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PubMed1981

[Investigations on neurotoxicity of chemical substances at the workplace. II. Determination of the motor and sensory nerve conduction velocity in persons occupationally exposed to pentachlorophenol (author's transl)].

We examined eighteen workers (three women, 15 men) in a pentachlorophenol (PCP) processing factory, with a mean activity of 12 years. PCP in blood and urine samples was analyzed by gas chromatography. To evaluate the peripheral nervous system the maximal motor as well as sensory nerve conduction velocities of the ulnar and/or median nerve were measured. The PCP-levels in plasma ranged between 0.02 and 1.5 ng/l, median 0.25 ng/l, and in urine between 13 and 1,224 micrograms/l, median 112 micrograms/l, or between 11 and 2,111 micrograms/g creatinine, median 111 micrograms/g creatinine. The median values of the neurophysiological parameters showed a mild degree of slowing in the PCP-collective. In the case of the sensory nerve conduction velocities, this decrease was significant. A dose-effect relationship between internal PCP-load and the different nerve conduction velocities could not be demonstrated. The individual evaluation of the toxicological and neurophysiological results gave hints that in some cases decreased nerve conduction velocity is caused by chronic exposure to PCP.

Adult↗
PubMed1987

Sister chromatid exchange and chromosomal breakage in pentachlorophenol (PCP) exposed workers.

A cytogenetic study was performed on 20 healthy workers exposed to pentachlorophenol (PCP) in concentrations ranging from 1.2 to 180 micrograms/m3 (Maximum Concentration at the workplace is 500 micrograms/m3) for 3 to 34 years. PCP was determined in the blood plasma of all probands, yielding concentrations between 23 and 775 micrograms/l (Biological Tolerance Value is 1000 micrograms/l). In vitro PCP up to 90 mg/l was added to phytohaemagglutinin stimulated lymphocytes of normal healthy donors without any effect on sister chromatid exchange (SCE) or chromosomal aberrations (CA), whereas a slowdown of cell proliferation could be detected in the presence of 60 mg PCP/l. In vivo we neither observed a relation between PCP concentrations and the number of SCE nor an increase of CA.

Adult↗
PubMed1979

Evidence that induction and suppression of mutations and recombinations by chemical mutagens in S. cerevisiae during mitosis are jointly correlated.

Mutagen-induced intergenic and interallelic recombination as well as forward mutation were studied in one and the same strain of S. cerevisiae. In nontoxic dose ranges, the induction of mutants and recombinants was parallel after treatment with ethyl methanesulfonate (EMS), methyl methanesulfonate (MMS), N-methyl-N'-nitro-M-nitrosoguanidine (MNNG), triethylene melamine (TEM), 4-nitroquinoline 1-oxide (4-NQO), sodium nitrite (NaNO2), and 1-fluoro-2,4-dinitrobenzene (2,4-DNFB). Acridine orange (AO) after treatment without light induced recombinants, but reduced the frequency of spontaneous mutations. In combination with TEM, AO exerted the same effect, i.e., reduced its mutagenic effect and enhanced its recombinogenic effect. 4,5,6-Trichloro-2-(2,4-dichlorophenoxy) phenol (Cl5-predioxin) induced mutants and intergenic recombinants, but specifically reduced the spontaneous frequency of interallelic recombinants. In combination with TEM, it enhanced its mutagenic and intergenic recombinogenic effects but reduced its interallelic recombinogenic effect. The main conclusions of the present study, that is 1. Essentially similar lesions can lead to different genetic consequences, and 2. Induction of mutation and recombination are jointly correlated, i.e., suppression of mutations leads to an enhancement of recombinations, while suppression of recombinations leads to an enhancement of mutations, are used to set up a speculative concept for mutation and recombination induction in the diploid yeast cell during mitosis.

