1、Designation: E884 82 (Reapproved 2012)Standard Practice forSampling Airborne Microorganisms at Municipal Solid-Waste Processing Facilities1This standard is issued under the fixed designation E884; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers sampling of airborne microorgan-isms at municipal solid-waste processin
3、g facilities, hereafterreferred to as facilities. Investigators should consult PracticeD1357 for the general principles of conducting an air-samplingprogram.1.2 This practice applies only to sampling airborne bacteriaand fungi, not viruses. Since sampling airborne viruses issignificantly more diffic
4、ult than sampling bacteria and fungi,reliable methods of sampling viruses are not yet available.2. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis ofAtmospheresD1357 Practice for Planning the Sampling of the AmbientAtmosphere2.2 Other Standards:Microbiolog
5、ical Methods for Monitoring the Environment,Water and Wastes3Air Sampling Instruments for the Evaluation ofAtmosphericContaminants43. Definitions3.1 microbiological aerosolan airborne particle partiallyor exclusively composed of microorganisms including bacteriaand fungi.3.2 For definitions of other
6、 terms used in this practice, referto Terminology D1356.4. Summary of Practice4.1 Concentrations of selected airborne bacteria and fungiare determined using both liquid impinger and multi-stageimpactor samplers.4.2 Procedures are included for selecting sampling loca-tions; determining numbers of sam
7、ples, types of microorgan-isms to be sampled, intervals between sample collection andanalysis; choosing sampling equipment; preserving samples;and reporting results.5. Significance and Use5.1 Bacteria and fungi present in municipal solid wastes (aswell as in other forms of waste) may become airborne
8、 as dustsduring waste processing. Several investigations to determinethe health significance of these microbiological aerosols havebeen hindered by the lack of standardized procedures forsampling airborne bacteria and fungi in an industrial environ-ment and by the absence of standards for assessing
9、their healthsignificance. Because it is difficult to correlate airborne levelsof bacteria and fungi with epidemiological data, this standard isdesigned to permit the formation of a data base to aid in theassessment of the health significance of airborne microorgan-isms. It is intended that the use o
10、f this practice will improvesampling precision and thereby facilitate comparisons betweensampling results.6. Apparatus6.1 Two types of samplers are used in each samplingprogram for microbiological aerosols at waste processingfacilities (5).56.1.1 Multi-Stage Impactor, for collection of airborne mi-c
11、robes on agar plates. It is recommended that an impactor beused for sampling all of the types of bacteria and fungi listedin 10.6.1.61This practice is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct responsibility of Subcommittee D34.01.02 onSampling Techniques.Curr
12、ent edition approved Nov. 1, 2012. Published November 2012. Originallyapproved in 1982. Last previous edition approved in 2006 as E884 - 82(2006) DOI:10.1520/E0884-82R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annu
13、al Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from National Technical Information Service (NTIS), 5301 ShawneeRd, Alexandria, VA 22312, http:/www.ntis.gov. Request EPA-600/8-78-017.4Available from American Conference of Govern
14、mental Industrial Hygienists,Inc. (ACGIH), 1330 Kemper Meadow Dr., Cincinnati, OH 45240, http:/www.acgih.org.5The boldface numbers in the parentheses refer to the list of references at the endof the method.6The six-stage and two-stage microbiological samplers manufactured by Ander-son Samplers, Inc.
