Municipal Environmental Research EPA-600 2-79-131
Laboratory August 1979
Cincinnati OH 45268
&ER&
Analysis of
Airborne Viable
Bacteria at Solid
Waste Processing
ilities
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2 Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7 Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-79-131
August 1979
ANALYSIS OF AIRBORNE VIABLE BACTERIA AT
SOLID WASTE PROCESSING FACILITIES
by
M. W. Fletcher and D. E. Fiscus
Midwest Research Institute
Kansas City, Missouri 64110
Contract No. 68-02-1871
Project Officer
Carlton C. Wiles
Solid and Hazardous Waste Research Division
Municipal Environmental Research Laboratory
Cincinnati, Ohio 45268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Municipal Environmental Research
Laboratory, U. S. Environmental Protection Agency, and approved for publi-
cation. Approval does not signify that the contents necessarily reflect
the views and policies of the U. S. Environmental Protection Agency, nor
does mention of trade names or commercial products constitute endorsement
or recommendations for use.
ii
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FOREWORD
The Environmental Protection Agency was created because of increasing
public and government concern about the dangers of pollution to the health and
welfare of the American people. Noxious air, foul water, and spoiled land are
tragic testimony to the deterioration of our natural environment. The complex-
ity of that environment and the interplay between its components require a
concentrated and integrated attack on the problem.
Research and development is a necessary first step in problem solution,
and it involves defining the problem, measuring its impact, and searching for
solutions. The Municipal Environmental Research Laboratory develops new and
improved systems technology to minimize the adverse economic, social, health,
and aesthetic effects of pollution. This publication is one of the products of
that research.
The St. Louis-Union Electric-Environmental Protection Agency refuse fuel
project was the first use demonstration of solid waste as a supplementary fuel
in power plant boilers for generating electricity. In addition to the fuel
demonstration, research tasks were conducted to evaluate the relative levels
of airborne bacteria and viruses at the St. Louis Refuse Processing Plant and
other waste handling facilities for purposes of hazard assessment.
This report was prepared as an evaluation of the analytical methodologies
used to determine airborne microbiological emissions. The total research pro-
gram is fully discussed in the report, "Assessment of Bacteria and Virus Emis-
sions at a Refuse Derived Fuel Plant and Other Waste Handling Facilities,"
EPA-600/2-78-152, U.S. Environmental Protection Agency, August 1978.
Francis T. Mayo, Director
Municipal Environmental Research
Laboratory
iii
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ABSTRACT
This report presents a synopsis of aerobiological testing methodologies
used by Midwest Research Institute during studies conducted for the Environmen-
tal Protection Agency. The purpose of the programs was to determine relative
levels of airborne bacteria and virus aerosols within and around waste handling
facilities. The facilities tested were the St. Louis Refuse Processing Plant,
the Browning Ferris/Raytheon Service Company Resource Recovery Plant (Houston),
and three other types of waste handling facilities: an incinerator, a waste
treatment plant, and a landfill. The report presents microbiological air sam-
pling methodologies, sample handling procedures, and laboratory analysis meth-
odologies. It also includes a general discussion of pertinent considerations
with recommendations for future research, and an extensive bibliography.
This report is of interest to those involved in measuring airborne micro-
organisms at waste handling and processing facilities. A complete discussion
of the entire research program is contained in the report entitled "Assessment
of Bacteria and Virus Emissions at a Refuse Derived Fuel Plant and Other Waste
Handling Facilities," EPA-600/2-78-152, U.S. Environmental Protection Agency,
August 1978.
This report was submitted as part of Contract No. 68-02-1871, by Midwest
Research Institute under the sponsorship of the U.S. Environmental Protection
Agency and covers work done during the period 1975 through 1978.
IV
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CONTENTS
Foreword
Abstract iv
Figures • • • vi
Tables vi
Acknowledgment vii
1. Summary of Recommendations. 1
2. Introduction 3
3. Aerosol Sampling Devices and Field Methodology 5
St. Louis program. 5
Houston program 6
4. Aerosol Sample Handling Procedures 7
St. Louis program 7
Houston program. ............ 8
5. Sample Preparation and Microbiological Analysis ....... 10
Sample preparation 10
Microbiological analysis procedures 14
6. Discussion 24
General considerations 24
Aerosol sampling devices 25
Microbiological analysis of aerosol samples. . 27
Bacteriological analysis .......... 28
Virus analysis 29
Future work 31
References 32
Bibliography 38
v
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FIGURES
Number
Page
1 Microbiology sample processing procedure - St. Louis
program 11
2 Bacterial analysis spectrum - St. Louis program 12
3 Microbiology sample handling procedure - Houston program. . . 13
4 Bacterial analysis spectrum - Houston program 15
TABLES
Number Page
1 Flow Sheet for Viral Concentration Procedures of Aerosol
Samples on Filter Media (Phase Separation Method) 21
2 Monolayer Plaque Assay Technique 22
3 Recommended Bacterial Assay Methods for RDF Facility
Aerosol Samples 30
vi
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ACKNOWLEDGMENT
This report was prepared by Midwest Research Institute for the Municipal
Environmental Research Laboratory, U.S. Environmental Protection Agency,
Cincinnati, Ohio, under EPA Contract No. 68-02-1871. The project officer for
the Environmental Protection Agency was Carlton C. Wiles.
This report was written by Messrs. M. W. Fletcher and D. E. Fiscus.
However, many of Midwest Research Institute's personnel contributed to the
programs which resulted in this publication. Foremost among the contributors
are Dr. F. Wells, Dr. W. Spangler, Mr. R. Flippin, Mr. P. Gorman, Mr. M.
Golembiewski, and Dr. K. P. Ananth. Other contributors were Mr. B. DaRos,
Mr. T. Merrifield, Mr. R. White, Mr. M. P. Schrag, and Dr. L. J. Shannon.
The assistance and support of these scientists are gratefully acknowledged.
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SECTION 1
SUMMARY OF RECOMMENDATIONS
Airborne microorganism emissions from refuse-derived fuel (RDF) and other
waste handling facilities are not well characterized. Further research should
be conducted to better define their qualitative and quantitative nature. The
following summary of recommendations will aid future research attempts to
characterize microbial aerosol emissions.
Hi-Vol air samplers are not recommended to sample for airborne micro-
organisms because of the deleterious effects on microbial viability
due to desiccation.
AGI-30 impingers with gelatin-milk impinger fluid (or other suitable
collection menstruum) are recommended for quantitative sampling for
airborne bacteria and virus both in and around waste handling facili-
ties.
. AGI-30 impingers should not be operated for periods greater than 10 to
30 min.
. Sampling for airborne microorganisms with an AGI-30 in the presence of
large particulates may necessitate the addition of a dry modified
Greenburg-Smith impinger preceding the AGI-30 impinger. The contents
of both impingers should be analyzed if quantitative microbiological
results are desired.
The Andersen impactor is recommended only for microorganism counts by
particle size. The Andersen impactor is not recommended for quantita-
tive airborne microorganism concentrations because airborne particu-
lates may contain more than one microbial cell. Multiple microbial
cells per particle may result in only one colony count and the true
count may thereby be underestimated.
The Andersen impactor should not be operated for periods exceeding
30 min.
AGI-30 impinger and Andersen impactor sampling devices should always
be included as reference sampling devices if another sampler is to be
principally used.
-------
Although not tested in these studies, the Litton large-volume air sam-
pler (LVS) may be used to sample for specific airborne microorganisms,
i.e., Salmonella, Staphylococcus, and Klebsiella, and viruses. These
microorganisms may occur at threshold detection levels with the AGI-30
impinger, but still may be present at epidemiologically significant
levels.
Bacterial analysis of aerosol samples should be initiated within 4 hr
of collection.
Virus analysis of aerosol samples should be initiated as soon as possi-
ble. If delays are unavoidable, the samples should be quick-frozen and
stored at -70°C.
Only optimum media and/or methods which have undergone rigorous compar-
isons under identical conditions, preferably with aerosol samples,
should be used to analyze aerosol samples for microorganisms.
Monolayer plaque assay methods, with sensitive cell lines, are recom-
mended for titration of viruses. HeLa or KB cell lines are recommended
for titration of adenoviruses. Primary rhesus monkey kidney cells or
the continuous monkey kidney cell lines BGM or LLC-MIO? are recommended
for enterovirus titration.
Direct sample incorporation onto cell monolayers without prior sample
concentration is recommended for virus assays of samples containing
sufficiently large concentrations of viruses.
The phase separation method of virus concentration is one technique
recommended for samples containing low concentrations of viruses. Con-
centration efficiency controls should be conducted with a known virus
strain.
Use of microbial indicators of sanitary significance such as total
coliforms, fecal coliforms, and fecal streptococci in determining rela-
tive levels of air hazard should be avoided. The significance of these
indicators in the atmospheric environment has not been thoroughly es-
tablished.
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SECTION 2
INTRODUCTION
Concern that aerosol emissions might contain pathogenic microorganisms
from industrial and public utility facilities has prompted new interest in
aerobiological testing. Emissions assessments for airborne microorganisms
have recently been conducted at sewage treatment facilities (1-8), food pro-
cessing waste spray fields (9), cooling towers (10-12), and more recently
solid waste handling facilities with associated refuse derived fuel plants
(13,14).
Difficulties in quantitatively determining aerosolized microorganisms in
controlled laboratory systems are well known. The problem of accurately as-
sessing airborne microorganism concentrations under field conditions presents
even greater difficulties due to the increased number of uncontrollable envi-
ronmental variables. Additional quantitation variables arise from individual
choices of aerosol sampling devices and laboratory analysis procedures.
Midwest Research Institute (MRI) recently conducted aerosol emission
tests for bacteria and virus at the St. Louis-Union Electric Facility (14)
(hereafter referred to as the St. Louis program) and at the Houston/Browning
Ferris Industries (15) (hereafter referred to as the Houston program). Nu-
merous problems were encountered during these programs, primarily concerning
the nature of the particulate emissions at the refuse facilities tested and
the microbial viability variables of the sampling methods employed.
The purpose of this report is to present the aerosol sampling and micro-
biological assay procedures used during the St. Louis and Houston programs.
The report covers the air sampling devices, sample handling procedures in the
field, and microbiological analysis procedures used during the programs. Prob-
lems encountered with the methods are discussed and recommendations are made
with regard to future research. A bibliography is included to assist in future
research efforts.
This report is primarily concerned with procedures and methodologies.
Further information concerning the results obtained during the St. Louis and
Houston programs may be found in the following reports:
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Assessment of Bacteria and Virus Emissions at a Refuse Derived Fuel
Plant and Other Waste Handling Facilities (14).
Evaluation of Fabric Filter Performance at Browning Ferris Industries/
Raytheon Service Company Resource Recovery Plant, Houston, Texas -
Draft Report (15).
. Executive Summary - Assessment of Bacteria and Virus Emissions at a
Refuse Derived Fuel Plant and Other Waste Handling Facilities (16).
Dust and Airborne Bacteria at Solid Waste Processing Plants (17).
Comparative Assessment of Bacterial and Viral Field Sampling Methods
Used at Solid Waste Handling and Processing Facilities (18).
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SECTION 3
AEROSOL SAMPLING DEVICES AND FIELD METHODOLOGY
ST. LOUIS PROGRAM
The major aerosol sampling device for airborne microorganisms during the
St. Louis program was the Model GMWL-2000 Hi-Vol sampler.£' It was chosen as
the primary sampling device because it could simultaneously sample aerosols
for three parameters: microorganisms, physiochemical particulate morphology,
and trace metals. Hi-Vol samplers placed at upwind and downwind locations were
standard units. The Hi-Vol samplers used for in-plant sampling were standard
units equipped with a Model 230 CP Cyclone Preseparatork' to remove large par-
ticulates and eliminate filter overloading, which has been reported as one of
the Hi-Vol's major problems (19). All of the Hi-Vol samplers were operated at
a continuous sampling rate of 1,134 liters/min for 6 hr with Gelman Type AE
glass fiber filters—' serving as the collection medium.
Counts of airborne microorganisms by particle size were conducted with an
Andersen Model 10-800 sampler—' coupled with a backup modified Greenburg-Smith
impinger£/ to remove any viruses passing the Andersen impactor. Plate count
agar (27 ml) served as the collection medium for the Andersen impactor. The
Greenburg-Smith impinger contained 100 ml Hanks' balanced salt solution (BSS)
as the collection menstruum. The sampling train was operated at 27.96 liters/
min for 0.5 min at in-plant sites and 10 min at property line sites.
Greenburg-Smith impingers were used alone during special sampling appli-
cations for airborne microorganisms. Again, the collection menstruum was 100 ml
Hanks' BSS in all instances. The sampling rate was held constant at 27.96 li-
ters/min for 6 hr at each sampling site.
aj General Metal Works, Inc., 8368 Bridgetown Road, Cleaves, Ohio 45002.
b/ Sierra Instruments, P.O. Box 909, Carmel Valley, California 93924.
c/ Gelman Instrument Company, 600 South Wagner Road, Ann Arbor, Michigan
48106.
d/ Andersen Samplers, Inc., 4215-L Wendell Drive, Atlanta, Georgia 30336.
e/ Ace Glass, Inc., P.O. Box 688, Vineland, New Jersey 08360.
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HOUSTON PROGRAM
The sampling devices were modified somewhat for the Houston program be-
cause of the experience gained during the St. Louis testing. Only AGI-30 im-
pingers£/ and the Andersen Model 10-800 sampler were used as sampling devices.
AGI-30 impingers were used to collect air samples for quantitative deter-
minations of airborne bacteria and virus. At the baghouse inlet, the sampling
train consisted of a 1.52 m (5.0 ft) stainless steel probe with a 2.54-cm ID
(1.0-in. ) probe tip, a dry modified Greenburg-Smith impinger, and an AGI-30
impinger containing 25.0 ml gelatin-milk solution (same as collection medium
ii of White (20), but with omission of spermidine phosphate), a vacuum pump,
and a dry gas meter. The Greenburg-Smith impinger served to trap large parti-
cles that might otherwise plug the AGI-30 orifice. For sampling at the bag-
house outlet, the Greenburg-Smith impinger was omitted. Samples were taken
for 30-min intervals at 4.8 liters/min (0.18 cfm) for the baghouse inlet
and 3.6 liters/min (0.13 cfm) at the baghouse outlet. Samples at both sites
were taken from single points in the duct.
Andersen microbial impactors were used to quantitate bacterial concentra-
tions by particle size. Plate count agar (27 ml) containing 50 units Myco-
statinSL' antifungal agent per milliliter agar served as the collection medium.
Samples were collected from a single point in the duct using the same probe as
was used with the AGI-30 impingers. The baghouse inlet was sampled for 20 sec
at a flow rate of 27.0 liters/min (0.951 cfm). Sampling times were increased
to 10 min at the baghouse outlet to compensate for the lower particulate con-
centrations.
f/ Ace Glass, Inc., P.O. Box 688, Vineland, New Jersey 08360.
£/ Grand Island Biological Company, 3175 Staley Road, Grand Island, New
York 14072.
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SECTION 4
AEROSOL SAMPLE HANDLING PROCEDURES
The sample handling methodology was dependent upon the type of sampling
equipment used. The following are procedure descriptions for each type of
sampling device used.
ST. LOUIS PROGRAM
Hi-Vol Samplers
The Hi-Vol samplers were equipped with a filter support screen and an
open metal frame with a foam gasket to seal the filter edges in place. The
samplers were field-cleaned by wiping down the filter screen, metal frame,
and surrounding area inside the Hi-Vol with lint-free chemical wipes saturated
with 70% isopropyl alcohol. The residual alcohol was allowed to evaporate
prior to installing the sterile filter. All manipulations of the sterile fil-
ter during installation and removal were made while wearing sterile vinyl
gloves. After sampling, the filter was removed, placed in a sterile envelope,
labeled, and stored in a refrigerator until sample shipment.
Hi-Vol Sampler with Precyclone
Sample handling procedures for the Hi-Vol with precyclone sampler were
identical to the standard Hi-Vol with the exception of that used for the pre-
cyclone. The precyclone was cleaned of debris and cleaned with 70% isopropyl
alcohol prior to installing a new filter and initiating sampling.
Andersen Impactor with Backup Impinger
Andersen impactors and Greenburg-Smith impingers were field-sterilized in
a high-frequency ultraviolet light cabinet due to the unavailability of an
autoclave and the necessity of equipment turnover. In addition, prior to ultra-
violoet irradiation, the impingers were supplementally cleaned with 70% iso-
propyl alcohol. After the technicians discarded the alcohol, the impingers
were thoroughly rinsed twice with sterile Hanks' BSS prior to being filled with
100 ml fresh Hanks' BSS collection menstruum.
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Lids to the Andersen agar plates were stored in the ultraviolet cabinet
to prevent contamination during sampling. Following sampling, the Andersen
plates were individually removed, covered with their lids, labeled, and taped
together as a set. Impinger solutions were poured into labeled sterile-glass
bottles and sealed. Samples were stored in a refrigerator until shipment.
Impingers
Procedures used for the special sampling Greenburg-Stnith impingers were
identical to those used for the Andersen backup impingers discussed in the pre-
ceding section.
Sample Shipment
Packaged samples were placed in insulated shipping cartons with plastic
enclosed ice packages. Void spaces in the shipping containers were filled with
packing to prevent sample damage during shipping. Shipping containers were
strapped shut and sent by air express to MRI at the end of each sampling day.
HOUSTON PROGRAM
During the Houston program all materials were pre-sterilized at MRI and
shipped by air to Houston. Sufficient equipment was available so that sampling
devices were used only once in the field. The only piece of equipment reused
in the field was the stainless-steel sampling probe. Prior to each use, the
interior of the probe was thoroughly rinsed with absolute ethanol and carefully
ignited for sterilization purposes. The ends were then covered with sterile
squares of aluminum foil before transfer to the sample site. Individually bot-
tled gelatin-milk impinger solution was aseptically added to the AGI-30 impin-
gers with the aid of a propane torch on the day of sampling.
Upon completion of each sampling run, the volume of the AGI-30 was recon-
stituted with sterile distilled water and aseptically halved. One portion was
transferred to a sterile sample bottle, quickly frozen, and shipped by air to
MRI for viral analysis. The remaining portion was delivered in the impinger to
MBA Laboratories in Houston so that bacterial analysis could begin promptly.
Andersen impactor plates were packed in ice and sent to MRI on a daily basis.
During the initial tests at Houston, only the AGI-30 impinger solutions
were analyzed at the baghouse inlet. This procedure produced erroneous quanti-
tative results (15). During subsequent testing, two fractions at the baghouse
inlet were collected and analyzed. The first fraction consisted of pooled ster-
ile distilled water rinsings of: the probe tip to the Greenburg-Smith impinger;
the connector tubing between the Greenburg-Smith impingers and AGI-30; and the
Greenburg-Smith impinger interior. The second fraction consisted of the asep-
tically reconstituted volume of the AGI-30 impinger solution.
-------
All impingers were kept in an ice bath during sampling, but the samplers
were not shielded from direct sunlight during sampling.
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SECTION 5
SAMPLE PREPARATION AND MICROBIOLOGICAL ANALYSIS
Microbiological samples obtained during the St. Louis program were ana-
lyzed exclusively at MRI's microbiology labs. During the Houston program,
however, only the bacteria count by size (Andersen agar plates) and virus
assays were completed at MRI's labs. Analysis of total bacteria and bacteria
by species was conducted at MBA Laboratories, Houston, Texas. The analyses
were split during the Houston program because it was desirable to start the
bacterial assays within 4 to 6 hr of collection.
SAMPLE PREPARATION
St. Louis Program
The previous day's samples generally arrived in the lab shortly after
8:00 AM. The immediate sample processing procedure for the St. Louis samples
is depicted in Figure 1. The Andersen agar plates were unpacked and placed
inverted in a 35°C incubator. The Andersen backup impingers, one-half of the
Air Density Separator (ADS) samples, and one-half of the Hi-Vol filters were
unpacked and frozen at -70°C in a Revco Ultra-low Freezer for later viral
analysis. The remaining halves of the ADS samples and Hi-Vol filters, along
with the refuse samples and mobile filter impinger solutions, were processed
immediately for bacterial analysis.
Fluid samples such as the mobile filter impingers were prepared by vig-
orous shaking and distributed in appropriate 1:100 dilutions. Solid samples
such as the refuse samples, Hi-Vol filters, and ADS samples were diluted either
1:100 or 1:200 (w/w) with sterile distilled water and blended for 30 sec in a
sterile Waring blender. The resulting homogenates were used directly or after
subsequent 1:100 dilutions for inoculating the various media. The bacterial
analysis spectrum is depicted in Figure 2.
Houston Program
During the Houston program, samples were shipped as soon as possible
after collection either to MRI or to MBA Laboratories in Houston. The micro-
biology sample handling procedure is shown in Figure 3.
10
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MICROBIOLOGY SAMPLE PROCESSING PROCEDURE
ST. LOUIS PROGRAM
Receipt of
Iced Samples
Andersen
Plates
Mobile Filter
Impinger
Solutions
Placed in
Incubator
@35°Cfor
24-48hrs.
Refuse
Samples
Hi-Vol Filters
(Aseptically
Halved)
ADS Samples
(Aseptically
Halved)
Processed
Immediately
for Bacterial
Analysis
Processed
Immediately
for Bacterial
Analysis
1/2 Sample
Processed
Immediately
for Bacterial
Analysis
1/2 Sample
Frozen for
Later Viral
Analysis
@-70° C
Andersen
Back-up
Impingers
1/2 Sample
Processed
Immediately
for Bacterial
Analysis
Frozen (a) -70° C
for Later Viral
Analysis
Figure 1
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BACTERIAL ANALYSIS SPECTRUM
ST. LOUIS PROGRAM
Sample
Homogenate or Dilution Thereof
Total Plate Count
Total Coliform
Fecal Coliform Fecal Streptococci Salmonella, sp. Klebsiella sp. Stophylococcus aureus
Method:
Media:
Incub. Time:
Incub. Temp:
Level 2 Tests:
Pour Plate
PCA
48 hn.
35»C
(Proposed)
None
MPN(5-10. 5-1, 4 5-0. 1ml)
Lauryl Tryptose Broth &
Brilliant Green Lactose
Bile Broth
24 - 48 hrs.
