Sent: Tuesday, July 26, 2005 8:45 PM
Subject: JULY 26, 2005 - TO EPA, waste industry and U. Madison/Wisconsin - response respectfully
requested regarding risk from potentially infectious human and animal prions in both Class A and Class B
sewage sludge and effluent
Why the Stanfield & Gale and Wisconsin DNR Risk Assessments on prions in sludge are flawed: Because both depend
upon incorporation of the sewage sludge into the soil to dilute infectious prions. In fact, sewage sludge is
topdressed on grazing lands, hay fields and dairy pastures throughout the country. (see photos attached of cows
grazing in the fields with topdressed sewage sludge )
Even long time sludge proponent Rufus Chaney, of USDA, acknowledges the risk to cows, cattle, livestock,
from pollutants, xenobiotics, etc. in top dressed sewage sludge:
http://www.swissinfo.org/sen/swissinfo.html?siteSect=107&sid=5360272&cKey=1122372624000
SWISS - NO landspreading of sewage sludge because of risk of BSE prions . . . . . . July 2005
Because of the presence of trace elements and the risk of BSE, effluent sludge from central sewage
systems is no longer used as fertiliser, but instead must be burned and disposed of at landfills.”
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Dr. Angela Li-Muller, Toronto Public Health - on Human prions in sewage sludge . . . . . . from blood . . . . . . . .
" . . . the discovery that prion diseases can be transmitted through ingestion and the presence of infectivity in blood
components is a potential concern regarding land application of biosolids. There is a possibility for the blood from
infected patients to find its way into the sewage system. This can occur in situations where the patients have bleeding
lesions in their GI tract, or during their normal menstrual cycles, and where blood from diseased bodies are discharged
by funeral parlours. It is not clear if prions are deactivated during the sewage treatment process. * However, if they
were not, prions can persist in the field for as long as 6 years. Then there would be a real danger that they
may accumulate to a level of concern. People can be exposed through soil ingestion or ingestion of
animals that graze on infected pastures."
[* Helane'snote: US EPA, Stanfield & Gale, and numerous other scientists agree sewage sludge pathogen
reduction methods do not inactivate prions) ]
page 4 of 5 "More importantly, the experience with vCJD indicates that prion can be an entirely new class of infectious
pathogen, that prion diseases result from abnormality of protein conformation and ingestion can be a mode of disease
transmission. Already there is speculation that changes in protein shape may be responsible for common
neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases, which appear to have similarities with
vCJD (Prusiner, S. B. 2000)."
"It is not clear how much prions a person has to ingest to develop prion disease and whether prions can survive the
sewage treatment process. To prevent the onset of a possible public health mishap, it is important to eliminate all likely
pathways of infection. To be prudent, it is best to ensure that sewage treatment and/or pelletization process(es) provide
the necessary condition that would deactivate any prions that might find their way into the sewage system."
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----- Dr. Dennis Burke wrote:
http://www.crcwater.org/issues/19971218wac173308burke.html
The desire to produce "exceptional quality biosolids" is admirable and should be encouraged. The material however
is still a bio-hazard, and an infectious agent since it may contain sufficient numbers of bacteria, viruses,
fungi, and other infectious agents such as proteins that will cause disease in man. It must be treated as
such in order to protect public health. Attached are some of the referenced documents. I've included some
information on BSE, TSE, CJD. It's mandatory reading for anyone who believes that time and temperature, acid or
caustic, or incineration and burial will destroy indestructible proteins or prions, the TSE infective agent. It is also
mandatory reading for anyone who believes that a very small dose of an infective agent is not sufficient to create a
major epidemic.
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http://cipca.org/regulatory/factsheetcwdpretreatment.pdf
Posted to Internet in May 2005 by Curt McCormick, Pretreatment Coordinator, EPA Region 8: ( Colorado, Montana,
ND, SD, Utah, Wyoming)
"1. CRITICAL ISSUE: We are currently prohibiting the discharge of untreated, potentially prion-contaminated wastes to
POTWs. Typical treatment and disinfection processes used by non-domestic users and those used at Publicly Owned
Treatment Works (POTW) do not deactivate prions. Prions will pass through the POTW as a pollutant to be
released into receiving waters AND CONCENTRATED IN BIOSOLIDS. Biosolids are the solids produced by
POTWs and typically land applied to food and non-food (grazing) crops."