4-Nitroquinoline-1-oxide↗
PubMed1995

Identification of urinary metabolites of human subjects exposed to o-dichlorobenzene.

o-Dichlorobenzene (o-DCB) has adverse effects on the liver and kidney in animals. It also causes some irritation to the eyes and the upper respiratory system in humans. This study aimed to identify urinary metabolites of human subjects exposed to o-DCB. Urine samples were collected from three male workers exposed to o-DCB and were analyzed using a gas chromatograph-mass spectrometer. 2,3- and 3,4-dichlorophenols and 3,4- and 4,5-dichlorocatechols were detected in all the samples. Some amounts of the four metabolites were presumably present as conjugates, because they increased after heating with hydrochloric acid.

Catechols↗
PubMed1994

Physiological properties and substrate specificity of a pentachlorophenol-degrading Pseudomonas species.

A bacterial strain capable of utilizing pentachlorophenol (PCP) as sole source of carbon and energy for growth was isolated from enrichment cultures containing 100 mg/l PCP in a mineral salts medium inoculated with contaminated soil from a lumber treatment waste site. The isolate, designated strain SR3, was identified as a species of Pseudomonas by virtue of its physiological and biochemical characteristics. Mineralization of PCP by Pseudomonas sp. strain SR3 was demonstrated by loss of detectable PCP from growth medium, stoichiometry of chloride release (5 equivalents of chloride per mole of PCP), and formation of biomass consistent with the concentration of PCP mineralized. PCP-induced cells of strain SR3 showed elevated rates of oxygen consumption in the presence of PCP, and with different chlorinated phenols, with complete degradation of 2,3,5,6-, 2,3,6-, 2,4,6-, 2,4-, and 2,6-chloro-substituted phenols. Concentrations of PCP up to 175 mg/liter supported growth of this organism, but maximal rates of PCP removal were observed at a PCP concentration of 100 mg/liter. Based on its degradative properties, Pseudomonas sp. strain SR3 appears to have utility in bioremediation of soil and water contaminated with PCP.

Biodegradation, Environmental↗
PubMed1982

Metabolism and excretion of leptophos and its phenol in S and R larvae of the Egyptian cotton leafworm.

The metabolism and excretion of leptophos, 0-(4-bromo-2,5 dichlorophenyl) 0-methyl phenylphosphonothioate, and its phenol, 4-bromo-2,5-dichlorophenol, were examined in susceptible (S) and leptophos resistant (R) strains of the Egyptian cotton leafworm Spodoptera littoralis (Boisd.). Leptophos injected into the larvae is converted in vivo into at least five chloroform-soluble and two water-soluble products. Minor qualitative differences were observed between S and R larvae. Quantitatively, the disappearance of leptophos was faster in R (t1/2 = 2.5 hr) than in S (t1/2 = 21.5 hr) larvae. A small amount of leptophos oxon (2 to 7%) was detected in S larvae, but none in R larvae. The major degradation product was the free phenol and its amount was relatively higher in R (17 to 22%) than in S (5 to 5%) larvae. After 24 hr, 25% of the injected leptophos was excreted unchanged by R larvae, whereas less amount (15%) was excreted by S larvae. However, the amount of excreted phenol, in free form, by S and R larvae was almost equal (5 to 8%). Following injection of the phenol derivative, its disappearance was faster in S (t1/2 = 36 min) than in R (t1/2 = 72 min) larvae, whereas phenol excretion, 24 hr after injection, was significantly higher by R (37%) than by S (9%) larvae.

Animals↗
PubMedDate not supplied

Effect of pH on the accumulation kinetics of pentachlorophenol in goldfish.