35i0.5°C
None
MPN
Lauryl Tryptose Broth &
EC Broth
24 hrs.
44.5tO.2-C
Enteropathogenic
Serotypes
Isolation of Rep.
Colonies on EMB -
Nutrient Agor Slants
E. coli OK Polyantiserum
Pour Plate
KF Streptococci Agar
+ TTC
48 hrs.
3510. 5"C
None
Spread Plate & Enrichment
MacConkey Agar &
Brilliant Green Agar
Selenite Broth
24 - 48 hrs.
35'C
Serotyping
Spread Plate
MacConkey Agar
24 - 48 hrs.
35°C
Serotyping
Spread Plate
Staphylococcus
110 Medium
24 -48 hrs.
37°C
Coagulase
Production
Slide Agglutination
Figure 2
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MICROBIOLOGY SAMPLE HANDLING PROCEDURE
HOUSTON PROGRAM
Field Samples
Andersen Plates
AGI-30 Impinger
Solutions
Greenberg Smith
Impinger Solutions
Baghouse Hopper
Discharge
Shipped 1/2 Sample 1/2 Sample Shipped to One Sample One Sample
to MRI Shipped Shipped to MBA Labs Shipped to Shipped to
Placed in
Incubator
@28-30°C
for 48 hrs.
to MRI
1
1
Frozen @
-70°C for
Later Viral
Analysis
MBA Labs
i i
Processed
Immediately
for Bacterial
Analysis
\
Processed
Immediately
for Bacterial
Analysis
MRI
Frozen @
-70° C for
Later Viral
Analysis
MBA Labs
I
1
Processed
Immediately
for Bacterial
Analysis
Figure 3
13
-------
One-half of the AGI-30 impinger samples for virus analysis, Andersen impactor
plates, and baghouse hopper discharge samples was shipped to MRI for analysis.
The AGI-30 impinger and baghouse hopper discharge samples were stored frozen
at -70°C until virus analysis could be initiated. Andersen plates were unpacked
and placed inverted in a 28 to 30°G incubator.
The remaining halves of AGI-30 impinger, Greenburg-Smith impinger, and
baghouse hopper discharge samples were hand-carried to MBA Laboratories within
2 to 3 hr of sampling. Bacterial analysis by MBA Laboratories was initiated
immediately upon receipt of the samples.
Fluid samples such as the impinger solutions were used to inoculate media
as received or after a 1:6 dilution. Solid samples such as the baghouse hopper
discharge were diluted 1:90 (w/w) and vigorously shaken. The bacterial analysis
spectrum for the Houston samples is depicted in Figure 4.
MICROBIOLOGICAL ANALYSIS PROCEDURES
Aerosol samples obtained during the St. Louis and Houston programs were
analyzed for general and specific microorganism content (see Figures 2 and 4).
The following section presents the analytical methods used during analysis.
Bacteria Count by Size (Andersen Agar Plates)
St. Louis —
Plate count agar (Difco) in polystyrene petri plates (Falcon) served as
the collection medium for the Andersen aerosol samples. The plates were poured
to a depth of 27 ml with the aid of a sterile Cornwall syringe and allowed to
solidify. After solidification, excess moisture on the agar surface was evap-
orated by placing the plates in a sanitized laminar flow unit for approximately
20 min with the lids partially removed. The plates were then repacked in their
original packing sleeve and sealed with tape for shipment to the field.
Upon receipt of the inoculated Andersen agar plate samples at the lab, the
plates were unpacked and incubated in an inverted position at 35°C for 24 to
48 hr depending upon the degree of mold contamination. After this period,
bacterial counts were made on the basis of colonial morphology with the aid of
a Quebec colony counter. Select representative colonies were picked at random
from some of the Andersen plates and saved on typticase soy agar slants. These
cultures were then used for determination of morphology using gram staining
techniques.
14
-------
BACTERIAL ANALYSIS SPECTRUM
HOUSTON PROGRAM
Sample or Dilution Thereof
Total Plate Count Total Coliform Fecal Coliform Fecal Streptococci Salmonella. sp_. Klebsiella sp. Staphylococcus aureus
Method:
Media:
Incub. Time:
Incub. Temp:
Spread Plate
Plate Count Agar
24 hrs.
35°C
MPN (3-10.0, 3-1.0,
& 3-0. 1 ml)
Lactose Broth & Brilliant
Green Lactose Broth
24 - 48 hrs.
35"C
MPN
EC Broth
24 hrs.
44.5°C
Spread Plate
KF Streptococcal Agar
^ TTC
48 hrs.
35°C
Modified MPN
Lactose Broth
Selenite Cysline Broth
Salmonella-Sliigella Agar
Bismuth Sulfite Agar
24 - 48 his.
35°C
Enrichment MPN
Lactose Biolli
£MB Agar
24 - 48 hrs.
35°C
MPN (3-1.0, 3-0.
3-0.001, & 3-0
Trypticase Soy Brol
10% NaCI,
Baird Parker Agar,
48 hrs.
35°C
1,
.0001,
h with
Etc.
Figure 4
-------
Houston--
The Andersen aerosol plate count methods used on the Houston program were
the same as the St. Louis program with only a few modifications. In an effort
to control molds from overgrowing and masking the bacterial count, the anti-
fungal agent Mycostatin (nystatin) (21) was incorporated in the plate count
agar at 50 units/ml agar. The agar plates were incubated at 28 to 30°C for
48 hr prior to determining the following microbial counts: total count, bac-
teria, yeast, mold, and antinomycetes. The categorical microbial counts were
separated from the total count on the basis of colony morphological character-
istics. It should be noted that the categorical counts can be used as a guide
only to the relative population number. To obtain more absolute values, spe-
cial sampling and assay considerations would have to be implemented for each
microbial type. Isolates were not saved for morphology or gram-reaction deter-
minations.
Total Plate Count
St. Louis—
Total plate counts were determined according to Standard Methods (22).
Analyses of the filter pad slurry were determined in duplicate by the pour-
plate method with plate count agar. The solidified plates were incubated aero-
bically at 35°C for 48 hr. Longer incubation times at a lower temperature might
have given slightly higher counts but because mold spores were present in large
numbers, it was not possible to extend the incubation time beyond 48 hr without
overgrowth by fungi.
Isolated colonies were picked from representative plates and transferred
to trypticase soy agar slants. The cultures were then used for determination
of morphology and gram reaction.
Houston--
Total plate counts were conducted according to procedures detailed in
Standard Methods (22). The impinger samples were not diluted. Solid samples
were diluted 1:90 (w/w) and then homogenized. The samples were then analyzed
by the spread-plate method, using plate count agar. Plates were incubated
aerobically at 35°C for 24 hr prior to determining colony counts.
Standard Total Coliform MPN Tests
All coliform tests were conducted according to Standard Methods (22),
using most-probable-number (MPN) techniques.
16
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St. Louis —
Presumptive coliform tests during the St. Louis program were conducted
using lauryl tryptose broth (LST) as the enrichment medium. Five fermentation
tubes each of 10, 1, and 0.1 ml of the filter pad slurry were prepared and in-
cubated at 35°C. At the end of 24 hr, each tube was examined, and those showing
gas were recorded. Tubes showing no gas at 24 hr were reincubated for an addi-
tional 24 hr for a total of 48 hr. Formation of gas within 48 hr constituted
a positive presumptive test.
Confirmation of total coliforms was conducted by subculturing to brilliant
green lactose bile broth (BGLB) all LST tubes showing gas in 24 or 48 hr in the
presumptive test. The BGLB tubes were then incubated at 35°C for 48 hr. Forma-
tion of gas within 48 hr constituted a positive confirmed test.
Total coliform completion tests were conducted by streaking aliquots of
each BGLB tube showing gas onto eosin-methylene-blue (EMB) agar plates. The
EMB plates were incubated at 35°C for 24 hr and then observed for typical col-
onies (nucleated with or without metallic sheen). Typical colonies were sub-
cultured on nutrient agar slants and examined after 24 hr by use of the gram-
stain technique. Gram-negative cultures were considered to be coliform.
Houston—
Total coliform counts during the Houston program were also determined by
the MPN technique. Solid samples were diluted 1:90 (w/w) and the impinger sam-
ples 1:6. A lactose broth three-tube/three-dilution series of 10, 1.0, and
0.1 ml was used for both liquid and solid samples. After incubation at 35°C
for 48 hr, all tubes showing gas were transferred to BGLB for confirmation of
positive reaction. Coliform tests were not completed.
Fecal Coliform MPN Tests
St. Louis —
Fecal coliform tests (22) during the St. Louis program were conducted on
all LST tubes showing gas in the presumptive coliform test. The LST tubes were
used to inoculate tubes of EC medium. The EC tubes were then incubated in a
water bath at 44.5°C for 24 hr. Gas production in 24 hr constituted a positive
test and indicated the presence of coliform microorganisms of fecal origin.
Most probable number tables were used to determine probable fecal coliform
densities in the original sample.
Subcultures were made from positive EC tubes to EMB agar, and typical
colonies on the solid medium were then transferred to nutrient agar slants
and saved for serological typing for enteropathogenic Escherichia coli.
17
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Houston--
Fecal coliform counts were determined by the MPN technique (22). All lac-
tose tubes from the total coliform tests which showed gas production (positive
reaction) were used for fecal coliform analysis. EC media were inoculated from
each positive lactose tube and incubated at 44.5°C for 24 hr. Gas production
within 24 hr represented a positive test. Coliform densities were determined
from standard MPN tables.
Serological Typing of Escherichia coli
St. Louis—
Subcultures from nutrient agar slants were made to brain-heart infusion
agar (BHIA) of typical fecal coliform (EC) isolates. The BHIA cultures were
incubated overnight, and on the following day portions of each culture were
serologically tested against E. coli OK antiserum (poly) by the slide agglu-
tination technique as described by Difco Laboratories (23).
Fecal Streptococci
St. Louis —
Fecal streptococci were enumerated by a pour-plate technique utilizing KF
streptococci agar containing 0.01% 2,3,5-triphenyltetrazolium chloride (TTC).
Colonies appearing dark red or pink were counted as fecal streptococci.
Houston--
Fecal streptococci were enumerated by the spread-plate technique used
with KF streptococcal agar and TTC. Plates were incubated at 35°C for 48 hr.
All suspected colonies were examined microscopically for confirming morphol-
ogy.
Salmonella
St. Louis—
Salmonella tests were conducted on filter-pad slurry by direct-spread
plate and enrichment broth-spread plate techniques. Slurry-sample and 24 to
48 hr selenite broth enrichment aliquots were transferred to both MacConkey
and brilliant green agars. Typical colonies appearing colorless on MacConkey
agar and red or pink to nearly white on brilliant green agar were transferred
to triple sugar iron (TSI) agar slants. Cultures giving typical reactions for
Salmonella on TSI agar were transferred to trypticase soy agar slants and re-
tained for serological testing.
18
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Salmonella isolates were serologically tested using the slide agglutina-
tion technique (23) with salmonella polyvalent antisera. Positive reactors
were then tested using salmonella group specific antisera.
Houston--
One-miHi liter lactose broth aliquots from the coliform analysis procedure
were inoculated into selenite cystine broth (SCB) medium. After 24 hr incuba-
tion, inocula from SCB tubes were streaked onto salmonella-shigella (SS) agar
and incubated at 35°C for 48 hr. Typical salmonella colonies on SS agar were
picked and transferred to TSI slants. Following incubation, slants showing
typical salmonella reactions were tested for confirming biochemical reactions
in the following media: lysine decarboxylase, dulcitol, sucrose, lactose,
malonate, citrate, indole, and motility.
Klebsiella
St. Louis—
Tests for Klebsiella were conducted on filter pad slurry dilutions. The
spread-plate technique was used on MacConkey's agar. Typical red, mucoid-
appearing colonies were picked and transferred to additional MacConkey and EMB
agar plates for purity. Typical appearing colonies were transferred to BHIA to
serve as stocks to determine their respective biochemical reactions using the
API 20E system.—' Isolates possessing biochemical characteristics similar to
those reported for Klebsiella sp. were serologically tested with polyvalent
klebsiella antiserum.
Houston--
Positive lactose tubes from the coliform analysis procedure were streaked
onto EMB agar plates and incubated at 35°C for 24 hr. All colonies morphologi-
cally identified as typical Klebsiella were inoculated onto TSI slants. The
TSI slants exhibiting an acid slant with an acid butt, with or without gas,
were further tested for ornithine decarboxylase, indole, motility, and urease.
Only those isolates exhibiting typical klebsiella reactions were reported as
Klebsiella sp.
Staphylococcus aureus
St. Louis—
The presence of Staphylococcus aureus was determined by spread-plate
technique on Staphylococcus 110 agar plates. These plates were incubated at
37°C for 24 and 48 hr; all typical appearing colonies (light yellow to orange
h/ Analytical Products, 200 Express Street, Plainview, New York 11803.
19
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pigment) were transferred to brain-heart infusion slants. After overnight
growth, the isolates were tested for production of coagulase by the rabbit
serum EDTA coagulase tube test.
Houston—
S. aureus was determined by the MPN procedure detailed in the A.O.A.C.
Manual (24) A four-dilution/three-tube series of trypticase soy broth with
10% sodium chloride was inoculated and incubated at 35°C for 48 hr. Tubes
showing growth were streaked onto Baird Parker agar plates and incubated for
another 48 hr at 35°C. Plates were then examined for suspect colonies which
were transferred to brain-heart infusion broth (BHIB). The BHIB tubes were
incubated at 35°C for 24 hr, after which aliquots were subjected to the rabbit
serum EDTA coagulase tube test. Tubes showing a positive reaction after 4 hr
were reported as S_._ aureus.
Virus Methodology
St. Louis Program--
Samples for virus analysis were concentrated prior to virus titration.
Initially, samples were concentrated by the hydroxyapatite method. This con-
centration method was replaced early in the research by the more efficient
dextran sulfate-polyethylene glycol phase separation method of Shuvall (25)
(see Table 1). Most of the samples were concentrated by the phase separation
method.
Concentrated samples were analyzed for virus content by the monolayer
plaque assay technique of Schmidt (26) with minor modifications (see Table 2).
In all samples, 5- to 7-day old confluent 75 cm monolayers of heteroploid
monkey kidney cells, LLC-MK2 (GIBCO) were used. The monolayers were grown at
35°C in Earles' M-199 containing glutamine and supplemented with 10% fetal
calf serum, 0.22% NaHC03 for stoppered incubation, GIBCO1s antibiotic-
antimycotic amendment (penicillin, streptomycin, and fungizone) and GIBCO's
anti-PPLO amendment (tylocine).
Because of severe mold contaminations, samples for virus titration were
diluted 1:10 in Earles' BSS. One milliliter of the 1:10 sample dilution was
distributed over the monolayer after pouring off the growth medium. The flask
was incubated for 30 min at 37°C to allow virus attachment. The inoculum was
poured off and, in a darkened room, replaced with 10.0 ml of molten overlay
medium at 45 to 47°C consisting of the growth medium supplemented with 1.7 x
10'3% neutral red and 1.5% ion agar No. 2. The overlay was quickly distributed
over the monolayer and placed on a flat surface for 30 min to allow solidifica-
tion of the agar. The flasks were firmly sealed and incubated in the dark at
36 to 37°C. The tissue cultures were checked for plaque formation at 4, 7, and
20
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TABLE 1. FLOW SHEET FOR VIRAL CONCENTRATION PROCEDURES OF AEROSOL
SAMPLES ON FILTER MEDIA^/ (Phase Separation Method)
Homogenize weighed sample after diluting 1:100 (w/w) with distilled water.
Centrifuge at 1,080 x g for 15 min at 4°C.
^ Discard Ppt.
V
Neutralize supernatant to pH 7.2.
I
Add each of the following sequentially after each is thoroughly dissolved:
1.75% (w/w) (0.3 M) Dry sodium chloride
0.2% (w/w) Sodium dextran sulfate 2000
6.43% (w/w) Polyethylene glycol 4000
Allow to mix 1 hr using a magnetic stirrer.
Transfer mixture to separatory funnel and store at 4 C for 18 to 24 hr.
Collect bottom and interphase portions.
I
Follow the method below: (after Shuvall, H. I. et al., 1969)
To bottom and interphase portions, add KCl to 5.22% (w/w) (0.7 M)
to ppt. dextran sulfate.
Centrifuge at 2,500 g for 10 min at 4°C.
To supernatant, add 1.0 ml anesthetic grade diethyl ether per 4 ml
reconcentrate.
Shake mixture and hold at 4 C for 18 hr to kill contaminating
bacteria and molds.
Tissue culture assay for viruses.
ja/ This procedure may be modified to process impinger samples by elimi-
nating the initial homogenization and centrifugation steps.
21
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TABLE 2. MONOLAYER PLAQUE ASSAY TECHNIQUE^
1. Remove growth medium from 5- to 7-day old monolayers in 75 cm surface
area flasks and rinse with three 8 ml portions of Earles' balanced
salt solution.
2. Check monolayer for confluency.
3. Pipet 1.0 x 10 ml dilution of sample onto monolayer. Distribute the
inoculum over the monolayer and incubate for 30 min at 37°C.
4. Pour off inoculum.
5. Pipet and evenly distribute 10.0 ml of the following nutrient overlay
solution held at 45 to 47°G.
ml Final cone.
10X Earles1 M-199 + Glutamine (GIBGO) 10.0 IX
Fetal Calf Serum (inactivated at 56°C for 10.0 10%
30 min)
7.5% NaHC03 3.0 0.22%
Neutral Red (1:300) 0.5 1.7 x !Q-3%
10X Antibiotic-Antimycotic (penicillin, 1.0 IX
streptomycin, fungizone, GIBCO)
10X Anti-PPLO (tylocine, GIBCO) 1.0 IX
2% lonagar No. 2 in double distilled water 74.5 1.5%
6. Place bottles on a flat surface in a darkened room for 30 min to permit
the agar to solidify then firmly seal flasks.
7. Incubate the flasks in the dark at 36 to 37°C.
8. Check flasks for plaque formation at 4, 7, and 10 days.
a/ After: Reference 26.
22
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10 days. Suspected plaques were picked and transferred to fresh monolayers for
determining plaque reproducibility. Only reproducible plaques were considered
to be of viral origin.
Houston Program--
Samples for virus analysis during the Houston program were handled simi-
lar to those during the St. Louis program. Only differences will be stressed
here.
Houston samples were concentrated exclusively by the phase separation
method of Shuvall (25). The concentrated samples were analyzed by the mono-
layer plaque assay technique with confluent 75 cm monolayers of three cell
lines: 7-day cultures of heteroploid monkey kidney cells (LLC-MK2 )» 3-day
cultures of a neoplastic nasopharnyx cell line (KB), 3-day cultures of a pri-
mary human fetal lung fibroblast line (similar to WI-38). Both positive and
negative controls were run with field samples using the same concentration and
analysis procedure. Negative controls consisted of Earles1 BSS and a sterile
impinger blank. Positive controls were prepared by seeding an Earles' BSS
blank and a sterile impinger blank with attentuated polio type 1 virus.
23
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SECTION 6
DISCUSSION
GENERAL CONSIDERATIONS
The accurate assessment of microbiological air quality in ambient and
confined air has proven difficult in the past. Part of the assessment problem
is due to the diversity and variance in the number of: (a) microbiological
forms found in air, (b) particulate matter of unknown size and composition,
and (c) chemical composition of the air. In addition, evaluation of test data
is further complicated by the diversity of sampling methods and analytical
procedures employed by investigators in a variety of applications.
An accurate assessment of airborne microorganisms depends upon method
sensitivity and reproducibility; these important quantitative considerations
are influenced by many factors, including:
The air sampling device employed;
. Ability to obtain large statistically valid sample volumes (this may
necessitate large air volumes to be sampled by one sampler or an in-
crease in the number of sampling devices at a given point);
Maintenance of viable conditions for vegetative microorganisms during
and following sampling;
Disruption of the microbial particulate and microbial microcolonies
so that an accurate estimation of the absolute population can be made;
. A minimum of sample storage time prior to assay;
Proper choice of general, differential, or selective growth media for
the microorganism of concern; and
. Proper choice of environmental growth variables for the organism of
concern.
24
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AEROSOL SAMPLING DEVICES
Currently, a variety of sampling devices are being used to sample for
airborne microorganisms. Chief among those used today are: all glass impingers
(AGI-30), Andersen multistage impactors, cascade impactors, and Litton Large
Volume Samplers (LVS). These devices and other sampling considerations are
described elsewhere in more detail (27-33).
Biological collection efficiencies of airborne microorganisms sampling
devices vary greatly because of complex interactions of many variables. Some
of these variables are:
Physiological stage of the microorganisms, i.e., vegetative cells or
spores;
Physiological and structural state of the microorganisms, i.e., normal
or sublethally stress-damaged cells;
Method of collection by the sampling device, i.e., impaction, impinge-
ment, filtration, etc.;
. Volume of air sampled; and
. Environmental conditions during sampling.
Biological efficiencies may be altered because of the sampling device's effect
on microbial viability both during and following sampling. Complex and often
deleterious stressing effects such as desiccation, rehydration, oxidation,
radiation, osmotic shock, impaction shock, length of sampling time, collection
menstruum, sample retention time, etc., contribute to decreases in biological
efficiencies during aerosol sampling. Also, collection efficiencies and stress-
ing effects vary both between and within diverse microbiological groups that
may be assayed, i.e., bacteria, yeasts, molds, actinomycetes, or viruses which
require different considerations altogether.
Standard reference samplers for microbial aerosols have been recommended.
General agreement was reached at the First International Symposium on Aero-
biology (34) that the AGI-30 and the Andersen samplers be used as standard
reference samplers. In both cases, it was emphasized that methodology, i.e.,
techniques and materials, be rigorously and completely specified when report-
ing the results. The use of reference sampling devices with complete specifi-
cation of methodology has been a problem in the past. Unfortunately, the prob-
lem remains today. Defense of altered methodologies may rest on the undebatable
premise that environmental variables, type of information sought, or research
cost often necessitate individual alteration of published methodologies. How-
ever, it must be stressed that if altered methodologies are used by different
25
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investigators, this can and often does prevent meaningful comparisons of re-
sults even if the same type of sampling device is used.
