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8/7/2019 Field Survey of Enteric Viruses
http://slidepdf.com/reader/full/field-survey-of-enteric-viruses 1/16
Field Survey of Enteric VirusesIn Solid Waste Landfill Leachates
By: MARK D. SOBSEY, PHD
8/7/2019 Field Survey of Enteric Viruses
http://slidepdf.com/reader/full/field-survey-of-enteric-viruses 2/16
HUMAN ENTERIC VIRUSES
ARE VIRUSES THAT REPLICATE IN THEINTESTINAL TRACT OF MAN.
ARE SHED IN THE FECAL MATERIAL OFINDIVIDUALS WHO ARE INFECTED EITHERPURPOSELY (I.E. BY VACCINATION) ORINADVERTENTLY THROUGH CONSUMPTION OFCONTAMINATED FOOD OR WATER, BY
SWIMMING IN CONTAMINATED WATER, OR BYPERSONAL CONTACT WITH AN INFECTEDINDIVIDUAL
8/7/2019 Field Survey of Enteric Viruses
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Virus group Type Disease caused
ENTEROVIRUSES
Poliovirus 3 paralysis, meningitis
Echovirus 34 meningitis,respiratory disease, rash, diarrhea
Coxsackie Virus A 24 herpangina, respiratory disease ,meningitis,
fever
Coxsackie Virus B 6 myocuclitis, congenital heart, rash ,fever,
meningitis disease ,pleurodynia
Hepatitis type A 1 infectious hepatitis
Enteric Viruses Associated With Human Wastewater
8/7/2019 Field Survey of Enteric Viruses
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Objective of the study
To quantitatively determine if enteric virusesare present in leachates from municipal solid
waste landfills.
Municipal solid waste
> may contain fecal material from a number of
different sources, it is possible that solid waste
landfill leachate may contain enteric
pathogens including enteric viruses.
8/7/2019 Field Survey of Enteric Viruses
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Solid Waste Landfill Leachate Sources and Sample Points
variety of site characteristics and conditions influencethe occurrence of enteric viruses in the solid waste andthe leachate.
Leachate samples were obtained from a total of 21different municipal solid waste disposal sites.
Leachates samples were collected in northern regionsof the United States and from Southern
Canada,
.
8/7/2019 Field Survey of Enteric Viruses
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COLLECTION OF LEACHATE SAMPLES
samples were collected during the late fall,
winter, and early spring.
> Some leachate samples were collected in
July, October, and November, in order to
obtain samples during and shortly after the
late summer and early fall period of maximum
enteric virus excretion.
8/7/2019 Field Survey of Enteric Viruses
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Leachate samples collection
Every effort was made to maximize virus
recovery and to minimize virus loss or
inactivation in leachate samples.
Most of the samples were raw leachates that
had not been appreciably diluted with other
natural waters and had not migrated through
soils.
8/7/2019 Field Survey of Enteric Viruses
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COLLECTION OF LEACHATE SAMPLES
10.5 TO 20 LITERS OF LEACHATE WERE COLLECTED FROM
EACH SITE AND WERE PLACED IN 4 OR 20 LITER CAPACITY
POLYETHYLENE CONTAINERS FOR SHIPMENT. SINCE
REFRIGERATION IS NOT AVAILABLE IN THE AREA, THE
SAMPLES WERE KEPT IN AMBIENT TEMPERATURES DURINGTHE COLLECTION TRIP AND TRANSPORTATION TO THE
LABORATORY.
TIME PERIOD BETWEEN SAMPLE COLLECTION AND
PROCESSING FOR VIRUSES RANGED FROM1
TO10
DAYS AND AVERAGED 6.2 DAYS.
8/7/2019 Field Survey of Enteric Viruses
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TRANSPORT OF LEACHATE SAMPLES
Collected samples were promptly returned to thelaboratory for virological examination, and in most cases
they were maintained at low temperatures during
transit.
The time period between sample collection andprocessing was minimized, and the samples were
refrigerated during the storage period. Because
prolonged survival of enteric viruses in leachates
maintained at lower temperatures has been previouslyreported, minimal virus losses were expected during the
leachate storage periods that occurred in the study.
8/7/2019 Field Survey of Enteric Viruses
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8/7/2019 Field Survey of Enteric Viruses
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Results
� Enteric viruses were found in only one of 22 leachate
samples collected from 21 different municipal solid wastedisposal sites
� One virus-positive leachate sample was obtained from
newly placed refuse at a disposal site where sanitarylandfill practice was deficient.
� Two viruses found
> identified as poliovirus types 1 and 3, were found in a
sample volume of 11
.8 liters.� All of the other 21 leachate samples, which ranged in
volume from 10.3 to 18 liters, were negative for entericviruses.
