Pentachlorophenol sources

Harnly, M.F., Petreas, M.X., Flattery, J. and Goldman, F.R. 2000. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran contamination in soil and home-produced chicken eggs near pentachlorophenol sources. Environmental Science and Technology 34 1143-1149. 

Indirect discharge kraft mills were subject to performance standards for existing sources or new sources (PSES or PSNS, as applicable) for the control of pentachlorophenol and trichlorophenol. 

Slimicide and biocide toxic pollutants containing pentachlorophenol are used at mills in the pulp, paper, and paperboard industry. Initially, pentachlorophenol was used as a replacement for heavy metal salts, particularly mercuric types. Trichlorophenols are also used because of their availability as a byproduct from the manufacture of certain herbicides. Formulations containing organo-bromides and organo-sulfur compounds are also being used. Substitution of alternative slimicide and biocide formulations can lead to the virtual elimination of pentachlorophenol and trichlorophenol from these sources. 

TCP), and pentachlorophenol (PCP), in order of abundance. Minor amounts of other trichlorophenols and dichlorophenols may also be present, as well as recalcitrant polychlorinated phenoxyphenols (PCPPs) and PCDD/Fs as impurities [75, 76]. In Finland, approximately 30,000 tons of CP products were used between 1934 and 1988, when they were banned because of their potential toxicity to humans and the environment [77, 78]. The careless manufacturing and application of wood preservatives together with the lack of suitable waste disposal caused massive contamination of river sediments and sawmill sites. For example, the river Kymijoki in southern Finland was identified as the largest source of dioxins accumulating in fish in the entire Baltic area. Similar products were used in other European countries, especially Nordic countries with a large forestry industry, such as Sweden [79]. 

Previous production of pentachlorophenol, as well as the bleaching process in pulp and paper mills, has been shown to be a major source. Changes in industrial processes have resulted in a reduction of PCDD/PCDFs concentration in products. Whereas in the past the chemical industry and, to a lesser extent, the pulp and paper industry were considered to be the main sources of PCDD/PCDFs (and also the cause of many of today s contaminated sites in several industrialized countries), today s dioxin input is mainly due to thermal processes. There is still a considerable focus on waste incineration but, owing to requirements for dioxin reduction in stack gases set by several national authorities, the importance of this category has declined during the last years. Examples can be seen especially in the European emission inventories... 

Fig. 5.1 Extraction of Atrazine, lindane, pentachlorophenol and Diazinon from soil Source Reproduced with permission from the American Chemical Society [36]... 

Pentachlorophenol, a large-volume fungicide and wood preservative, contains relatively high levels of hexa-, hepta- and octachlorodibenzodioxins and essentially no tetrachlorodibenzo-p-dioxins [83-85] and polychlorodibenzo-p-dioxin incineration of materials containing chlorophenols readily produces mixtures of polychlorodibenzo-p-dioxins, but 2,3,7,8-tetrachlorodibenzo-p-dioxin is a minor component. On the other hand, the highly toxic 1,2,3,7,8-pentachloro isomer is a major component of polychlorodibenzo-p-dioxins and polychlorodibenzofurans usually produce mixtures of distinctly different relative component abundances [83], On the other hand, the preferential accumulation of certain isomers in animals may prevent source identification from analyses of biological samples. 

Source Hexachlorobenzene may enter the environment from incomplete combustion of chlorinated compounds including mirex, kepone, chlorobenzenes, pentachlorophenol, PVC, polychlorinated biphenyls, and chlorinated solvents (Ahling et al., 1978 Dellinger et al., 1991). In addition, hexachlorobenzene may enter the environment as a reaction by-product in the production of carbon tetrachloride, dichloroethylene, hexachlorobutadiene, trichloroethylene, tetrachloro-ethylene, pentachloronitrobenzene, and vinyl chloride monomer (quoted, Verschueren, 1983). 

Buser and Bosshardt reported on the results of a survey on the PCDD and PCDF contents of pentachlorophenol (PCP) and PCP-Na from commercial sources in Switzerland (UO). From the results, the grouping of the samples into two series can be observed a first series with generally low levels (hexa-CDD < 1 ppm) and a second series with much higher levels (hexa-CDD > 1 ppm) of PCDDs and PCDFs. Samples of high PCDD contents had also high PCDF contents. For most samples, the contents of these contaminants were in the order tetra- penta < hexa < hepta octa--CDD/CDF. The ranges of the combined levels of PCDDs and PCDFs were 2-l6 and 1-26 ppm, respectively, for the first series of samples, and 120-500 and 85 570 ppm, respectively, for the second series of samples. The levels of octa-CDD and octa-CDF were as high as 370 and 300 ppm, respectively (UP). 

Rappe et al. have reported on the analysis of two commercial chlorophenate formulations from Scandinavian sources using a 50. m OV-17 column (7). The tetrachlorophenol was known to contain approximately 5 2,U,6-tri-, 50 2,3,l, 6-tetra- and 10 pentachlorophenol as their sodium salt. The combined levels of PCDDs and PCDFs (tetra- to octa-) were 10 and l60 yg/g, respectively. Whereas on the earlier analyzed PCP samples 0 0 ] the... 

Hendriksen, H. V., Larsen, S. Ahring, B. K. (1992). Influence of a supplemental carbon source on anaerobic dechlorination of pentachlorophenol in granular sludge. Applied and Environmental Microbiology, 58, 365-70. 

As discussed in the earlier survey (1), a biogenic source of polychlorinated dibenzo-p-dioxins and dibenzofurans is peroxidase-catalyzed transformation of chlorophenols as first reported by Oberg and Rappe (2041-2044). More recent studies confirm these observations (2045-2048). In addition to lactoperoxidase and horseradish peroxidase, human leukocyte myeloperoxidase catalyzes in vitro formation of dioxins and dibenzofurans from chlorophenols (2046, 2047). Formation rates are in the pmol/mol range (Scheme 3.6) demonstrating that a human biosynthesis of dioxins and furans is not only possible but also likely. These observations are reinforced by the reported in vivo (rats) conversion of the pre-dioxin nona-chloro-2-phenoxyphenol to octachlorodibenzo-p-dioxin (OCDD) (2049), and the production of hepta- and octachlorodibenzo-p-dioxin in the feces of cows fed pentachlorophenol-treated wood (Scheme 3.7) (2050, 2051). 

The Binational Toxics Strategy between the USA and Canada has identified 12 bioaccumulative substances (referred to as Level-1 substances) having significant persistency and toxicity to the Great Lakes system, with the goal of reducing the sources of these substances to achieve naturally occurring levels [23]. Six of the 12 Level-1 substances are OC pesticides aldrin/dieldrin, chlordane, DDT, HCB, mirex, and toxaphene. Several other OC pesticides, such as endrin, heptachlor/heptachlor epoxide, hexachloro-cyclohexanes, tetra- and penta-chlorobenzenes, and pentachlorophenol, have been identified as Level-2 substances. 

In addition to the incineration processes, herbicides, CNP (2,4, 6-trichlorophenyl-4 -nitrophenyl ether) and PCP (pentachlorophenol) usage was reported as the major source of dioxins, especially during the late 1960s 1970s. While CNP contained particular non-toxic dioxin congeners such as 1,3,6,8-TeCDD and 1,3,7,9-TeCDD (Yamagishi et al.,... 

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