PB-223 345
A STUDY OF INSTITUTIONAL SOLID WASTES
WEST VIRGINIA UNIVERSITY
PREPARED FOR
ENVIRONMENTAL PROTECTION AGENCY
SEPTEMBER 1973
DISTRIBUTED BY:
National Technical Information Service
U. S. DEPARTMENT OF COMMERCE
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4. Title and Subtitle
A STUDY OF INSTITUTIONAL SOLID WASTES
BIBLIOGRAPHIC DATA
SHEET
1. Report No.
teport No.
EPA-670/2-73-083
I j. necipienc s *.i_i.c.a.. >••••
PB-223 345 _
5. "Report Date
1973 issuing date
6.
7. Author(s)
J. C. Burchinal
8- Performing Organization Rept.
No.
. Performing Organization Name and Address
Professor of Civil Engineering
West Virginia University
Morgantown, West Virginia
10. Project/Task/Work Unit No.
11. Contract/Grant No.
EP-00265
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
National Environmental Research Center
Office of Research and Development
Cincinnati, Ohio 45268
13. Type of Report & Period
Covered
final
14.
15. Supplementary Notes
16. Abstracts
Improved systems and equipment for handling and disposing of solid
wastes in multi-story buildings, especially institutions, are needed.
This study was undertaken to analyze various aspects of the solid waste
problem with a unit approach. Emphasis was placed on hospital wastes,
which are a special source of disease dissemination to the public, be-
cause of their disease-organism content. The study was carried out at
the West Virginia Medical Center over a 2-year period and was concerned
with the quantities of generation and physical and chemical qualities of
refuse produced at that time. Information from the study was coordinatec
with similar information obtained in other parts of the country to as-
certain compatibility of data and broaden the data base. Bacteriologi-
cal and virological studies are made. Safetv precautions, costs, and
recommended sampling procedures are given.
17. Key Words and Document Analysis. 17a. Descriptors
*Waste disposal, *Wastes , '"'Refuse disposal, Cost engineering, Costs,
^Hospitals, *Diseases, Disease vectors, Data, Data acauisition, Chemical
properties, Bacteriology, Virology, Safety, Sampling
NAtfSNAL TECHNICAL
INFORMATION SERVICE
U S Deoartmant ol Comm»rc«
SpringlMd. VA. 22151
17b. Idemifiers/Open-Ended Terms
*Solid waste disposal, Resource recovery, *West Virginia Medical
Center, *Institutional wastes
17c. COSATI Fie Id/Group 13-B
18. Availability Statement
Release to public
19. Security Class (This
Report)
UNCLASSIFlEn
Security Class (This
Page
UNCLASSIFIED
21. No. of gages
22. Price
USCOMM-DC I4B52-P72
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11
REVIEW NOTICE
The Solid Waste Research Laboratory of the
National Environmental Research Center - Cincinnati,
U.S. Environmental Protection Agency, has reviewed
this report and approved its publication. Approval
does not signify that the contents necessarily re-
flect the views and policies of this laboratory or
of the U.S. Environmental Protection Agency, nor
does mention of trade names or commercial products
constitute endorsement or recommendation for use.
The text of this report is reproduced by the
National Environmental Research Center - Cincinnati
in the form received from the Grantee; new prelimi-
nary pages have been supplied.
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Ill
FOREWORD
Man and his environerrmt must be protected from the
adverse effects of pesticides, radiation, noise and other
forms of pollution, and the unwise management of solid
waste. Efforts to protect the environment reauire a
focus that recognizes the interplay between the com-
ponents of our physical environment—air, water, and
land. The National Environmental Research Centers
provide this multidisciplinary focus through programs
engaged in
• studies on the effects of environmental
contaminants on man and the biosphere, and
• a search for ways to prevent contamina-
tion and to recycle valuable resources.
In an attempt to solve the problems involved in
solid waste disposal, this study investigated wastes
generated by a public health institution. Emphasis
was given to hospital wastes because of their disease
organism content, which can be particularly harmful
to man.
A. W. Breidenbach, Ph.D.
Director
National Environmental
Research Center, Cincinnati
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V
PREFACE
NATURE AND SCOPE OF REPORT
The report herein presented Is a compilation of several diverse but
coordinated investigative efforts on various aspects of solid waste management
in a teaching hospital (institution) made possible by a grant (EC 00265-02) to
the Department of Civil Engineering, West Virginia University by the Solid Waste
Management Office of the U. S. Environmental Protection Agency (formerly of the
, "3. Public Health Service).
The research plan on which the grant was based called for a comprehensive
investigation of all solid wastes generated by the teaching and hospital portions
of the University Medical Center complex over a two-year study period. Studies
of the quantities of refuse produced the physical, chemical, bacteriological,
and virological characteristics of the wastes were undertaken. Safety consider-
ations, handling costs, and future sampling procedures were spin-offs from this
investigation. This is a final report of the efforts expended in this study of
institutional solid wastes.
