ASTM E884-82(2001)
(Practice)Standard Practice for Sampling Airborne Microorganisms at Municipal Solid-Waste Processing Facilities
Standard Practice for Sampling Airborne Microorganisms at Municipal Solid-Waste Processing Facilities
SCOPE
1.1 This practice covers sampling of airborne microorganisms at municipal solid-waste processing facilities, hereafter referred to as facilities. Investigators should consult Practice D1357 for the general principles of conducting an air-sampling program.
1.2 This practice applies only to sampling airborne bacteria and fungi, not viruses. Since sampling airborne viruses is significantly more difficult than sampling bacteria and fungi, reliable methods of sampling viruses are not yet available.
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Standards Content (Sample)
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Designation:E884–82 (Reapproved 2001)
Standard Practice for
Sampling Airborne Microorganisms at Municipal Solid-
Waste Processing Facilities
This standard is issued under the fixed designation E 884; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 For definitions of other terms used in this practice, refer
to Terminology D 1356.
1.1 This practice covers sampling of airborne microorgan-
isms at municipal solid-waste processing facilities, hereafter
4. Summary of Practice
referred to as facilities. Investigators should consult Practice
4.1 Concentrations of selected airborne bacteria and fungi
D 1357 for the general principles of conducting an air-
are determined using both liquid impinger and multi-stage
sampling program.
impactor samplers.
1.2 This practice applies only to sampling airborne bacteria
4.2 Procedures are included for selecting sampling loca-
and fungi, not viruses. Since sampling airborne viruses is
tions; determining numbers of samples, types of microorgan-
significantly more difficult than sampling bacteria and fungi,
isms to be sampled, intervals between sample collection and
reliable methods of sampling viruses are not yet available.
analysis; choosing sampling equipment; preserving samples;
2. Referenced Documents and reporting results.
2.1 ASTM Standards:
5. Significance and Use
D 1356 Terminology Relating to Atmospheric Sampling
5.1 Bacteria and fungi present in municipal solid wastes (as
and Analysis
well as in other forms of waste) may become airborne as dusts
D 1357 Practice for Planning the Sampling of the Ambient
during waste processing. Several investigations to determine
Atmosphere
the health significance of these microbiological aerosols have
2.2 Other Standards:
been hindered by the lack of standardized procedures for
Microbiological Methods for Monitoring the Environment,
3 sampling airborne bacteria and fungi in an industrial environ-
Water and Wastes
ment and by the absence of standards for assessing their health
Air Sampling Instruments for the Evaluation of Atmo-
4 significance. Because it is difficult to correlate airborne levels
spheric Contaminants
ofbacteriaandfungiwithepidemiologicaldata,thisstandardis
3. Definitions designed to permit the formation of a data base to aid in the
assessment of the health significance of airborne microorgan-
3.1 microbiological aerosol—an airborne particle partially
isms. It is intended that the use of this practice will improve
or exclusively composed of microorganisms including bacteria
sampling precision and thereby facilitate comparisons between
and fungi.
sampling results.
1 6. Apparatus
This practice is under the jurisdiction of ASTM Committee D34 on Waste
Management and is the direct responsibility of Subcommittee D34.01.02 on
6.1 Two types of samplers are used in each sampling
Sampling Techniques.
program for microbiological aerosols at waste processing
Current edition approved July 30, 1982. Published May 1983.
facilities (5).
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Available from the National Technical Information Service, 5285 Port Royal
Road, Springfield, Va. 22161. Request EPA-600/8-78-017.
4 5
Available fromAmerican Conference of Governmental and Industrial Hygien- Theboldfacenumbersintheparenthesesrefertothelistofreferencesattheend
ists, 6500 Glenway Avenue, Building D-5, Cincinnati, OH 45211. of the method.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E884–82 (2001)
6.1.1 Multi-Stage Impactor, for collection of airborne mi- impinger, and record any significant loss during sampling.
crobes on agar plates. It is recommended that an impactor be After sampling, the volume must be reconstituted to the
used for sampling all of the types of bacteria and fungi listed original or the actual volume carefully calculated because a
in 10.6.1. known volume must be used for quantitative work.
6.1.2 All-Glass Impinger, for collection of airborne mi-
8. Precautions
crobes in a liquid medium. It is recommended that an impinger
8.1 Due to the nature of municipal refuse, common sense
be used for sampling fecal coliforms and for determination of
dictates that some precautions should be observed when
total plate count.
sampling dusts at municipal solid-waste processing facilities.
6.2 Air Sampling Pumps, providing approximately 40 Lper
Recommended safety practices include wearing hard hats,
min (1.4 CFM) free-flow capacity.
safety shoes, safety glasses, gloves, and respirators as well as
6.3 Additional equipment such as carts, stands, and tool
washing hands before eating or smoking.
boxes are routinely used during dust-sampling programs.
