Formation of chlorodibenzofurans by irradiation of chlorinated diphenyl ethers

Norström, Åke; Andersson, Kurt; Rappe, Christoffer

doi:10.1016/0045-6535(76)90051-5

Cited by 63 publications

(27 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The uptake and excretion of PCDEs by juvenile Atlantic salmon were similar to those of PCBs, but PCDEs were more persistent [20]. Also of environmental significance is the fact that PCDEs are possible precursors of the highly toxic PCDDs and PCDFs, e.g., photochemical reactions might convert PCDEs to PCDFs [21].…”

Section: Introductionmentioning

confidence: 97%

Ethoxyresorufin‐O‐deethylase induction potency of polychlorinated diphenyl ethers in H4IIE rat hepatoma cells

Koistinen

Sanderson

Giesy

et al. 1996

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

Abstract-Polychlorinated diphenyl ethers (PCDEs) are structurally similar to polychlorinated biphenyls (PCBs), and some PCDE congeners have been reported to cause toxic responses similar to those caused by some of the non-ortho-substituted PCBs, which are mediated by the aryl hydrocarbon receptor (AhR). Twenty-nine PCDEs were tested for their potency as AhR agonists relative to 2,3,7,3,7, by measuring their ability to induce the cytochrome P-450 1A1-associated enzyme activity, ethoxyresorufin-O-deethylase (EROD), in the H4IIE rat hepatoma cell bioassay. All PCDE congeners tested were found to be inactive as EROD inducers except for PCDE 156, which was a weak EROD inducer with a 2,3,7,8-TCDD equivalency factor of about 1.2 ϫ 10 Ϫ5 . During this study we determined that small amounts of polychlorinated dibenzofurans (PCDFs) that occurred as impurities in the PCDE preparations were the cause of the apparent EROD induction initially measured in our experiments. Once the PCDF impurities were removed by purification on florisil, little or no activity could be attributed to the PCDEs.

show abstract

Section: Introductionmentioning

confidence: 97%

Ethoxyresorufin‐O‐deethylase induction potency of polychlorinated diphenyl ethers in H4IIE rat hepatoma cells

Koistinen

Sanderson

Giesy

et al. 1996

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

show abstract

“…They can either undergo a dechlorination reaction or else a ring closure whereby chlorinated dibenzofurans are formed ( Figure 2). 15 For this photolytic ring closure to occur, there must be at least one ortho chlorine in the PCDE. When PCDEs were heated in sealed quartz ampules, PCDFs were formed primarily through loss of ortho HC1 and ortho H 2 .…”

Section: Chemistry and Photochemistry Of Pcdesmentioning

confidence: 99%

Polychlorinated diphenyl ethers—A review

Becker

Phillips

Safe

1991

Toxicological & Environmental Chemistry

View full text Add to dashboard Cite

Polychlorinated diphenyl ethers (PCDEs) have been identified as by-products formed in the synthesis of chlorinated phenols. Analytical surveys have shown that PCDE residues are present in sediments, fish, wildlife, and human tissues. The uptake and persistence of PCDEs in laboratory animals resembled that observed for the polychlorinated biphenyls (PCBs), however, in metabolic studies, ortho hydroxylation of the PCDEs was the dominant oxidative pathway. Studies indicate that PCDE congeners elicit a broad spectrum of toxic and biochemical responses in laboratory animals including the induction of several cytochrome P-450-dependent monooxygenase enzyme activities. In contrast with the coplanar PCBs which are significantly more toxic than their monoortho coplanar analogs, the coplanar PCDE congeners and their monoorthochloro-substituted analogs were equipotent. These data suggest that the PCDEs may contribute significantly to the toxicity of halogenated aromatics associated with chlorinated phenol-derived contaminated areas such as toxic chemical waste dumpsites.

show abstract

“…There was thus a growing body of research on the behavior and fate of PCDEs in the environment, especially in relation to the photolysis of organics [13,[18][19][20], and such works have shown that the main photoproducts of PCDEs are dechlorinated PCDEs and PCDFs [21]. PCDD/Fs are usually detected in emissions, organisms, soil, ash, and sediments, and considered as a group of highly toxic pollutants [22].…”

Section: Introductionmentioning

confidence: 99%