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PubMed2005

Evidence of genetic damage in grass gobies and mussels from the Venice lagoon.

The presence of genetic damage has been investigated in two native species of the Venice lagoon: the common mussel Mytilus galloprovincialis and the grass goby Zosterisessor ophiocephalus. Two sampling campaigns were performed in summer 1998 and 1999. Aromatic-like DNA adducts were analysed in selected tissues of gobies and mussels by using the 32P-postlabelling assay. In 1999, micronuclei and other nuclear abnormalities were additionally scored on gill cells and haemocytes of individual mussels whereas inorganic (As, Cd, Cr, Hg, Ni, Pb, Sn) as well as organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and other chlorinated compounds) were measured in the total mussel pulp. Compared to the lagoon inlet area, gobies and mussels from the industrial district (Marghera) showed significant DNA adduct levels and increased frequencies of cytogenetic alterations (evidence of genetic damage was absent or inconsistent in other sites). The substantial levels of aromatic and chlorinated contaminants detected in mussels from Marghera also support the exposure of native organisms to genotoxic agents.

Animals↗

PubMed2005

Bioactive metabolites from the fungus Nectria galligena, the main apple canker agent in Chile.

The phytopathogenic fungus Nectria galligena Bres. is the most common canker disease agent of hardwood trees. The terpenoids colletochlorin B, colletorin B, ilicicolin C, E, and F, as well as the phytotoxin alpha,beta-dehydrocurvularin have been isolated from liquid cultures of N. galligena obtained from the xylem of infected apple trees in central Chile. Ilicicolin C and F and alpha,beta-dehydrocurvularin were active against Pseudomonas syringae with IC50 values of 28.5, 28.5, and 14.2 microg/mL, respectively, in the same range as streptomycin and penicillin G (11 and 15 microg/mL, respectively). All of the compounds showed moderate inhibitory activity toward the enzymes acetylcholinesterase (AChE) and beta-glucuronidase. The most active enzyme inhibitors were colletochlorin B and ilicicolin C and E, with IC50 values of 30-36 microg/mL in the AChE assay and 32-43 microg/mL in the beta-glucuronidase test. All of the chlorinated compounds showed some toxicity toward human lung fibroblasts, with IC50 values in the range of 64-120 microg/mL. alpha,beta-Dehydrocurvularin proved to be the most toxic compound, showing IC50 values less than 12 microg/mL. The effect of the isolated compounds on seed germination and radicle and epicotyl growth was assessed in lettuce and millet seeds. At 100 and 200 microg/disk, alpha,beta-dehydrocurvularin significantly reduced radicle length and epicotyl growth in Lactuca sativa. This is the first report on the occurrence of colletochlorin B, colletorin B, ilicicolin C, E, and F, as well as alpha,beta-dehydrocurvularin associated to N. galligena.

Anti-Bacterial Agents↗

PubMed1979

Utilization of chlorobenzoates by microbial populations in sewage.

Microorganisms in sewage decomposed 3.4-dichlorobenzoate and m-, p-, and o-chlorobenzoates. As the substrate disappeared, populations capable of growing on these compounds proliferated. Neither 2,4-dichlorobenzoate nor 2,3,6-trichlorobenzoate was destroyed by the sewage microflora. The addition of glucose or benzoate and m-chlorobenzoate to the sewage did not promote degradation of 2,4-di- or 2,3,6-trichlorobenzoates. The populations responsible for the biodegradation of the chlorinated compounds were initially less than 100 cells/ml. During the metabolism of m-chlorobenzoate, 5-chlorosalicylate and 4-chlorocatechol were formed.

Bacteria↗

PubMed1987

Tandem capillary gas chromatography in pesticide residue analysis.

Maximum residue levels of pesticides in food and feed are often below the 0.1 ppm level. On capillary columns, the maximum injection volumes are 5-10 microliters in the splitless mode, although of course some (acceptable) overloading of the GC column occurs. Injection of larger volumes (up to 100 microliters) is possible only when the solvent can be removed whilst at the same time the compounds of interest are concentrated in a small zone. The advantage of such a procedure is obvious: the limit of detection is improved by a factor of 10-20, so a concentration step can be omitted. A Chrompack MUSIC (MUltiple Switching Intelligent Controller) kit was connected with a Tracor 550 gas chromatograph with an electron-capture detector for chlorinated compounds. Data are presented that show that gel permeation chromatography on Bio-Beads SX-3 as a clean-up medium in combination with MUSIC allows the detection of sub-ppm levels of organochlorine pesticides in grains, fats and vegetables by splitless injection of a 100-microliters sample on to the chromatographic column.