AUTHORSHIP CREDITS
Authorship credit for information contained in chapters of this report is
due to the following participants in the project:
Waste Generation R. Zaltzman, E. G. Cleveland, L. P. Wallace
F. Zepeda
Physical Characteristics R. Zaltzman, L. P. Wallace, F. Zepeda
Chemical Characrer_i•• tji.cs R. Zaltzman, A. A. Galli, R. L. Morris
Bacterio?.c g ic aT_ Sr..tJ ^es R. Zaltzman, D. H. Armstrong, R. J. Smith
J. A. Trigg
Viro logic-..' .";j; LCS T. A. DiNicola
Cost Studies J. I. Usmiani
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VI
Safety Consideration J. C. Burchinal
Introduction
Problem Evaluation
Data and Sample Collection J. C. Burchinal
Recommended Sampling Procedures L. P. Wallace
Summary
Overall Editing
ACKNOWLEDGMENTS
The project staff is indebted to many individuals for information,
cooperation, and assistance during the report period. Among those who have
been particularly helpful are:
R. Zaltznuin, Department of Civil Engineering, West Virginia University
B. Linsky, Daparttr.ent of Civil Engineering, West Virginia University
Dr. B. E. Kirk, Department of Microbiology, West Virginia University
Dr. H. A. Wilson, Department of Bacteriology, West Virginia University
Dr. C. E. Andrews, Provost of Health Sciences, West Virginia University
H. Harper, Administrative Assistant to the Provost, -West Virginia University
E. L. Staples, Director, University Hospital, West Virginia University
L. D. Miller, Associate Director, University Hospital, West Virginia
University
H. George, Executive Housekeeper, University Hospital, West Virginia
University
Mrs. S. StaallvGod, Director, Dietary Department, University Hospital,
West Virginia University
Dr. D. F. Kohn, Director, Aninal Laboratories, University Hospital,
Uest Virginia University
Dr. D. L. Kimrr.al, Chairman, Anatomy Department, University Hospital,
West Virginia University
J. A, Ambrose, Physical Plant, Medical Center, West Virginia University
3. L. Gale, Physical Plant, Solid Waste Collection, West Virginia UniversU;
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TABLE OF CONTENTS
Page
Preface v
Nature and Scope of Report . • v
Authorship Credits v
Acknowledgements Y "^
Table of Contents v ^1
List of Tables r*
List of Figures xl
I - INTRODUCTION , 1
Need for Study 1
Objectives of Study. 2
Organization for Study 3
Nature and Scope of Study 4
II - DATA AND SAMPLE COLLECTION 5
Literature Survey and Problem Discussion. 5
Facility Description 11
Medical Center 11
Engineering Laboratories. 13
Sampling Procedure. 13
Hospital Sampling Procedures. 14
Basic Sciences Sampling Procedures 19
Initial Sample Preparation 20
III - SOLID WASTE GENERATION BY MEDICAL CENTER AND INDIVIDUAL UNITS 22
Introduction 22
Statistical Procedures 22
Results and Discussion 23
Total Wastes Generated 23
Unit Wastes Generated 28
Waste Disposal Practices 41
Conclusions and Recommendations , 45
Waste Generation 45
Waste Handling. ., 47
Facilities - Operational Recommendations 48
IV - PHYSICAL AND CHEMICAL COMPOSITION OF MEDICAL CENTER SOLID WASTES.... 50
Introduction 50
Physical Analyses....« 50
Solid Waste Densities 52
Waste Classification 55
Conclusions. 53
Chemical Analysis 59
Sample Preparation 59
Moisture Content 59
Volatile Solids Content 70
Ash Residue. 71
Gross Calorific Value 72
Sulfur Content 73
Phosphorus Content 74
Nitrogen Content 75
Carbon Content 75
Hydrogen Content 76
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Vlll
Page
V - BACTERIOLOGICAL AND VIROLOGICAL STUDIES 78
Introduction 78
PHASE 1 • Bacteriological Studies 78
Methods and Materials 79
Collection and Preparation of Samples 80
Analysis • 81
Results and Discussion 85
Conclusions 91
PHASE 2 - Bacteriological Studies 92
Collection of Samples 92
Analys is 93
Results and Discussion < 97
Conclusions 116
PHASE 3 - Bacteriological Studies « 117
Solid Waste Handling 118
Methods and Materials 119
Results and Discussion 122
Conclusions 132
Virological Studies 133
Introduct ion 133
Methods and Materials 133
Results and Discussion 137
Persistence Studies 142
Conclusions 156
VI - SAFETY PRECAUTIONS, COSTS AND RECOMMENDED SAMPLING PROCEDURE * 160
Safety Precautions k 160
Solid Wastes Handl ing Costs 161
Recommended Sampling Procedures 162
VII - SUMMARY 164
List of References 169
Appendix A 177
Appendix B 188
Appendix C •. 205
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IX
Table II-l
Table II-2
Table III-1
Table III-2
Table III-3
Table III-4
Table III-5
Table III-6
Table III-7
Table III-8
Table IV-1
Table IV-2
Table IV-3
Table IV-4
Tahle IV-5
Table IV-6
Table IV-7
Table IV-8
Table IV-9
Table IV-10
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
IV-11
IV-12
IV-13
IV-14
IV-15
IV-16
IV-17
IV-18
IV-19
IV-20
IV-21
Table V-l
Table V-2
Table V-3
Table V-4
Table V-5
Table V-6
Table V-7
Table V-8
Table V-9
LIST OF TABLES
Page
Hospital stations and sampling frequency 15
Basic Sciences stations and sampling frequency 17
Daily solid waste generation totals.