During the St. Louis program, the Hi-Vol air sampler was chosen as the
primary aerosol sampling device for several reasons. First, the Hi-Vol sam-
pler could sample large volumes of air (1,000 to 1,200 liters/min), which
theoretically would increase the representativeness of the samples obtained
without increasing the number of samples taken at a single location. Second,
the samples obtained by the Hi-Vol sampler would be used simultaneously for
three separate parameters to be measured, i.e., microorganisms, physiochemi-
cal particulate morphology, and trace metals. Both of these features made the
Hi-Vol sampler attractive in terms of the time and manpower savings. Unfortu-
nately, the Hi-Vol air sampler was run for 6 hr as a compromise for the non-
microbiological parameters to be assessed. As a result, the microbiological
samples suffered severe exposure to desiccation and oxidation factors. Unfor-
tunately, AGI-30 impingers were not run concurrently as references at St. Louis.
The experience gained, however, was applied on the Houston program.
The AGI-30 impinger and Andersen impactor should always be used as ref-
erence airborne microorganism sampling devices during aerosol emission research
(34). Quantitative airborne bacteria and virus concentrations should be as-
sessed with the AGI-30 impinger containing a collection menstruum compatible
with the microorganism(s ) sought. Gelatin-milk or one-half strength tryptic
soy broth should be used as the collection menstruum for bacteria. Gelatin-
milk or tissue culture medium with serum should be used for viruses. In all
instances, menstruum compatibility tests should be conducted with a suitable
test microorganism prior to use in order to determine effects on microbial
viability.
Sampling times for microbial aerosols should be closely monitored. Sam-
pling times with the AGI-30 impinger should be for 10 min or less. Absolute
maximum sampling times with an AGI-30 should be 30 min. Prolonged sampling
may cause significant microbial die-off as a result of complex sampling ef-
fects. Regardless of sampling time, it is advisable to set up control sam-
pling devices inoculated with an appropriate test microorganism to ascertain
the effects of sampling under field test conditions. In sampling areas contain-
ing large particulates, it may be necessary to add a dry Greenburg-Smith im-
pinger prior to the AGI-30 (as was done at Houston) to prevent clogging of the
AGI-30 orifices. Rinsings of both impingers and their connector tubing should
be included for quantitative analysis.
The Andersen sampler is recommended only for sizing aerosol particles
containing microorganisms. The Andersen sampler should not be used for quanti-
tative microbial aerosol concentrations because a colony resulting from one
aerosol particle may have contained more than one microbial cell. Sampling
times with the Andersen impactor should not exceed 30 min. Prolonged sampling
at waste handling facilities may result in excessive build-up of sample on the
26
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sieve plates thereby altering particle sizing efficiency. In addition, pro-
longed sampling may cause desiccation of the microbiological medium employed
leading to altered concentrations of the medium's components. Increased con-
centration of media components over the recommended level may lead to toxic
levels especially if selective media are used. As with the AGI-30, it is
recommended that control sampling devices be set up with appropriate test
microorganisms to determine the effects on microbial viability of sampling
under field test conditions.
The Andersen sampler might also be considered as a quantitative sampling
device for airborne viruses. Andersen samplers have been modified and used as
samplers for airborne viruses (39-42).
It is recommended that both Andersen and AGI-30 sampling devices be
shielded from direct exposure to sunlight. Research by Fedorak (35) has shown
that significant microbial losses are encountered from exposure of sampling
devices to direct sunlight during sampling.
Although not specifically tested during the St. Louis or Houston programs,
results indicate that the Litton LVS may be included especially in sampling
for specific low concentration microorganisms such as Salmonella sp., Klebsiella
sp., Staphylococcus aureus, and viruses. The LVS Model M is capable of sampling
at 1,000 liters/min, which is 35 times greater than the Andersen sampler (28.3
liters/min) and 80 times greater than the AGI-30 (12.5 liters/min). The signif-
icance of using the LVS to detect viruses at epidemiologically significant low
concentration has been demonstrated (36-38). The LVS is currently marketed by
Sci-Med Environmental Systems, Inc.i/
It is urged that extreme diligence be shown in reporting all aspects of
the sampling procedure. It is also important to specify what the final sample
constitutes, i.e., the collection medium only, the collection medium plus
rinsings of the connector tubing (if applicable), etc.
MICROBIOLOGICAL ANALYSIS OF AEROSOL SAMPLES
Microbiological analysis of aerosol samples should be initiated as soon
as possible after collection. It is desirable that sample analysis begin with-
in the upper limit of 4 to 6 hr to avoid alteration of microorganism concentra-
tion due to growth (increase in number) or die-off. Sample analysis delays
were encountered during the St. Louis program because of logistical problems.
During the Houston program, these problems were alleviated by contracting a
qualified local laboratory to conduct the assays. The alternatives would be
to maintain a field laboratory or rent space at a local hospital or school.
i/ 2411 Pilot Knob Road, St. Paul, Minnesota 55120.
27
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If delays are unavoidable, bacteriological samples can be stored in ice up to
4 hr; however, die-off needs to be considered. Samples for virus analysis
should be quickly frozen in dry ice or liquid nitrogen and stored at -70 C
until analysis.
Standardized analytical procedures have been established for the micro-
biological analysis of food (24,43,44); water (22); solid waste (45); and
clinical specimens (46-50). However, standard analytical procedures for micro-
bial aerosol samples have not been established. The unique stresses to which
aerosolized microorganisms are exposed present difficulties in choosing an
optimal medium for their recovery. General growth media would provide, perhaps,
a greater recovery of aerosol-stressed microorganisms than would differential
or selective media. However, the advantages of general media are often lost
by overgrowth of the desired vegetative microbial forms by the more resistant
and perhaps less important spore-formers.
BACTERIOLOGICAL ANALYSIS
Numerous differential and selective media have been developed for assess-
ment of genera or classes of microorganisms. Yet, even with optimal samples,
qualitative accuracy and quantitative recovery will vary with media type. Com-
parisons of media for recovery of specific microorganisms are relatively com-
mon in the literature for clinical, food, and water samples, etc. Although
these comparisons may be used as guidelines for media selections for assay of
microbial aerosol samples, they cannot be applied with certainty because of
the unique stresses exerted on aerosolized microorganisms. The comparison of
media for the enumeration of Staphylococcus aureus in aerosol samples by Smith
(51) is one of the few such studies applied to aerosol samples. Clearly this
is an area of aerobiological research that needs further amplification.
Indicator microorganisms such as total coliforms, fecal coliforms, and
fecal streptococci have been used for a number of years for assessing microbial
quality of food and water. Indicators are particularly cost-effective where
the pathogenic species, whose presence are used to indicate, are present at
low levels and the cost of sensitive methods are prohibitive. In the absence
of microbial air standards or thorough research methods needed to establish
them, indicator species may be of value in determining relative levels of air
hazard subject to further research.
Microbiological indicator systems such as total coliforms, fecal coli-
forms, and fecal streptococci are currently being used to assess ambient and
confined air quality levels (13,14). Since these indicators possess real prob-
lems in assessing quality of the aqueous systems for which they were developed,
use of such indicators in air quality assessments is open to conjecture. Coli-
form organisms have been found associated with a wide variety of nonfecal en-
vironmental sources including vegetation (53), soils (54), and insects (53,55).
28
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Aerosols from these common sources may be generated easily and may cause
erroneously high background counts. In addition, solid waste retention times
may alter the original ratio of coliforms to pathogens. Further research is
essential to clarify the meaning of conventional microbial indicators in the
atmospheric environment and to establish their relationship to pathogens in
that medium, if the indicators are to be of value in assessing microbial air
hazard.
Research should be conducted to ascertain optimal media-methodology com-
binations for quantitation of aerosol-stressed microorganisms. During the
St. Louis and Houston programs, reliance was placed on standard microbiological
procedures. Until research is conducted comparing the various media of choice,
under identical conditions with field aerosol samples, it is recommended that
several types of media/methods be used concurrently. If this is not possible,
emphasis should be placed on media/methods which have undergone rigorous com-
parisons under identical conditions for optimal differential, selective, and
quantitative abilities. The research programs of Gabis (56), Raymond (57), and
Niskanen (58) are good examples of studies of this nature, even though the
studies are not concerned with aerosol samples.
At the present time, MRI recommends the bacteriological methods outlined
in Table 3 for analysis of aerosol emission samples obtained at waste handling
facilities. It should be noted that some of the procedures represent modifi-
cations of the ones used during the St. Louis and Houston programs.
VIRUS ANALYSIS
Previous research during the earlier 1975 St. Louis test program (unpub-
lished) established that virus concentration procedures were necessary for
virus-containing aerosol samples obtained at solid waste-type facilities.
Initial samples for virus analysis during the St. Louis program were concen-
trated according to the hydroxyapatite method as conducted during the 1975
program. Concern over concentration efficiency of the hydroxyapatite method
led to comparisons between the hydroxyapatite and dextran sulfate-polyethylene
glycol phase separation method (25) with both T-l bacteriophage and attenuated
polio virus type 1. With bacteriophage T-4, percent recovery of the phase
separation method was 18.2% as compared to 0.1% for the hydroxyapatite method.
The phase separation method gave 23.9% recovery with polio virus type 1 as
compared to 0.1% for the hydroxyapatite method. These tests proved the phase
separation method to be significantly more efficient. As a result, the phase
separation method was used to concentrate the remainder of the samples.
A large number of virus concentration procedures have been described in
the literature. These concentration procedures can be divided into seven main
groups (59): sample incorporation, ultrafiltration, freezing, two-phase sep-
aration, ultracentrifugation, electrophoresis, and adsorption and elution.
The phase separation method was chosen over the other methods for several
29
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TABLE 3. RECOMMENDED BACTERIAL ASSAY METHODS FOR RDF FACILITY AEROSOL SAMPLES
A^say Mi thud
Total pi jte count or Pour or spread platej
(count by particle t Lze ) Ajidert.cn pi a tea
Total colitorm MHN
Fecal colUunm. MPN
Salmon^ 11 a iip» iiuri ctuiieiit
Spread plate
9t.ai>hvlticoccub duruui) Spread plate
t-U.-iii.j
Tr y p 1 1 c b L> y agar "•"
5U uiiitb/nil Myi:osLdtin
(Nyst.aLin)
Lauryl Lry[jtose broth +
bri 1 1 iant green bi LG
2Z broLh
Lauryi. tryptuse broth +
KC medium
0.017= TTC
I^vinu EMb agar
Lactose broth +
Bismutli sulfiLe agar
Bismuth sulf ite ^gar
Bdird Parker agar
lncub.it J on InciibdLi on
t.'inp. (° C.) Linu; (hr)
2ti - J5 48
J5 48
35 48
44.5 + 0.2 J4
J5 4d
'15 24
J5 24
35 48
J5 4b
J5 - 37 48
Verii icatious
Unpublished data and
1'arkiuson (21)
Re^onanended Standard Mucliodb Standard Mcttmds (22)
(22)
Standard Methods (22)
(22)
Recommended Swing (50) tuing (50)
Recojimended Ewing (50) Gabis (56)
Dtfco (23)
-
Kdcoiimitinded Kaynian (57 ) Rayman ( *j 1 )
Niskanen (58)
-------
reasons. The method is recommended for concentrating samples containing
viruses associated with particulates (22) as would be expected with aerosols.
The method was the most promising to use with samples collected on filter
media. Large or small volumes of sample can be concentrated by means of the
phase separation method. The procedure is not difficult and time-consuming,
and is thus conducive to processing large numbers of samples.
Many problems exist in the concentration of viruses at low levels from
samples. To eliminate these problems, it is recommended that direct incorpora-
tion incorporation be the method of choice. If concentration of samples is un-
avoidable because of low virus content, the phase separation method is recom-
mended for concentration of virus-containing samples.
Contamination of tissue culture monolayers by molds contained in the sam-
ples was a problem during the St. Louis and Houston programs. If severe mold
or other microbiological contamination problems exist, they may be controlled
to a limited extent by higher concentrations of antibiotics providing cell
toxicity does not occur. Controls should be run to ensure that the antibiotic
levels do not interfere with cell line viability and sensitivity.
Monolayer plaque assay methods according to Schmidt (26) are recommended
for virus analysis of aerosol samples. Particular attention should be focused
on virus sensitivity in the choice of cell lines for virus titration. For
adenovirus titrations, HeLa or KB cell lines are recommended (15,60). Monkey
kidney cell lines, e.g., BGM or LLC-MK2, are recommended for titration of
enteroviruses (14,61).
FUTURE WORK
Currently, ASTM Committee E-38.07 (62) is developing microbial air sam-
pling and analysis standards for resource recovery plants. Development of
standards for particular applications may well be the correct approach. How-
ever, general standards, included in all research studies at least as a ref-
erence so that studies may be validly compared, need also to be established.
31
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REFERENCES
1. Napolitano, P. J., and D. R. Rowe. Microbial Content of Air Near Sewage
Treatment Plants. Water and Sewage Works, 113:480-483, 1966.
2. Randall, C. W., and J. 0. Ledbetter. Bacterial Air Pollution From Acti-
vated Sludge Units. Am. Ind. Hyg. Assoc. J., 27:506-519, 1966.
3, Glaser, J. R., and J. 0. Ledbetter. Sizes and Number of Aerosols Gener-
ated by Activated Sludge Aeration. Water and Sewage Works, 114:219-
221, 1967.
4. Adams, A. P., and J. C. Spendlove. Coliform Aerosols Emitted by Sewage
Treatment Plants. Science, 169:1218-1220, 1970.
5. Goff, G. D. Microbiological Aerosols Generated by a Sewage Treatment
Process. Master of Science Thesis, University of Utah, Salt Lake City,
Utah, 1975.
6. Goff, G. D., J. C. Spendlove, A. P. Adams, and P. S. Nicholes. Effects
of Environmental Conditions on Emission of Microbial Aerosols From
Trickling Filter Sewage Treatment Plants. Health Services Rep., 88:
640-652, 1973.
7. Fannin, K. An Assessment of the Airborne Emission of Selected Viruses by
Wastewater Treatment. Ph.D. Thesis, University of Michigan, Ann Arbor,
Michigan, 1976. 113 pp.
8. Edmonds, R. L., and W. Littke. Coliform Aerosols Generated From the Sur-
face of Dewatered Sewage Applied to a Forest Clearcut. Appl. Environ.
Microbiol., 36(6):972-974, 1978.
9. Parker, D. T., J. C. Spendlove, J. A. Bondurant, and J. H. Smith. Micro-
bial Aerosols From Food-Processing Waste Spray Fields. J. Water Poll.
Contr. Fed., 49(12):2359-2365, 1977.
10. Adams, A. P., M. Garbett, H. B. Rees, and B. G. Lewis. Bacterial Aero-
sols From Cooling Towers. J. Water Poll. Contr. Fed., 50(10):2362-
2369, 1978.
32
-------
11. Adams, A. P., J. C. Spendlove, M. Garbett, and B. Lewis. Emission of Mi-
crobial Aerosols From Vents of Cooling Towers: I. Particle Size,
Source Strength, and Downwind Travel. Developments in Industrial
Microbiology, 21 (to be published), 1978.
12. Spendlove, J. C., A. P. Adams, E. Rengers, and R. K. Dumbauld. Emission
of Microbial Aerosols From Vents of Cooling Towers: II. Diffusion
Model Comparisons. Developments in Industrial Microbiology, 21 (to be
published), 1978.
13. Duckett, E. J. Microbiological Analysis of Dusts at the Equipment Test
and Evaluation Facility. TR 78-16. National Center for Resource Re-
covery, Inc., Washington, D.C., 1978.
14. Fiscus, D. E., P. G. Gorman, M. P. Schrag, and L. J. Shannon. Assessment
of Bacteria and Virus Emissions at a Refuse Derived Fuel Plant and
Other Waste Handling Facilities. EPA-600/2-78-152, U.S. Environmental
Protection Agency, Cincinnati, Ohio, 1978. 203 pp.
15. Golembiewski, M. A., and K. P. Ananth. Evaluation of Fabric Filter Per-
formance at Browning Ferris Industries/Raytheon Service Company Re-
source Recovery Plant, Houston, Texas. EPA Contract No. 68-02-2166,
Draft Report, U.S. Environmental Protection Agency, Cincinnati, Ohio,
1977. 72 pp.
16. Fiscus, D. E., P. G. Gorman, M. P. Schrag, and L. J. Shannon. Executive
Summary - Assessment of Bacteria and Virus Emissions at a Refuse De-
rived Fuel Plant and Other Waste Handling Facilities. EPA Contract No.
68-02-1871, Draft Report, U.S. Environmental Protection Agency,
Cincinnati, Ohio, 1978. 39 pp.
17. Fiscus, D. E., P- G. Gorman, M. P. Schrag, and L. J. Shannon. Dust and
Airborne Bacteria at Solid Waste Processing Plants. EPA Contract No.
68-02-1871, Final Report, U.S. Environmental Protection Agency,
Cincinnati, Ohio, 1978. 37 pp.
18. Gorman, P. G., D. E. Fiscus, M. P. Schrag, and L. J. Shannon. Compara-
tive Assessment of Bacterial and Viral Field Sampling. Methods Used at
Solid Waste Handling and Processing Facilities. EPA Contract No. 68-
02-1871, Draft Report, U.S. Environmental Protection Agency,
Cincinnati, Ohio, 1978. 20 pp.
19. Olin, J., and J. L. King. High Volume Air Samplers. Poll. Eng., 7(1):
30-32, 1975.
33
-------
20. White, L. A., D. J. Hadley, D. E. Davids, and R. Naylor. Improved Large
Volume Sampler for the Collection of Bacterial Cells From Aerosols.
Appl. Microbiol., 29(3):335-339, 1975.
21. Parkinson, D., T. R. G. Gray, and S. T. Williams. Methods for Studying
the Ecology of Soil Micro-Organisms. IBP Handbook No. 19. F. A. Davis
Company, Philadelphia, Pennsylvania, 1971. 116 pp.
22. American Public Health Association, American Water Works Association, and
Water Pollution Control Federation. Standard Methods for the Examina-
tion of Water and Wastewater. 14th Edition, American Public Health As-
sociation, Washington, D.C., 1976. 1193 pp.
23. Difco Laboratories. Supplemental Literature. Difco Publication No.
0236, Difco Laboratories, Detroit, Michigan, 1972. 480 pp.
24. Horwitz, W., ed. Official Methods of Analysis of the Association of Of-
ficial Analytical Chemists. 12th Edition, Association of Official
Analytical Chemists, Washington, D.C., 1975. 1094 pp.
25. Shuvall, H. I., B. Fatall, C. Cymbalista, and N. Goldblum. The Phase-
Separation Method for the Concentration and Detection of Viruses in
Water. Water Research, 3(4):225-240, 1969.
26. Schmidt, N. J. Tissue Culture Techniques for Diagnostic Virology. In:
Diagnostic Procedures for Viral and Rickettsial Infections, 4th Edi-
tion, E. H. Lennette and N. J. Schmidt, eds. American Public Health
Association, Inc., New York, New York, 1969. pp. 79-178.
27. Wolf, H. W., P. Skaliy, L. B. Hall, M. M. Harris, H. M. Decker, L. M.
Buchanan, and C. M. Dohlgren. Sampling Microbiological Aerosols.
Public Health Monograph No. 60, Public Health Service Publication No.
686, U.S. Department of Health, Education, and Welfare, Superinten-
dent of Documents, U.S. Government Printing Office, Washington, D.C.,
1965. 53 pp.
28. Davies, R. R. Air Sampling for Fungi, Pollens, and Bacteria. In:
Methods of Microbiology, Volume 4, C. Booth, ed. Academic Press,
New York, New York, 1971. pp. 367-404.
29. Anderson, J. D., and C. S. Cox. Microbial Survival. In: Airborne
Microbes, 17th Symposium of the Society for General Microbiology.
University Press, Cambridge, Massachusetts, 1967. pp. 203-226.
34
-------
30. Akers, T. G. Survival of Airborne Virus, Phage, and Other Minute Mi-
crobes. In: An Introduction to Experimental Aerobiology, R. L.
Dimmick, A. B. Akers, R. J. Heckly, and W. Wolochow, eds. Wiley
Interscience, New York, New York, 1969. pp. 296-339.
31. Akers, A. B., and W. D. Won. Assay of Living, Airborne Microorganisms.
In: An Introduction to Experimental Aerobiology, R. L. Dimmick, A. B.
Akers, R. J. Heckly, and W. Wolochow, eds. Wiley Interscience, New
York, New York, 1969. pp. 59-99.
32. Green, H. L., and W. R. Lane. Particulate Clouds: Dusts, Smokes, and
Mists. E. and F. N. Spon, Ltd., London, 1957.
33. Bachelor, H. W. Aerosol Samplers. Adv. Appl. Microbiol., 2:31-64, 1960.
34. Dimmick, R. L., ed. First International Symposium of Aerobiology - 1963.
University of California, Berkeley, California, 1963. 405 pp.
35. Fedorak, P. M., and D. W. S. Westlake. Effect of Sunlight on Bacterial
Survival in Transparent Air Samplers. Can. J. Microbiol., 24:618-619,
1978.
36. Couch, R. B., T. R. Gate, R. G. Douglas, Jr., P. J. Gerone, and
V. Knight. Effect of Route of Inoculation on Experimental Respiratory
Viral Diseases in Volunteers and Evidence for Airborne Transmission.
Bacteriol. Rev., 30(3):517-531, 1966.
37. Gerone, P. J., R. B. Couch, G. V. Keefer, R. G. Douglas, E. B.
Derrenbacher, and V. Knight. Assessment of Experimental and Natural
Viral Aerosols. Bacteriol. Rev., 30:576-583, 1966.
38. Winkler, W. G. Airborne Rabies Virus Isolation. Bull. Wildlife Dis.
Assoc., 4:37-40, 1968.
39. Jensen, M. M. Inactivation of Virus Aerosols by Ultraviolet Light in a
Helical Baffle Chamber. In: First International Symposium on Aero-
biology - 1963, R. L. Dimmick, ed. University of California, Berkeley,
California, 1963. pp. 219-226.
