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PubMed2003

Formation of aldehydes upon ClO2 disinfection.

Carbonyl compounds are considered to be the most common ozonation by-products. Apart from well-known chlorites and chlorates, chlorine dioxide (ClO(2)) also generates organic by-products. The goal of this paper is an investigation into the influence of disinfection with ClO(2) on the aldehydes formation. Three types of waters were disinfected with different doses of ClO(2) at the various pH values. The results of size exclusion chromatography show that the reaction of ClO(2) with humic fraction of natural organic matter proceeds mainly on an aromatic part of the molecules. The results obtained indicate that the level of carbonyls concentration can significantly increase with the time of ClO(2) reaction with carbonyl precursors in treated water. There is no noticeable correlation between quantity of aldehydes and pH value of disinfected water. The range of "productivity" of aldehydes in water treated with chlorine dioxide is similar to the range estimated for the carbonyls formed upon ozonation.

Aldehydes↗
PubMed2002

Monitoring of air pollution by polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans of pine needles in Korea.

The atmospheric contamination levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were evaluated from the analysis of pine needles in South Korea. Pine needles were collected from 30 sampling points at five main cities in South Korea (Busan, Daegu, Gwangju, Changwon and Jeju island). The highest concentrations of PCDDs/DFs (2.19-26.88 pg I-TEQ/g of dry weight) were measured at Busan. where is the city of the highest population density and traffic volume among five cities. The lowest concentration was detected at Jeju with 0.62 pg I-TEQ/g dry weight. suggesting Jeju could be an environmental background area in Korea. The dominant homologues of PCDDs/DFs in pine needles were the lower chlorine-substituted compounds such as tetra CDDs and CDFs, and the distribution ratios of PCDDs/DFs decreased with increase of the number of chlorine substituents. Homologue profiles of pine needle samples were similar to PCDDs/DFs profiles of the vapor phase in the ambient air, and thus the pine needles absorbed the vapor phase of PCDDs/DFs from air. Results suggested that pine needles could be used as an indicator of the atmospheric contamination for PCDDs/DFs in Korea.

Air Pollutants↗
PubMed2006

Cancer mortality in workers exposed to organochlorine compounds in the pulp and paper industry: an international collaborative study.

The objective of this study was to evaluate cancer mortality in pulp and paper industry workers exposed to chlorinated organic compounds. We assembled a multinational cohort of workers employed between 1920 and 1996 in 11 countries. Exposure to both volatile and nonvolatile organochlorine compounds was estimated at the department level using an exposure matrix. We conducted a standardized mortality ratio (SMR) analysis based on age and calendar-period-specific national mortality rates and a Poisson regression analysis. The study population consisted of 60,468 workers. Workers exposed to volatile organochlorines experienced a deficit of all-cause [SMR = 0.91; 95% confidence interval (CI), 0.89-0.93] and all-cancer (SMR = 0.93; 95% CI, 0.89-0.97) mortality, with no evidence of increased risks for any cancer of a priori interest. There was a weak, but statistically significant, trend of increasing risk of all-cancer mortality with increasing weighted cumulative exposure. A similar deficit in all-cause (SMR = 0.94; 95% CI, 0.91-0.96) and all-cancer (SMR = 0.94; 95% CI, 0.89-1.00) mortality was observed in those exposed to nonvolatile organochlorines. No excess risk was observed in cancers of a priori interest, although mortality from Hodgkin disease was elevated (SMR = 1.76; 95% CI, 1.02-2.82) . In this study we found little evidence that exposure to organochlorines at the levels experienced in the pulp and paper industry is associated with an increased risk of cancer, apart from a weak but significant association between all-cancer mortality and weighted cumulative volatile organochlorine exposure.

Humans↗
PubMed2001

Levels of short and medium chain length polychlorinated n-alkanes in environmental samples from selected industrial areas in England and Wales.

Electron capture or negative ion chemical ionisation gas chromatography-mass spectrometry was employed to measure concentrations of short and medium chain length polychlorinated n-alkanes extracted from samples of water, river sediment, benthos, fish, soil, digested sewage and earthworms. Analysis of samples from 20 aquatic and eight agricultural sites indicated that short and medium chain length polychlorinated alkanes were present in the following concentration ranges: sediment < 0.2-65.1 mg/kg dry weight, water < 0.1-1.7 micrograms/l, fish < 0.1-5.2 mg/kg wet weight, benthos < 0.05-0.8 mg/kg wet weight, digested sewage 1.8-93.1 mg/kg dry weight, soil < 0.1 mg/kg dry weight, and earthworms < 0.1-1.7 mg/kg wet weight. It is clear from this study that these compounds are widely distributed in the UK environment, although it is not yet possible to fully assess the risks posed to either wildlife or humans by their continued use. Further study of these compounds is indicated.

