Allan, In keeping with your anti-hydrolic bias, please don't mention anything on this list that has to do with aquatic systems, whether fresh, salt or brackish, eh?
No mention of moose, duckweed, Azolla, watercress, or heaven forfend, evil seaweed should be made, because of their quasi-hydroponic proclivities. Let's keep this list on the bovodynamic straight and narrow, buddy. No phytoplankton need apply. All turf, no surf, eh? OK, on a serious note, PCB remediation in a solid state, composting context has been claimed by one Philip Fredericks at EarthCare Technologies Inc, www.ecticompost.com Using high C:N, medium temperature and inoculation with select microbes, he says he has taken materials with substantial loads of things like chlordane, PCBs, PCEs and dioxins to non-detect at parts per trillion. He says, and I quote: "The organisms that break down the chlorinated compounds are mesophiles that do their work in mid temp, high C/N ratio, aerobic environs that the "Compost Man" and other experts still avow cannot be done. In the presence of high nitrogen, these microbes will NOT produce the enzymes that convert these compounds to H2O, CO2 and free chlorine gas." Other researchers are excited about the potential of white rot fungi to remediate recalcitrant materials. I did a bit of web searching the other day and found a number of sites discussing this: See http://www.msu.edu/user/michel/pcbrefs.htm http://ehpnet1.niehs.nih.gov/docs/1995/Suppl-5/abra-abs.html http://bib.gbf.de/ergebnisbericht/1998/englisch/section_c/c4/c4-1english.htm l http://biology.gcsu.edu/facultyres/Andrei_Barkovskii/facultybarkovskii.htm http://bib.gbf.de/ergebnisbericht/1997/englisch/section_c/c4/c4-1english.htm l http://www.google.com/search?q=cache:byakUN8YDbkC:www.mcilvainecompany.com/s ite/sitenl24/Japanese%2520Firm%2520Uses%2520New%2520Fungus%2520to%2520Treat% 2520Dioxin%2520in%2520Soil.htm+bioremediation+dioxin&hl=en http://www.ftns.wau.nl/imb/Publication/journal.html http://www.ftns.wau.nl/imb/research/wrf/xeno.html http://www.ftns.wau.nl/imb/research/wrf.html http://www.wkap.nl/prod/b/0-306-46102-1?a=1 (some cutting and pasting of the above urls may be needed) Another interesting website mentions the potential of earthworms in assisting remediation: http://soilwater.ucr.edu/andrew_profile.htm ********************* I harbor no ill will towards you, Allan, for leaving your down-to-earth terrestrial bias and taking us out to sea in this aquatic anaerobic news item, but in the future please don't tease the hydroponicists with such info when perfectly earthy alternatives seem to be worth digging into. ;-) Frank ----- Original Message ----- From: "Allan Balliett" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, January 10, 2002 5:06 PM Subject: SFW: Anaerobic Bacteria Remdiates PCBs > I never thought of this that seriously until Elaine mentioned it on > the list yesterday, today, my co-worker Tim was breaking this story > in the Baltimore press -AB > > Welcome Progress on PCB Decontamination > By Tim Zink > Distributed 1/10/02 by Blue Ridge Press > Words: 838 > > There may be reason for hope in the effort to contain and minimize the > damage to the public health and natural environment inflicted by > polychlorinated biphenyls (PCBs). After seven years of experiments on > PCB-laden sediments taken from the Inner Harbor in Baltimore, Md., a team of > researchers reportedly has identified the first strain of anaerobic > bacterium known to break down the strong chlorine bonds within these > chemical compounds. > > According to the Environmental Protection Agency, over 1.5 billion pounds of > PCBs were manufactured and sold in the U.S. before the 1976 Toxic Substances > Control Act banned domestic production and trade of the compounds. Long > prized because of their chemical stability, flame resistance and performance > as an insulator, PCBs were used in products ranging from electrical > equipment to insecticides. But they are now known to carry significant > risks. > > Limited research into a direct causal link between PCB exposure and cancer > in humans has come close to finding a smoking gun, but inconsistencies among > studies have made clear proof elusive. Still, the Agency for Toxic > Substances and Disease Registry has concluded that, "Based on the evidence > of cancer in animals, the Department of Health and Human Services has stated > that PCBs may reasonably be anticipated to be carcinogens." > > Further, a 1996 EPA study