The kinetics of accumulation of pentachlorophenol (PCP) at various pH values were investigated to explore how pH-dependent accumulation might influence PCP toxicity. Goldfish (Carassius auratus) were exposed to 5 micrograms PCP/L in a static system buffered with 7.5 mM bicine or N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid (BES) at pH 7.0, 8.0, or 9.0. The amount of PCP in the fish, concentration of PCP in water, and the total amount of metabolites in the system were measured after exposure of fish from 1 to 96 hr. Equations for these variables based on a two compartment pharmacokinetic model were fitted simultaneously to the data using NONLIN, which uses an iterative nonlinear least squares technique. Uptake clearance, metabolic clearance, and apparent volume of distribution of PCP decreased as pH increased. The decrease in PCP accumulation with increased pH was not due solely to a pH-induced decrease in uptake. In addition, the distribution of PCP within the fish was altered by changes in the external pH. The pH-associated changes in distribution may have altered access of PCP to sites of metabolism, thereby altering the metabolic clearance. The pH-related changes in the pharmacokinetics of PCP resulted in a decrease in its bioconcentration factor with an increase in pH and account both for the decreased capacity of the fish to accumulate PCP and for its reduced LC50.

Animals↗
PubMedDate not supplied

Residues of chlorinated phenols and phenoxy acid herbicides in the urine of Arkansas children.

Urine samples from 197 Arkansas children were analyzed for eight chlorinated phenols and four chlorinated phenoxy herbicides by using a new procedure that combined gas chromatography with tandem mass spectrometry. With the detection limit of 1 part per billion (ppb), six of these pesticides were detected in more than 10% of the samples. 2,5-Dichlorophenol (a metabolite of p-dichlorobenzene), and pentachlorophenol were detected in 96% and 100%, respectively, of the children's urine at median concentrations of 9 ppb and 14 ppb, respectively. 2,4,5-Trichlorophenol was detected in 54% of the children's urine at a median concentration of 1 ppb. One trichlorophenol and three other dichlorophenols were found in 3% to 27% of the samples. The herbicide 2,4-dichlorophenoxyacetic acid was observed in 20% of all samples. The concentrations of all analytes are reported as background or reference levels for use in future studies. The finding of 2,5-dichlorophenol as a ubiquitous contaminant merits further study.

2,4-Dichlorophenoxyacetic Acid↗
PubMedDate not supplied

Pentachlorophenol measurements in body fluids of people in log homes and workplaces.

Human exposure to pentachlorophenol (PCP) was evaluated in the normal population (controls), residents of PCP-treated log homes, and persons exposed primarily in the workplace. Blood and urine samples were analyzed by gas chromatography after extraction and acetylation. For 34 controls, serum PCP values ranged from 15-75 ppb with a mean of 40 ppb. For 123 residents of log homes, serum levels ranged from 69-1,340 ppb with a mean of 420 ppb. In such homes, serum levels for children were significantly higher than those for parents, averaging 1.8 times greater. Serum and urine values for workers varied widely, depending on the workplace, with serum levels ranging from 26 to 84,900 ppb of PCP. Urinary concentrations when corrected for creatinine values correlated well (r = 0.92) with serum concentrations. Coating PCP-treated logs of home interiors with a sealant reduced serum PCP levels in the residents.

Adolescent↗
PubMedDate not supplied

Pentachlorophenol: environmental partitioning and human exposure.

This paper uses a six compartment environmental partitioning model to explore the transport and accumulation of pentachlorophenol (PCP) within and between various environmental media. Environmental concentrations were then used to estimate the amount of PCP entering the food chain and the long-term, average daily intake of PCP by the general population of the U.S. Results show that PCP partitions mainly into soil (96.5%) and that the food chain, especially fruits, vegetables, and grains, accounts for 99.9% of human exposure to PCP. The long-term, average daily intake of PCP is estimated to be 16 micrograms/day, which agrees well with a previous estimate of 19 micrograms/day (Geyer et al. 1987).

Chlorophenols↗
PubMed1982

Effects of phenol, 2,4-dimethylphenol, 2,4-dichlorophenol, and pentachlorophenol on embryo, larval, and early-juvenile fathead minnows (Pimephales promelas).