Alkanes↗
PubMed2005

Application of a dialysis sampler to monitor phytoremediation processes.

A cylindrical dialysis sampler (1.2 m in length; 5 cm in diameter) was designed and constructed to sample small-scale phytoremediation processes in the root zone of poplar trees. The study site was a 183-tree plantation of hybrid poplars located at Aberdeen Proving Ground, Maryland, at the J-Field Area of Concern. The grove was planted in 1996 to intercept a chlorinated solvent plume containing 1,1,2,2-tetrachloroethane (1,1,2,2-TeCA, trichloroethene (TCE) and daughter products. Two dialysis samplers were installed: one directly in the poplar grove (approximately 0.3 m from the trunk of a mature tree) and the other outside of the grove but in the plume. Data collected included concentrations of chlorinated VOCs, organic acids, chloroacetic acids, Cl-, and dissolved gases (ethane, ethene, CH4, CO2). At the control location, the VOC profile was dominated by cis-1,2-dichloroethene (cis-1,2-DCE) and trans-1,2-dichloroethene (trans-1,2-DCE) with concentrations ranging from 0.88-4.5 to 4.4-17.6 mg/L, respectively. Concentrations of VOCs were similar across the vertical profile. At the tree location, 1,1,2,2-TeCA and TCE were the dominant VOCs detected but as opposed to the control location were highly variable within the root zone, with the greatest variability associated with locations in the sampler where roots were observed. This highly variable profile at the tree location is indicative of VOC rhizosphere biodegradation and uptake near the active roots. This variability appears to be on the centimeter scale, emphasizing the importance of these high-resolution samplers for the study of rhizosphere influences.

Acetates↗
PubMed1999

Enhancement of electron-capture detection of methyl bromide in air by iodination.

An instrumentally simple and cost-effective method for the direct analysis of methyl bromide in ambient air is described. The method is based on the separation of sample components by gas chromatography, the conversion of methyl bromide to methyl iodide by reaction with an inorganic iodide salt, and the detection of the methyl iodide thereby produced by an electron-capture detector. Of the 20 different inorganic salts investigated here for conversion of methyl bromide to methyl iodide, zinc iodide was found to provide the greatest conversion efficiency. In addition, zinc iodide was found to provide high conversion efficiency at a modest reaction temperature, thereby minimizing both the thermal decomposition of compounds within the reaction volume and the level of column bleed introduced to the detector. The reactions of several other brominated and chlorinated organic compounds with zinc iodide have also been characterized. The successful application of this instrument to the quantitative determination of methyl bromide in a local background air sample is then demonstrated.

Air↗
PubMed2001

Chlorometabolite production by the ecologically important white rot fungus Bjerkandera adusta.

Two strains of the basidiomycete, Bjerkandera adusta (DAOM 215869 and BOS55) produce in static liquid culture, phenyl, veratryl, anisyl and chloroanisyl metabolites (CAM's) (alcohols, acids and aldehydes) as well as a series of compounds not previously known to be produced by Bjerkandera species: 1-phenyl, 1-anisyl, 1-(3-chloro-4-methoxy) and 1-(3,5-dichloro-4-methoxy) propan-1,2-diols, predominantly as erythro diastereomers with IR, 2S absolute configurations. 1-Anisyl-propan-1,2-diol and 1-(3,5-dichloro-4-methoxy)-propan-1,2-diol are new metabolites for which the names Bjerkanderol A and B, respectively, are proposed. Experiments with static liquid cultures supplied with 13C6- and 13C9-L-phenylalanine showed that all identified aromatic compounds (with the exception of phenol) can be derived from L-phenylalanine. For the aryl propane diols, the 13C label appeared only in the phenyl ring and the benzylic carbon, suggesting a stereoselective re-synthesis from a C7 and a C2-unit, likely aromatic aldehyde and decarboxylated pyruvate, respectively. Other compounds newly discovered to be derived from phenylalanine by this white rot fungus include phenylacetaldehyde and phenylpyruvic, phenylacetic, phenyllactic, mandelic and phenyl glyoxylic (benzoyl formic) acids. For both strains, cultures supplied with Na37Cl showed incorporation of 37Cl in all identified chlorometabolites. Veratryl alcohol and the CAM alcohols, which occur in both strains and can be derived from L-phenylalanine (all 13C-labelled), have reported important physiological functions in this white rot fungus. Possible mechanisms for their formation through the newly discovered compounds are discussed.