Comparison of solid waste generation rates
Solid waste generation by hospital units (Initial Study)
Solid waste generation by hospital units (Supplemental Study).
Solid waste generation by basic sciences units (Initial Study)
Solid waste generation by basic sciences units (Supplemental..
Study)
Personnel classifications and room use categories
Solid waste generation equations
Weight-volume relationships
Mean hourly solid waste generation totals
Hospital areas generating wastes and their typical waste
products
Additional hospital areas generating wastes and their typical
waste products
A.P.W.A. classification of refuse materials
Medical Center classification of refuse materials
Unit weight by categories
Daily hospital refuse generation by category
Daily Basic Sciences refuse generation by category
Mean Medical Center and food service waste generation by
category
Sampling data for the main kitchen
Moisture content
Volatile solids content
Ash residue
Gross calorific value
Sulfur content
Phosphorus content
Nitrogen content
Carbon content
Hydrogen content
Chemical test comparisons
Total and individual counts
Microbial counts of organisms in Groups I-V
Counts of specific organisms in Groups III and V
Geometric mean of bacterial counts
Airborne bacterial counts from loose refuse
Airborne bacterial counts from bagged refuse
Frequency distribution of total colonies of bagged and loose
refuse
Distribution of colonies from loose and bagged refuse on
Anders en Sampler stages
Effect on virus recovery of autoclaving and pulverizing solid
waste samples prior to artificial contamination with
vaccinia virus, Poliovirus 1 or Coxsackievirus A-9
24
25
29
31
32
33
35
39
53
54
56
57
58
59
60
64
65
66
67
70
71
72
73
74
75
75
76
76
77
98
101
104
108
123
124
126
131
139
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LIST OF TABLES (continued)
Table V-10 Lffect of the pH of the extraction medium upon the recovery
of virus from autoclaved, yalverized samples of solid
waste artifically contaminated 24 hours previously
with vaccinia virus, Policvirus 1, Coxsackievirus
A-9 and influenza virus PR-8
Table V-ll Recovery of Poliovirus 1 and Coxsackievirus A-9 from arti-
fically contaminated solid waste suspended in distilled
water
Table V-12 Persistence of vaccinia virus, Poliovirus 1, Coxsackievirus
A-9 and influenza virus PR-8 on cotton balls at room
temperature
Table V-13 Persistence of vaccinia virus, Poliovirus 1,, Coxsackievirus
A-9 and influenza virus PR-8 on paper towels at room
temperature
Table V-14 Persistance of vaccinia virus, Poliovirus 1, Coxsackievirus
A-9 and influenza virus PR-8 on cotton cloth at room
temperature
""able V-15 Persistance of vaccinia virus, Poliovirus 1, Coxsackievirus
A-9 and influenza virus PR-8 on surgical gauze at room
temperature
Tible V-16 Persistance of vaccinia virus, Poliovirus 1, Coxsackievirus
A-9 and influenza virus PR-8 on wax coated paper cups at
room temperature
Table V-17 Persistance of vaccinia virus, Poliovirus 1, Coxsackievirus
A-9 and influenza virus PR-8 on an autoclaved, pulverized
solid waste mixture at room temperature
Table V-18 Persistance of vaccinia virus, Poliovirus 1, Coxsackievirus
A-9 and influenza virus PR-8 on an autoclaved, pulverized
sample of office papers at room temperature
Table V-19 Persistance of vaccinia virus, Poliovirus 1, Coxsackievirus
A-9 and influenza virus PR-8 on an autoclaved, pulverized
sample of paper towels, tissues and bags at room tem-
perature
able V-20 Persistance of vaccinia virus, Poliovirus 1, Coxsackievirus
A-9 and influenza virus PR--8 on an autoclaved, pulverized
sample of paper and plastic cups at room temperature
able V-21 Persistance of vaccinia virus, Poliovirus 1, Coxsackievirus
A-9 and influenza virus PR-8 on an a.atoclaved, pulverized
sample of surgical tapes, gauze ard bandages at room
temperature
Table V-22 Effect on virus recovery of pulverizing paper towels after
artificial contamination with vaccinia virus, and Cox-
sackievirus A-9. Transmission cf virus from contaminated
to uncontaminated paper towels by direct contact
Table VI-1 Labor efficiencies for refuse sorting, sampling and grinding..