40. Guerin, L. F., and C. A. Mitchell. A Method for Determining the Concen-
tration of Airborne Virus and Size Droplet Nuclei Containing the Agent.
Can. J. Comp. Med. Vet. Sci., 28:283-287, 1964.
41. Thomas, G. An Adhesive Surface Sampling Technique for Airborne Viruses.
J. Hyg., Camb., 68:273-282, 1970.
35
-------
42. Thomas, G. Sampling Rabbit Pox Aerosols of Natural Origin. J. Hyg.,
Camb., 68:511-517, 1970.
43. Thatcher, F. S., and D. S. Clark, eds. Microorganisms in Foods: Their
Significance and Methods of Enumeration. University of Toronto Press,
Toronto, 1968. 234 pp.
44. International Commission on Microbiological Specifications for Foods.
Microorganisms in Foods: 2. Sampling for Microbiological Analysis:
Principles and Specific Applications. University of Toronto Press,
Toronto, 1974. 213 pp.
45. Bender, D. F., M. L. Peterson, and H. Stierli, eds. Physical, Chemical,
and Microbiological Methods of Solid Waste Testing. EPA-6700-73-01,
U.S. Environmental Protection Agency, Cincinnati, Ohio, 1973.
46. Blair, J. E., E. H. Lennette, and J. P. Truant, eds. Manual of Clinical
Microbiology. American Society for Microbiology, Bethesda, Maryland,
1970. 727 pp.
47a Finegold, S. M., W, J. Martin, and E. G. Scott. Bailey and Scott's Di-
agnostic Microbiology. 5th Edition, C. V. Mosby, St. Louis, Missouri,
1978. 514 pp.
480 Haley, L. D., and C. S. Galloway. Laboratory Methods in Medical Mycol-
ogy. (CDC) 78-8361. Center for Disease Control, U.S. Department of
Health, Education, and Welfare, Atlanta, Georgia, 1978. 225 pp.
49. Lennette, E. H., and N. J, Schmidt. Diagnostic Procedures for Viral and
Rickettsial Infections. 4th Edition, American Public Health Associa-
tion, Inc., New York, New York, 1969. 978pp.
50. Ewing, W. H. Differentiation of Enterobacteriaceae by Biochemical Reac-
tions. (CDC) 75-8270. Center for Disease Control, U.S. Department of
Health, Education, and Welfare, Atlanta, Georgia, 1973. 61 pp.
51. Smith, R. F., J. H. Jorgensen, C. L. Bettge, and S. L. Dayton. Evalua-
tion of Selective and Differential Media in The Isolation and Enumera-
tion of Airborne Staphylococcus aureus. Health Laboratory Science,
9(4):284-288, 1972.
52. Goff, G. D., J. C. Spendlove, A. P. Adams, and F. S. Nicholes. Emission
of Microbial Aerosols From Sewage Treatment Plants That Use Trickling
Filters. Health Services Rep., 88:640-652, 1973.
36
-------
53. Geldreich, E. E., B. A. Kenner, and P. W. Kabler. Occurrence of Coli-
forms, Fecal Coliforms, and Streptococci on Vegetation and Insects.
Appl. Microbiol., 12(l):63-69, 1964.
54. Geldreich, E. E., G. B. Huff, R. H. Bordner, P. W. Kabler, and H. F.
Clark. The Faecal Coli-Aerogenes Flora of Soil From Various Geographi-
cal Areas. J. Appl. Bacteriol., 25(l):87-93, 1962.
55. Steinhaus, E. A. A Study of the Bacteria Associated With Thirty Species
of Insects. J. Bacteriol., 42:757-790, 1941.
56. Gabis, D. A., and J. H. Silliker. ICMSF Methods Studies: IX. The In-
fluence of Selective Enrichment Broths, Different Planting Media and
Incubation Temperatures on the Detection of Salmonella in Dried Foods
and Feed Ingredients. Can. J. Microbiol., 23(9):1225-1231, 1977.
57. Raymond, M. K., J. J. Devoyod, U. Purvis, D. Kusch, J. Lanier, R. J.
Gilbert, D. G. Till, and G. A. Jarvis. ICMSF Methods Studies: X. An
International Comparative Study of Four Media for the Enumeration of
Staphylococcus aureus in Foods. Can. J. Microbiol., 24(3):274-281,
1978.
58. Niskanen, A., and M. Aalto. Comparison of Selective Media for Coagulase-
Positive Enterotoxigenic Staphylococcus aureus. Appl. Environ.
Microbiol., 35(6):1233-1236, 1978.
59. Katzenelson, E. Virologic and Engineering Problems in Monitoring Viruses
in Water. In: Viruses in Water, G. Berg, H. L. Bodily, E. H.
Lennette, I. L. Melnick, and T. G. Metcalf, eds. American Public
Health Association, Washington, D.C., 1976. pp. 152-164.
60. Bernard, P., and M. A. Salvatore. Adenoviruses. In: Manual of Clinical
Microbiology. 2nd Edition, E. H. Lennette, E. H. Spaulding, and J. P.
Truant, eds. American Society for Microbiology, Washington, D.C.,
1974. pp. 695-702.
61. Dahling, D. R., G. Berg, and D. Berman. BGM, a Continuous Cell Line More
Sensitive Than Primary Rhesus and African Green Kidney Cells for the
Recovery of Viruses From Water. Health Laboratory Science, 11(4):275-
282, 1974.
62. ASTM E-38.07. Subcommittee on Health and Safety Aspects of Resource Re-
covery.
37
-------
BIBLIOGRAPHY
Aach, R. D., J. Evans, and J. Losee. Epidemic of Infectious Hepatitis Pos-
sibly Due to Airborne Transmission. Am. J. Epidemiol., 87:99-109, 1968.
Adams, A. P., and J. C. Spendlove. Coliform Aerosols Emitted by Sewage
Treatment Plants. Science, 169:1218-1220, 1970.
Adams, A. P., M. Garbett, H. B. Rees, and B. G. Lewis. Bacterial Aerosols
from Cooling Towers. Journal WPCF, 50(10):2362-2369, 1978a.
Adams, A. P., J. C. Spendlove, M. Garbett, and B. Lewis. Emission of Micro-
bial Aerosols from Vents of Cooling Towers: I. Particle Size, Source
Strength, and Downwind Travel. Developments in Industrial Microbiol.,
21, 1978b.
Akers, A. B., and W. D. Won. Assay of Living, Airborne Microorganisms. In:
An Introduction to Experimental Aerobiology, R. L. Dimmick, A. B. Akers,
K. J. Heckly, and W. Wolochow, eds. Wiley Interscience, New York, 1969.
pp. 59-99.
Akers, T. G. Survival of Airborne Virus, Phage and Other Minute Microbes.
In: An Introduction to Experimental Aerobiology, R. L. Dimmick, A. B.
Akers, R. J. Heckly, and W. Wolochow, eds. Wiley Interscience, New York,
1969. pp. 296-339.
Akers, T. G., S. B. Bond, and L. J. Goldberg. Effect of Temperature and
Relative Humidity on Survival of Columbia-SK Group Viruses. Appl. Mi-
crobiol., 14:361-364, 1966.
Akers, T. G., S. B. Bond, C. Papke, and W. R. Leif. Virulence and Immu-
nogenicity in Mice of Airborne Encephalomyocarditis Viruses and Their
Infectious Nucleic Acids. J. Immunol., 97:379-385, 1966b.
Akers, T. G., and M. T. Hatch. Survival of a Picorna-Virus and Its In-
fectious Ribonucleic Acid After Aerosolization. Appl. Microbiol., 16:
1811-1813, 1968.
38
-------
Akers, T. G., S. H. Madin, and F. L. Schaffer. The Pathogenicity in Mice
of Aerosols of Encephalorayocarditis Group Viruses or Their Infectious
Nucleic Acids. J. Immunol., 100:2-18, 1968.
Akers, T. G., C. M. Prato, and E. J. Dubovi. Airborne Stability of Simian
Virus 40. Appl. Microbiol., 26(2):146-148, 1973.
Albrecht, C. R. Bacterial Air Pollution Associated with the Sewage Treat-
ment Process. MA Thesis, University of Florida, Gainsville, 1958.
Albrink, W. S. Pathogensis of Inhalation Anthrax. Bacteriol. Rev., 25:
268-273, 1961.
Almeida, J. D., G. D. Chisholm, A. E. Kulatilake, A. B. MacGregor, D. H.
Mackay, E. P. N. O'Donoghue, R. Shackman, and A. P. Waterson. Possible Air-
borne Spread of Serum-Hepatitis Virus with a Haemodialysis Unit. Lancet,
2:849-850, 1971.
Andersen, A. A. New Sampler for the Collection, Sizing, and Enumeration of
Viable Airborne Particles. J. Bacteriol., 76:471-484, 1958.
Andersen, A. A. A Sampler for Respiratory Health Hazard Assessment. Am.
Ind. Hyg. Assoc. J., 27:160-165, 1966.
Andersen, A. A., and M. R. Andersen. A Monitor for Airborne Bacteria. Appl.
Microbiol., 10:181-184, 1962.
Anderson, J. D. Biochemical Studies of Lethal Processes in Aerosols of
Escherichia coli. J. Gen. Microbiol., 45:303, 1966.
Anderson, J. D., and C. S. Cox. Microbial Survival. In: Airborne Microbes
17th Symp. of the Society for General Microbiology, University Press,
Cambridge, 1967. pp. 203-226.
Anderson, J. D., and G. T. Crouch. A New Principle for the Determination
of Total Bacterial Numbers in Populations Recovered from Aerosols. J. Gen.
Microbiol., 47:49-52, 1967.
Andrews, C. H., P. P. Laidlaw, and W. Smith. The Susceptibility of Mice to
the Viruses of Human and Swine Influenza. Lancet, 2:859-862, 1934.
39
-------
Andrews, C. H. The Complex Epidemiology of Respiratory Virus Infections.
Science, 146:1274-1277, 1964.
Annear, D. I. Recoveries of Bacteria After Drying on Cellulose Fibres.
A Method for the Routine Preservation of Bacteria. Aust. J. Exp. Biol.
Med. Sci., 40:1, 1962.
Anonymous. Airborne Transmission of Smallpox. World Health Organ. Chron.,
24:311-315, 1970.
Armstrong, D. H. Portable Sampler for Microorganisms in Incinerator Stack
Emissions. Appl. Microbiol., 19(1):204-205, 1970.
Armstrong, D. Microbiological Studies of Compost Plant Dust. National En-
vironmental Research Center, Office of Research and Monitoring, U.S. EPA,
Cincinnati, Ohio. EPA R2-72-131, 1972.
Artenstein, M. S., and F. C. Cadigan, Jr. Air Sampling in Viral Respira-
tory Disease. Arch. Environ. Health, 9:58, 1964.
Artenstein, M. S., and W. S. Miller. Air Sampling for Respiratory Disease
Agents in Army Recruits. Bacteriol. Rev., 30(3):571-575, 1966.
Artenstein, M. S., W. S. Miller, J. H. Rust, Jr., and T. H. Lamson. Large
Volume Air Sampling of Human Respiratory Disease Pathogens. Am. J. Epi-
demiol., 85:479-485, 1967.
Artenstein, M. S., W. S. Miller, T. H. Lamson, and B. L. Brandt. Large
Volume Air Sampling for Meningococci and Adenoviruses. Am. J. Epidemiol.,
87:567, 1968.
Asset, G., L. E. Gongwer, and S. Ryan. Nasal Penetration of Particles of
Small Inertia in Experimental Animals. Arch. Ind. Health, 13:597-601,
1956.
Babich, H., and G. Stotzky. Air Pollution and Microbial Ecology. Grit.
Rev. Environ. Control, 4:353-421, 1974.
Babich, H., and G. Stotzky. Atmospheric Sulfur Compounds and Microbes.
Environ. Res., 15:513-531, 1978.
Babich, H., and G. Stotzky. Atmospheric Pollution and Microorganisms. ASM
News, 44(10):547-550, 1978.
40
-------
Bachelor, H. W. Aerosol Samplers. Adv. Appl. Microbiol., 2:31-64, 1960.
Bang, B. G., and F. B. Bang. Responses of Upper Respiratory Mucosae to
Dehydration and Infection. Ann. New York Acad. Sci., 106:625-630, 1963.
Bang, Fredrick. Ecology of Respiratory Virus Transmission: A Comparison
of Three West Bengal Communities. Amer. J. of Trop. Med. Hyg., 24, 1975.
Barbeito, M. Microbiological Safety Evaluation of an Industrial Refuse In-
cinerator. Appl. Microbiol., 16:2, 1968.
Bateman, J. B., P- A. McCaffrey, R. J. O'Connor, and G. W. Monk. Relative
Humidity and the Killing of Bacteria. The Survival of Damp Serratia
marcescens in Air. Appl. Microbiol., 9:567, 1961.
Bateman, J. B., C. L. Stevens, W. B. Mercer, and E. L. Carstensen. Rela-
tive Humidity and the Killing of Bacteria: The Variation of Cellular
Water Content with External Relative Humidity or Osmolality. J. Gen.
Microbiol., 29:207, 1962.
Beard, C. W., and B. C. Easterday. Aerosol Transmission of Hog Cholera.
Cornell Vet., 55:630-636, 1965a.
Beard, C. W., and B. C. Easterday. An Aerosol Apparatus for the Exposure
of Large and Small Animals: Description and Operating Characteristics.
Am. J. Vet. Res., 26:174-182, 1965.
Beard, C. W., and B. C. Easterday. The Influence of the Route of Adminis-
tration of Newcastle Disease Virus on Host Response. 1. Aerological
and Virus Isolation Studies. J. Infect. Dis., 117:55-61, 1967.
Beard, C. W., and D. P. Anderson. Aerosol Studies with Avian Mycoplasma.
1. Survival in Air. Avian. Dis., 11:54-57, 1967.
Beebe, J. M., and G. W. Pirsch. Response of Air-Borne Species of Pasteurella
to Artificial Radiation Simulating Sunlight Under Different Conditions of
Relative Humidity. Appl. Microbiol., 6:127, 1958.
Beebe, J. M. Stability of Disseminated Aerosols of Pasteurella tularensis
Subjected to Simulated Solar Radiations at Various Humidities. J. Bact.,
78:18, 1959.
Bell, J. A., T. G. Ward, R. J. Huebner, W. P. Rowe, R. G. Suskind, and R. S.
Paffenbarger, Jr. Studies of Adenoviruses (APC) in Volunteers. Am. J.
Public Health, 46:1130-1146, 1956.
41
-------
Bell, J. H. Woolsorters Disease at Bradford. Lancet, 1:819-820, 1880.
Bell, N. L., and J. R. Burleigh. Atmospheric Dispersal of Southern Corn
Leaf Blight Spores Over the Midwest in 1971. In: Proceedings of Work-
shop/Conference II. Ecological Systems Approaches to Aerobiology: II.
Development, Demonstration, and Evaluation of Models. US/IBP Aerobiology
Program Handbook, No. 3, The University of Michigan, Ann Arbor. National
Center for Atmospheric Research, Boulder, Colorado, July 12-14, 1972.
R. L. Edmonds and W. S. Benninghoff, eds, 1972.
Benbough, J. E. Death Mechanisms in Airborne Escherichia coli. J. Gen.
Microbiol., 47:325-333, 1967.
Benbough, J. E. The Effect of Relative Humidity on the Survival of Air-
borne Semliki Forest Virus. J. Gen. Virol., 4:473-477, 1969.
Benbough, J. E. Some Factors Affecting the Survival of Airborne Viruses.
J. Gen. Virol., 10:209-220, 1971.
Benbough, J. E., and A. M. Hood. Viricidal Activity of Open Air. J. Hyg.,
Camb., 69:619-626, 1971.
Benda, R., M. Fuchsova, and L. Danes. Experimental Airborne Infection of
Monkeys with Tick-Borne Encephalitis. Acta Virol., 6:46-52, 1962.
Bender, D. F., M. L. Peterson, and H. Stierli, eds. Physical, Chemical and
Microbiological Methods of Solid Waste Testing. EPA-6700-73-01, U.S.
Environmental Protection Agency, Cincinnati, Ohio, 1973.
Benedict, R. G., E. S. Sharpe, J. Gorman, G. B. Meyers, E. F- Baer, H. H.
Hall, and R. W. Jackson. Preservation of Microorganisms by Freeze-Drying.
II. The Destructive Action of Oxygen. Additional Stabilizers for
Serratia marcescens. Experiments with Other Microorganisms. Appl.
Microbiol., 9:256-262, 1961.
Benstein, D. A High-Volume Sampler for the Determination of Particle Size
Distribution in Ambient Air. JAPCA, 26:11, 1976.
Bernstein, S. H. Observations on the Effects of Housing on the Incidence
and Spread of Common Respiratory Diseases Among Air Force Recruits. Am.
J. Hyg., 65:162-171, 1957.
Blair, J. E. Factors Determining the Pathogenicity of Staphylococci. Ann.
Rev. Microbiol., 12:491-506, 1958.
42
-------
Blanchard, D. C., and L. Syzdek. Mechanism for the Water-to-Air Transfer
and Concentration of Bacteria. Science, 170:626-628, 1970.
Bloom, H. H., B. R. Forsyth, K. M. Johnson, and R. M. Chanock. Relation-
ship of Rhinovirus Infection to Mild Upper Respiratory Disease. I. Re-
sults of a Survey in Young Adults and Children. J. Am. Med. Assoc.,
186:38-45, 1963.
Bloom, H. H., B. R. Forsyth, K. M. Johnson, M. A. Mufson, H. C. Turner,
M. B. Davison, and R. M. Chanock. Patterns of Adenovirus Infections in
Marine Corps Personnel. I. A 42-Month Survey in Recruit and Non-Recruit
Populations. Am. J. Hyg., 80:328-342, 1964.
Bolotovskii, V. M. Necessary Conditions for the Successful Production of
Experimental Infection with Ornithosis Virus Aerosol. Probl. Virol.,
4:102-106, 1959.
Bourdillon, R. B., 0. M. Lidwell, and J. C. Thomas. A Slit Sampler for
Collecting and Counting Airborne Bacteria. J. Hyg., 41:197, 1941.
Bourdillon, R. B., 0. M. Lidwell, and J. E. Lovelock. Studies in Air Hygiene,
Medical Research Council Special Report Series No. 262, His Majesty's Sta-
tionary Office, London, England, 1948, 356 pp.
Bovallius, A., B. Bucht, R. Roffey, and P. Anas. Three-Year Investigation
of the Natural Airborne Bacterial Flora at Four Localities in Sweden.
Appl. Environ. Microbiol., 35:847-852, 1978.
Bovallius, A., B. Bucht, R. Roffey, and P. Anas. Long-Range Air Transmis-
sion of Bacteria. Appl. Environ. Microbiol., 35(6):1231-1232, 1978.
Boyland, E., J. H. Gaddum, and F. F. McDonald. Nasal Filtration of Airborne
Droplets. J. Hyg., 45:290-296, 1947.
Brachman, P. S., R. Erlich, H. F. Eichenwald, V. J. Cabelli, T. W. Kethley,
S. H. Madin, J. R. Maltman, G. Middlebrook, J. D. Morton, I. H. Silver,
and E. K. Wolfe. Standard Sampler for Assay of Airborne Microorganisms.
Science, 144(3624):1295, 1964.
Brachman, P. S., A. F. Kaufmann, and F. G. Dalldorf. Industrial Inhalation
Anthrax. Bacteriol. Rev., 30:646-657, 1966.
Breese, B. B., J. Stanbury, H. Upham, A. J. Calhoun, R. L. Van Buren, and
A. S. Kennedy. Influence of Crowding on Respiratory Illness in a Large
Naval Training Center. War Medicine, 7:143-146, 1945.
43
-------
Brown, A. D. The Survival of Airborne Microorganisms. I. Experiments
Near 0° with Some Psychrophilic Bacteria. Aust. J. Biol. Sci., 6:463,
1953.
Brown, A. D. The Survival of Airborne Microorganisms. II. Experiments
with Escherichia coli Near 0°C. Aust. J. Biol. Sci., 6:470-480, 1953.
Brown, A. D. The Survival of Airborne Microorganisms. III. Effects of
Temperature. Aust. J. Biol. Sci., 7:444, 1954.
Buchan, R. M. Atmospheric Dispersion of Particulate Emissions from an
Activated Sludge Unit. Ph.D. Dissertation. The University of Oklahoma,
Oklahoma City, 1972.
Buchanan, L. M., H. M. Decker, D. E. Frisque, C. R. Phillips, and C. M.
Dahlgren. A Novel Multi-Slit High Volume Sampler. Bacteriol. Proc.,
A77:13-14, 1968.
Buchanan, L. M., D. E. Frisque, C. R. Phillips, and C. M. Dahlgren. Novel
Multi-Slit Large Volume Air Sampler. Appl. Microbiol., 16:1120-1123, 1968.
Buchanan, L. M., J. B. Harstad, J. C. Phillips, E. Lafferty, C. M. Dahlgren,
and H. M. Decker. Simple Liquid Scrubber for Large-Volume Air Sampling.
Appl. Microbiol., 23(6):1140-1144, 1972.
Buckland, F. E., and D. A. J. Tyrrell. Experiments on the Spread of Colds.
I. Laboratory Studies on the Dispersal of Nasal Secretion. J. Hyg., 62:
365-377, 1964.
Buckland, F. E., M. L. Bynoe, and D. A. J. Tyrrell. Experiments on the
Spread of Colds. II. Studies in Volunteers with Coxsackievirus A 21.
J. Hyg., 63:327-343, 1965.
Buckland, F. E., and D. A. J. Tyrrell. Loss of Infectivity on Drying Various
Viruses. Nature,(London) 195:1063-1064, 1962.
Cameron, D. J. S., R. F. Bishop, G. P. Davidson, R. R. W. Townley, I. H.
Holmes, and B. J. Ruck. Rotavirus Infections in Obstetric Hospitals.
Lancet, 2:124-125, 1975.
Chappal, W. A. Animal Infectivity of Aerosols of Monkey B Virus. Ann.
New York Acad. Sci., 85:931-934, 1960.