15、 have been found to be satisfactory.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16.1.2 All-Glass Impinger, for collection of airborne mi-crobes in a liquid medium. It is recommended that an impingerbe used for sampling fecal colifo
16、rms and for determination oftotal plate count.76.2 Air Sampling Pumps, providing approximately 40 L permin (1.4 CFM) free-flow capacity.6.3 Additional equipment such as carts, stands, and toolboxes are routinely used during dust-sampling programs.7. Reagents and Materials7.1 Agars for Use with the M
17、ulti-Stage Impactor:7.1.1 Littman Oxgall, for total number of fungi present andfor identification of the following species of fungi: (a) Asper-gillus flavus and (b) A. fumigatus.7.1.2 Vogel and Johnson, selective for Staphylococcus au-reus.NOTE 1A fungicide such as nystatin should be used with these
18、 agars.7.1.3 Levine eosin methylene blue, specific for entericsincluding Klebsiella spp. (Note 1)7.1.4 Trypticase soy, for total bacteria count. (Note 1)7.2 Liquid Media for Use in Impingers:7.2.1 Lactose Broth with Antifoam A, for analysis of fecalcoliform and total plate count.7.2.2 The exact amou
19、nt of Antifoam A to be added shouldbe determined prior to field sampling. Sufficient antifoamshould be added to prevent loss of fluid from the impinger, butexcess should be avoided.7.3 Media Preparation:7.3.1 Conduct the following according to MicrobiologicalMethods for Monitoring the Environment, W
20、ater and Wastes(14):(a) laboratory quality assurance, (b) selection and use oflaboratory apparatus, (c ) washing and sterilization, and (d)preparation of culture media.7.3.2 Preincubate all sampling media to determine if con-tamination has occurred and to dry the agar surface. Excessiveevaporation f
21、rom the media or excessive contamination of theexterior surfaces of the petri dishes must be guarded againstduring this preliminary incubation.7.3.3 Media level in the sampling container is critical tocollection efficiency.7.3.3.1 ImpactorThe petri dishes must be of such a sizethat the agar surface
22、is at the manufacturers specified distancebelow each stage. The manufacturer of the Andersen impactorspecifies 27 mL of agar per standard Andersen petri dish. Theagar surface must be smooth and free of bubbles to ensure aneven air flow.7.3.3.2 ImpingerFor the all glass impinger, 20 mL ofbroth is rec
23、ommended (17). Autoclave impingers, and thenaseptically add 20 mL of sterile broth. Mark its level on theimpinger, and record any significant loss during sampling.After sampling, the volume must be reconstituted to theoriginal or the actual volume carefully calculated because aknown volume must be u
24、sed for quantitative work.8. Precautions8.1 Due to the nature of municipal refuse, common sensedictates that some precautions should be observed whensampling dusts at municipal solid-waste processing facilities.Recommended safety practices include wearing hard hats,safety shoes, safety glasses, glov
25、es, and respirators as well aswashing hands before eating or smoking.9. Sampling9.1 Location and Number of Sampling Sites:9.1.1 All sampling shall be carried out during normal plantoperations.9.1.2 Use not less than two sampling locations inside thefacility at work sites or zones where employees are
26、 most likelyto be exposed to airborne dust concentrations (7). (Note 2)Among these locations, those where sampling equipment canbe located without interfering with facility operations shall bepreferred.NOTE 2Examples of potential sampling locations are (a) on a tippingfloor near or on a front end lo
27、ader; (b) at a hand-picking station along aconveyor belt; and (c ) along catwalks or platforms in frequent use byemployees.9.1.3 Outside the facility, locate at least one sampling site300 m (1000 ft) upwind from the facility and at least onesampling site 100 m (330 ft) downwind from the facility.Mea
28、sure the distances upwind and downwind from the samepoint, the point at which the emissions leave the facility or, inthe case of multiple discharge points, from a central pointequidistant from the discharge points.9.1.4 Carefully measure and record the actual distances ofthe sampling sites from the
29、points of emission and winddirection and velocity.9.2 Position of Sampling InletLocate the sampling inlet(s)1.5 m (5 ft) above the floor level to approximate the breathingzone of a worker or other person exposed to the dusts. Locatethe vacuum pumps where they will not disturb the air flowpatterns ar
30、ound the sampling inlet(s).9.3 Number of Samples:9.3.1 Inside the facility, collect not less than 5 replicatesamples at each sampling site.9.3.2 Outside the facility, collect not less than 3 replicatesamples at the upwind site(s) and not less than 5 replicatesamples at the downwind site(s).9.3.3 Wid
31、e variations in reported microbiological aerosollevels within facilities make it unlikely that the collection offive samples will yield a tight distribution of results; therefore,where economically feasible, it is recommended that thesample size be increased to more than five.9.4 Air Temperature:9.4
32、.1 Collect samples when the air temperature at thesampling site is above 5C (40F).9.4.2 At temperatures below 5C (40F), the samplingmedium may crystallize, thus affecting recovery of microor-ganisms.10. Procedure10.1 Record air temperature and relative humidity for eachlocation sampled.7Air sampling