Table A-l Mean hospital unit population - Monday-Friday
lable A-2 Mean hospital unit population - Saturday-Sunday
|able A-3 Mean Basic Sciences unit population - Monday-Friday
Table A-4 Mean daily waste production
fable A-5 Solid waste production rate calculations
Table A-6 Soiled linen quantities
Table C-l Hospital stations and sampling data
Page
140
141
143
144
145
147
148
149
150
152
153
154
155
163
178
180
182
183
184
186
226
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xi
LIST OF FIGURES
Page
Figure III-l Solid waste flow chart. 42
Figure IV-1 Physical analysis process 51
Figure V-l Flow diagram for bacteriological examination 82
Figure V-2 Incinerator and chute closet area 120
Figure V-3 Anders en sieve sampler 121
Figure V-4 Colony size distribution - loose refuse 128
Figure V-5 Colony size distribution - bagged refuse 129
Figure V-6 Scatter diagram of stage 6 organisms per total organisms per
cubic foot of air 130
Figure C-l Histogram for bacterial counts Test. 0 219
Figure C-2 Histogram for bacterial counts Test 1 220
Figure C-3 Histogram for bacterial counts Test 2. 221
Figure C-4 Histogram for bacterial counts Test 3 222
Figure C-5 Histogram for bacterial counts Test 4 223
Figure C-6 Brewer anaerobic jar 225
Figure C-7 Comparison of the total microbial counts for 15 nursing
stations 229
Figure C-8 Comparison of the group I bacterial counts for 15 nursing
stations 230
Figure C-9 Comparison of the group TI bacterial counts for 15 nursing
stations 231
Figure C-10 Comparison of the group III bacterial counts for 15 nursing
stations 232
Figure C-ll Comparison of the group IV bacterial counts for 15 nursing
stations 233
Figure C-12 Comparison of the group V bacterial counts for 15 nursing
stations 234
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I. INTRODUCTION
Need for Study
It is almost unbelievable that multi-million dollar buildings to serve
specific purposes would be designed without proper consideration for the collection
and disposal of the solid wastes being produced by the occupants of such build-
ings. Locally and nationally, there has been a lack of progress in developing
improved systems and equipment for handling and disposing of solid wastes in
multi-story buildings, especially institutions,, Newly constructed buildings are
in many cases still utilizing solid waste handling systems that were conceived
decades ago, and it is not unusual to find rows of garbage cans lined up behind
a multi-million dollar monumental building serving today's institutional needs,,
Since a great number of institutions are somewhat repetitious in the solid
waste which they produce, it appeared that a study could well be undertaken to
make an analyses of various aspects of the solid waste problem based on a unit
approach. Institutional facilities such as hospitals, school buildings, dormi-
tories, and apartments fall under this general description.
Although tremendous progress has been made in the field of medicine with
new methods and equipment being developed for the care and treatment of hospital
patients, to date, very little progress has been made in developing new methods
for disposing of solid waste from these institutions. The large quantities and
wide diversities of solid wastes handled and disposed by health care facilities
orpa^f a multitude of sanitation, economic, and administrative problems for these
institutions.
The concentration of people having disease organisms places solid waste
from hospitals as a potential source of disease dissemination to the public.
Because of the dearth of reliable data on the characteristics and contamination
potential of the wastes from medical care facilities, investigations were needed
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to properly characterize the types, quantities, and points of origin of refuse
originating within health care facilities. With this information, hospital
administrators, designers, public health officials would be in a better position
to develop the necessary solutions in order to properly handle this problem.
Recognizing that there are hospitals in every major community in the United
States, acknowledging that most of these facilities already in existence have
I
not provided solutions to existing problems, and observing the trend toward the
increased use of single service or "disposable" items, a study, of this nature
was imperative.
Objectives of Study
As outlined in the proposal accepted by the Solid Waste Management Office
for award of the grant to study the problems of institutional solid waste, the
following specific aims are enumerated:
1. To determine the physical and chemical composition of the solid
wastes from one medical school and hospital referral complex.
2. To determine whether bacteria and viruses are present in significant
degrees and to do some isolation and identification.
3. To provide a classification basis and obtain quantity values for the
wastes from the significant floors and departments.
4. To establish a safe procedure for studies on potential pathogenic
wastes.
5. To provide information about solid wastes on a waste-producing unit
basis that can be used by designers in establishing waste handling
procedures and facilities for hospitals and other medical complexes.
f. To develop a sampling procedure that could be used in future solid
waste studies including statistical analysis of the data to determine
the percent errors and confidence in the sampling procedure.
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In accomplishing these aims or objectives, reliable data on the character
and quantity of refuse produced would provide a data base to which quantities
expected in the future could be added. A reliable data base for each of the
various wards, departments, and laboratories of such an institution, would allow
progress to be made in overcoming the problems associated with waste management
in such institutions.
Organization for Study
The overall project direction was provided by the principal investigator,
Professor J. C. Burchinal, Department of Civil Engineering, West Virginia
University who has been active in teaching and investigating sanitary engineering
problems for many years. Cooperation with and by the administrative and opera-
ional personnel of the Medical Center, imperative for successful undertaking of
such a project, was obtained.
