptuses occurred only at maternally toxic dosages.

Animals↗
PubMedDate not supplied

Oral (gavage) two-generation (one litter per generation) reproduction study of pentachlorophenol (penta) in rats.

The potential for pentachlorophenol (penta) to induce general and reproductive/developmental toxicity was evaluated in Crl Sprague-Dawley rats, employing a two-generation reproduction toxicity study. Penta was administered by gavage at doses of 0, 10, 30, and 60 mg/kg/day. In both generations, the parental animals (30/sex/group) were intubated daily for 10 weeks before cohabitation and continuing through cohabitation, gestation, and lactation periods. Intubation of the F1 generation was begun 28 days postpartum. Animals were evaluated daily for mortality and general toxicity (clinical observations, body weights and gains, feed consumption). Organ weights were recorded and histopathological evaluations were made. Specific indices of reproductive function evaluated included estrous cycles, mating and fertility, parturition, lactation, viability, and growth and development of offspring, including sexual maturation, sperm parameters, and numbers of ovarian primordial follicles. All deaths in the parental rats were unrelated to penta. Expected metabolic effects of penta, sporadic increased liver weights associated with hepatocellular centrilobular hypertrophy and vacuolation and lipofuscin pigmentation, were evident in the 10-, 30-, and 60-mg/kg/day dose group P1 and F1 animals. Toxicity, in the form of liver pathology (single cell necrosis), reduced body weights and associated reductions in organ weights, and reduced feed consumption were noted in both generations at the 30- and 60-mg/kg/day doses. Developmental toxicity associated with these doses included reduced pup weights and viability. The 60-mg/kg/day dose also resulted in delayed sexual maturation, decreased spermatid counts, small prostates and testes, decreased implantations, reduced fertility, and increased resorptions of embryos. Based on these results, it was concluded that 30 mg/kg/day is the lowest-observable-adverse-effect level (LOAEL) and 10 mg/kg/day is the no-observable-adverse-effect level (NOAEL) for both reproductive and general toxicity. These findings are consistent with results from previously conducted studies wherein reproductive/developmental toxicity was observed only at doses that also induced general toxicity. It differs from previous findings in that the NOAEL for general toxicity is two to three times higher for the more pure product than for products produced and tested previously. In addition, the results did not indicate bioaccumulation of penta. Thus, penta did not selectively affect reproduction or development of the offspring of rats at a dose of 10 mg/kg/day, a dose that is 7000 to 20,000 times higher than human exposure.

Administration, Oral↗
PubMed2006

Ecotoxicity of pentachlorophenol in contaminated soil as affected by soil type.

Four uncontaminated soils were chosen with a wide range of pH, organic carbon, and clay content to allow us to determine the properties that were most influential on pentachlorophenol (PCP) toxicity. The soils were contaminated in the laboratory at concentrations of 50 and 100 mg/kg and target organisms were exposed to the contaminated soil. Germination and emergence of lettuce seedlings was found to be dependent upon PCP concentration and soil type, and responses were highly correlated to extractable concentrations. Earthworms were sensitive to PCP, regardless of soil properties, and mortality was observed in most samples at the 100 mg/kg concentration. Toxic responses by the worms were not strongly related to soil properties or extractable concentrations. The importance of soil chemical and physical properties on toxicity and bioavailability depends upon the target organism. In the case of lettuce seedlings, PCP is acquired through the aqueous phase; therefore, the chemical interaction between PCP and soil controls toxicity. Since earthworms ingest soil and potentially can change the chemical environment of exposure, the impact of soil properties on PCP toxicity is less apparent.

Aluminum Silicates↗
PubMed2003

Oral bioavailability of pentachlorophenol from soils of varying characteristics using a rat model.

Evidence accumulated during the last two decades suggests that only a fraction of any chemical in soil is available to organisms, and soil-related effects on bioavailability should be considered in optimizing soil remediation cleanup levels. In the current study, the absolute and relative bioavailabilities of pentachlorophenol (PCP) from freshly spiked and environmentally aged soils varying in organic carbon content, clay content, and pH were examined using a rat model. PCP is a broad-spectrum biocide widely used as a wood preservative, and thus is ubiquitous in the environment. Soils and corn oil containing equivalent levels of PCP were administered to male Sprague-Dawley rats by gavage at 2 dose levels: 100 and 200 microg/kg body weight. Equivalent doses were also given intravenously. The areas under the plasma concentration of PCP versus time curves were calculated, and absolute and relative bioavailabilities of PCP from each soil were determined. At a dose of 100 microg/kg body weight, the absolute bioavailabilities of PCP across soils ranged from 36% to 65%, and the relative bioavailabilities ranged from 48% to 82%. At the higher dose level (200 microg/kg body weight), absolute and relative bioavailability ranges were somewhat higher at 46% to 77% and 52% to 87%, respectively. All soils decreased absolute PCP bioavailability significantly at both dose levels and relative bioavailability at the lower PCP dose level. At the higher dose level, only one of the two field-contaminated soils decreased the relative PCP bioavailability. The data indicate that PCP-soil interactions do significantly decrease the oral bioavailability of PCP from soil, but no obvious correlation was observed between soil properties and bioavailabilities.