Basidiomycota↗
PubMed1995

Metabolites with nematicidal and antimicrobial activities from the ascomycete Lachnum papyraceum (Karst.) Karst. V. Production, isolation and biological activities of bromine-containing mycorrhizin and lachnumon derivatives and four additional new bioactive metabolites.

Eight novel bioactive metabolites were isolated from submerged cultures of the ascomycete Lachnum papyraceum (Karst.) Karst, when CaBr2 was added to the cultures after the onset of secondary metabolism. Four of these metabolites (16 to 19) are bromo analogues of mycorrhizin A and lachnumon, while (l'Z)-dechloromycorrhizin A (12) and the papyracons A (13), B (14), and C (15) are non-halogenated compounds structurally related to the mycorrhizins. All compounds exhibited antimicrobial, cytotoxic, nematicidal and phytotoxic activities. The brominated mycorrhizins and lachnumons were found to be slightly less active than the chlorine-containing compounds. All mycorrhizin derivatives were mutagenic in the Ames test, suggesting DNA-alkylating properties.

Animals↗
PubMed1985

Sources and fate of polychlorinated dibenzodioxins, dibenzofurans and related compounds in human environments.

Several of the major incidents resulting in potential human exposures to polychlorinated dibenzodioxins (PCDDs) and/or polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and related compounds which have occurred in the U.S. in recent periods have resulted from improper disposal of hazardous chemical wastes. Prominent examples of such environmental contamination episodes are the Love Canal, into which ton quantities of chlorinated organic compounds containing substantial concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were deposited; numerous sites in the State of Missouri which were contaminated by the dumping of chlorinated organic wastes containing various PCDDs and possibly PCDFs, and PCBs; and the environs of a 2,4-D/2,4,5-T manufacturing plant site in Arkansas, which were contaminated with PCDDs. Environmental assessments of such sites have revealed extensive contamination of soils, waterways, fish and other biological species with these toxic compounds, which in turn could lead to human exposures. Other recently identified sources of PCDDs, PCDFs and related compounds in human environments include stack effluents from municipal refuse incineration, and fires and explosions involving electrical devices containing PCBs and polychlorinated benzenes. Data obtained in assessments of such incidents are presented, and the implications of these findings with respect to the distribution and persistence of PCDDs, PCDFs and related chemicals in the environment and possible effects on humans are discussed.

Accidents↗
PubMed2003

Gas chromatographic-mass spectrometric method for the determination of bisphenol A and its chlorinated derivatives in urban wastewater.

The simultaneous determination of trace amounts of endocrine disruptors such as bisphenol A (BPA) and its monochloro, dichloro, trichloro and tetrachloro derivatives in wastewater has been developed using gas chromatography-mass spectrometry (GC-MS). Compounds were previously extracted from the aqueous samples using a liquid-liquid extraction procedure with a mixture of dichloromethane:carbon tetrachloride (25/75). After extraction, solvent was removed and a silylation step was carried out with N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA). The silylated compounds were identified and quantified by GC-MS using an HP1-MS column. The retention times were 6.64 min for BPA silylated, 7.26 min for Cl-BPA silylated, 7.99 min for Cl(2)-BPA silylated, 8.85 min for Cl(3)-BPA silylated and 9.95 min for Cl(4)-BPA silylated. A clean-up is not necessary using SIM mode. Deuterated anthracene (2H(10)-anthracene) was used as an internal standard. The detection limits obtained were 0.3, 0.6, 2.0, 4.5 and 13.0 ng L(-1) for silylated BPA, Cl-BPA, Cl(2)-BPA, Cl(3)-BPA and Cl(4)-BPA, respectively. The proposed method was applied satisfactory to the determination of these chemicals, in different types of wastewater previously spiked with different amounts of these chemicals at concentration levels ranging from 0.01 to 2.50 microg L(-1) for BPA, 0.05-2.50 micro L(-1) for Cl-BPA and 0.05-5.00 microg L(-1) for Cl(2)-BPA, Cl(3)-BPA and Cl(4)-BPA, respectively. The method was validated following standard addition methodology.

Benzhydryl Compounds↗
PubMed1988

Studies of the leaching of atrazine, of its chlorinated derivatives, and of hydroxyatrazine from soil using 14C ring-labeled compounds under outdoor conditions.

By the use of unperturbed-structure soil columns placed under field conditions, we have evaluated the migration of various 14C ring-labeled s-triazinic compounds (atrazine, its chlorinated derivatives, hydroxyatrazine) into leached water over a 1-year period. The results obtained by determination of the leached radioactivity allow us to establish a classification of the mobility for each product and its possibility of contaminating infiltration water in the soil. Qualitative analysis of the leached residues confirms the predominant presence of deethylated atrazine.

Adsorption↗