Physical analyses were made in the Civil Engineering Laboratory after
collection and transport from the Medical Center. Chemical analyses were made
in the engineering complex with assistance from the Chemical Engineering Depart-
ment when needed. Virological studies were conducted by the Department of
Microbiology under the direction of Dr. B. E. Kirk. Bacteriological studies
were undertaken primarily in the Sanitary Engineering Labs of the Engineering
Sciences Building. Cost studies were made by direct interrogation of hospital
administrative personnel and examination of hospital documents. Statistical
studies were made with the assistance of the Statistical Department under the
direction of Dr. S. Wearden, with most analyses being run at the University Computer
Center on the 360/75 IBM computer system. Project direction of control was maintained
by Professor Burchinal and his staff, with assistance from Professor R. S. Zaltzman
and with extensive use of graduate students in conducting specific portions of the
study. In addition, large numbers of students were employed as part-time collectors
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sorters, grinders, and monitors of solid waste generation, production, handling,
and disposal for the various portions of the study. The final report is a
compilation of information obtained from individual dissertations, theses, and
problem reports during the course of the two-year study period.
Nature and Scope of Study
While it would be beneficial to obtain information from many institutions,
it was decided to limit this investigation to the West Virginia University Medical
Center complex because of funds and distances involved. The study is primarily
concerned with quantities and qualities of refuse being produced at the present
time. This project did not try to obtain speculative information on expected
quantities or changes in solid waste patterns in future years or in future
institutions. It was felt that with a reliable data base, predictions on future
quantities could be made as information becomes available.
Information from this study was coordinated with similar information obtained
in other parts of the country to ascertain compatability of data and broaden the
data base. The project was conducted over a two-year study period and with
sufficient repetition to statistically validate results. Most previous studies
have been limited in nature or restricted to total institutional waste output.
Invcot.igations in this project concentrated on quantities being produced at the
i-.uit level, which had never been done before with any statistical reliability.
While the main purpose of this study was to determine quantities and types
of wastes produced from a Medical Center complex, it provided an opportunity to
observe in detail the waste handling practices of such an institution and make
i ecommendations for improving such procedures. This investigation was not
envisioned as a panacea for all hospital solid waste problems, but rather as a
necessary piece of data in the total plan to overcome current hospital problems.
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II. DATA AND SAMPLE COLLECTION
Literature Survey and Problem Discussion
An extensive literature search was undertaken to determine what information
was available on the problems of hospital solid wastes. Over 250 documents
dealing with solid waste were reviewed. Many of these documents had been
previously abstracted by Professor R. G. Bond and A. F. Iglar of the University
of Minnesota School of Public Health. An annotated Bibliography of these documents
is being prepared for publication.
Generally, the available literature concerned with solid waste disposal is
written in a "popular" style, i.e. nontechnical and slanted toward the "layman".
Since World War II, however, the literature has become somewhat more technical
with studies being conducted on particular sanitation or contamination problems.
Very little information was found on refuse composition and quantities, except
in a general nature pertaining to waste produced by the entire institution.
Most of the reports published, however, were estimates, and until recently, very
little actual weighing and measuring of volumes and quantities has been accomplished.
The problems relating to infectious wastes produced in hospitals has been
recognized for a considerable period of time. In 1908, Morse (1) wrote: "The
need for a sanitary and convenient way for disposal of waste matter has always
been recognized by those in charge of institutions devoted to the prevention and
mitigation of human suffering." Morse elaborated on problems related to infectious
waste produced in hospitals and cited records of waste handlers who contracted
fatal diseases from exposure to infected matter. According to Morse, the first
hospital waste incinerator was installed in 1891 at a New York hospital on West
17th Street. Prior to this, all burning of waste was practiced in hospital heat-
ing plants "to the detriment of the boilers." Lacking any acceptable disposal
alternatives, public health authorities in the past, have insisted on incinerating
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hospital wastes because of their potential infectious nature. Consequently,
incineration for sterilization and volume reduction is required by statute in a
majority of U. S. communities.
Because a large portion of the wastes originating in a hospital complex
comes from the preparation or scrapping of food its handling and disposal are
important to proper waste management. According to Overton (2) much of this
food waste has been sent to pig farms in the past. The balance of waste produced
in a hospital, including the ash removed after incineration, has been deposited at
private or city dumps and infrequently at sanitary landfills.
Four main factors have gradually brought about changes in methods of storing,
handling, and disposing of the diversified types of solid wastes generated in
medical care institutions:
1. Spread of infection 3. Cost of labor
2. Safety of handling waste 4. Use of single-service or disposable
items
Literature written about hospital wastes has been directly or indirectly
centered around one or more of these inter-related factors. Problems of safely
handling solid wastes vary from the increased use of radioactive materials for
patient care (3,4,5) to the use of discarded needles and syringes being picked
up from waste disposal areas by drug addicts and children (6,7,8). Hospital waste
collectors have been punctured by protruding needles from waste bags and sacks,
or by placing arms or hands into the waste in order to compress it (9,10).