44
-------
Chatigny, M. A. Aerobiological Containment. Dev- Ind. Microbiol., 15:48-55,
1974.
Chian, E. S. K., and F. B. DeWalle. Compilation of Methodology Used for
Measuring Pollution Parameters of Sanitary Landfill Leachate. EPA-600/3-
75-011, U.S. Environmental Protection Agency, Cincinnati, Ohio, 1975.
8 pp.
Clark, C. S., E. J. Cleary, G. M. Schiff, C. C. Linnemann, J. P. Phair, and
T. M. Briggs. Disease risks of occupational exposure to sewage. J. Environ.
Eng. Div. Am. Soc. Civ. Eng., 102:375-388, 1976.
Constantine, D. G. Rabies Transmission by Nonbite Route. Public Health
Rept., (U.S.), 77:287-289, 1962 (U.S. Govt. Printing Office).
Constantine, D. G. Rabies Transmission by Air in Bat Caves. Public Health
Rept. Publ. No. 1617, 1967 (U.S. Govt. Printing Office).
Converse, J. L., and R. E. Reed. Experimental Epidemiology of Coccidioidomy-
cosis. Bacteriol. Rev., 30:678-694.
Cooper, R. Virus Survival in Solid Waste. Water Resources, 9:733-739, 1975.
Couch, R. B., T. R. Gate, P- J. Gerone, W. F. Fleet, D. J. Lang, W. R.
Griffith, and V. Knight. Production of Illness with a Small-Particle
Aerosol of Coxsackie A2i- J. Clin. Invest., 44:535-542, 1965.
Couch, R. B., P. J. Gerone, T. R. Gate, W. R. Griffith, D. W. Ailing, and
V. Knight. Preparation and Properties of a Small-Particle Aerosol of
Coxsackie A-21. Proc. Soc. Exp. Biol. Med., 118:818-822, 1965.
Couch, R. B., T. R. Gate, R. G. Douglas, Jr., P- J. Gerone, and V. Knight.
Effect of Route of Inoculation on Experimental Respiratory Viral Diseases
in Volunteers and Evidence for Airborne Transmission. Bacteriol. Rev.,
30(3):517-531, 1966.
Couch, R. B., T. R. Gate, W. F. Fleet, P- J. Gerone, and V. Knight. Aerosol
Induced Adenovirus Illness Resembling the Naturally Occurring Illness in
Military Recruits. Am. Rev. Respirat. Diseases, 93:529-535, 1966.
Cox, C. S. The Survival of Escherichia coli Atomized into Air and Into
Nitrogen from Distilled Water and from Solution of Protecting Agents,
as a Function of Relative Humidity- J. Gen. Microbiol., 43:383-399,
1966.
45
-------
Cox, C. S., and F. Baldwin. The Use of Phage to Study Causes of Loss of
Viability of Escherichia coli in Aerosols. J. Gen. Microbiol., 44:15-22,
1966.
Cox, C. S. The Survival of Escherichia coli in Nitrogen Under Changing
Conditions of Relative Humidity. J. Gen. Microbiol., 45:283, 1966.
Cox, C. S. Protecting Agents and Their Mode of Action. 1st Int. Symp. on
Aerobiol., p. 345. Published by Naval Biological Laboratory, Naval Supply
Center, Oakland, California 1965.
Cox, C. S. The Aerosol Survival and Cause of Death of Escherichia coli K-12.
J. Gen. Microbiol., 54:169-175 1968.
Cox, C. S. The Cause of Loss of Viability of Airborne Escherichia coli K-12.
J. Gen. Microbiol., 57:77-80 1969.
Cox, C. S. Aerosol Survival of Pasteurella tularensis Disseminated from the
Wet and Dry States. Appl. Microbiol., 21:3, 1971.
Cox, C. S. Inactivation Kinetics of Some Microorganisms Subject to a Variety
of Stresses. Appl. Environ. Microbiol., 31:836-846, 1976.
Cox, C. S., and F. Baldwin. A Method for Investigating the Cause of Death
of Airborne Bacteria. Nature, (London) 202:1135, 1964.
Gown, W. B., T. W. Kethley, and E. L. Fincher. The Critical-Orifice Liquid
Impinger as a Sampler for Bacterial Aerosols. Appl. Microbiol., 5:119-124,
1957.
Dahlgren, C. M., H. M. Decker, and J. B. Harstad. A Slit Sampler for Col-
lecting T3 Bacteriophage and Venezuelan Equine Encephalomyelitis Virus.
I. Studies with T3 Bacteriophage. Appl. Microbiol., 9:103-105, 1961.
Danes, L., J. Libich, and R. Benda. Experimental Airborne Infection of Mice
with Tick-Borne Encephalitis Virus. Acta Virol., 6:37-45, 1962.
Davenport, F. M. Pathogenesis of Influenza. Bacteriol. Rev., 25:294-299,
1961.
46
-------
Davis, G. W., R. A. Griesemer, J. A. Shadduck, and R. L. Farre. Effect of
Relative Humidity on Dynamic Aerosols of Adenovirus 12. Appl. Microbiol.,
21:676-679, 1971.
Davis, M. S., and J. B. Bateman. Relative Humidity and the Killing of
Bacteria. II. Selective Changes in Oxidative Activity Associated with
Death. J. Bacteriol., 80:580-584, 1950.
Davis, M. S., and J. B. Bateman. Relative Humidity and the Killing of
Bacteria. I. Observations on Escherichia coli and Micrococcus
lysodeikticus. J. Bacteriol., 80:577-579, 1960.
Davies, R. R. Air Sampling for Fungi, Pollens, and Bacteria. In: Methods
of Microbiology, Vol. 4, C. Booth, ed. Academic Press, New York, 1971.
pp. 367-404.
Davies, R. R., and W. C. Noble. Dispersal of Bacteria on Desquamated Skin.
Lancet, 2:1295-1297, 1962.
Decker, H. M., L. M. Buchanan, D. E. Frisque, M. E. Filler, and C. M.
Dahlgren. Advances in Large-Volume Air Sampling. Contam. Cont., 8:13-17,
1969.
Decker, H. M., R. W. Kuehne, L. M. Buchanan, and R. Porter. Design and
Evaluation of a Slit-Incubator Sampler. Appl. Microbiol., 6:398-400, 1958.
Decker, H. M., and M. E. Wilson. A Slit Sampler for Collecting Airborne
Micro-Organisms. Appl. Microbiol., 2:267-269, 1954.
de Jong, J. C. The Survival of Measles Virus in Air in Relation to the Epi-
demology of Measles. Arch. Ges. Virusforsch., 16:97-102, 1965.
de Jong, J. C. On the Mechanism of Decay of Poliovirus and Encephalomyo-
carditis Virus in Aerosols. In: Proc. 3rd Int. Symp. Aerobiol., J. H.
Silver, ed. Academic Press, Inc., New York, 1969. pp. 210-211.
de Jong, J. C., M. Harmsen, and T. Trouwborst. The Infectivity of Nucleic
Acid of Aerosol-Inactivated Poliovirus. J. Gen. Virol., 18:83-86, 1973.
de Jong, J. C., M. Harmsen, T. Trouwborst, and K. C. Winkler. Inactivation
of Encephalomyocarditis Virus in Aerosols: Fate of Virus Protein and
Ribonucleic Acid. Appl. Microbiol., 27(l):59-65, 1974.
de Jong, J. D., and K. C. Winkler. The Inactivation of Poliovirus in Aero-
sols. J. Hyg., Camb., 66:557-565, 1968.
47
-------
De Jong, J. G., and K. C. Winkler. Survival of Measles Virus in Air. Nature,
201:1054-1055, 1964.
DeOme, K. B. Effect of Temperature, Humidity, and Glycol Vapour on Viability
of Air-Borne Bacteria. Am. J. Hyg., 40:239-250, 1944.
Dewald, R. R. Kinetics Studies on the Destructive Auction of Oxygen on Lyo-
philized Serratia marcescens. Appl. Microbiol., 14:568-572, 1966.
Diaz, L. F., L. Riley, G. Savage, and G. J. Trezek. Health Aspect Consi-
erations Associated with Resource Recovery. Compost Sci., Summer, 1976.
Dimmick, R. L. Jet Disperser for Compacted Powders in the One to Ten Micron
Range. Arch. Ind. Health, 20:8, 1959.
Dimmick, R. L. Characteristics of Dried Serratia marcescens in the Airborne
State. J. Bacteriol., 80:289, 1960.
Dimmick. R. L. Measurement of the Physical Decay of Aerosols by a Light
Scatter Method Compared to a Radioactive Tracer Method. J. Hyg., Camb.,
58:373, 1960.
Dimmick, R. L. Delayed Recovery of Airborne Serratia marcescens After Short-
Time Exposure to Ultraviolet Irradiation. Nature (London), 187:251, 1960.
Dimmick, R. L., ed. First International Symposium on Aerobiology - 1963.
University of California, Berkeley, California, 1963, 405 pp.
Dimmick, R. L. Introduction to the Symposium (Current Problems in Aerobi-
ology). In: Developments in Industrial Microbiology, Vol. 15. Proceed-
ings of the 30th General Meeting of the Society of Industrial Microbiology,
E. D. Murray and A. W. Bourquin, eds. Amer. Inst. of Biol. Sci.,
Washington, D.C., 1974. pp. 19.
Dimmick, R. L., and A. B. Akers. An Introduction to Experimental Aerobiology.
Wiley Interscience, New York, 1969. 494 pp.
Dimmick, R. L., R. S. Heckly, and D. P. Hollis. Free-Radicle Formation Dur-
ing Storage of Freeze-Dried Serratia marcescens. Nature (London), 192:
776, 1961.
Dimmick, R. L., and R. J. Heckly. An Approach to Study of Microflora in
Atmosphere. Proc. Atmospheric Biol. Conf., University of Minnesota,
Minneapolis, 1964. pp. 187-198.
48
-------
Dimmick, R. L., P. A. Straat, H. Wolochow, G. V. Levin, M. A. Chatigny, and
J. R. Schrot. Evidence for Metabolic Activity of Airborne Bacteria. J.
Aerosol. Sci., 6:387-393, 1975.
Dimmock, N. A. Production of Uniform Droplets. Nature (London), 116:686,
1950.
Dimmock, N» J. Differences Between the Thermal Inactivation of Picorna-
viruses at 'High1 and 'Low1 Temperatures. Virology, 31:338-353, 1967.
Donaldson, A. I., K. A. J. Herniman, J. Parker, and R. F. Sellers. Further
Investigations on the Airborne Excretion of Foot-and-Mouth Disease Virus.
J. Hyg., Camb., 68:557-564, 1970.
Donaldson, A. The Survival of Foot and Mouth Disease Virus in Open Air
Conditions. J. Hyg., Camb., 74:409-416, 1975.
Dowling, H. F. Airborne Infections—The Past and the Future. Bacteriol.
Rev., 30(3):485-487, 1966.
Druett, H. A., D. W. Hendersen, L. Packman, and S. Peacock. Studies on
Respiratory Infection: I. The Influence of Particle Size on Respira-
tory Infection with Anthrax Spores. J. Hyg., 51:359-371, 1953.
Druett, H. A., and K. R. May. A Wind Tunnel for the Study of Airborne In-
fections. J. Hyg., 50:69-81, 1952.
Druett, H. A., and K. R. May. Unstable Germicidal Pollutant in Rural Air.
Nature, 220:395-396, 1968.
Druett, H. A., J. M. Robinson, D. W. Henderson, L. Packman, and S. Peacock.
Studies on Respiratory Infection. II. The Influence of Aerosol Particle
Size on Infection of the Guinea Pig with Pasteurella pestis. J. Hyg.,
54:37-48, 1956.
Dubovi, E. J. Biological Activity of the Nucleic Acids Extracted from Two
Aerosolized Bacterial Viruses. Appl. Microbiol., 21:761-762, 1971.
49
-------
Dubovi, E. J., and T. G. Akers. Airborne Stability of Tailless Bacterial
Viruses S-13 and MS-2. Appl. Microbiol., 19:624-628, 1970.
DuBuy, H. G., and L. R. Crisp. A Sieve Device for Sampling Airborne Micro-
Organisms. Public Health Kept., 59:829-832, 1944.
DuBuy, H. G., A. Hollaender, and M. D. Lackey. A Comparative Study of
Sampling Devices for Airborne Micro-Organisms. Public Health Kept. Supp.
No. 184, Washington, D.C., (U.S. Govt. Printing Office), 1945.
Duckett, E. J. Microbiological Analysis of Dusts at the Equipment Test and
Evaluation Facility. TR78-16, National Center for Resource Recovery, Inc.,
Washington, D.C., 1978.
Dunklin, E. W., and T. T. Puck. The Lethal Effect of Relative Humidity on
Airborne Bacteria, j. Exp. Med., 87:87-101, 1948.
Dunklin, E. W., and T. P- Theodore. The Lethal Effect of Relative Humidity
on Airborne Bacteria. J. Exp. Med., 87:2, 1948.
Edmonds, R. L. Prediction of Spread of Fomes annosus in Forests. In: Pro-
ceedings of Workshop Conference II. Ecological Systems Approaches to
Aerobiology: II. Development, Demonstration and Evaluation of Models.
US/IBP Aerobiology Program Handbook No. 3. National Center for Atmospheric
Research, Boulder, Colorado, July 12-14, 1972. R. L. Edmonds and W. S.
Benninghoff, edsu The University of Michigan, Ann Arbor, 1973.
Edmonds, R. L., and W. Littke. Coliform Aerosols Generated from the Sur-
face of Dewatered Sewage Applied to a Forest Clearcut. Appl. Environ.
Microbiol., 36(6):972-974, 1978.
Edmonds, R. L., and W. S. Bennighoff. Aerobiology and Its Modern Implica-
tions. Report No. 3, Aerobiology Program: U.S. Component of the Inter-
national Biological Program, Ann Arbor, Michigan, 1973.
Edward, D. G., W. J. Elford, and P- P. Laidlaw. Studies on Airborne Virus
Infections. I. Experimental Technique and Preliminary Observations on
Influenza and Infectious Ectroraelia. J. Hyg., Camb., 43:1-15, 1943.
Ehrlich, R. Effects of Air Pollutants on Respiratory Infection. Arch.
Environ. Health, 6:638-642, 1963.
Ehrlich, R. Effects of Atmospheric Humidity and Temperature on the Survival
of Airborne Flavobacterium. Appl. Microbiol., 20:884-887, 1970.
50
-------
Ehrlich, R. Survival of Airborne Microorganisms at Different Environmental
Temperatures. In: Developments in Industrial Microbiology, Vol. 15,
E. D. Murray and A. W. Bourquin, eds. Amer. Inst. Biol. Sci., Washington,
D.C. 1974. pp. 28-32.
Ehrlich, R., and S. Miller. Effect of Relative Humidity and Temperature
on Airborne Venezuelan Equine Encephalitis Virus. Appl. Microbiol., 22:
194-199, 1971.
Ehrlich, R., S. Miller, and L. S. Idoine. Effect of Environmental Factors
on the Survival of Airborne T-3 Coliphage. Appl. Microbiol. 12:479-482,
1964.
Ehrlich, R., S. Miller, and L. S. Idoine. Use of Slit Sampler in Comparison
with Impinger. Appl. Microbiol., 14:328, 1966.
Ehrlich, R. , S. Miller, and R. L. Walker. Relationship Between Atmospheric
Temperature and Survival of Airborne Bacteria. Appl. Microbiol., 19:245-
249, 1970.
Elliot, L. F., T. M. McCalla, and J. A. Deshazer. Bacteria in the Air of
Housed Swine Units. Appl. Environ. Microbiol., 32(2):270-273, 1976.
Emmons, C. W. Isolation of Coccidioides from Soil and Rodents. Public
Health Rept., 57:109-111, 1942.
Engelbrecht, R. S., and P. Amirhor. Stability of Bacteria and Viruses in
Sanitary Landfill Leachate. Report submitted to Diaper Research Committee,
Tissue Division, American Paper Institute, Inc., New York, 1975.
Epidemiology of Chronic Respiratory Diseases: A Literature Review. NTIS
Publication No. PB-237375, 1974.
Ewing, W. H. Differentiation of Enterobacteriaceas by Biochemical Reactions.
DHEW Publication No. (CDC) 75-8270, U.S. Department of Health, Education,
and Welfare, Public Health Service, Center for Disease Control, Atlanta,
Georgia, 1973. 61 pp.
Expert Committee on Respiratory Diseases, First Report. Publication No. 170,
World Health Organ., Geneva, 1959.
Faber, H. K., and R. J. Silverberg. Experimental Airborne Infection with
Poliomyelitis Virus. Science, 94:566-568, 1941.
51
-------
Fair, G. M., and w. F. Wells. Measurement of Atmospheric Pollution and
Contamination by Sewage Treatment Works. Proc. 19th Ann. Mtg. N.J.
Sew. Works Assoc., 19:20-27, 1934.
Fannin, K. An Assessment of the Airborne Emission of Selected Viruses by
Wastewater Treatment. Ph.D. Thesis, University of Michigan, Ann Arbor,
Michigan, 1976. 113 pp.
Fannin, K. F. Airborne Coliphages from Wastewater Treatment Facilities.
J. Appl. Environ. Microbiol., 31(5):705-710, 1976.
Farrow, W. M. Tropical Soil Fungi. Mycologia, 46:632-646, 1954.
Fedorak, P. M., and D. W. S. Westlake. Effect of Sunlight on Bacterial
Survival in Transparent Air Samplers. Can. J. Microbiol., 24:618-619,
1978,
Ferry, R. M., and T. G. Maple. Studies of the Loss of Viability of Stored
Bacterial Aerosols. I. Micrococcus candidus. J. Infect. Dis., 95:142,
1954.
Ferry, R. M., W. F. Brown, and E. B. Damon. Studies on the Loss of Viability
of Stored Bacterial Aerosols. II. Death Rates of Several Non-Pathogenic
Organisms in Relation to Biological and Structural Characteristics. J.
Hyg., 56:125-150, 1958.
Ferry, R. M., L. E. Farr, and M. G. Hartman. The Preparation and Measure-
ment of the Concentration of Dilute Bacterial Aerosols. Chem. -Rev.,
44:389-414, 1949.
Ferry, R. M., L. E. Farr, Jr., J. Rose, and M. R. Blau. A Study of Freshly
Generated Bacterial Aerosols of Micrococcus candidus and Escherichia coli,
J. Infect. Dis., 88:256-271, 1951.
Fincher, E. L., and G. F. Mallison. Intramural Sampling of Airborne Micro-
organisms. In:. Air Sampling Instruments for Evaluation of Atmospheric
Contaminants, 4th ed., Cincinnati. American Conference of Governmental
Industrial Hygienists, 1972.
Finkelstein, H. Air Pollution Aspects of Biological Aerosols (Microorgan-
isms). U.S. Department of Commerce, National Bureau of Standards, 1969.
First, M. W. Aerosols in Nature. Arch. Intern. Med., 131:24-32, 1973.
52
-------
First, M. W., and L. Silverman. Air Sampling with Membrane Filters. A.M.A.
Arch. Indust. Hyg. and Occup. Med., 7:1-11, 1953.
Furcolow, M. L. Airborne Histoplasmosis. Bacteriol. Rev., 25:301-309, 1961.
Furcolow, M. C., R. W. Menges, and H. W. Larsh. An Epidemic of Histoplas-
mosis Involving Man and Animals. Ann. Intern. Med., 43:173-181, 1955.
Gabis, D. A., and J. H. Silliker. ICMSF Methods Studies IX. The Influence
of Selective Enrichment Broths, Different Planting Media and Incubation
Temperatures on the Detection of Salmonella in Dried Foods and Feed In-
gredients. Can. J. Microbiol., 23(9): 1225-1231, 1977.
Gardner, P. S. Viruses, Bacteria, and Respiratory Disease in Children.
Brit. Med. J., 1:1077-1080, 1960.
Gardner, P. S. The Application of Immunofluorescent Antibody Techniques to
the Rapid Diagnosis of Virus Infection. In: 3rd Int. Symp. on Aerobio.
I. H. Silver, ed. Academic Press, New York, 1970.
George, E. S., C. B. Ward, and V. J. Cabelli. The Development of the Multiple
Orifice Impinger (MOI) as an Answer to the Problem of Prolonged Operation
(Aspiration) in the All Glass Impinger. In: First Int. Symp. on Aerobiol.,
R. L. Dimmick, ed. University of California, Berkeley, California, 1963,
pp. 201-207.
Gerone, P. J., R. B. Couch, G. V. Keefer, R. G. Douglas, E. B. Derrenbacher,
and V. Knight. Assessment of Experimental and Natural Viral Aerosols.
Bacteriol. Rev., 30:576-583, 1966.
Gerschman, R., D. L. Gilbert, S. W. Nye, P. Dwyer, and W. 0. Fenn. Oxygen
Poisoning and X-Irradiation: A Mechanism in Common. Science, 119:623-
626, 1954.
Glaser, J. R., and J. 0. Ledbetter. Sizes and Numbers of Aerosols Gener-
ated by Activated Sludge Aeration. Water and Sewage Works, 114:219-221, 1967,
Glysson, E. A. The Microbiological Quality of Air in an Incinerator Environ-
ment. Proceedings of the 1974 ASME National Incinerator Conference,
Miami, Florida, pp. 87-97.
Goetz, A. Basic Problems in the Detection of Microbiological Air Pollution.
Am. Indust. Hyg. A. Quart., 16:113, 1955.
53
-------
Goff, G. D. Microbiological Aerosols Generated by a Sewage Treatment Process.
Master of Science Thesis. University of Utah, Salt Lake City, 1972.
Goff, G. D., J. C. Spendlove, A. P. Adams, and S. Nicholas. Emission of
Microbial Aerosols from Sewage Treatment Plants that Use Trickling Filters.
Health Services Rept., 88:640-652, 1973.
Goff, G. D., J. C. Spendlove, A. P- Adams, and P. S. Nicholes. Effects of
Environmental Conditions on Emission of Microbial Aerosols from Trickling
Filter Sewage Treatment Plants. Health Services Rept. 88:640-652, 1973.
