Mobility and survival of Salmonella Typhimurium and human adenovirus from spiked sewage sludge applied to soil columns.
OBJECTIVE
This study investigated the survival and transport of sewage sludge-borne pathogenic organisms in soils.


RESULTS
Undisturbed soil cores were treated with Salmonella enterica ssp. enterica serovar Typhimurium-lux (STM-lux) and human adenovirus (HAdV)-spiked sewage sludge. Following an artificial rainfall event, these pathogens were analysed in the leachate and soil sampled from different depths (0-5 cm, 5-10 cm and 10-20 cm) after 24 h, 1 and 2 months. Significantly more STM-lux and HAdV leached through the soil cores when sewage sludge was present. Significantly more STM-lux were found at all soil depths, at all time periods in the sewage sludge treatments, compared to the controls. The rate of decline of STM-lux in the controls was more rapid than in the sewage sludge treatments. Survival and transport of HAdV were minimal.


CONCLUSIONS
The presence of sewage sludge can significantly influence the transport and survival of bacterial pathogens in soils, probably because of the presence of organic matter. Environmental contamination by virus is unlikely because of strong soil adsorption.


CONCLUSIONS
This study suggests that groundwater contamination from vertical movement of pathogens is a potential risk and that it highlights the importance of the treatment requirements for biosolids prior to their application to land.
Horswell
J
J
Institute of Environmental Science and Research Ltd, PO Box 50-348, Porirua, New Zealand. jacqui.horswell@esr.cri.nz
Hewitt
J
J
Prosser
J
J
Van Schaik
A
A
Croucher
D
D
Macdonald
C
C
Burford
P
P
Susarla
P
P
Bickers
P
P
Speir
T
T
D000256:Adenoviridae; D003140:Communicable Disease Control / Q000379:methods; D006801:Humans; D050296:Microbial Viability; D012486:Salmonella typhimurium; D012722:Sewage / Q000382:microbiology* / Q000821:virology*; D012987:Soil; D012988:Soil Microbiology; D014871:Water Microbiology
D012722:Sewage; D012987:Soil