Waste disposal activities have been singled out as one of the possible causes of
increased hospital acquired infection (11,12). Not only is control of the spread
of disease organisms important to patients and employees within the hospital, but
it is also important to the population at large. Letourneau (13,14) has reported
on potential infection from bandages, garbage, vomitus, casts, dressings, feces,
and tools and/or equipment used to handle these wastes. Consequently, most
hospitals have special procedures for handling wastes from contagious disease
patients or from surgical or intensive care areas. Starkey (15,16) claims that
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handling of wastes is probably the largest factor in the transmission of
infection, while Bond and Michaelson (15) concluded in their research project that
waste did not disseminate significant amounts of bacterial contamination. Airborne
contamination resulting from dumping wastes from one receptable to the other has
been verified (18,19). The use of plastic liners in waste receptacles that can
be closed and the liner removed without dumping contents, or the use of the paper
sack container systems have resulted in a reduction in some of the problems
associated with waste handling (20,21,22,23,24,25,26,27). These systems have also
reduced labor costs due to the ease of handling refuse in this manner (28,29),
Other labor saving devices used in hospitals and institutions inplude gravity
chutes, grinders, pulpers, compactors, crushers, and balers to reduce volume,
and in many cases, mechanically handle waste (30). These devices are not without
problems however.
Recognizing that gravity chutes can reduce labor, many have been installed
only to become fire hazards because cigarettes or burning materials have been
cropped into them (31,32,33). Without proper air locks on door openings the chutes
act as chimneys with air rising up and spreading contamination into surrounding
corridors and patient areas (34,35,36,37,38). The spread of contamination occurs
as refuse is dropped down from upper floors and the piston action of the wastes
pushes the air out through inadequate doorways into surrounding corridors and
patient areas.
Grinders have been used and are being used primarily to process food wastes,
and some experiments have been conducted on grinding needles and syringes for dis-
charge to the sewer and transportation to the sewage treatment facility (39,40,41).
Grinders exist that are capable of handling most wastes produced in a hospital
but most sewage facilities throughout the United States are not capable of accept-
ing such quantities and types of wastes.
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Pulpers are being used in hospitals with reported savings in labor and space,
(42,43,44) but only limited information is currently available. Compactors and
crushers are finding increased usage for wastes other than infectious or wastes
having excessive liquid content (45,46,47,48).
Incinerators still constitute the major waste reduction equipment used in
hospitals, but increased air pollution control requirements make most existing
hospital incinerators obsolete (49,50). Major renovations or the addition of
pollution control equipment are usually required. Increased quantities of wastes
are being imposed on already overloaded incinerators resulting in more pollution,
including particles going up the stack not even burned. Consequently, poorly
operated or overloaded facilities are not providing bacteriological sterilization
of the waste, but may indeed be spreading air-borne contamination throughout the
community (51,52). Incineration of increased quantities of .synthetic materials
mainly polyvinyl chloride, has resulted in high concentrations of chlorine gas
which combines with water to form hydrochloric acid and cause extensive corrision
in the incinerators and/or air pollution control devices (53,54).
Recent literature has shown that attempts to reduce the amount of manual
labor for waste handling have resulted in the adoption of automatic or mechanical
techniques from industrial materials handling systems (55,56). Monorails (57),
automatic elevators (58) automatic conveyors (59), central vacuum systems (60),
pneumatic tubes (61,62,63) and on-floor incinerators (64) or crushers, are some
of the newer techniques employed in modern hospitals (65,66,67).
Perhaps the most significant of the four main factors previously enumerated
is the fourth, namely, the increased use of single-service or disposable items
(68). Greater patient safety, more convenience, reduced labor resulting in
increased economy are all claimed to result from the use of single-service items,
Wnile it is true that patient safety and reduction of disease spread are of prime
importance in hospital operations, disposable items have not necessarily produced
an overall economy to hospitals (69,70). Labor can be saved in departments
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formerly autoclaving or preparing articles for reuse but labor must be increased
in departments that receive, store, distribute, collect and dispose of the single
use items. Where disposables replace reusables, these changes have required larger
storage areas, larger waste containers, more waste carts, increased incinerator
loads, and increased waste handling (47,71,72,73,74,75,76,77). Costs that sometimes
do not enter the budgets of smaller hospitals or community-owned hospitals include
increased disposal costs. Where hospitals must pay for waste disposal, they are
acutely aware of the increased costs disposables have wrought.
Many disposables do not relate directly to patient safety, but more to patient
convenience. Everyone concerned with the use of these disposables should be fully
aware of the load on disposable facilities both in and outside the hospital that
are caused by these usages, especially in facilities designed years ago with grossly
inadequate waste handling capacities. The overall environmental impact caused by
decisions to use disposables also needs careful consideration especially in light
of possible uses of complete plastic isolation rooms, operating rooms, disposable
dishes and linens in general usage, plus types and uses of disposables not presently
expected (78,79,80,81,82).
