Studies on the mechanism of PCDD/PCDF formation during the bleaching of pulp

LaFleur, Lawrence E.; Brunck, B.; McDonough, Thomas Joseph; Ramage, K.; Gillespie, W. J.; Malcolm, Earl W.

doi:10.1016/0045-6535(90)90336-r

Cited by 32 publications

(28 citation statements)

References 1 publication

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“…These compounds are not created intentionally, but are produced inadvertently by a number of human activities and natural processes. Industrial or municipal waste incineration, manufacture and use of certain herbicides 1,2) and pulp bleaching 3) are considered to be major sources of dioxins to the environment. Currently, the main source of PCDDs and PCDFs (PCDD/DFs) in Japan 4) is combustion at waste incinerators.…”

Section: Introductionmentioning

confidence: 99%

Atmospheric Deposition of Polychlorinated Dibenzo-p-dioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs) in Kanazawa, Japan

Oka

Kakimoto²,

Miyata³

et al. 2006

JOURNAL OF HEALTH SCIENCE

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Section: Introductionmentioning

confidence: 99%

Atmospheric Deposition of Polychlorinated Dibenzo-p-dioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs) in Kanazawa, Japan

Oka

Kakimoto²,

Miyata³

et al. 2006

JOURNAL OF HEALTH SCIENCE

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“…Pulp mill effluents from chlorine bleaching contain predominantly the 2, 3, 7, 8‐substituted tetra‐ and pentachlorinated congeners [42], whereas combustion sources strongly favor the non‐2, 3, 7, 8‐substituted congeners [12, 43]. In sediments, median concentrations of the non‐2, 3, 7, 8‐substituted TCDDs and PnCDDs are enhanced six‐ and threefold, respectively, over the 2, 3, 7, 8‐substituted congeners, which suggests predominantly a combustion source for the non‐2, 3, 7, 8 congeners at the mill sites.…”

Section: Resultsmentioning

confidence: 99%

Bioavailability of chlorinated dibenzo‐p ‐dioxins and dibenzofurans to dungeness crab (Cancer magister) at marine pulp mill sites in British Columbia, Canada

Yunker¹,

Cretney²

2000

Enviro Toxic and Chemistry

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Abstract-Synchronous samples of sediment and Dungeness crab (Cancer magister) hepatopancreas, which were obtained for monitoring and assessment purposes at British Columbia, Canada, marine pulp mill sites between 1990 and 1995, were used to calculate biota-sediment accumulation factors (BSAFs) for individual chlorinated dibenzo-p-dioxin and dibenzofuran congeners (PCDD/Fs). The BSAFs for individual pairs of samples were highly variable, and no systematic trends were apparent in the observed accumulation factors over time, with crab size, with crab lipid concentration, with sediment percent organic carbon, or among mill sites or depositional environments. Composition and source differences in sedimentary PCDD/Fs, which are apparent as principal components analysis class separations in the sediment data set, also did not correlate with differences in BSAFs. This independence from environmental factors provides a valuable endorsement of the BASF concept for the formulation of aquatic effects-based sediment-quality criteria and human risk-assessment guidelines. However, BSAF values did exhibit a significant, nonlinear decrease with increasing log K ow and with sediment and crab PCDD/F concentrations. The correlation between BSAFs and sediment concentrations accounts for between 14 and 81% of the variability in the BSAF values. The PCDD/F congeners that are present in low concentrations and/or have reduced bioavailability are the congeners that have the strongest correlations between the BSAFs and the sediment PCDD/F concentrations. Congeners that are bioavailable to Dungeness crab exhibit poorer correlations between the BSAFs and sediment concentrations.

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“…Until recently the use of chlorine bleaches was widespread. The presence of dioxin in the mill effluent [57] appears to arise via the direct chlorination of organic precursors in the pulp [58]. The aromatic precursors are thought to be naturally occurring phenolic compounds in the wood pulp (e.g., lignin) and dibenzodioxin and furan contaminants (from paints, defoamers or lube oil) [59].…”

Section: Chlorine Bleaching Of Paper Pulpmentioning

confidence: 99%

Dioxin sources and industrial emissions control — a review

Ritchie

2000

International Journal of Environmental Studies

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Dioxin, the collective term for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, are generated during various chemical and high temperature processes. They have been shown to be toxic to humans and animals with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exhibiting the greatest toxicity. Dioxin has been shown to exhibit immunotoxicity, reproductive and developmental toxicity in several animals. Epidemiological studies on groups of humans with prolonged or elevated exposure to dioxin have indicated increased cancer rates above threshold levels of exposure. Conversely, other studies have concluded that dioxin is a net anticarcinogen. There has been much study aimed at quantifying the relative contributions of the identified dioxin sources to the environmental load. Although some data suggests that burning of vegetation produces measurable amounts of dioxin it is rather industrial process waste streams which emit the greatest amounts. Processes implicated include organic chemical synthesis, metal processing, paper pulp bleaching and incineration of organic materials. Dioxin emission reduction strategies for high temperature processes have focussed upon the minimisation of the conditions at which dioxin forms in exhaust streams. Additionally, screening of process materials has been practised as have substitution of process chemicals in the pulp and paper bleaching industry.

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Studies on the mechanism of PCDD/PCDF formation during the bleaching of pulp

Cited by 32 publications

References 1 publication

Atmospheric Deposition of Polychlorinated Dibenzo-p-dioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs) in Kanazawa, Japan

Atmospheric Deposition of Polychlorinated Dibenzo-p-dioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs) in Kanazawa, Japan

Bioavailability of chlorinated dibenzo‐p ‐dioxins and dibenzofurans to dungeness crab (Cancer magister) at marine pulp mill sites in British Columbia, Canada

Dioxin sources and industrial emissions control — a review

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