8/7/2019 Field Survey of Enteric Viruses
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Virological Examination of Leachate Samples Characteristics & Conditions of MSW Disposal Sites
Sit
eN
o.
Collectio
n
date
Leachate
vol.
processe
s (liters)
Stor
ageTim
e
(day
s)
Leachate
concen-
trate
vol(ml)
No. of
confirme
d viruses
Type Age Refuse
Depth(ft)
Refuse
CoverFre-
quency
% of
Residen-Tial
Refuse
1 11-18-75 10.3 4 56 0 SLF 5 25 Daily 55
2 11-18-75 10.8 6 54 0 SLF 7 65 Daily 100
3 11-18-75 10.9 5 47 0 SLF 8 90 Daily 50
4 11-19-75 11.4 5 59 0 SLF 3 30 Daily 80
5 2-4-76 12.2 9 25 0 Test Cell 2 10 No cover 100
6 2-4-76 11.8 7 54 2 LF 2 15 Periodic >50
7 2-4-76 11.8 8 50 0
LF >10 35Periodic
<508 2-4-76 14.7 4 25 0 SLF 3-4 20 Daily 70
9 2-5-76 12.0 10 40 0 SLF 1 40 Daily 80
10 3-8-76 15.6 6 50 0 SLF 5 60 Daily 65
11 3-9-76 16.0 6 52 0 SLF 2.5 15 Periodic 35-40
Virus isolates were identified as poliovirus types 1 and 3 by neutralization tests
8/7/2019 Field Survey of Enteric Viruses
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Virological Examination of Leachate Samples Characteristics & condition of MSW
Disposal Sites
Site
No
Collection
date
Leachate
Vol.
Processed
(liters)
Storage
time
(days)
Leachate
concentrate
Vol (ml)
No. of
confir
med
Viruse
s
Type Age Refuse
Depth
(ft)
Refuse
Cover
Fre-
quency
% of
Residen-
Tial
Refuse
12 3-10-76 18.0 6 50 0 LF 6 22 Final 45
13 3-11-76 16.4 6 45 0 SLF 3-4 8 Daily No data
14 5-7-76 13.0 2 26 0 LF 8 13 Periodic 85
15 5-17-76 15.0 8 29 0 SLF 5 140 Daily 33
16 5-18-76 15.0 8 26 0 LF >10 variable Periodic 80
17 5-19-76 12.6 9 28 0 SLF 3 16 Daily 99
18 5-19-76 15.0 8 25 0 SLF 13 60 Daily 99
19 5-21-76 15.0 8 52 0 SLF 11 50 Daily 75
20 7-14-76 15.0 1 27 0 SLF 4 40 Daily 30
21 10-10-76 16.0 5 30 0 SLF 15 15 Daily >50
22 11-8-76 16.0 5 34 SLF 2 150 Daily >50
8/7/2019 Field Survey of Enteric Viruses
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OTHER FINDINGS
FECAL COLIFORM CONCENTRATIONS IN LEACHATE WERE
GENERALLY LOWER THAN TOTAL COLIFORM CONCENTRATIONS.
LEACHATE FROM THE MAJORITY OF THE SITES DID NOT CONTAINDETECTABLE LEVELS OF FECAL COLIFORM BACTERIA.
FECAL COLIFORM CONCENTRATION EXCEED 1000 ORGANISMS/100ML IN TWO LEACHATE SAMPLES.
FECAL COLIFORM WERE NOT DETECTED IN ENTERIC VIRUS-POSITIVE LEACHATE SAMPLE.
NO ENTERIC VIRUSES WERE FOUND IN LEACHATES HAVING HIGHFECAL COLIFORM CONCENTRATIONS.
8/7/2019 Field Survey of Enteric Viruses
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Treated sewage effluents have considerably greater
enteric virus concentrations than solid waste landfillleachates.
Virus concentrations of perhaps 103 to 105 infectiousunits per liter. Conventional primary and secondarytreatment followed by chlorination can reduce this
virus concentration by about 99 per cent. Treated sewage effluents are likely to contain from 10'
to 103 infectious units per liter.
Compared to the vast quantities of treated sewageeffluents that are continuously discharged to surface
waters and are increasingly disposed of by landapplication, the enteric virus contribution to theenvironment from municipal solid waste landfillleachate is negligible.
8/7/2019 Field Survey of Enteric Viruses
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Low concentrations of enteric viruses in raw
leachates .
Opportunities for further virus reductions by
thermal inactivation, removal in soil and
dilution in ground or surface waters.
Leachates from properly operated sanitary
landfills do not constitute an environmental
or public health hazard due to enteric viruses.