Few of the articles reviewed had specific information on the types and quantities
of waste produced. Because of the tradition in hospitals to report most everything
on a per patient basis, refuse generation figures have varied anywhere from 3
pounds per patient per day (83) to over 20 pounds per patient per day (84,68). As
early as 1937 refuse generation was reported at 7 pounds per patient per day (2)
and as late as 1965, 6 pounds per patient per day was still being reported (55),
with others reporting at 8 pounds per patient per day (42,47). In 1966, however
it was reported a staggering 19 pounds per patient per day, including 8.3 pounds of
garbage and 10.7 pounds of readily burnable materials (69). The unfortunate problem
of reporting on a patient per day basis is that this method does not take into
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10
account the type of hospital or the type of service the patient is receiving and
is therefore misleading. Consequently, attempts were made to report waste on a
gross population basis which would include not only patients, but total number of
doctors, nurses, maintenance, and administrative people employed at a hospital
(85,61). Quantities of refuse produced on a per dapita basis also varied but
over a smaller range. Since the patients are there 24 hours per day and most of
the workers only on 8 hour shifts, an equivalent population was defined by taking
into account those who would be on duty and patients during an equivalent 8 hour
shift (85,61). In a comprehensive study conducted in Los Angeles (61) it was
shown that when the amount of refuse produced from seven different hospitals was
equated to the number of bed patients, values ranged from 3-1/2 pounds per bed
patient per day to 16-1/2 pounds per bed patient per day. Whein the number of
doctors, nurses, orderlies, janitors, volunteers, and out-patients, and other
workers in the hospital was added to make an equivalent population based upon an
8 hour shift, values from the same seven hospitals ranged between 3 and 5-1/2
pounds per capita per day respectively. This approach seems logical since
patients requiring extensive care and producing large quantitfes of waste usually
require a larger number of attendants to take care of them and supply the materials.
Thus, by taking into consideration more than just the patient, we have a more
realistic approach to waste quantity generation. By using an'equivalent population,
hospitals serving different patient needs are more comparable in terms of refuse
generation, and design criteria can be more meaningful for architects and hospital
administrators. No studies were found in the literature pertaining to types
and quantities of hospital wastes produced by each unit within the hospital. Since
the location of various units of the hospital to sources of supply and disposal
will significantly affect materials handling costs, it is imperative that this
unit generation information be ascertained.
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11
Specific literature as to the bacteriological or virological contamination of
refuse was lacking, however, articles were found concerning virus contamination of
bedding materials (86,87), and survival in waste water or sewage treatment
facilities (88,89,90). The paucity of information relative to the specific aims
of this project pointed out the need for reliable data to be obtained.
Facility Description
Medical Center
The health care institution used for this study was the West Virginia Uni-
versity Medical Center located in Morgantown, West Virginia. This modern, 438
bed, teaching hospital and research complex was built in 1960 and provides
hospitalization, out-patient care, and specialized diagnostic, medical and surgical
procedures on general and referral patients, as well as emergency care for the
critically ill and accident victims. Complete teaching programs are conducted for
the Schools of Medicine, Dentistry, Pharmacy, and Nursing, including clinical and
post-graduate training, as well as in-service training for supportive personnel.
In addition, the medical center actively supports many research efforts. This
facility was studied because of its diversity of operations and because of its
relationship to similar institutions throughout the country.
Physically, the entire medical center is in one large building but administra-
tively and functionally it is divided into the Hospital section and the Basic Science
or teaching section. Each section has separate staffs and schedules which made it
easier to obtain refuse production data for each individual unit and still have
meaningful information for the two major sections and for the entire complex. The
hospital portion of the medical portion of the medical center has 11 floors in-
cluding the basement and ground floors where most of the support services are
located. The ninth (top) floor houses the air conditioning equipment. Floors 1
and 2 house clinics, X-ray, emergency rooms, admissions, records, and administration,
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12
Floors 3 through 8 are primarily for inpatient care. In the Basic Sciences
portion of the Center much of the ground floor is used as animal quarters. Floors
1 through 5 contain laboratories, class rooms and offices and are used primarily
for teaching and research.
Various methods of solid wastes disposal and volume reduction are utilized
within the Center. These include incineration, burial, selling, and discharge to
the sanitary sewer. Three incinerators are used: a general pbrpose incinerator
located on the basement floor of the Hospital, an animal incinerator located in
the animal quarters section of Basic Sciences, and a human destructor located on
the fourth floor of Basic Sciences. Radioactive wastes are disposed of by periodic
burial; bone, meat, and grease wastes from food preparation are sold to a rendering
firm, and most other food wastes are disposed of through garbage grinders into the
municipal sanitary sewer system. Other wastes, plus incinera'tor ash, are placed
in bulk storage containers, located at the loading dock, for mechanical collection
by the University refuse disposal service. These wastes are then transported to
the municipal landfill.
In the Hospital, a 24" diameter gravity refuse chute receives combustible
waste and services all floors. This chute terminates in a room adjacent to the
general purpose incinerator room. Needles, syringes, bottles, cans, and other
noncombustible refuse are stored on each floor and are collected on carts for
transport by elevator to the loading dock refuse storage containers. Waste from
the Basic Sciences section is collected on carts for transport to either the
general purpose incinerator or to the loading dock refuse stbrage containers.
The average daily bed occupancy at the Medical Center during the study period
was 402 plus visits by an average of 496 out-patients per day. In the Hospital
section these patients were served by an average daily staff of 1201 assisted by
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13
142 volunteers and students. The staff consisted of: 483 doctors, administrators,
and supervisors; 124 secretaries and clerks; 223 technicians, lab assistants, and
food service personnel; 305 nurses, aids, and orderlies; and 66 housekeeping and
maintenance personnel. (See Table A-l, A-2, Appendix A).