33、 impinger No. 7540 manufactured byAce Glass, Inc. (AGI 30) hasbeen found to be satisfactory.E884 82 (2012)210.2 Label all impingers to denote sampling run and loca-tion. Label all petri dishes to denote sampling run, location,and stage of impactor.10.3 Air-Flow Rates:10.3.1 Determine the air-flow ra
34、te by an in-line flow meter.Where this is not possible, calibrate air-flow rate with agas-flow meter according to the procedure described in Ref(16). The recommended flow rate for the Andersen impactor is28.3 L/min. The optimum flow rate for the all-glass impinger is12.5 L/min.10.3.2 Maintain a cons
35、tant air-flow rate through the samplerduring the sampling time. Before sampling, allow the vacuumpump to warm up for not less than 1 min. Use clamps,T-shapedconnectors, and in-line membrane filters with 1-mm pore sizeto pull filtered air through the pump during the warmup withoutpulling air through
36、the sampler. Select clamps and T-shapedconnectors that will not alter the flow rate through thesamplers.10.3.3 Secure all connections to keep the air loss less than4 % of the average sampling rate or less than 0.00057 m3/min(0.02 ft3/min), whichever is smaller. Measure the leakage-flowrate with a su
37、itable dry-gas meter connected to the dischargeside of the vacuum pump while the inlet to the samplingapparatus is plugged and a 380-mm (15-in. Hg) vacuum isdrawn. A lower vacuum may be used provided it is notexceeded during sampling.NOTE 3Many of the vane-type air sampling pumps (including the onef
38、urnished for use with theAndersen sampler) use a needle valve to controlthe air flow through the sampler by bleeding in air that bypasses thesampler. The air flow through the pump is therefore constant, and ameaningful measure of the flow through the sampler can only be made atthis location in the s
39、ample stream.10.4 Sampling timeThe length of time needed to collecteach sample is dependent upon the type of sampler used andthe concentration of microbiological aerosols present in the air.Trial sampling runs may be necessary to determine if asatisfactory plate loading can be obtained within the li
40、mitationsof the equipment used.10.4.1 For the all-glass impinger operating at a flow rate of12.5 L/min, the normal sampling time is 20 min.10.4.2 When using a multistage impactor, choose the sam-pling time to avoid overloading the impaction plates, that is,the loading on any of the plates should not
41、 exceed 300 coloniesper plate. The sampling time for the multistage impactors willvary depending on the medium used for sampling collectionand the concentration of airborne dust. Suggested initialsampling times for the various media are in Table 1.10.5 Care During Sampling and TransportCollect, pack
42、,transport, and manipulate the sample prior to analysis in amanner that safeguards against any change in the microbialactivity in the sample, such as, extreme heat and cold andradiation, including sunlight. Use the proper media to ensurepreservation of the sample until its identification. If samples
43、must be shipped prior to analysis, positive controls should beincluded with each shipment. Federal regulations must befollowed when they apply to these shipments.10.5.1 Care During Sampling with the Impactor:10.5.1.1 Carry out impactor loading and unloading in anatmosphere of minimal microbial activ
44、ity, preferably in aportable polyethylene glove bag or a similar container. Invertthe petri dishes immediately when the sampler is unloaded.Sanitize the impactor with a 70 % alcohol solution and drythoroughly between samplings. Do not sanitize in the glovebag. To provide a control check for contamin
45、ation, load andunload the impactor without sampling using a set of trypticasesoy agar petri dishes, and then subject these petri dishes to thesame processing steps and analytical procedures applied to thesamples.10.5.1.2 Minimize uneven distribution of colonies on theplates by centering the plates o
46、n the three pegs in each stage ofthe impactor and, once loaded, handling the impactor carefullyto maintain this position.10.5.2 Care During Sampling with the Impinger:10.5.2.1 Include a negative (sterile) control with the im-pingers to determine whether the samples become contami-nated while in tran
47、sit or at the test site.10.5.3 Preserve all samples by placing each one in a closedcontainer at 4 6 2C immediately after taking them. Protect theplates from direct contact with the ice to prevent contamina-tion.NOTE 4Sealed ice packets have been found to be satisfactory andconvenient for this purpos
48、e.10.5.4 Return the samples to the laboratory as soon aspossible and not later than 6 h after sampling. Process thesamples and place in a incubator as soon as possible.10.5.5 For impinger samples, rinse the neck of the impingerand add this material to the sample. The volume of the rinsesolution must
49、 be measured so that the final sample volume isknown.10.6 Identification of Colonies:10.6.1 Analyze for the types of bacteria and fungi listed in10.6.1.1-10.6.1.4. This is a minimum list of bacteria and fungirecommended for identification and quantification. Individualinvestigators may wish to sample for additional organisms.Among the other microorganisms that have been sampled atfacilities are Aspergillus niger, Mycobacterium species andother members of the Actinomycetales order.10.6.1.1 Total plate count (impactor) (Note 5),10.6.1.2 Total plate count (impinger) (No