9. Sampling
7. Reagents and Materials
9.1 Location and Number of Sampling Sites:
7.1 Agars for Use with the Multi-Stage Impactor:
9.1.1 All sampling shall be carried out during normal plant
7.1.1 Littman Oxgall, for total number of fungi present and
operations.
for identification of the following species of fungi: (a) As-
9.1.2 Use not less than two sampling locations inside the
pergillus flavus and (b) A. fumigatus.
facility at work sites or zones where employees are most likely
7.1.2 Vogel and Johnson, selective for Staphylococcus au-
to be exposed to airborne dust concentrations (7). (Note 2)
reus.
Among these locations, those where sampling equipment can
NOTE 1—Afungicide such as nystatin should be used with these agars.
be located without interfering with facility operations shall be
preferred.
7.1.3 Levine eosin methylene blue, specific for enterics
including Klebsiella spp. (Note 1)
NOTE 2—Examples of potential sampling locations are (a) on a tipping
7.1.4 Trypticase soy, for total bacteria count. (Note 1)
floor near or on a front end loader; (b) at a hand-picking station along a
7.2 Liquid Media for Use in Impingers: conveyor belt; and (c) along catwalks or platforms in frequent use by
employees.
7.2.1 Lactose Broth with Antifoam A, for analysis of fecal
coliform and total plate count.
9.1.3 Outside the facility, locate at least one sampling site
7.2.2 The exact amount of Antifoam A to be added should
300 m (1000 ft) upwind from the facility and at least one
be determined prior to field sampling. Sufficient antifoam
sampling site 100 m (330 ft) downwind from the facility.
should be added to prevent loss of fluid from the impinger, but
Measure the distances upwind and downwind from the same
excess should be avoided.
point, the point at which the emissions leave the facility or, in
7.3 Media Preparation:
the case of multiple discharge points, from a central point
7.3.1 Conduct the following according to Microbiological
equidistant from the discharge points.
Methods for Monitoring the Environment, Water and Wastes
9.1.4 Carefully measure and record the actual distances of
(14):(a) laboratory quality assurance, (b) selection and use of
the sampling sites from the points of emission and wind
laboratory apparatus, (c) washing and sterilization, and (d)
direction and velocity.
preparation of culture media.
9.2 PositionofSamplingInlet—Locatethesamplinginlet(s)
7.3.2 Preincubate all sampling media to determine if con-
1.5 m (5 ft) above the floor level to approximate the breathing
tamination has occurred and to dry the agar surface. Excessive
zone of a worker or other person exposed to the dusts. Locate
evaporation from the media or excessive contamination of the
the vacuum pumps where they will not disturb the air flow
exterior surfaces of the petri dishes must be guarded against
patterns around the sampling inlet(s).
during this preliminary incubation.
9.3 Number of Samples:
7.3.3 Media level in the sampling container is critical to
9.3.1 Inside the facility, collect not less than 5 replicate
collection efficiency.
samples at each sampling site.
7.3.3.1 Impactor—The petri dishes must be of such a size
9.3.2 Outside the facility, collect not less than 3 replicate
that the agar surface is at the manufacturer’s specified distance
samples at the upwind site(s) and not less than 5 replicate
below each stage. The manufacturer of theAndersen impactor
samples at the downwind site(s).
specifies 27 mL of agar per standard Andersen petri dish. The
9.3.3 Wide variations in reported microbiological aerosol
agar surface must be smooth and free of bubbles to ensure an
levels within facilities make it unlikely that the collection of
even air flow.
five samples will yield a tight distribution of results; therefore,
7.3.3.2 Impinger—For the all glass impinger, 20 mL of
where economically feasible, it is recommended that the
broth is recommended (17). Autoclave impingers, and then
sample size be increased to more than five.
aseptically add 20 mL of sterile broth. Mark its level on the
9.4 Air Temperature:
9.4.1 Collect samples when the air temperature at the
sampling site is above 5°C (40°F).
The six-stage and two-stage microbiological samplers manufactured byAnder-
9.4.2 At temperatures below 5°C (40°F), the sampling
son Samplers, Inc. have been found to be satisfactory.
medium may crystallize, thus affecting recovery of microor-
AirsamplingimpingerNo.7540manufacturedbyAceGlass,Inc.(AGI30)has
been found to be satisfactory. ganisms.
E884–82 (2001)
TABLE 1 1 Suggested Initial Sampling Times
10. Procedure
Suggested Initial
10.1 Record air temperature and relative humidity for each
Type of Media Sampling Time,
A
location sampled.
min.
