field survey of enteric viruses

8/7/2019 Field Survey of Enteric Viruses

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Field Survey of Enteric VirusesIn Solid Waste Landfill Leachates

By: MARK D. SOBSEY, PHD



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



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



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.



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,

.



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.



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.



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.



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.



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.



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



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



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.



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.



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.

field survey of enteric viruses

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