Chromatography, Gas↗

PubMed2001

Rapid detection of multiple chlorinated bis(bibenzyls) in bryophyte crude extracts using laser desorption/ionization time-of-flight mass spectrometry.

Chlorinated bis(bibenzyls) of the bazzanine type were detected in crude bryophyte plant extracts of Bazzania trilobata from different locations using laser desorption/ionization time-of-flight (LDI-TOF) mass spectrometry without addition of an additional chemical matrix. The degree of chlorination could be identified by the characteristic isotope patterns. These results suggest that these chlorinated compounds are not artefacts of an incidental occurrence, or of the sample preparation, but are genuine natural products produced by the liverwort or by an endosymbiotic metabolism.

Bryopsida↗

PubMed2002

Linear free energy relationships on rate constants for dechlorination by zero-valent iron.

By correlation analysis, molecular structural factors governing surface area-normalized rate constants (k) for dechlorination by zero-valent iron, were identified. Twenty-nine quantum chemical descriptors computed by MNDO, AM1 and PM3 Hamiltonians for gas-phase and the conductor-like screening model (COSMO) for incorporating solvent (H2O) effects were studied. Besides the energy of the lowest unoccupied molecular orbital (E(LUMO)), the character of carbon-chlorine bonds (C-Cl bonds) and especially the strength of C-Cl bonds was found significant in governing the magnitude of log k. By PLS analysis, six two-parameter linear free energy relationships (LFER) were obtained. The best two-parameter LFER model was the one using E(LUMO) and C (the Coulombic interaction energy of the two-center term for the C-Cl bonds) computed by PM3/H2O method as molecular structural descriptors. Chlorinated compounds with high E(LUMO) and C values tend to have low dechlorination rate constants.

Carbon↗

PubMed2002

Volatile organic compound emissions during the composting of biosolids from a domestic wastewater treatment plant.

VOCs emitted by two composting static piles of biosolids coming from the "El Salitre" wastewater treatment plant (Bogotá, Colombia) were analysed during the composting process. Each pile in its sampling time was maintained with a different aeration system. The sampling was made using Solid Phase Microextraction (SPME); separation and identifications were made using Gas Chromatography (GC) coupled to Mass Spectrometry (MS). Aliphatic and aromatic hydrocarbons, chlorinated compounds, ketones, mercaptans, alcohols and amines were identified in concentrations greater than the norms stipulated by the EPA for inhalation in humans beings. The emission behavior varied according to the aeration system used.

Alcohols↗

PubMedDate not supplied

[Combined use of active chlorine and coagulants for drinking water purification and disinfection].

The authors made an experimental study of the efficiency of water purification procedures based on the combined use of active chlorine and coagulants and hygienically evaluated the procedures. The study included the evaluation of water disinfection with various coagulants and active chlorine; the investigation of the processes of production of deleterious organic chlorine compounds; the assessment of the quality of water after its treatment. The coagulants representing aluminum polyoxychloride: RAX-10 (AQUA-AURATE 10) and RAX-18 (AQUA-AURATE 18), and aluminum sulfate, technically pure grade were tested. The treatment of river water with the coagulants RAX-10 and RAX-18, followed by precipitation, filtration, and chlorination under laboratory conditions, was shown to result in water disinfection to the levels complying with the requirements described in SanPiN 2.1.4.1074-01. RAX-18 showed the best disinfecting activity against total and heat-tolerant coliform bacteria, but also to the highly chlorine-resistant microrganisms--the spores of sulfite-reducing Clostridia, phages, and viruses. Since the coagulants have an increased sorptive capacity relative to humus and other organic substances, substitution of primary chlorination for coagulant treatment may induce a reduction in the risk of formation of oncogenically and mutagenically hazardous chlorinated hydrocarbons.

Chlorine↗

PubMed2005

UASB performance for bleached and unbleached kraft pulp synthetic wastewater treatment.

This paper presents the performance of two bench scale Upflow Anaerobic Sludge Blanket reactors (UASB) used for the treatment of synthetic substrates that simulate bleached and unbleached cellulose pulp plant wastewaters. The control reactor was fed with diluted black liquor and the treatment reactor with the same substrate plus a mixture of chlorinated organics. The total concentration of the chlorinated compounds was gradually increased from 2.5 mg l-1 to 15.0 mg l-1. The average COD removal efficiency during the last phase of the experiment was 81% in the control reactor and 76% in the treatment reactor. These results indicate the capability of UASB reactors to treat this kind of wastewater and the low impact of the chlorinated organics on COD removal efficiency. The minimum overall chlorinated organics removal efficiency was 71% and the maximum was 99.7%. The experiment indicates that under the conditions used in this research the presence of chlorinated organics does not negatively impact the treatment process.

