Pathogens

Pathogen is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host. Some of the concern in the debate is about the pathogen content of sewage sludge. This concern was increased by the tragedy at Walkerton where Eschericha coli and other pathogens contaminated the drinking water supply of this Ontario town. Land application of sewage sludge can lead to the transfer of pathogens through contamination of ground water, drinking water wells or through food contamination from eating food grown in sludge spread land. Dr. Jim Smith, EPA expert on pathogens indicates that: "conceded that the 503 sludge rule never was subjected to a vigorous risk assessment based on the harmful health effects which may arise from bacteria in the sludge."

Parasites linked to sewage fertiliser
Blastocystis hominis, stomach bug ususaly found in dirty water emerged in Third World countries and doctors fear that it might be due to the Sydney Water Biosolids Strategy, which turns 180,000 tonnes of human waste into fertiliser yearly. Professor Thomas Borody said that in the past 10 to 15 years, 1500 people had been diagnosed with D. fragilis and Blastocystis in his practice. "If we are going to be using foods grown on crops which use these biosolids it would be good to have a certain level of assurance that they are not carrying pathogens," he said.

Articles and resources
Parasite Ova in anaerobically digested sludge, JSTOR Jounal Vol. 53, No. 8, Aug., 1981 Parasitic contamination in wastewater and sludge samples in Tunisia using three different detection techniques. PubMed.gov, PMID: 20352447 Parasitic contamination in wastewater and sludge samples in Tunisia using three different detection techniques., Johns Hopkins University website, Accessed May 9, 2011

Related SourceWatch articles

 * Sewage sludge
 * Biosolids