Administration, Oral↗
PubMed1977

Effects of pentachlorophenol on the development of estuarine communities.

Pentachlorophenol affected the composition of communities of estuarine organisms developed in sand from planktonic larvae in estuarine water that flowed through ten control aquaria and ten aquaria per exposure concentration averaging 7, 76, or 622 microgram/liter. Annelids, arthropods, and mollusks were the numerically dominant phyla when animals were collected in a 1-mm-mesh sieve after 9 wk of exposure. Mollusks were markedly fewer at 7 microgram/liter; annelids and arthropods at 76 microgram/liter. Almost no animals occurred at 622 microgram/liter. The total numbers of individuals and species were significantly less (alpha=0.01) in aquaria exposed to 76 microgram/liter than in those unexposed or exposed to 7 microgram/liter.

Animals↗
PubMed1981

Subchronic administration of technical pentachlorophenol to lactating dairy cattle: immunotoxicologic evaluation.

Eight lactating Holstein-Friesian dairy cattle were randomly allotted as pairs to eight a control or a treatment group fed technical pentachlorophenol (penta) from 6 +/-1 wk postpartum for about 135 d (0.2 mg/kg.d for 75-84 d followed by 2.0 mg/kg.d for 56-62 d). Jugular blood was drawn periodically for immunologic studies. Leukocyte differentials and lymphocyte subpopulations (e.g., T and B cells) were enumerated for each blood specimen. Several in vitro and in vivo assays were conducted to evaluate lymphocyte functions, including (1) quantitation of serum immunoglobulins G, M, and A; (2) induction of blastogenesis in vitro, using concanavalin A and leukoagglutinin as mitogens; (3) measurement of extent of skin reaction to injected purified protein derivative in BCG-sensitized cattle to evaluate delayed hypersensitivity; and (4) quantitation of antibody formation in response to injected sheep red blood cells. Neutrophil function was evaluated by latex particle phagocytosis and chemiluminescence. The results showed no statistically significant differences between control and pent-treated cattle during eigher treatment period. Also, no histopathologic changes were noted in lymphoid tissues including spleen, thymus, and lymph node.

Animals↗
PubMed1986

Enhanced withdrawal from chickens of hexachlorobenzene (HCB) and pentachlorophenol (PCP) by colestipol, mineral oil, and/or restricted feeding.

Young chickens fed hexachlorobenzene (HCB) or pentachlorophenol (PCP) for 14 d at 10 ppm in the diet contained body burdens of 573 or 362 micrograms, respectively. These diets were withdrawn (d 0) and replaced for 21 d with diets containing 5% mineral oil (MO), or 5% colestipol (CO), a bile-acid-binding resin, or the chickens were restricted in feed intake to 50% of controls (50-RF), fed MO plus 50-RF, or CO plus 50-RF. Without any treatment during withdrawal, body burdens were reduced to 63% and 70% of the d 0 values for HCB and PCP, respectively. MO, CO, or 50-RF reduced body burdens of HCB to 37% of d 0 burdens, but the combination treatments with 50-RF reduced body burdens to 19% of d 0 values. PCP was at 35% of the d 0 burdens from 50-RF, while all other treatments had reduced body burdens to nondetectable amounts of less than 0.7 micrograms/bird by d 21 of withdrawal. Body fat was not reduced by mineral oil, but was reduced to some extent by CO, and was markedly reduced by 50-RF. 50-RF always reduced body burdens of PCP or HCB alone or in combination with MO or CO. These data are discussed in relationship to the nonbiliary excretion of xenobiotics.

Adipose Tissue↗
PubMed1987

Effects of pentachlorophenol on the in vitro and in vivo antibody response.

The effects of pentachlorophenol (PCP) on selected parameters reflecting immunocompetence of female B6C3F1 mice were measured following subchronic exposure (14 d) and direct exposure in culture. Daily exposure was by gastric intubation of 10, 30, or 100 mg/kg of technical-grade PCP (PCP-T), or 100 mg/kg of EC-7, a PCP preparation purified to reduce contamination (PCP-P), or 100 mg/kg of the vehicle, corn oil. There were no effects on the antibody responses of spleen-cell suspensions from either PCP-T- or PCP-P-treated mice stimulated with antigen in culture. In contrast, when mice were immunized during the exposure to PCP-T, there was a dose-related suppression of the IgM antibody response to sheep red blood cells (SRBC) measured on both d 4 (peak day) and d 5. There was no change in the antibody response of mice exposed to PCP-P. The differential activity was not observed following direct addition, since both PCP-T and PCP-P suppressed the in vitro antibody response by spleen-cell suspensions from untreated mice. The suppression was associated with a decrease in cell viability, indicating that both preparations were directly cytotoxic. These results indicate that the in vitro antibody assay will be of limited value in determining the mechanism of immunosuppression by PCP. The lack of effect on the antibody response by splenocytes from PCP-T-treated mice indicates that the dysfunction is not due to a direct suppression of the capabilities of immunocompetent cells.

Animals↗