Embryos of fathead minnows were more resistant to phenol, 2,4-dimethylphenol (2,4-DMP), 2,4-dichlorophenol (2,4-DCP), and pentachlorophenol (PCP) than were larval or juvenile life stages. Growth of 28-day-old fish was the most sensitive indicator of stress during exposures to phenol, 2,4-DMP, and PCP, whereas survival was the most sensitive indicator of toxic effects from 2,4-DCP exposure. Based on these effects, the estimated maximum acceptable toxicant concentration for fathead minnows in Lake Superior water lies between 1,830 and 3,570 micrograms/L for phenol; 1,970 and 3,110 micrograms/L for 2,4-DMP; 290 and 460 micrograms/L for 2,4-DCP; and 44.9 and 73.0 micrograms/L for PCP.

Animals↗
PubMed1980

Uptake, elimination, and metabolism of three phenols by fathead minnows.

Uptake rates of total 14C in fathead minnows (Pimephales promelas) exposed to sublethal concentrations of radiolabeled test compounds followed the order: phenol > 2,4,5-trichlorophenol > p-nitrophenol. Mean whole body 14C concentration factors were 15,800, 1,850, and 180 for phenol, 2,4,5-trichlorophenol, and p-nitrophenol exposures, respectively. Only minor amounts of tissue 14C was parent compound after 28 days of exposure in fish exposed to phenol and p-nitrophenol, while 78.6% of the 14C was parent compound in 2,4,5-trichlorophenol exposed fish. Tissue 14C in fish exposed to 2,4,5-trichlorophenol was eliminated at a faster rate than in fish exposed to phenol or p-nitrophenol. Observed mean 14C depuration half-lives for lower and higher exposures combined were 387, 150, and 12 hours for phenol, p-nitrophenol, and 2,4,5-trichlorophenol, respectively. Parent compound comprised 1.5, 2.7, and 0.7% of total 14C for phenol, 2,4,5-trichlorophenol, and p-nitrophenol, respectively, after 28 days of depuration. The percentage of acetone-unextractable 14C increased from the end of uptake to the end of depuration for phenol and 2,4,5-trichlorophenol, and decreased slightly for p-nitrophenol. 14C contribution from polar metabolites increased relative to total 14C during the depuration phase for 2,4,5-trichlorophenol and p-nitrophenol.

Animals↗
PubMed1980

Clinical findings in workers exposed to pentachlorophenol.

Comparative findings are presented on the health and exposure status of groups of individuals in Hawaii with and without occupational exposure to pentachlorophenol (PCP). Occupational exposure to PCP occurred through employment at firms engaged in the treatment of wood with either PCP alone or PCP plus other compounds as preservative chemicals. Mean serum levels were 0.32 ppm for 32 control individuals, 1.72 ppm for 24 workers exposed to PCP and other wood preservative chemicals, and 3.78 ppm for 22 workers exposed to PCP as the sole preservative chemical. Age-standardized prevalence rates were significantly higher among the PCP-exposed than among the controls for low-grade infections or inflammations of the skin and subcutaneous tissue, protective membrane of the eyes and the mucosa membrane of the upper respiratory tract. Strong to moderate statistical associations were observed between PCP exposure and increased occurrence of bands (immature leucocytes) and basophils, increased plasma cholinesterase, alkaline phosphatase, gamma globulin and uric acid, and decreased serum calcium. Despite these statistical associations, laboratory values considered to be clinically abnormal were few and not significantly greater in occurrence among the PCP-exposed individuals.

Adult↗
PubMed1981

Synergism, antagonism, and additivity of phenol, pentachlorophenol, and dinitrophenol to a fish (Notopterus notopterus).

The toxicity of phenol (P), pentachlorophenol (PCP), and dinitrophenol (DNP) was determined separately and in different combinations with a test fish, Notopterus notopterus, using the procedure of Schubert et al. (1978) that provided a simple, sensitive, and quantitative index of synergism, antagonism and additivity. The combination (P + DNP)/PCP was found to be the most synergistic, while (PCP + DNP)/P was antagonistic in nature. The (DNP + P)/PCP combination was additive in its effect. The other combinations were also synergistic, but to a lesser extent than the (P + DNP)/PCP combination.

Animals↗