Goldberg, L. J. Studies on the Experimental Epidemiology of Respiratory
Infections. IV. A Particle Size Analyzer Applied to the Measurement
of Viable Airborne Bacteria. J. Infect. Dis., 87:133-141, 1950.
Goldberg, L. J. Application of the Microaerofluormeter to the Study of Dis-
persion of a Fluorescent Aerosol into a Selected Atmosphere. J. Appl.
Microbiol., 7(l):68-72, 1968.
Goldberg, L. J., and W. R. Leif. The Use of a Radioactive Isotope in De-
termining the Retention and Initial Distribution of Airborne Bacteria in
the Mouse. Science, 112:299-300, 1950.
Goldberg, L. J., and I. L. Shechmeister. Studies on the Experimental Epi-
demiology of Respiratory Infections. V. Evaluation of Factors Related
to Slit Sampling of Airborne Bacteria. J. Infect. Dis., 88:243-247, 1951.
Goldberg, L. J., H. M. S. Watkins, M. S. Dolmatz, and N. A. Schlamm. Studies
on the Experimental Epidemiology of Respiratory Infection. VI. The Rela-
tionship Between Dose of Microorganisms and Subsequent Infection or Death
of a Host. J. Infect. Dis., 94:9-21, 1954.
Goldberg, L. J., and H. M. S. Watkins. Preliminary Studies with a Continu-
ous Impinger for Collection of Bacterial and Viral Aerosol Samples. In:
First Int. Symp. on Aerobiol., R. L. Dimmick, ed. University of California,
Berkeley, California, 1963. pp. 211-216.
Goldberg, L. J., H. M. S. Watkins, E. E. Boerke, and M. A. Chatigny. The
Use of a Rotating Drum for the Study of Aerosols Over Extended Periods
of Time. Am. J. Hyg., 68:85-93, 1958.
Goodlow, R. J., and F. A. Leonard. Viability and Infectivity of Microorgan-
isms in Experimental Airborne Infection. Bacteriol. Rev., 25:182-187,
1961.
54
-------
Green, H. L., and W. R. Lane. Particulate Clouds: Dusts, Smokes, and
Mists (2nd ed.). E. and F. N. Spon Ltd., 1964, London.
Green, L., and G. Green. Direct Method of Determining the Viability of a
Freshly Generated Mixed Bacterial Aerosol. Appl. Microbiol., 16:78-81,
1968.
Greenburg, L., and G. W. Smith. A New Instrument for Sampling Aerial Dust.
Bureau of Mines Reports of Investigations, No. 2392, 1922, 3 pp.
Greenburg, L., and J. J. Bloomfield. The Impinger Dust Sampling Apparatus
as Used by the United States Public Health Service. Public Health Rept.,
47:654-675, 1932.
Gregory, P. Airborne Microbes. Seventh Symposium of the Society for General
Microbiology, held at the Imperial College, London, 1967.
Gregory, P- H. The Microbiology of the Atmosphere. Leonard Hill (Books), Ltd.,
and Interscience Publishers, Inc., 1962. 251 pp.
Gregory, P. H. The Microbiology of the Atmosphere. Interscience Publishers,
New York, 1973.
Griffith, W. R. A Mobile Laboratory Unit for Exposure of Animals and Human
Volunteers to Bacterial and Viral Aerosols. Am. Rev. Respirat. Dis., 89:
240-249, 1961.
Grigoryova, L. V. The Problem of Detection of a Virus Aerosol Under Experi-
mental Conditions (A Russian Study). Vop. Sanit. Bakt. Virus. Department
of Microbiology of the Kiev Institute for the Advancement of Doctors, and
the Laboratory of Sanitary Bacteriology and Virology, of Ukrainian Insti-
tute of Communal Hygiene, 1965. pp. 114-119.
Grunnet, K., and C. Tramsen. Emission of Air Borne Bacteria From a Sewage
Treatment Plant. Rev. Int. Oceanog. Med. (Yug.), 34:177, 1974.
Guerin, L. F., and C. A. Mitchell. A Method for Determining the Concentra-
tion of Airborne Virus and Size Droplet Nuclei Containing the Agent. Can.
J. Comp. Med. Vet. Sci., 28:283-287, 1964.
Guyton, H. G., L. M. Buchanan, and F. T. Lense. Evaluation of Respiratory
Protection of Contagion Masks. Appl. Microbiol., 4:141-143, 1956.
55
-------
Guyton, H. G., R. Porter, and F. T. Lense. Evaluation of Soluble Gelatin
Foam for Possible Use as a Medium for Sampling Airborne Microorganisms.
Physical Defense Division, Fort Detrick, Maryland. Personnel Protection
Branch Memorandum Report No. 19-55, 1955.
Hadeed, S. J. Dangers of Wastewater Aerosols: Evidence to Date. J. Water
Poll. Control Fed., 48:631-632, 1976.
Hahon, N., and M. H. McGavran. Airborne Infectivity of the Variola-Vaccinia
Group of Poxviruses for the Cynomolgus Monkey Macaca irus. J. Infect.
Dis., 109:294-298, 1961.
Hahon, N., and R. M. Nakamura. Quantitative Assay of Psittacosis Virus by
the Fluorescent Cell-Counting Technique. Virology, 23:203-208, 1964.
Happ, J. W., J. B. Harstad, and L. M. Buchanan. Effects of Air Ions on Sub-
micron T^ Bacteriophage Aerosols. Appl. Microbiol., 14:888-891, 1966.
Hanson, R. P., S. E. Sulkin, E. L., Buescher, W. McD. Hammon, R. W. McKinney,
and T. H. Worly. Arbovirus Infections of Laboratory Workers. Science,
138:1283-1286, 1967.
Harp, C. H., D. F. Hershey, and A. Novak. Survey in the Philadelphia Area
of the Occurrence and Distribution of Bacillus anthracis in Textile Mills
Using Goat Hair and Wool. SR 240, CmlC, R&D Cmd., BWL Safety Division,
Ft. Detrick, Frederick, Maryland, 1955.
Harper, G. J. Airborne Microorganisms: Survival Tests with Four Viruses.
J. Hyg., Camb., 59:479-486, 1961.
Harper, G. J. The Influence of Environmental on the Survival of Airborne
Virus Particles in the Laboratory. Arch. Ges. Virusforsch., 13:64-71,
1963.
Harper, G. J. Some Observations on the Influence of Suspending Fluids on
the Survival of Airborne Viruses. First Int. Symp on Aerobiol., R. L.
Dimmick, ed. University of California, Berkeley, California, 1963. pp.
335-341.
Harper, G. J., and J. D. Morton. The Respiratory Retention of Bacterial
Aerosols; Experiments with Radioactive Spores. J. Hyg., 51:372-385, 1953.
56
-------
Harper, G. J., A. M. Hood, and J. D. Morton. Airborne Microorganisms: A Tech-
nique for Studying Their Survival. J. Hyg., Camb., 56:364, 1958.
Harris, N. D. The Influence of the Recovery Medium and the Incubation Tempera-
ture on the Survival of Damaged Bacteria. J. Appl. Bacteriol., 26:387-397,
1963.
Harris, W. B., and M. Eisenbud. Dust Sampler Which Simulates Upper and Lower
Lung Deposition. A.M.A. Arch. Indust. Hyg. and Occup. Med., 8:446-452, 1953.
Harstad, J. B. Sampling Submicron Tl Bacteriophage Aerosols. Appl. Microbiol.,
13:899-908, 1965.
Hatch, M. T. Effect of Relative Humidity on Inactivation and Reactivation of
Pasteurella pestis bacteriophage in aerosols. Bacteriol. Proc., 97:150,
1967.
Hatch, M. T., and R. L. Dimmick. A Study of Dynamic Aerosols of Bacteria Sub-
jected to Rapid Changes in Relative Humidity. In: 1st Inter. Symp. on
Aerobiol., University of California, Berkeley, California, 1965. pp. 265-
281.
Hatch, M. T., and R. L. Dimmick. Physiological Response of Airborne Bacteria
to Shifts in Relative Humidity. Bacteriol. Rev., 30(3):597-603, 1966.
Hatch, M. T., and J. C. Warren. Enhanced Recovery of T3 Coliphage and
Pasteurella pestis Bacteriophage by Means of a Presampling Humidification
Technique. Appl. Microbiol., 17:685-689, 1969.
Hatch, M. T., and H. Wolochow. Bacterial Survival: Consequences of the Air-
borne State. In: An Experimental Approach to Aerobiology. R. L. Dimmick,
and A. B. Akers, eds. Wiley Interscience, New York, 1969.
Hatch, T. F. Distribution and Deposition of Inhaled Particles in Respiratory
Tract. Bacteriol. Rev., 25:237-240, 1961.
Hatch, T. F., and P. Gross. Pulmonary Deposition and Retention of Inhaled
Aerosols. Academic Press, New York, 1964, 192 pp.
Hayakawa, I., and C. P. Poon. Short Storage Studies on the Effect of Tempera-
ture and Relative Humidity on the Viability of Airborne Bacteria. Am.
Ind. Hyg. Assoc. J., 26:150, 1965.
57
-------
Hayes, D. K., W. L. Bamesberger, and V- J. Cabelli. The Influence of Storage,
Aerosolization and Rehydration on the Permeability of Pasteurella tularensis
to Phosphate Ions. In: 1st. Int. Symp. on Aerobiol., R. L. Dimmick, ed.
University of California, Berkeley, California, 1963. pp. 389-396.
Heckly, R. J., R. L. Dimmick, and N. Guard. Studies on Survival of Bacteria:
Rhythmic Response of Microorganisms to Freeze-Drying Additives. Appl.
Microbiol., 15:1235-1239, 1967.
Hemmes, J. H., K. C. Winkler, and S. M. Kool. Virus Survival as a Seasonal
Factor in Influenza and Poliomyelitis. Nature, 188(4748):430-431, 1960.
Hemmes, J. H., K. C. Winkler, and S. M. Kool. Virus Survival as a Seasonal
Factor in Influenza and Poliomyelitis. Antonie van Leeuwenhoek J. Microbiol.
Serol., 28:221-233, 1962.
Henderson, D. W. An Apparatus for the Study of Airborne Infection. J. Hyg.,
Camb., 50:53-68, 1952.
Hers, F., and C. Winkler, ed. Airborne Transmission and Airborne Infection:
Concepts and Methods Presented at the 6th Int. Symp. on Aerobiol., The
Netherlands. John Wiley and Sons, New York, 1973. pp. 201, 202,
165.
Hess, G. E. Effects of Oxygen on Aerosolized Serratia marcescens. Appl.
Microbiol., 13:781-787, 1965.
Hickey, John, and Parker Reist. Health Significance of Airborne Micro-
organisms from Wastewater Treatment Processes, Parts I and II. Journal WPCF,
47(12):2741-2773.
Higgins, F. B. Bacterial Aerosols from Bursting Bubbles. Ph.D. Disser-
tation. Georgia Institute of Technology, Atlanta, Georgia, 1964.
Higgins, I. T. T. Epidemiology of Chronic Respiratory Disease: A Litera-
ture Review. National Technical Information Service, PB-237375, U.S.
Department of Commerce.
Hinton, N. A., J. R. Maltman, and J. H. Orr. The Effect of Desiccation
on the Ability of Staphvlococcus pyogenes to Produce Disease in Mice.
Am. J. Hyg., 72:343-350, 1960.
58
-------
Hirst, J. M. An Automatic Volumetric Spore Trap. Ann. of Appl. Biol.,
39:257-265, 1952.
Hogan, M. D., J. P. Ranson, D. Pappagianus, G. Eu Danald, and A. D. Bell.
Isolation of Coccidioides immitis from Air. Unpublished Report from
Sixth Army Med. Lab., Fort Baker, California, 1955.
Hood, A. M. Infectivity of Pasteurella tularensis Clouds. J. Hyg., 59:
497-504, 1961.
Hood, A. M. Infectivity of Influenza Virus Aerosols. J. Hyg., 61:331-335,
1963.
Houwink, E. H., and W. Rolvink. The Quantitative Assay of Bacterial Aerosols
by Electrostatic Precipitation. J. Hyg., 55:544-563, 1957.
Hugh-Jones, M., W. H. Allan, F. A. Dark, and G. J. Harper. The Evidence
for the Airborne Spread of Newcastle Disease. J. Hyg., Camb., 71:325-
339, 1973.
Hyslop, N. St. G. Airborne Infection with the Virus of Foot and Mouth Dis-
ease. J. Comp. Pathol., 75:119-126, 1965.
Hyslop, N. Observations on Pathogenic Organisms in the Airborne State.
Tropical Animal Health Proceedings, 4:28-40, 1972.
Hyland, F., B. F. Graham, F- H. Steinmetz, and Martyn A. Vickers. Maine
Air-Borne Pollen and Fungus Spore Survey. University of Maine, Orono,
1953.
Jackson, G. G., H. F= Dowling, T. 0. Anderson, L. Riff, J. Saporta, and
M. Turck. Susceptibility and Immunity to Common Upper Respiratory Viral
Infections--the Common Cold. Ann. Intern. Med., 53:719-736, 1960.
Jacobson, A. R. Viable Particles in the Air. In: Air Pollution, Vol. 1,
A. C. Stern, ed. Academic Press, Inc., New York, 1968. pp. 95-119.
Jagger, J. Inhibition by Sunlight of the Growth of Escherichia coli B/r.
Photochem. Photobiol., 22:67-70, 1975.
Jakab, G. J., and E. C. Dick. Experimental Parainfluenza (Sendai) Virus
Infection of Mice by Aerosol. Bacteriol. Proc., 76:147, 1967.
59
-------
James, H. A., C. Zippin, and C. E. Meyers. The Recovery of Aerosolized
Bacteria from Humans. Arch. Environ. Health, 2:391-396, 1961.
Jensen, M. M. Inactivation of Airborne Viruses by Ultraviolet Irradiation.
Appl. Microbiol., 12:418-420, 1964.
Jensen, M. M. Inactivation of Virus Aerosols by Ultraviolet Light in a
Helical Baffle Chamber. In: 1st Int. Symp. on Aerobiol., R. L. Dimmick,
ed. University of California, Berkeley, California, 1963. pp. 219-226.
Jones, W. P. Development of the Venturi Scrubber. Indust. and Engin.
Chem., 41:2424, 1949.
Jost, R., and H. Fey. Rapid Detection of Small Numbers of Airborne Bacteria
by a Membrane Filter Fluorescent-Antibody Technique. Appl. Microbiol.,
20:861-865, 1970.
Kalter, S. S., and C. H. Millstein. Efficacy of Methods for the Detection
of Viruses in Treated and Untreated Sewage. In: Virus Survival in Water
and Wastewater Systems. Water Resources Symposium No. 7, J. F. Malina
and B. P. Sagik, eds. Center for Research in Water Resources, University
of Texas in Houston, Texas, 1974„ pp. 33-44.
Kass, E. H., G. M. Green, and E. Goldstein. Mechanism of Antibacterial Action
in Respiratory System. Bacteriol. Rev., 30(3):488-497, 1966.
Katzenelson, E. Virologic and Engineering Problems in Monitoring Viruses in
Water. In: Viruses in Water, G. Berg, H. L. Bodily, E. H. Lennette,
J. L. Melnick and T. G. Metcalf, eds. Am. Pub. Health Assoc., Washington,
D.C., 1976. pp. 152-164.
Katzenelson, E. Dispersion of Enteric Bacteria by Spray Irrigation. J. WPCF,
48(4):710-716, 1976.
Kazantzis, M. G. Air Contamination from High Speed Dental Drills. Proc.
Roy. Soc. Med., 54:242-244, 1961.
Kenline, P. A. The Emission, Identification, and Fate of Bacteria Airborne
from Activated Sludge and Extended Aeration Sewage Treatment Plants.
PhD Thesis. University of Cincinnati, Cincinnati, Ohio, 1968.
Kenline, P. A., and P. V. Scarpino. Bacterial Air Pollution from Sewage
Treatment Plants, Am. Ind. Hyg. Assoc., 33:346-352, 1972.
60
-------
Kethley, T. W., E. L. Fincher, and W. B. Cown. The Kffect of Sampling
Method Upon the Apparent Response of Airborne Bacteria to Temperature
and Relative Humidity. J. Infect. Dis., 100:97-102, 1957.
Kethley, T. W., M. T. Gordon, and C. Orr, Jr. A Thermal Precipitator
for Aerobacteriology. Science, 116(3014):368-369, 1952.
King, Eo D., R. A. Mill, and C. H. Lawrence. Airborne Bacteria from an
Activated Sludge Plant. J. Environ. Health, 36:50-54, 1973.
Knight, V., P. J. Gerone, W. R. Griffith, R. B. Couch, T. R. Gate, K. M.
Johnson, D. J. Lang, H. E. Evans, A. Spickard, and J. A. Kasel. Studies
in Volunteers with Respiratory Viral Agents. Small Particle Aerosol:
Heterotypic Protection; Viral Chemotherapy; Bovine Reovirus in Man.
Am. Rev. Respirat. Dis., 88:135-143, 1963.
Koch, G. Influence of Assay Conditions on Infectivity of Heated Poliovirus.
Virology, 12:601, 1960.
Kramer, C. L., S. M. Pady, and C. T. Rogerson. Kansas Aeromycology III:
Cladosporium. Trans. Kan. Acad. Sci., 62:200-207, 1959.
Kramer, C. L., S. M. Pady, C. T. Rogerson, and L. 0. Ouye. Kansas Aero-
mycology II. Materials, Methods and General Results. Trans. Kan. Acad.
Sci., 62(3):184-199, 1959.
Kuehne, R. W., and H. M. Decker. Studies on the Continuous Sampling of
Serratia marcescens Using a Slit Sampler. Appl. Microbiol., 5:321, 1957.
Kuehne, R. W., and W. S. Gochenour, Jr. A Slit Sampler for Collecting T3
Bacteriophage and Venezuelan Equine Encephalomyelitis Virus. II. Studies
with Venezuelan Equine Encephalomyelitis Virus. Appl. Microbiol., 9:106-
107, 1961.
Kuehne, R. W., W. D. Sawyer, and W. S. Gochenour, Jr. Infection with Aero-
solized Attenuated Venezuelan Equine Encephalomyelitis. Am. J. Hyg.,
75:347-350, 1962.
Kundsin, R. B. Characterization of Mycoplasma Aerosols as to Viability,
Particle Size, and Lethality of Ultraviolet Irradiation. J. Bacteriol.,
91:942-944, 1966.
Langer, G., P- Pierrard, and G. Yamate. Further Development of an Electro-
static Classifier for Submicron Air-Borne Particles. Int. J. Air Wat.
Pollut., 8:167, 1964.
61
-------
Langmuir, A. D. Public Health Implications of Airborne Infection—Medical
Aspects. Bacteriol. Rev., 25:356-358, 1961.
Larson, E. W. Some Requirements and Characteristics of Aerobiological
Research. In: Developments in Industrial Microbiology, Vol. 15, E. D.
Murray and A. W. Bourquin, eds. Am. Inst. of Biol. Sci., Washington,
D.C., 1974. pp. 33-37.
Larson, E. W., G. J. Spahn, R. L. Peters, and R. J. Huebner. Investigations
of Survival Properties of Airborne Murine Leukemia Virus. J. Nat. Cancer
Inst., 44:937-941, 1970.
Landahl, H. D., and Tracewell. Penetration of Airborne Particles Through
the Human Nose. J. Ind. Hyg. Toxicol., 31:55-59, 1949.
Landahl, H. D. On the Removal of Airborne Droplets by the Human Respiratory
Tract. I. The Lung. Bull. Math. Biophys., 12:43, 1950.
Leach, R. H., and W. J. Scott. The Influence of Rehydration on the Viability
of Dried Microorganisms. J. Gen. Microbiol., 21:295-307, 1959.
Ledbetter, J., and C. Randall. Bacterial Emissions from Activated Sludge
Units. Ind. Med. Surg., 34:130-133, 1965.
Lee, D., ed. Environmental Factors in Respiratory Disease. Academic Press,
New York, 1972.
Lee, R. E., and M. Garbett. Carboxymethylcellulose Ether Media for Cold
Weather Aerosol Sampling. Appl. Microbiol., 14:133, 1966.
Lee, R. E., Jr., K. Harris, and G. Akland. Relationship Between Viable
Bacteria and Air Pollutants in an Urban Atmosphere. J. Am. Ind. Hyg.
Assoc., 34:164-170, 1973.
Leif, W. R., and A. P. Krueger. Studies on the Experimental Epidemiology
of Respiratory Infections. I. An Apparatus for the Quantitative Study
of Airborne Respiratory Pathogens. J. Infect. Dis., 87:103-116, 1950.
Lemon, H. M. A Method for Collection of Bacteria from Air and Textiles.
Proc. Soc. Exp. Biol., and Med., 54:298-301, 1943.
Lennette, E. H., and H. Koprowski. Human Infection with Venezuelan Equine
Encephalomyelitis Virus: Report of Eight Cases of Infection Acquired in
the Laboratory. J. Am0 Med. Assoc., 123:1088-1095, 1943.
62
-------
Lester, W. The Influence of Relative Humidity on the Infectivity of Air-
borne Influenza A Virus (PR8 strain). J. Exp. Med., 88:361-368, 1948.
Letter to the Editor. Standard Sampler for Assay of Air-Borne Microorgan-
isms. Science, 144:1295, 1964.
Lidwell, 0. M. Impaction Sampler for Size Grading Airborne Bacteria-
Carrying Particles. J. Sci. Instr., 36:3-8, 1959.
Lidwell, 0. M. , and E. J. Lowbury. Survival of Bacteria in Dust. I. The
Distribution of Bacteria in Floor Dust. J. Hyg., 48:6-20, 1950.
Lidwell, Oo M., W. C. Noble, and G. W. Dolphin. The Use of Radiation to
Estimate the Numbers of Micro-Organisms in Airborne Particles. J. Hyg.,
57:299-308, 1959.
Lidwell, 0. M., R. W. Morgan, and R. E. 0. Williams. The Epidemiology of the
Common Cold. IV. The Effect of Weather. J. Hygo, 63:427-439, 1965.
Lidwell, 0. M., and W. C. Noble „ A Modification of the Andersen Sampler
for Use in Occupied Environments. J. Appl, Bacteriol., 28:280-282, 1965.