Bacteria, Anaerobic↗

PubMed2005

Probing the active site tightness of DNA polymerase in subangstrom increments.

We describe the use of a series of gradually expanded thymine nucleobase analogs in probing steric effects in DNA polymerase efficiency and fidelity. In these nonpolar compounds, the base size was increased incrementally over a 1.0-A range by use of variably sized atoms (H, F, Cl, Br, and I) to replace the oxygen molecules of thymine. Kinetics studies with DNA Pol I (Klenow fragment, exonuclease-deficient) in vitro showed that replication efficiency opposite adenine increased through the series, reaching a peak at the chlorinated compound. Efficiency then dropped markedly as a steric tightness limit was apparently reached. Importantly, fidelity also followed this trend, with the fidelity maximum at dichlorotoluene, the largest compound that fits without apparent repulsion. The fidelity at this point approached that of wild-type thymine. Surprisingly, the maximum fidelity and efficiency was found at a base pair size significantly larger than the natural size. Parallel bypass and mutagenesis experiments were then carried out in vivo with a bacterial assay for replication. The cellular results were virtually the same as those seen in solution. The results provide direct evidence for the importance of a tight steric fit on DNA replication fidelity. In addition, the results suggest that even high-fidelity replicative enzymes have more steric room than necessary, possibly to allow for an evolutionarily advantageous mutation rate.

Base Pairing↗

PubMed1989

Anaerobic Degradation of Chloroaromatic Compounds in Aquatic Sediments under a Variety of Enrichment Conditions.

Anaerobic degradation of monochlorophenols and monochlorobenzoates in a variety of aquatic sediments was compared under four enrichment conditions. A broader range of compounds was degraded in enrichments inoculated with sediment exposed to industrial effluents. Degradation of chloroaromatic compounds was observed most often in methanogenic enrichments and in enrichments amended with 1 mM bromoethane sulfonic acid. Degradation was observed least often in enrichments with added nitrate or sulfate. The presence of 10 mM bromoethane sulfonic acid prevented or inhibited degradation of most compounds tested. Primary enrichments in which KNO(3) was periodically replenished to maintain enrichment characteristics degraded chlorobenzoates, but not chlorophenols. In contrast, primary enrichments in which Na(2)SO(4) was periodically replenished failed to degrade any chloroaromatic compounds. Upon transfer to fresh medium, none of the sulfate enrichments required the presence of Na(2)SO(4) for degradation, while only two nitrate enrichments required the presence of KNO(3) for degradation. As a class of compounds, chlorophenols were degraded more readily than chlorobenzoates. However, as individual compounds 3-chlorobenzoate, 2-chlorophenol, and 3-chlorophenol degradation was observed most often and with an equal frequency. Within the chlorophenol class, the relative order of degradability was ortho > meta > para, while that of chlorobenzoates was meta > ortho > para, In laboratory transfers, 2-chlorobenzoate, 3-chlorobenzoate, and 2-chlorophenol degradation was most easily maintained, while degradation of para-chlorinated compounds was very difficult to maintain.

Journal Article↗

PubMed1988

Genetic effects of chlorinated ethylenes in the yeast Saccharomyces cerevisiae.

The chlorinated ethylenes 1,1-dichloroethylene (vinylidene chloride), trans-1,2-dichloroethylene, trichloroethylene, and tetrachloroethylene (perchloroethylene) were assayed for their ability to induce mitotic gene conversion and point mutation as well as mitotic aneuploidy in diploid strains of the yeast Saccharomyces cerevisiae. From strain D7 late logarithmic-phase cells grown in 20% glucose liquid medium, containing a high level of cytochrome P-450, as well as stationary-phase cells combined with an exogenous metabolic activating system (S9) were used, in order to activate the chlorinated compounds and to produce electrophilic mutagenic intermediates. Only 1,1-dichloroethylene exhibited a dose-dependent genetic activity, while the other ethylenes did not. The 2 ways of metabolic activation were compared and were found to cause approximately the same effect. In contrast to the findings with strain D7, vinylidene chloride, trans-1,2-dichloroethylene, and trichloroethylene induced, without metabolic activation, mitotic chromosomal malsegregation in strain D61.M. The presence of liver homogenate as an activating system did not enhance the respective frequencies of chromosome loss. In the case of tetrachloroethylene, sufficient data have not become available, since this compound showed a highly toxic effect towards yeast cells, decreasing the rate of surviving cells to less than 30% at a concentration of 9.8 mM.