10.2 Label all impingers to denote sampling run and loca-
Littman-Oxgall 1.5
Vogel and Johnson 8
tion. Label all petri dishes to denote sampling run, location,
Levine eosin methylene blue 10
and stage of impactor.
Trypticase soy 0.5
10.3 Air-Flow Rates: A
The initial sampling times suggested above are based on reported concentra-
tion levels in an enclosed facility. These times are subject to adjustment based
10.3.1 Determine the air-flow rate by an in-line flow meter.
upon the initial test results.
Where this is not possible, calibrate air-flow rate with a
gas-flow meter according to the procedure described in Ref
(16). The recommended flow rate for theAndersen impactor is
included with each shipment. Federal regulations must be
28.3L/min.Theoptimumflowratefortheall-glassimpingeris
followed when they apply to these shipments.
12.5 L/min.
10.5.1 Care During Sampling with the Impactor:
10.3.2 Maintain a constant air-flow rate through the sampler
10.5.1.1 Carry out impactor loading and unloading in an
during the sampling time. Before sampling, allow the vacuum
atmosphere of minimal microbial activity, preferably in a
pumptowarmupfornotlessthan1min.Useclamps,T-shaped
portable polyethylene glove bag or a similar container. Invert
connectors, and in-line membrane filters with 1-mm pore size
the petri dishes immediately when the sampler is unloaded.
topullfilteredairthroughthepumpduringthewarmupwithout
Sanitize the impactor with a 70 % alcohol solution and dry
pulling air through the sampler. Select clamps and T-shaped
thoroughly between samplings. Do not sanitize in the glove
connectors that will not alter the flow rate through the
bag. To provide a control check for contamination, load and
samplers.
unload the impactor without sampling using a set of trypticase
10.3.3 Secure all connections to keep the air loss less than
soy agar petri dishes, and then subject these petri dishes to the
4 % of the average sampling rate or less than 0.00057 m /min
same processing steps and analytical procedures applied to the
(0.02 ft /min), whichever is smaller. Measure the leakage-flow
samples.
rate with a suitable dry-gas meter connected to the discharge
10.5.1.2 Minimize uneven distribution of colonies on the
side of the vacuum pump while the inlet to the sampling
plates by centering the plates on the three pegs in each stage of
apparatus is plugged and a 380-mm (15-in. Hg) vacuum is
the impactor and, once loaded, handling the impactor carefully
drawn. A lower vacuum may be used provided it is not
to maintain this position.
exceeded during sampling.
10.5.2 Care During Sampling with the Impinger:
10.5.2.1 Include a negative (sterile) control with the im-
NOTE 3—Manyofthevane-typeairsamplingpumps(includingtheone
pingers to determine whether the samples become contami-
furnished for use with theAndersen sampler) use a needle valve to control
nated while in transit or at the test site.
the air flow through the sampler by bleeding in air that bypasses the
sampler. The air flow through the pump is therefore constant, and a
10.5.3 Preserve all samples by placing each one in a closed
meaningful measure of the flow through the sampler can only be made at
containerat4 62°Cimmediatelyaftertakingthem.Protectthe
this location in the sample stream.
plates from direct contact with the ice to prevent contamina-
tion.
10.4 Sampling time—The length of time needed to collect
each sample is dependent upon the type of sampler used and
NOTE 4—Sealed ice packets have been found to be satisfactory and
the concentration of microbiological aerosols present in the air.
convenient for this purpose.
Trial sampling runs may be necessary to determine if a
10.5.4 Return the samples to the laboratory as soon as
satisfactoryplateloadingcanbeobtainedwithinthelimitations
possible and not later than 6 h after sampling. Process the
of the equipment used.
samples and place in a incubator as soon as possible.
10.4.1 For the all-glass impinger operating at a flow rate of
10.5.5 For impinger samples, rinse the neck of the impinger
12.5 L/min, the normal sampling time is 20 min.
and add this material to the sample. The volume of the rinse
10.4.2 When using a multistage impactor, choose the sam-
solution must be measured so that the final sample volume is
pling time to avoid overloading the impaction plates, that is,
known.
theloadingonanyoftheplatesshouldnotexceed300colonies
10.6 Identification of Colonies:
per plate. The sampling time for the multistage impactors will
10.6.1 Analyze for the types of bacteria and fungi listed in
vary depending on the medium used for sampling collection
10.6.1.1-10.6.1.4. This is a minimum list of bacteria and fungi
and the concentration of airborne dust. Suggested initial
recommended for identification and quantification. Individual
sampling times for the various media are in Table 1.
investigators may wish to sample for additional organisms
...
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