Lighthart, B. Survival of Airborne Bacteria in High Urban Concentration
of Carbon MonoxLde. Appl. Microbiol., 25:86-91, 1973.
Lighthart, B., V. E. Hiatt, and A. T. Rosaano. The Survival of Airborne
Serratia marcescens in Urban Concentration of Sulfur Dioxide. In: J. Air
Pollut. Control Assoc., 21:639-642, 1971.
Lighthart, B., and A. S. Frisch. A Model to Evaluate the Airborne Bac-
terial Concentration from a Continuous Source. In: Proceedings of
Workshop/Conference II. Ecological Systems Approaches to Aerobiology:
II. Development, Demonstration and Evaluation of Models. US/IPB
Aerobiology Program Handbook, No. 3. National Center of Atmospheric
Research, Boulder, Colorado, July 12-14, 1973. R. L. Edmonds, and W. S.
Benninghoff, eds. The University of Michigan, Ann Arbor, Michigan, 1973.
Lighthart, B. Estimation of Viable Airborne Microbes Downwind from a Point
Source. Appl. Environ. Microbiol., 700-704, 1976.
Lion, M. B., and E. D. Bergmann. The Effect of Oxygen on Freeze-Dried
Escherichia coli. J. Gen. Microbiol., 24:191, 1961.
Lion, M. B. and E. D. Bergmann. Substances Which Protect Lyophilized
Escherichia coli Against the Lethal Effect of Oxygen. J. Gen. Microbiol.,
25:291, 1961.
63
-------
Lion, M. B. Quantitative Aspects of the Protection of Freeze-Dried
Escherichia coli Against the Toxic Effect of Oxygen. J. Gen. Microbiol.,
32:321, 1963.
Litton Systems, Inc. Applied Science Division. Report No. 3028.
Minneapolis, 1966.
Lloyd, R. S. Occurrence of Anthrax Bacilli in the Carpet-Wool Industry in
the United States. Arch. Ind. Hyg., 6:421-424, 1952.
Loosli, C. G. The Pathogenesis of Experimental Airborne Influenza Virus A
Infection in Mice. J. Infect. Dis., 84(2):153-168, 1949.
Loosli, C. G., H. M. Lemon, 0. H. Robertson, and E. Appel. Experimental
Airborne Influenza Infection. Influences of Humidity on the Survival
of Virus in Air, Proc. Soc. Exp. Biol. Med0, 53:205-206, 1943.
Luckiesh, M. Sampling Devices for Air-Borne Bacteria. J. Bacteriol.,
52:55-65, 1946.
Luckiesh, Mo, L. L. Holladay, and A. H. Taylor. Sampling Air for Bacterial
Content. Gen. Elec. Rev., 49:8-17, 1946.
Lund, E., and E. Lycke. The Effect of Oxidation and Reduction on the In-
fectivity of Poliomyelitis Virus. Arch. Ges. Virusforsch., 11:100, 1961.
Lurie, M. B. Experimental Epidemiology of Tuberculosis. The Prevention
of Natural Airborne Contagion of Tuberculosis in Rabbits by Ultra-Violet
Irradiation. J. Exp. Med., 79:559-572, 1944.
Lurie, M. B., A. G. Heppleston, S. Abramson, and I. B. Swartz. An Evalua-
tion of the Method of Quantitative Airborne Infection and Its Use in the
Study of the Pathogenesis of Tuberculosis. Am. Rev. Tuberc., 61:765-797,
1950.
Lurie, M. B., S. Abramson, and A. G. Heppleston. On the Response of
Genetically Resistant and Susceptible Rabbits to the Quantitative In-
halation of Human Type Tubercle Bacilli and the Nature of Resistance to
Tuberculosis. J. Exp. Med., 95:119-134, 1952.
Lurie, Ho I., and M. Way. The Isolation of Dermatophytes from the Atmo-
sphere of Caves. Mycologia, 49:178-180, 1957.
MacLean, D. M., R. M. Bannatyne, and K. F. Givan. Myxovirus Dissemination
by Air. Can. Med. Assoc. J., 96:1449, 1967.
64
-------
Mahar, H. Evaluation of Selected Methods for Chemical and Biological Test-
ing of Industrial Particulate Emissions. U.S. EPA Publication No.
600/2-76-137. Washington, B.C., May 1976.
Maltman, J. R. The Effect of Desiccation on Staphylococci. III. Dose and
Virulence Reactivation of Dried Staphylococci. Suffield Tech. Paper No.
191, 1960.
Maltman, J- R. Bacterial Responses to Desiccation and Rehydration. In:
1st Int. Symp. on Aerobiol., University of California, Berkeley, California,
1965. pp. 291-301.
Maltman, J. R., J. H. Orr, and N. A. Hinton. The Effect of Desiccation on
Staphylococcus pyogenes with Special Reference to Implications Concerning
Virulence. Am. J. Hyg., 72:335-342, 1960.
Mancinelli, R. L., and W. A. Shulls. Airborne Bacteria in an Urban Environ-
ment. Appl. Environ. Microbiol., 35 (6):1095-1101, 1978.
May, K. R. The Cascade Impactor; An Instrument for Sampling Coarse Aerosols.
J. Scio Instr., 22:187-195, 1945.
May, K. R. An Improved Spinning Top Homogeneous Spray Apparatus. J. Appl.
Phys., 20:932, 1949.
May, K. R. A Size Selective Aerosol Sampler, the Tilting Pre-Impinger.
Ann. Occupational Hyg., 2:93-106, 1960.
May, K. R. Calibration of a Modified Andersen Bacterial Aerosol Sampler.
Appl. Microbiol., 12:37-43, 1964.
May, K. R. A Multistage Liquid Impinger. Bacteriol. Rev., 30(3):559-576,
1966.
May, K. R. Physical Aspects of Sampling Airborne Microbes. In: Airborne
Microbes--17th Symp. of the Soc. for Gen. Microbiol., P. H. Gregory and
J. L. Monteith, eds. Cambridge University Press, London, 1967, pp. 60-80.
May, K. R. Prolongation of Microbial Air Sampling by a Monolayer on Agar
Gel. Appl. Microbiol., 18:513-514, 1969.
May, K. R,., and H. A. Druett. The Pre-Impinger: A Selective Aerosol
Sampler. Brit. J. Indust. Med., 10:142-151, 1953.
May, K. R., and G. J. Harper. The Efficiency of Various Liquid Impinger
Samplers in Bacterial Aerosols. Brit. J. Ind. Med., 14:287-297, 1957.
65
-------
May, K. R., and H. A. Druett. A Microthread Technique for Studying the
Viability of Microbes in a Simulated Airborne State. J. Gen. Microbiol.,
51:353-366, 1968.
May, K. R., H. A. Druett, and L. P- Packman. The Toxicity of Open Air to
a Variety of Microorganisms. Nature, 221:1146, 1969.
Mayhew, C. J., W. D. Zimmerman, and N. Hahon. Assessment of Aerosol Sta-
bility of Yellow Fever Virus by Fluorescent-Cell Counting. Appl. Mi-
crobiol., 16:263-266, 1968.
Mayhew, C. J., and H. Nicholas. Assessment of Aerosol Mixtures of Different
Viruses. Appl. Microbiol., 20(3):313-316, 1970.
Mazur, P., and W. H. Weston. Effects of Spray Drying on the Viability of
Fungus Spores. J. Bacteriol., 71:257, 1955.
McDade, J. J., and L. B. Hall. An Experimental Method to Measure the In-
fluence of Environmental Factors on the Viability and Pathogenicity of
Staphylococcus aureus. Am. J. Hyg., 77:98, 1963.
McDade, J. J., and L. B. Hall. Survival of Gram-Negative Bacteria in the
Environment. I. The Effect of Relative Humidity on Surface Exposed
Organisms. Am. J. Hyg., 80:192, 1964.
McDade, J. J., and L. B. Hall. Survival of Staphylococcus aureus in the
environment. 1. Exposure on Surfaces. Am. J. Hyg., 78:330-337, 1963.
McKissick, G. E., R. A. Griesemer, and R. L. Farrell. Aerosol Transmission
of Rauscher Leukemia in Mice. J. Nat. Cancer Inst., 45:625-635, 1970.
McKissick, G. E., L. G. Wolfe, R. L. Farrell, R. A. Griesemer, and A. Hellman.
Aerosol Transmission of Oncogenic Viruses. In: 3rd Int. Symp. on Aerobiol.
I. H. Silver, ed. Academic Press, London, 1970.
Melnick. J. L., J. Emmons, J. H. Coffey, and H. Schoof. Seasonal Distri-
bution of Coxsackie Viruses in Urban Sewage and Flies. Am. J. Hyg.,
59:164-184, 1954.
Mercer, T. Aerosol Technology in Hazard Evaluation. Academic Press,
New York, 1973.
Miles, A. A. The 'Cascade' Method of Detection and Separation of Airborne
Clusters of Bacteria. Studies in Air Hygiene. Med. Res. Council Spec.
Rept. Seru 262:38-46, 1948,
66
-------
Miller, L. F. Discussion of Incidence Acute Respiratory Disease and
Pneumonia in Naval Personnel. Conference on Newer Respiratory Disease
Viruses, NIH, October 1962. Am. Rev. Respirat. Dis., 88(2):55-57, 1963.
Miller, L. F. The Relationship of the Pattern of Respiratory Illnesses of
Navy Recruits to Routine Inoculations. Presented to Commission on Influ-
enza of Armed Forces Epidemiclogical Board, Ann Arbor, Michigan, 1963,
pp. 14-16.
Miller, W. S., R. A. Scherff, C. R. Piepoli, and L. S. Idoine. Physical
Tracers for Bacterial Aerosols. Appl. Microbiol., 9:248, 1961.
Miller, W. S., P. Demchak, C. R. Rosenberger, J. W. Dominik, and J. L.
Bradshaw. Stability and Infectivity of Airborne Yellow Fever and Rift
Valley Fever Viruses. Am. J. Hyg., 77:114-121, 1963.
Miller, W. S., and M. S. Artenstein. Aerosol Stability of Three Acute
Respiratory Disease Viruses. Proc. Soc. Expt. Biol. Med., 125:222-227,
1967.
Mitchell, R. B., J. D. Fulton, and H. V. Ellingston. A Soluble Gelatin Foam
Sampler for Airborne Micro-Organisms at Surface Levels. Am. J. Public
Health, 44:1334-1339, 1954.
Monk, G. W., M. L. Elbert, C. L. Stevens, and P. A. McCaffrey. The Effect of
Water on the Death Rate of Serratia marcescens. J. Bacteriol., 72:368, 1956,
Monk, G. W., and R. D. Mattuck. Biological Cloud Dynamics. Bull. Math.
Biophys., 18:57, 1956.
Monk, G. W., and P. A. McCaffrey. Effect of Sorbed Water on the Death Rate
of Washed Serratia marcescens. J. Bacteriol., 73:85, 1957.
Monk, G. W., P. A. McCaffrey, and M. S. Davis. Studies on the Mechanism of
Sorbed Water Killing of Bacteria. J. Bacteriol., 73:661, 1957.
Monto, A. The Tecumseh Study of Respiratory Illness. Am. J. Epidemiol.,
97:5, 1973.
Morris, E. J., Hu M. Darlow, J. F. H. Peel, andW. C. Wright. The Quanti-
tative Assay of Mono-Dispersed Aerosols of Bacteria and Bacteriophage by
Electrastatic Precipitation. J. Hyg., 59:487-496, 1961.
Morrow, P. E. Evaluation of Inhalation Hazards Based Upon the Respirable
Dust Concept and the Philosophy and Application of Selective Sampling.
Am. Ind. Hyg. Assoc. J., 25:213-236, 1964.
67
-------
Mortimer, E. A., E. Waliksky, A. J. Gonzaga, and C. H. Rammelkamp. Role of
Airborne Transmission in Staphylococcal Infections. Brit. Med. J., 1:319-
322, 1966.
Moulton, S., T. T. Puck, and H. M. Lemon. An Apparatus for Determination
of the Bacterial Content of Air. Science, 97:51-53, 1943.
Napolitano, P. J., and D. R. Rowe. Microbial Content of Air Near Sewage
Treatment Plants. Water Sewage Works, 113:480-483, 1966.
Naylow, H. B., and P- A. Smith. Factors Affecting the Viability of Serratia
marcescens During Dehydration and Storage. J. Bacteriol., 52:565-573,
1946.
Nelson, K. Capture of Aerosol Particles by Spherical Collectors. JAPCA,
8:8, 1974.
Nir, Y. D. Airborne West Nile Virus Infection. Am. J. Trop0 Med. Hyg.,
8:537-539, 1959.
Nir, Y. D., A. Beemer, and R» A. Goldwasser. West Nile Virus Infection
in Mice Following Exposure to a Viral Aerosol. Brit. J. Expt. Pathol.,
46:443-449, 1965.
Niskanen, A., and M. Aalto. Comparison of Selective Media for Coagulase-
Positive Enterotoxigenic Staphylococcus aureus. Appl. Environ. Microbiol.,
35(6):1233-1236, 1978.
Noble, W. C. Sampling Airborne Microbes: Handling the Catch. In: Airborne
Microbes, 17th Syrap. Soc. for Gen. Microbiol., P- H. Gregory and J. L.
Monteith, eds. Cambridge University Press, London, 1967. pp. 81-
101.
Noble, W. C. Recognizing Airborne Bacteria. In; 3rd Int. Symp. on Aerobiol.,
I. H. Silver, ed. Academic Press, New York, 1970.
Noble, W. C., 0. M. Lidwell, and D. Kingston. The Size Distribution of
Airborne Particles Carrying Microorganisms. J. Hyg., Camb., 61:385-391,
1963.
Noller, E., and J, C. Spendlove. An Appraisal of the Soluble Gelatin Foam
Filter as a Sampler of Bacterial Aerosols. Appl. Microbiol., 4:237-243,
1956.
68
-------
Olin, J., and J. L. King. High Volume Air Samplers. Poll. Eng., 7(l):30-32,
1975.
Orr, C., Jr., M. T. Gordon, and M. Kordecki. Thermal Precipitation for
Sampling Airborne Microorganisms: Comparison with Other Methods. Appl.
Microbiol., 4:116-118, 1956.
Ostrom, C. A., H. Wolochow, and H. A. James. Studies on the Experimental
Epidemiology of Respiratory Diseases. IX. Recovery of Airborne Bacteria
from the Oral Cavity of Humans. J. Infect. Dis., 102:251-257, 1958.
Pady, S. M. An Improved Slit Sampler for Aerobiological Investigations.
Trans. Kans. Acad. Sci., 57:157-163, 1954.
Pady, S. M. Quantitative Studies of Fungus Spores in the Air. Mycologia,
49:339-353, 1957.
Pady, S. M., and L. Kapica. Fungi in Air Masses Over Montreal During 1950
and 1951. Can. J. Bot., 34:1-15, 1956.
Parker, D. T., J. C. Spendlove, J. A. Bondurant, and J. H. Smith. Microbial
Aerosols from Food-Processing Waste Spray Fields. Journal WPCF, 49(12):
2359-2365, 1977.
Pathak, V. K., and S. M. Pady. Numbers and Viability of Certain Airborne
Fungus Spores. Mycologia, 57:301-311, 1965.
Pereira, M. R., and M. A. Benjaminson. Broadcast of Microbial Aerosols by
Stacks of Sewage Treatment Plants and Effects of Ozonation on Bacteria
in the Gaseous Effluent. Public Health Rept., 90(3):208-212, 1975.
Perry, W. D., A. C. Siegel, and C. H. Ramelkamp, Jr. Transmission of Group
A Streptococci. II. The Role of Contaminated Dust. Am. J. Hyg., 66:
96-101, 1957.
Perrott, G. St. J., and F. E. Linder. Data on Acute Upper Respiratory
Diseases. Public Health Rept., 73:121-128, 1958.
Peterson, M. Microbiological Evaluation of Incinerator Operations. Appl.
Microbiol., 18:8-13, 1969.
Peterson, M. L. Pathogens Associated with Solid Waste Processing. U.S.
Environmental Protection Agency (SW-49r), U.S. Environmental Protection
Agency, Cincinnati, Ohio, 1971. 24 pp.
69
-------
Peterson, M. The Occurrence and Survival of Viruses in Municipal Waste.
Ph.D. Thesis, Environmental Health Science, University of Michigan,
1971.
Peterson, M. Soiled Disposable Diapers: A Potential Source of Viruses.
AJPH, 64:9, 1974.
Peterson, M. L., and A. J. Klee. Studies on the Detection of Salmonellae
in Municipal Solid Waste and Incinerator Residue. Intern. J. Environ.
Studies, 2:125-132, 1971.
Philips, C. Sampling Microbiological Aerosols in the Lower Atmosphere.
Proceedings of the Atmospheric Biology Conference, 1965.
Plotkin, S. A., and M. Katz. Minimal Infective Doses of Viruses for Man
by the Oral Route. In: Transmission of Viruses by the Water Route,
G. Berg, ed. J. Wiley and Sons, New York, 1967.
Pohjanpelto, P. Stabilization of Poliovirus by Cystine. Virology, 6:472,
1958.
Poon, C. Studies on the Instantaneous Death of Airborne Escherichia coli.
Am. J. Epidemiol., 84:1-9, 1966.
Poon, C. Viability of Long-Storaged Airborne Bacterial Aerosols. J. Sanit.
Eng. Div. Proc. Am. Soc. Civil Eng., 94, SA6:1137-1146, 1968.
Proctor, D. F. Airborne Disease and Upper Respiratory Tract. Bacteriol.
Rev., 30(3):498-513, 1966.
Rammelkamp, C. H., A. J. Morris, F. J. Catanzaro, L. W. Wannamaker,
R. Chamovitz, and E. C. Marple. Transmission of Group A Streptococci.
III. The Effect of Drying on the Infectivity of the Organism for Man.
J. Hyg., 56:280-287, 1958.
Ramskill, E. A., and W. L. Anderson. The Inertial Mechanism in the Mechani-
cal Filtration of Aerosols. J. Colloid. Sci., 6:416-428, 1951.
Randall, C. W., and J. 0. Ledbetter. Bacterial Air Pollution from Activated
Sludge Units. Am. Ind. Hyg. Assn. J., 27:506-519, 1966.
Raymond, M. K., J. J. Devoyod, U. Purvis, D. Kusch, J. Lanier, R. J. Gilbert,
D. G. Till, and G. A. Jarvis. ICMSF Methods Studies. X. An International
Comparative Study of Four Media for the Enumeration of Staphylococcus
aureus in Foods. Can. J. Microbiol.,/24(3):274-281, 1978.
70
-------
Rechsteiner, J. Phenomena of Decay in Respiratory Syncytial Virus.
Bronder-Offset, Rotterdam, 1968.
Record, B. R., R. Taylor, and D. S. Miller. The Survival of Escherichia
coli on Drying and Rehydration. J. Gen. Microbiol., 28:585, 1962.
Renshaw, F. Use of Midget Impingers and Membrane Filters for Determining
Particle Counts. JAIHA, 1966.
Respiratory Diseases: Task Force Report on Problems, Research Approaches,
Need: The Lung Program. National Heart and Lung Institute, U.S. Depart-
ment of HEW, Publication No. (NH)73-432, 1972.
Riley, R. Airborne Infections. Am. J. Med., 57:466-475, 1974
Riley, R. L., and F. O'Grady. Airborne Infection; Transmission and Con-
trol. The Macmillan Company, New York, 1961. 180 pp.
Riley, R. L., C. C. Mills, F. O'Grady, L. U. Sultan, F. Wittstadt, and
D. W. Shivpuri. Infectiousness of Air from a Tuberculosis Ward. Am.
Rev. Respirat. Dis., 85:511-525, 1962.
Ringrose, R. E., B. McKown, F. G. Felton, B. 0. Barclay, H. G. Muchmore,
and E. R. Rhoades. A Hospital Outbreak of Serratia marcescens Associated
with Ultrasonic Nebulizers. Ann. Intern. Med., 68:719, 1968.
Robertson, 0. H., M. Hamburger, Jr., C. G. Loosli, T. T. Puck, H. M. Lemon,
and H. Wise. A Study of the Nature and Control of Airborne Infection in
Army Camps. J. Am. Med. Assoc., 126:993-999, 1944.
Rodebush, W. H. General Properties of Aerosols. In: Handbook on Aerosols.
Atomic Energy Commission. U.S. Govt. Printing Office, Washington, D.C.,
1950, pp. 60-63.
Rogerson, C. T. Kansas Aeroraycology I: Comparison of Media. Trans. Kans.
Acad. Sci., 61:155-162, 1958.
Rosebury, T. Experimental Airborne Infection. The Williams and Wilkins
Company, Baltimore, Maryland, 1947.
Rossano, A. T., Jr., and L. Silverman. Electrostatic Effects in Fiber Fil-
ters for Aerosols. Heat, and Ventil., 51:102, 1954.
Rountree, P. M., and M. A. Beard. Observations on the Distribution of
Staphylococcus aureus in the Atmosphere of a Surgical Ward. J. Hyg., Camb.,
60:387, 1962.
71
-------
Rountree, P. M. The Effect of Desiccation on the Viability of Staphylococcus
aureus. J. Hyg., Camb., 61:265-272, 1963.
Rowe, W. P., J. R. Seal, R. J. Huebner, J. E. Whiteside, R. L. Woolridge,
and H. C. Turner. A Study of the Role of Adenoviruses in Acute Respira-
tory Infections in a Navy Recruit Population. Am. J. Hyg., 64:211-219,
1956.
Rubbo, S. D., T. A. Pressley, B. C. Stratford, and S. Dixson. Vehicles of
Transmission of Airborne Bacteria in Hospital Wards. Lancet, 2:397-400,
1960.
Rylander, R. Measurement of Different Mechanisms of Elimination of Bacteria
from the Lung. Bacteriol. Rev., 30(3):514-516, 1966.
Saslaw, S., H. N. Carlisle, G. L. Wolfe, and C. R. Cole. Rocky Mountain
Spotted Fever: Clinical and Laboratory Observations of Monkeys After
Respiratory Exposure. J. Infect. Dis., 116:243-255, 1966.