found that " S PCBs also have significant > ecological and human health effects other than cancer, including > neurotoxicity, reproductive and developmental toxicity, immune system > suppression, liver damage, skin irritation, and endocrine disruption." > > Which makes the discovery of a PCB-dechlorinating bacterium a major > development, especially since communities nationwide are struggling to > assess and reduce the levels of PCB contamination which have befallen them. > January 2002 saw the start of the second lawsuit brought by citizens of > Anniston, Ala., where a Monsanto Co. factory released immense amounts of > PCBs into the air, soil and water over several decades. Recent inquiries > allegedly have found that high-ranking officials from Monsanto, the largest > U.S. PCB manufacturer, knew PCBs posed serious threats to human health long > before production was halted. If proven in court - and if effective cleanup > technologies can be developed - the company's chemical division spinoff, > Solutia Inc., may be held responsible for shouldering broad cleanup measures > and public health studies. > > Similar stakes may come into play in New York, where federal regulators > recently mandated that the General Electric Co. remove PCB-contaminated > sediments from stretches of the Hudson River. Debate has continued to flare, > however, because in some places the sediments on the river bottom appeared > to be naturally lessening the levels of PCB contamination. At other sites in > the Hudson, PCB levels in sediments remained constant. Ultimately, a lack of > scientific certainty over the best course of cleanup has delayed remediation > efforts. > > For several reasons, the collaborative sediment analysis performed by > researchers from the University of Maryland's Biotechnology Institute and > the Medical University of South Carolina, funded by the U.S. Office of Naval > Research, could mark the beginning of real progress on these fronts. > > First, while scientists have known that certain aerobic microbes were able > to dechlorinate lesser-concentrated PCBs, many within the scientific > community were skeptical of ever finding a microbe capable of breaking down > the compounds with greater chlorine concentration. Most PCBs commercially > produced in the U.S. fall in the latter category. > > Second, by identifying one of the bacterium necessary for dechlorination of > PCBs to occur, the researchers have sped the emergence of practical > microbial probes that can guide cleanup activities. Such probes could be > used to test sediments on site for the presence of the bacterium necessary > to break down PCBs, allowing relatively quick and accurate decision making > on cleanup options. In the Hudson River cleanup, for example, microbial > probes might allow for on-the-spot testing on whether sediments would break > down naturally or require dredging, eliminating complex lab sampling that > can consume many months and dollars. > > Kevin Sowers, the principal researcher from UMBI, considers his team's > research a big step toward greater understanding and treatment of PCB > contamination. "But a lot more steps need to be taken in the future," he > said. "We've found organisms (that cause PCBs to break down) and identified > them, next we need to study how exactly they work." There are over 200 known > chemical arrangements that PCBs may demonstrate. The recently identified > bacterium is especially promising, though, because it broke down the > arrangements common in PCBs marketed under the Monsanto Aroclors brand name, > which claimed the bulk of the historical U.S. market. > > Linda Chrisey of the Office of Naval Research characterized the Navy's > response to the recent findings as "excited, but cautious." It remains to be > proven, she noted, whether causing PCBs to break down also definitively > reduces their toxicity, among other concerns. That said, Chrisey also > indicated that facilities command personnel at two naval installations with > possible PCB contamination issues have offered to contribute sediments for > future analyses. > > The public and its legislators should share this enthusiasm. PCBs have > proven themselves to be persistent adversaries to human and ecological > health, and progress toward their breakdown should be cheered - and further > advanced. > > Tim Zink is an editor of Blue Ridge Press and a former National Geographic > staff member. > > More of Tim's work at http://www.brces.org > >
