Thursday, March 19, 2009

Toxic Chemicals of Pulp and Paper which inhibit bacterial growth

1.Dioxin(Polychlorinated dibenzo-p-dioxins (PCDDs)):-Dioxin is a heterocyclic, organic, antiaromatic compound with the chemical formula C4H4O2. There are two isomers, 1,2-dioxin (or o-dioxin) and 1,4-dioxin (or p-dioxin). The ortho isomer 1,2-dioxin is very unstable due to its peroxide-like characteristics.

Polychlorinated dibenzo-p-dioxins (PCDDs), biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were found to induce several specific stresses within bacterial cells.The cellular toxicity within the bacteria was found to increase when exposed to mixtures of dioxins, PCBs, and PBDEs, possibly from synergistic effects.
{http://www.setacjournals.org/perlserv/?request=get-pdf&doi=10.1897%2F02-465}

2.The toxicity of dioxins and Dibenzofurans (polychlorinated dibenzo-p-furans (PCDFs) )varies with the position and number of chlorine atoms attached to the aromatic rings. In general, their toxicity increases with increasing chlorine substitution. Those dioxins and dibenzofurans that have chlorine atoms at the 2,3 and 7 positions are particularly toxic. Tetrachlorodibenzo-p-dioxin and tetrachlorodibenzo- furan, which have chlorine atoms at the 2,3,7, and 8 positions, are considered the most toxic of the dioxins and dibenzofurans (4), with 2,3,7,8-tetrachlorodibenzo-p-dioxin referred to as one of the most toxic substances known.
{http://www.madsci.org/posts/archives/2000-01/948068271.Mi.r.html}

3.3-chloro-4-(dichloromethyl)- 5-hydroxy-2(5H)-furanone (MX):The most potent bacterial mutagen in pulp mill effluents was identified as 3-chloro-4-(dichloromethyl)- 5-hydroxy-2(5H)-furanone (MX). This compound was found to be responsible for 30 to 50% of the mutagenicity of chlorination-stage effluents. In the Ames test, MX demonstrated a mutagenic potential nearly two-fold greater than the extremely potent mould metabolite aflatoxin B1.
{
http://dsp-psd.tpsgc.gc.ca/Collection-R/LoPBdP/BP/bp292-e.htm#C.%20Dioxins%20and%20Furans(txt)}

4.Sodium Dithionite: Toxic to bacteria and Fish.
{
http://books.google.co.in/books?id=bEGHgosxxPwC&pg=PA560&lpg=PA560&dq=Sodium+Hydrosulfite+toxic+to+bacteria&source=web&ots=YFkcxTbWbE&sig=luZB06gOK8KL8jBPjsIdWNhZPiA&hl=en&sa=X&oi=book_result&resnum=8&ct=result#PPA560,M1}

5.Titanium dioxide : Used in pulp and paper for Filler to increase the opacity and brightness of paper. Used in coating also. Photocatalysis by titanium dioxide is internationally recognized as one of the new sterilization materials, which can kill almost all kinds of bacteria.
{http://www.ecosmarte.com.au/nano/antibacterial.htm}

6.Anthraquinone : The anthraquinones aloe-emodin and Rhein were found to be inhibitory to Bacillus subtilis and Staphylococcus aureus . However, the related anthraquinone, Chrysophanol, was not inhibitory to these strains. None of the anthraquinones tested inhibited the yeast Candida (Fuzellier et al., Ann. Pharm. Fr., 39(4) 313-318 (1981)). Diaminoanthraquinones were shown to exhibit toxicity against gram positive cocci but not gram negative bacteria (Haran et al., Isr. J. Med. Sci., 17(6):485-496 (1981)). These results typify the sporadic and unpredicatable antimicrobial effects of the anthraquinones.
{http://www.freepatentsonline.com/EP0665775.html}



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