SCIENTIFIC STUDY of ILLNESSES reported by residents living near sludge sites. >The Athens EPA laboratory approved a two-year study of illnesses reported by residents living near nine land application sites with high incidences of Staphylococcus aureus infections. Two children (Tony Behun and 17 year old Daniel Pennock) in Pennsylvania died of S. aureus infections after exposure to sewage sludge; and, EPA's web site lists S. aureus as a possible public health risk with sewage sludge. Some of the results of the study, which was co-authored by microbiologist Dr. David Lewis, University of Georgia researchers and a pediatrician in California who is treating children exposed to sewage sludge, were presented by invitation to a conference on sludge held on November 2, 2001 by Boston University's School of Public Health. The study's research paper has been cleared by the Athens EPA laboratory for submission to a scientific journal. The research paper will be published in a peer-reviewed journal. reference FOUNDATIONS IN MICROBIOLOGY, Second Edition by Talaro-Talaro. Page 551 Growth and Physiological Characteristics of Staphylococcus aureus. Currently 31 species have been placed in the genus Staphylococcus, S. aureus is considered the most serious pathogen. It can grow anywhere between 10-46 degrees C. The species is a facultative anaerobe, whose growth is enhanced in the presence of O2 and CO2. This species is "considered the most resistant of all non-spore-forming pathogens, with well developed capacities to withstand high salt ";(7.5-10%), extremes in pH, and high temperatures (up to 60 degrees C for 60 minutes). It also remains viable after months of air drying, and resists the effects of many disinfectants and antibiotics. These properties contribute to the reputation of S. aureus as a troublesome hospital pathogen. Perhaps no other bacterial pathogen produces as many virulence factors as does S. aureus.
Below you will find a brief summary pertaining to Staph. aureus and the ineffective treatment of "Class B sludge. Please note;
. S. aureus is a facultative anaerobe, whose growth is enhanced in the presence of O2 and CO2. Treatment of sludge: Anaerobic Digestion - Sludge is treated in the absence of air.
. S. aureus has capacities to withstand extremes in pH. Treatment of sludge: Lime Stabilization - Lime is added to sludge to raise the pH to 12 for 2 hours of contact.
. S. aureus remains viable after months of air drying. Treatment of sludge: Air Drying - Sludge is dried for 3 months at 0-10 degrees C.
. S. aureus has capacities to withstand high temperatures (up to 60 degrees C for 60 minutes). Treatment of sludge: Aerobic Digestion - Sludge is agitated with air or oxygen between 40 days at 20 degrees C or 60 days at 15 degrees C.
Anaerobic Digestion - Sludge is treated in the absence of air between 15 days at 35 degrees to 55 degrees C or 60 days at 20 degrees C.
. S. aureus grows between 10-46 degrees C. Treatment of sludge: Air Drying 0-10 degrees C, Aerobic Digestion 15-20 degrees and Anaerobic Digestion 20-55 degrees C.
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