Biotransformation↗

PubMed1996

Health effects of working in pulp and paper mills: exposure, obstructive airways diseases, hypersensitivity reactions, and cardiovascular diseases.

Workers in the pulp and paper industry are exposed to different substances, such as hydrogen sulfide and other reduced sulfur compounds, chlorine, chlorine dioxide, sulfur dioxide, terpenes, and paper dust. The exposure level depends on the process, i.e., sulfite, sulfate, groundwood, bleachery, or paper production. Hitherto, exposures have been poorly described and more studies are certainly needed. Workers with repeated exposure peaks to chlorine, e.g., bleachery workers, seem to have an impaired lung function and an increased prevalence of respiratory symptoms. Exposure to high levels of paper dust, (> 5 mg/m3) causes impaired lung function. Therefore, exposure to respiratory irritants is an important, and probably overlooked, occupational risk among certain groups of pulp and paper workers. Some studies indicate that sulfate workers with high exposure to reduced sulfur compounds have an increased mortality due to ischemic heart disease. However, before any definite conclusions can be drawn, the impact of important confounders, such as shift-work and smoking habits have to be further evaluated.

Air Pollutants, Occupational↗

PubMed1989

Pesticide residue control in the years 1983-1985.

Levels of organochlorinated, organophosphate, dithiocarbamic, benzimidazolic, and phthalimidic compounds, as well as some other pesticide residues obtained from Regional Laboratories in the years 1983-1985, were assembled and presented as a part of a study aimed at evaluating food contamination. Approximately 2000 samples of vegetables, fruits, cereals, and food of animal origin were analyzed by local laboratories during the years 1983, 1984, and 1985. Samples were randomly obtained from the market, at production levels, or sometimes at custom sites. Approximately 10,000 determinations of single compounds or classes of compounds were carried out. The analytical results are presented and compared with the Italian maximum residue limits. In the majority of the samples analyzed, either there were no residues or the residues were below the permitted level for the specific pesticide in each commodity. High levels of residues were present in a few cases, mainly with respect to some fungicides in fruits and vegetables and chlorinated compounds in some animal products.

Edible Grain↗

PubMed2003

Use of regenerated ferric oxide for CO destruction and suppressing dioxin formation in flue gas in a pilot-scale incinerator.

Catalytic destruction of chlorinated compounds is one of the key methods in reducing pollutant emissions. For the purpose of utilizing waste materials, a catalyst was regenerated from ferric ion sludge, obtained from the addition of iron salts to precipitate heavy metals. The sludge was dewatered, heated (800 degrees C for 4 h), and ground into smaller particles. The regenerated ferric oxide particles were then used as the oxidation catalyst to destroy CO formation during the combustion of three chlorinated solvents and to suppress dioxin formation in flue gas in a real waste solvent. In the presence of catalyst, the combustion efficiency (ratio of CO(2) to the sum of CO(2) and CO) for chlorobenzene was more than 98% at 850 degrees C in a pilot-scale incinerator. The destruction and removal efficiencies of chlorobenzene, 2,4-dichlorophenol and trichlorofluoroethane were more than three nines. In the absence of catalysts, the flue gas emission from a real waste could not meet the regulatory dioxin standard of 0.1 ng-TEQ/Nm(3) even with the powdered activated carbon injection. The use of catalyst at either 100 or 300 g/h, however, was able to meet the emission standard.

Air Pollutants↗

PubMedDate not supplied

Antitumor activity of phenothiazine-related compounds.