Sattar, S. A., E. J. Synek, J. C. N. Westwood, and P. Neals. Hazard Inher-
ent in Microbial Tracers: Reduction of Risk by the Use of Bacillus
stearothemophilus Spores in Aerobiology. Appl. Microbiol., 23(6):1053-
1059, 1972.
Sawyer, W. Hospital Airborne Bacteria as Estimated by the Andersen Sampler
Versus the Gravity Settling Culture Plate. Amer. J. Clinical Pathol.,
58:5, 1972.
Sawyer, W. D., J. V. Jemski, A. L. Hogge, Jr., H. T. Eigelsbach, E. K. Wolfe,
H. G. Dangerfield, W. S. Gochenour, Jr., and D. Crozier. Effect of
Aerosol Age on the Infectivity of Airborne Pasteurella tularensis for
Macaca mulatta and Man. J. Bacteriol., 91:2180-2184, 1966.
Schneiter, R., J. E. Dunn, and B. H. Caminita. Studies in Connection with
the Selection of a Satisfactory Culture Medium for Bacterial Air Sampling.
Public Health Report, 60:789-806, 1945.
Schulman, J. L., and E. D. Kilbourne. Airborne Transmission of Influenza
Infection in Mice. Nature, 195:1129-1130, 1962.
Schulman, J. L., and E. D. Kilbourne. Experimental Transmission of Influ-
enza Virus Infection in Mice. I. The Period of Transmissibility. J.
Exp. Med., 118:257-266, 1963.
72
-------
Scott, W. J. The Effect of Residual Water on the Survival of Dried Bacteria
During Storage. J. Gen. Microbiol., 19:624, 1958.
Sehl, F. W., and B. J. Havens, Jr. A Modified Air Sampler Employing Fiber
Glass. AMA Arch. Indust. Hyg. and Occup. Med., 3:98-100, 1951.
Sellers, R. F., and J. Parker. Airborne Excretion of Foot and Mouth Disease
Virus. J. Hyg., Camb., 67:671-677, 1969.
Sellers, R. F., and K. A. J. Herniman. The Effects of Spraying on the Amounts
of Airborne Foot and Mouth Disease Virus Present in Loose-Boxes. J. Hyg.,
Camb., 70:551-556, 1972.
Sellers, R. F., and K. A. J. Herniman. The Airborne Excretion by Pigs of
Swine Vesicular Disease Virus. J. Hyg., Camb., 72:61-65, 1974.
Shechmeister, I. L. Studies on the Experimental Epidemiology of Respiratory
Infections. III. Certain Aspects of the Behavior of Type A Influenza
Virus as an Airborne Cloud. J. Infect. Dis., 87:128-132, 1950.
Shechmeister, I. L., and L. J. Goldberg. Studies on the Experimental Epi-
demiology of Respiratory Infections. II. Observations on the Behaviour
of Aerosols of Streptococcus zooepidermicus. J. Infect. Dis., 87:117,
1950.
Shipe, E. L., M. E. Tyler, and D. N. Chapman. Bacterial Aerosol Samplers.
II. Development and Evaluation of the Shipe Sampler. Appl. Microbiol.,
7:349-354, 1959.
Sigel, M. M., T. F. Scott, W. Henle, and 0. H. Janton. Q Fever in a Wool
and Hair Processing Plant. Am. J. Public Health, 40:524-532, 1950.
Sigel, M. M., D. F. Rippe, A. R. Beasley, and M. Dorsey, Jr. Systems for
Detecting Viruses and Viral Activity. In: Viruses in Water, G. Berg,
H. L. Bodily, E. H. Lennette, J. L. Melnick, and T. G. Metcalf, eds.
Am. Pub. Health Assoc., Washington, D.C., 1976. pp. 139-151.
Silver, I. H. Viability of Microbes Using a Suspended Droplet Technique.
1st Int. Symp. on Aerobiol., University of California, Berkeley, California,
1965. pp. 319-326.
Silverman, L., and F. J. Viles, Jr. A High Volume Air Sampling and Filter
Weighing Method for Certain Aerosols. J. Indust. Hyg. and Toxicol.,
30:124-128, 1948.
73
-------
Skaliy, P. Air-Borne Bacteria Studies in the Detroit, Michigan, Area.
Final Report. Contract CD3-1633, sponsored by the Detroit City Health
Department, the Michigan Department of Health and the Public Health
Service, 1953.
Slote, L. Viral Aerosols. J. Environ. Health, 38:5, 1976.
Smith, L. P., and M. E. Hugh-Jones. The Weather Factor in Foot and Mouth
Disease Epidemics. Nature, 223:712-715, 1969.
Smith, R. F., J. H. Jorgensen, C. L. Bettge, and S. L. Dayton. Evaluation
of Selective and Differential Media in the Isolation and Enumeration of
Airborne Staphylococcus aureus. Health Laboratory Science, 9(4):284-
288, 1972.
Smith, T. F. Virology Laboratory Procedure Manual. Mayo Foundation,
Rochester, Minnesota, 1978. 148 pp.
Snyder, W. C. and H. N. Hansen. Advantages of Natural Media and Environ-
ments in the Culture of Fungi. Phytopath., 37:369-371, 1957.
Sobsey, M. D. Methods for Detecting Enteric Viruses in Water and Wastewater.
In: Viruses in Water, G. Berg, H. L. Bodily, E. H. Lennette, J. L.
Melnick, and T. G. Metcalf, eds. Am. Pub. Health Assoc., Washington, D.C.,
1976. pp. 89-127.
Songer, J. R. Influence of Relative Humidity on the Survival of Some Air-
borne Viruses. Appl. Microbiol., 15:35-42, 1967.
Sonkin, L. S. Application of the Cascade Impactor to Studies of Bacterial
Aerosols. Am. J. Hyg., 51:319-342, 1950.
Sopier, C. A Study of Bacterial Aerosols at a Wastewater Plant. Journal WPCF
48(10):2367-2379, 1976.
Sorber, C. A., S. A. Schaub, and H. T. Bausum. An Assessment of a Potential
Virus Hazard Associated with Spray Irrigation of Domestic Wastewaters;
In: Virus Survival in Water and Wastewater Systems, J. F. Malina, Jr.,
and B. P- Sagik, eds. Water Resources Symposium Number Seven. Center
for Research in Water Resources. The University of Texas at Austin, 1974.
241 pp.
Sorber, C. A., and K. J. Guter. Health and Hygiene Aspects of Spray Irriga-
tion. Amer. J. Pub. Health, 65(l):47-52, 1975.
74
-------
Spendlove, J. C. Production of Bacterial Aerosols in a Rendering Plant
Process. Pub. Health Kept., 72:176-180, 1957-
Spendlove, J. C. Industrial, Agricultural and Municipal Microbial Aerosol
Problems. Developments in Industrial Microbiology, 15:20-27, 1974.
Spendlove, J. C., A. P- Adams, E. Rengers, and R. K. Dumbauld. Emission
of Microbial Aerosols from Vents of Cooling Towers. II. Diffusion Model
Comparisons. Developments in Industrial Microbiol., 21:(to be published),
1978.
Spicer, C0 C. Influence of Some Meteorological Factors in the Incidence
of Poliomyelitis. Brit. J. Prevent, and Social Med., 13:139-144, 1959.
Spickard, A., H. Evans, V. Knight, and K. Johnson. Acute Respiratory Dis-
ease in Normal Volunteers Associated with Coxsackie A-21 Viral Infection.
III. Response to Nasopharyngeal and Enteric Inoculation. J. Clin. Invest
42:840-852, 1963.
Stevens, R. E. Preliminary Study—Air Contamination With Microorganisms
During the Use of the Air Turbine Handpiece. JADA, 66(2):237-239, 1963.
Sulkin, E. S. Laboratory Acquired Infections. Bacteriol. Rev., 25:203-207,
1961.
Thomas, G. An Adhesive Surface Sampling Technique for Airborne Viruses.
J. Hyg., Camb., 68:273-282, 1970.
Thomas, G. Sampling of Airborne Viruses. In: 3rd Int. Symp. on Aerobiol.,
I. H. Silver, ed. Academic Press, New York, 1970.
Thome, H. V., and T. M. Burrows. Aerosol Sampling Methods for the Virus
of Foot and Mouth Disease and the Measurement of Virus Penetration Through
Aerosol Filters. J. Hyg., 58:409-418, 1960.
Tigertt, W. D., A. S. Benenson, and W. S. Gochenour. Airborne Q Fever.
Bacteriol. Rev., 25:285-293, 1961.
Treskunov, A. A. Principles of Development of Instruments for Determining
Bacterial Contamination of the Air. Biomedical Engineering, 5:36-37,
1971.
75
-------
Trouwborst, T., and J. C. DeJong. Interaction of Some Factors in the
Mechanism of Inactivation of Bacteriophage MS-2 in Aerosols. Appl.
Microbiol., 26(3):252-257, 1973.
Trouwborst, T., and S. Kuyper. Inactivation of Bacteriophage T3 in
Aerosols: Effect of Prehumidification on Survival After Spraying from
Solutions of Salt, Peptone, and Saliva. Appl. Microbiol., 27(5):834-837,
1974.
Trouwborst, T., J. C. DeJong, and K. C. Winkler. Mechanism of Inactivation
of Aerosols of Bacteriophage Tl. J. Gen. Virol., 15:235-242, 1972.
Trouwborst, T., and K. C. Winkler. Protection Against Aerosol-Inactivation
of Bacteriophage Tl by Peptides and Amino Acids. J. Gen. Virol., 17:
1-11, 1972.
Turner, A., and G. Hill. Calibration of the Andersen 2000 Disposable Air
Sampler. Department of Environmental Sciences and Engineering, School of
Public Health, University of North Carolina Chapel Hill, North Carolina.
Tyler, M. E., and E. L. Shipe. Bacterial Aerosol Samplers. I. Development
and Evaluation of the All-Glass Impinger. Appl. Microbiol., 7:337-348,
1959.
Tyler, M. E., E. L. Shipe, and R. B. Painter. Bacterial Aerosol Samplers.
III. Comparison of Biological and Physical Effects in Liquid Impinger
Samplers. Appl. Microbiol., 7:355-362, 1959.
Tyrrell, D. A. J. The Spread of Viruses of the Respiratory Tract
by the Airborne Route. In: Airborne Microbes, Seventeenth Symp. Soc.
Gen. Microbiol., P. H. Gregory and J. L. Monteith, eds. Cambridge Uni-
versity Press, London, 1967.
Vlodavets, V. V. Dynamics of the Bacterial Aerosol in Dust and Drop Phases.
Mikrobiologiya, 33:91, 1964.
Vlodavets, V. V., E. I. Zuikova, and M. A. Motova. A Comparative Evaluation
of the Methods of Bacteriologic Investigation of Air at Negative Tempera-
tures. Microbiologiya, 27:632.
Vlodavets, V. V., S. Y. Gaidamovich, and V. R. Obukhova. Methods of Trapping
Influenza Virus in the Droplet Phase of an Aerosol. Problems of Virology,
5:728, 1960.
76
-------
Walton, W. H., and W. C. Prewitt. The Production of Sprays and Mists of
Uniform Drop Size by Means of Spinning Disc Type Sprayers. Proc. Phys.
Soc., 62B:341, 1949.
Warren, J. C., T. G. Akers, and E. J. Dubovi. The Effect of Prehumidifica-
tion on Sampling of Selected Airborne Viruses. Appl. Microbiol., 18:
893-896, 1969.
Watkins, H. M. S., L. J. Goldberg, E. E. Deig, and W. R. Leif. Behavior
of Colorado Tick Fever, Vesicular Stomatitis, Neurovaccinia and En-
cephalomyocarditis Viruses in the Airborne State. In: 1st Int. Symp.
on Aerobiol., 1963, Dimmick, ed. University of California, Berkeley,
California, 1965. pp. 381-388.
Webb, S. J. Chloramphenicol and the Survival of Airborne Bacteria. Nature,
London, 183:1072, 1959.
Webb, S. J. Factors Affecting the Viability of Airborne Bacteria. I.
Bacteria Aerosolized from Distilled Water. Can. J. Microbiol. 5:649-669,
1959.
Webb, S. J. Factors Affecting the Viability of Airborne Bacteria. II. The
Effect of Chemical Additives on the Behaviour of Airborne Cells. Can. J.
Microbiol., 6:71-87, 1960.
Webb, S. J. Factors Affecting the Viability of Air-Borne Bacteria. III.
The Role of Bonded Water and Protein Structure in the Death of Air-Borne
Cells. Can. J. Microbiol., 6:89, 1960.
Webb, S. J. Factors Affecting the Viability of Air-Borne Bacteria. IV.
The Inactivation and Reactivation of Air-Borne Serratia marcescens by
Ultraviolet and Visible Light. Can. J. Microbiol., 7:607, 1961.
Webb, S. J. Factors Affecting the Viability of Airborne Bacteria. V. The
Effect of Desiccation on Some Metabolic Systems of Escherichia coli.
Can. J. Microbiol., 7:621-632, 1961.
Webb, S. J. Factors Affecting the Viability of Airborne Bacteria. VII.
The Relationship Between the Structure of Chemical Additives and Their
Action on Airborne Cells. Can. J. Biochem. Physiol., 41:867, 1963.
77
-------
Webb, S. J. The Effect of Relative Humidity and Light on Air-Dried
Organisms. J. Appl. Bacteriol., 26:307-313, 1963.
Webb, S. J. Bound Water, Metabolites and Genetic Continuity. Nature,
London, 203:374, 1964.
Webb, S. J. Bound Water in Biological Integrity. Charles C. Thomas,
Springfield, Illinois, 1965.
Webb, S. J. Radiation, Relative Humidity and the Mechanism of Microbial
Death in Aerosols. 1st Int. Symp. on Aerobiol., 1963. University of
California, Berkeley, California, 1965. pp. 369-377.
Webb, S. J., R. Bather, and R. W. Hodges. The Effect of Relative Humidity
and Inositol on Airborne Viruses. Can. J. Microbiol., 9:87-92,
1963.
Webb, S. J., D. V- Cormack, and H. G» Morrison. Relative Humidity, Inositol
and the Effect of Radiation on Air-Dried Microorganisms. Nature, London,
201:1103-1105, 1964.
Webb, S. J., and M. D. Dumasia. Bound Water, Inositol and the Effect of
X-Rays on Escherichia coli. Can. J. Microbiol., 10:877, 1964.
Webb, S. J., M. D. Dumasia, and J. Singh Bhorjee. Bound Water, Inositol,
and the Biosynthesis of Temperate and Virulent Bacteriophage by Air Dried
Escherichia coli. Can. J. Microbiol., 11:141-150, 1965.
Wells, M. W. The Seasonal Patterns of Measles and Chickenpox. Am. J. Hyg.,
40:279-317, 1944.
Wells, W. F., and H. W. Brown. Recovery of Influenza Virus Syspended in
Air and Its Destruction by Ultraviolet Radiation. Am. J. Hyg., 24(2):
407-413, 1936.
Wells, W. F., and M. W. Wells. Airborne Infection. J. Am. Med. Assoc.,
107:1698-1103, 1936.
Wells, W. F., and p. Zapposid. The Effects of Humidity on Beta Streptococci
Atomized in Air. Science, 96:277-278, 1948.
78
-------
Wells, W. F. Airborne Contagion and Air Hygiene. Harvard University Press,
Cambridge, Massachusetts, 1955.
Westwood, J. C. N., E. A. Boulter, E. T. Bowen, and H. B. Maber. Experi-
mental Respiratory Infection with Pox Viruses. 1. Clinical, Virological,
and Epidemiological Studies. Brit. J. Exp. Path., 48:453, 1966.
White, L. A., D. J. Hadley, D. E. Davids, and R. Naylor. Improved Large
Volume Sampler for the Collection of Bacterial Cells from Aerosols. Appl.
Microbiol., 29(3):335-339, 1975.
White, R. J., and S. H. Madin. Pathogenesis of Murine Hepatitis: Route of
Infection and Susceptibility of the Host. Am. J. Vet. Research, 25:1236-
1240, 1964.
Williams, R. E. 0. Epidemiology of Airborne Staphylococcal Infection.
Bacteriol. Rev., 30(3) -.660-677, 1966.
Williams, R. E. 0. Spread of Air Borne Bacteria Pathogenic for Men. In:
Air Borne Microbes., P- H. Gregory and J. L. Monteith, eds. Cambridge
University Press, 1967- 268 pp.
Williamson, A. E., and H. B. Gotaas. Aerosol Sterilization of Airborne
Bacteria. Ind. Med. Surg. 11, Ind. Hygiene Section 3, Section 1:40, 1942.
Willoughby, D. S. Nutritional Factors Affecting the Aerosol Stability of
Microorganisms. I. The Effect of Growth Medium. Suffield Techn. Paper
No. 259 (unclassified), 1962.
Wilson, W. L. The Construction of Automatic Continuous and Intermittent
Sampling Devices. In: Encyclopedia of Instrumentation for Industrial
Hygiene. University of Michigan Institute of Industrial Health, Ann Arbor,
1956, pp. 546-550.
Winkler, W. G. Airborne Rabies Virus Isolation. Bull. Wildlife Dis. Assoc.,
4:37-40, 1968.
Winslow, C.-E. A. The Role of the Molecular Filter Membrane in the Field
of Public Health. (Editorial). Am. J. Pub. Health, 43:766-768, 1953.
Wolf, H. W., M. M. Harris, and W. R. Dyer. Staphylocoecus aureus in Air
of an Operating Room. J. Am. Med. Assoc., 169:1983-1987, 1959.
79
-------
Wolf, H. W., P. Skaliy, L. B. Hall, M. M. Harris, H. M. Decker, L. M.
Buchanan, and C. M. Dohlgren. Sampling Microbiological Aerosols. Public
Health Monograph No. 60, Public Health Service Publication No. 686,
U.S. Department of Health, Education, and Welfare, Superintendent of
Documents, U.S. Govt. Printing Office, Washington, D.C., 1965, 53 pp.
Wolf, L. G., R. A. Griesmer, and R. L. Farrell. Experimental Aerosol Trans-
mission of Yaba Virus in Monkeys. J. Nat. Cancer Inst., 41:1175-1195, 1968.
Wolf, W. R. Study of the Vibrating Reed in the Production of Small Droplets
and Solid Particles of Uniform Size. Rev. Sci. Instrum., 32:1124, 1961.
Wolfe, E. K., Jr. Quantitative Characterization of Aerosols. Bacteriol.
Rev., 25:194-202, 1961.
Wolfe, E. K. Microbial Survival in Air. In: 3rd Int. Symp. on Aerobiol.,
I. H. Silver, ed. Academic Press, New York, 1970. pp. 214-215.
Won, W. D., and H. Ross. A Freeze-Tolerant Solid Medium for Detection and
Sampling of Airborne Microorganisms at Subzero Temperature. Cryobiol.,
3:88-93, 1966.
Won, W. D., and H. Ross. Effect of Diluent and Relative Humidity on Ap-
parent Viability of Airborne Pasteurella pestis. Appl. Microbiol., 14:
742-745, 1966.
Won, W. D., and H. Ross. A Modified Freeze-Tolerant Base for Solidifying
Media for Sampling Microbial Aerosols at Subzero Temperatures. Bacteriol.
Proc., A121:21, 1967.
Won, W. D., and H. Ross. Behavior of Microbial Aerosols in a -30°C Environ-
ment. Cryobiology, 4:337-340, 1968.
Woodcock, A. H. Bursting Bubbles and Air Pollution. Sew. Ind. Wastes,
27:1189-1192, 1955.
Wright, D. N., G. D. Bailey, and M. T. Hatch. Survival of Airborne Myco-
plasma as Affected by Relative Humidity. J. Bacteriol., 95:251-254, 1968.
Wright, T. J., V. W. Greene, and H. J. Paulus. Viable Microorganisms in an
Urban Atmosphere. JAPCA, 19:337, 1969.
Zentner, R. J. Techniques of Aerosol Formation. Bact. Rev., 25:188, 1961.
80
-------
Zenter, R. J. Physical and Chemical Stresses of Aerosolization. Bacteriol.
Rev., 30(3):551-558, 1966.
Zimmerman, L. Survival of Serratia marcescens After Freeze-Drying or Aero-
solization at Unfavourable Humidity. I. Effects of Sugars. J. Bact.,
84:1297, 1962.
Zimmerman, L. Additives to Increase Aerosol Stability. In: 1st Int. Symp.
on Aerobiol., University of California, Berkeley, 1965. pp. 285-287.
81
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-79-131
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
ANALYSIS OF AIRBORNE VIABLE BACTERIA AT SOLID WASTE
PROCESSING FACILITIES
5. REPORT DATE
August 1979 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
M. W. Fletcher and D. E. Fiscus
8. PERFORMING ORGANIZATION REPORT NO.
MRI Project No. 4033-L
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Midwest Research Institute
425 Volker Boulevard
Kansas City, Missouri 64110
10. PROGRAM ELEMENT NO.
1NE624, SOS WF, Task 6.1
11. CONTRACT/GRANT NO.
68-02-1871
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory—Gin.,OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Analytical Methods
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
See also EPA-600/2-78-152 and EPA-600/2-79-090.
Project Officer: Carlton C. Wiles 513/684-7881.
16. ABSTRACT
This report presents a synopsis of aerobiological testing methodologies used by
Midwest Research Institute during studies conducted for the Environmental Protection
Agency. The purpose of the programs was to determine relative levels of airborne
bacteria and virus aerosols within and around waste handling facilities. The
facilities tested were the St. Louis Refuse Processing Plant, the Browning Ferris/
Raytheon Service Company Resource Recovery Plant (Houston), and at three other types
of waste handling facilities, i.e., an incinerator, a waste treatment plant, and a
landfill. The report presents microbiological air sampling methodologies, field
sample handling procedures, and laboratory analysis methodologies. It also includes
a general discussion of pertinent considerations, recommendations for future research,
and an extensive bibliography.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
Bacteria
Viruses
Microorganisms
Wastes
Refuse disposal
Air pollution
Laboratory methods
Air emissions
Ambient air
Refuse derived fuel
13B
8. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
90
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77)
82
U.S. GOVERNMENT PRINTING OFFICE' 1979 -657-060/5418
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