One of the biggest challenges in health care is the fight against tumors. Some phenothiazines have antitumor activity on HEp-2 tumor cells. In this study, we tested the antitumor effects of three series such as 10-nonsubstituted phenothiazines, 10-[n-(phthalimido)alkyl]-2-substituted-10H-phenothiazines and 1-(chloroethyl)-3-(2-substituted-10H-phenothiazines-10-yl)alkyl-1-ureas with H, Cl and CF3 substitution at position C2. The TCID50 of phenothiazines was affected by the H, Cl and CF3 at C2. Trifluoromethyl derivative of phenothiazine showed potent (R = CF3, TCID50 = 4.7 micrograms) activity, whereas the chlorine derivative of phenothiazine (R = Cl, TCID50 = 62.5 micrograms) had a relatively weak effect. In the group of 10-[n-(phthalimido)alkyl]-2-substituted-10H-phenothiazines, 10-[3-(phthalimido)propyl]-10H-phenothiazine (R = H, n = 3, TCID50 = 11.5 micrograms), 10-[4-(phthalimido)butyl]-10H-phenothiazine (R = H, n = 4, TCID50 = 7.8 micrograms) and 10-[3-(phthalimido)propyl]-2-trifluoromethyl-10H- phenothiazine (R = CF3, n = 3, TCID50 = 11.5 micrograms) was very effective. On the other hand, TCID50 of 10-[3-(phthalimido)propyl]-2-chloro-10H-phenothiazine (R = Cl, n = 3, TCID50 = 75.0 micrograms), 10-[4-(phthalimido)butyl]-2-chloro-10H-phenothiazine (R = Cl, n = 4, TCID50 = 31.3 micrograms) and 10-[4-(phthalimido)butyl]-2-trifluoromethyl-10H-phenothiazine (R = CF3, n = 4, TCID50 = 50.0 micrograms) were about 4-8 times less effective than 10-[4-(phthalimido)butyl]-10H-phenothiazine (R = H, n = 4, TCID50 = 7.8 micrograms). Among six 1-(chloroethyl)-3- (2-substituted-10H-phenothiazin-10-yl)alkyl-1-ureas, two chlorine compounds such as 1-(2-chloroethyl)-3-(2-chloro-10H-phenothiazin-10-yl)propyl-1-urea (R = Cl, n = 3, TCID50 = 6.3 micrograms), 1-(2-chloroethyl)-3-(2-chloro-10H-phenothiazin-10-yl) butyl-1-urea (R = Cl, n = 4, TCID50 = 7.8 micrograms), and 1-(2-chloroethyl)-3-(2-trifluoromethyl-10H-phenothiazin-10-yl)buty l-1-ur ea (R = CF3, n = 4, TCID50 = 7.8 micrograms) were significantly active. Tests showed that the substitution at 2C position apparently affected the anti-HEp-2 tumor cell activity; that the length of the aliphatic side chain at 10N contributes to the anti-tumor activity; and that the TCID50 values of the derivatives with butylene group (-C4H8-) were lower than those with propylene group (-C3H6-) except 10-[4-(phthalimido) butyl]-2-trifuoromethyl-10H-phenothiazine and 1-(2-chloroethyl)-3-(2-chloro-10H-pheno-thiazin-10-yl) butyl-1-urea.

Antineoplastic Agents↗

PubMed2006

ClcR-based biosensing system in the detection of cis-dihydroxylated (chloro-)biphenyls.

Polychlorinated biphenyls (PCBs) are a group of organic pollutants that are persistent when released into the environment. Among the metabolites of PCBs, dihydroxylated PCBs are also considered as toxic compounds. Various studies have shown that dihydroxylated PCBs affect the reproductive, immune, nervous, and endocrine systems. Detection of these chemicals in environmental and biological samples could provide first-hand information about their levels and lead to a better understanding of their role in toxicity. To that end, we developed a sensing system for the detection of dihydroxylated PCBs based on the clc operon. The Pseudomonas putida clc operon encodes a catabolic pathway for degradation of chlorocatechols, which are major metabolites of a large number of chlorinated compounds. In P. putida, the expression of these genes is regulated by a protein encoded by the gene clcR located upstream from the clcABD genes. We demonstrate here for the first time that dihydroxy PCBs can also induce the clc operon. Our sensing system employs P. putida bacteria harboring a plasmid in which the reporter gene, lacZ, is under the control of the regulatory protein ClcR. Consequently, when exposed to dihydroxy PCBs, the bacteria express beta-galactosidase in an amount related to the concentration of the corresponding dihydroxy PCB. Various dihydroxylated PCBs, differing in the number and position of chlorines and in the position of hydroxyls, were tested for their ability to induce expression of beta-galactosidase. Detection limits as low as 1 x 10(-6) mol L(-1) were obtained for various dihydroxylated PCBs.

Biosensing Techniques↗

PubMed1989

Potentiation of the poliocidal effectiveness of free chlorine by a buffer.

Poliovirus 1 was inactivated by free chlorine at pH 9.0 three times more rapidly in boric acid (0.05 M)-NaOH buffer than in purified (carbon-filtered, deionized) water. Thus, at a given concentration of free chlorine, it took three times longer to inactivate the same fraction of the poliovirus in purified water than in the boric acid-NaOH buffer. Conversely, in a given period of time, three times more chlorine was required to inactivate a given percentage of the virus in purified water than in the boric acid-NaOH buffer. Buffers are almost always used to control pH in disinfection studies with free chlorine and with other chlorine compounds also. The use of buffers for pH control in such disinfection studies may distort the resulting data and, at least for waters that contain little salt, may cause serious overestimation of the rates at which viruses are inactivated.

Boric Acids↗