In the Basic Sciences section an average staff of 860 served 1069 students
and provided research and support to the Hospital. The staff consisted of: 409
doctors, professors, and supervisors; 104 secretaries and clerks; 329 technicians,
lab assistants, and shop personnel; and 18 maids and janitors. (See Table A-3,
Appendix A).
All virological studies for this project were performed in the microbiological
laboratories located on the second floor of the Basic Sciences section.
Engineering Laboratories
The University Engineering Sciences building houses laboratories used by the
Civil Engineering Department which were made available during this study. A large
laboratory in the sub-basement was used for sorting, weighing, and grinding the
solid wastes collected and transported from the Medical Center. Sanitary Engineer-
ing laboratories on the basement and ground floor were used for physical, chemical,
and bacteriological analysis. The description of specific tests performed and the
equipment used are included in the respective chapters later in the report.
Administrative and clerical work was conducted in the Civil Engineering
offices on the sixth floor and most data processing was handled at the computer
terminal on the seventh floor.
Sampling Procedure
Based on the initial work conducted by E. G. Cleveland in 1968 (29) a
comprehensive sampling program for the entire Medical Center was established. This
consisted of dividing the wards and departments of the hospital and the Basic
Sciences section into sampling stations that were easy to isolate and that
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contributed comparable amounts of refuse. Care was taken to include all waste from
each nursing station and to keep this separate from other nursing stations. Waste
from entire departments or laboratory functions was collected separately where
possible. In this way it was possible to keep concurrent records on amounts of
refuse produced and personnel generating it while not overloading the laboratory
capabilities of the project. Table II-l and Table II-2 list the sampling stations
selected and show the frequency of sample collection. From these lists one can
see the range of services provided by this institution.
Hospital Sampling Procedures
The entire quantity of refuse generated from each sampling station was collected
during a 24 hour period on each day of the week, (but not during the same week.)
Two full weeks were needed to sample each station one time or 14 weeks total to
obtain this set of data. The sampling was conducted over an 18 month period.
The standard procedure for collection was to station a man in front of a refuse
chute and have him intercept all the refuse generated and place it into thirty
gallon containers lined with a size 9, 3 mil polyethelene bags. When the container
was full, the liner was tied shut and identified with a tag showing the date, time,
and point of origin. The liner full of refuse was then removed from the container
and stored nearby until picked up and transported to the laboratory for analysis.
When loads contained heavy items such as glass, metal, plaster casts, or excessive
moisture, additional liners were used to protect against breakage and possible
spillage in either the hospital or laboratory. All refuse originating from
contagious disease areas was handled separately and was delivered by hospital
personnel in marked and sealed containers. Personnel conducting the study were
required to wear white laboratory coats while on duty, and masks and gloves if
handling potentially dangerous materials. At first, sample collectors remained on
duty the entire 24 hour period but it was found that after 11:00 P.M. very little
-------
Table II-l Hospital stations anc. sampling frequency
(24 Hour Samples)
STATION
83
82
72
71
62
61
52
51
LOCATION
8th
7th
6th
5th
Floor
II
Floor
ii
Floor
ii
Floor
ii
Code
META
PSYC
GMED
GMED
FED
GYN
SURG
SURG
UNIT
Function
Metabolic care
Psychiatric care
General Medicine
General Medicine
Pediatrics
Gynecology, Neurology,
Ears, Nose, and Throat
General Surgery
Surgerv, Cardio Vascular Care,
FREQUENCY
Non-consecutive Consecutive
Davs Days
9
9
9
9
9
9
9
9
Urology, Eye, Chest, Burn Care
40 4th Floor OB Maternity, New Born Care
32 3rd Floor ORTH Orthopedics
31 " OrfTH Orthopedics, Neurosurgery
36 " OR Operating Rooms
37 " 1C Intensive Care Unit, Recovery
Rooms
9
9
9
9
20
21
22
23
24
25
26
2nd Floor 2ND
" XRAY
" BLAB
" REG
" ENT
" CP
Combined 2nd Floor Units
X-Ray Laboratories
Blood Bank, Blood Laboratories
Regional Medical Program
Ears, Nose, Throat Offices
Cardio Pulmonary Laboratorie ;
Milioglraphy La'uoiato'i
5
5
5
5
5
5
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CD
Table II-1 (Contiiued)
STATION
11
12
13
14
15
LOCATION
1st Floor
it
11
it
ii
Code
ER
CLIN
ADMN
CAFE
GIFT
UNIT
Function
Emergency Rooms
Outpatient Clinics
Administrative Area
Coffee Shop
Gift Shop
FREQUENCY
Non-consecutive Consecutive
Days Days
9
9
9
9
9
5
GO Ground Floor GRND
Combined Ground Floor Units
except Kitchen and Cafeteria
Gl
G2
BO
Bl
B2
B3
B4
B5
ii
it
Basement
Floor
it
it
M
ii
it
DIET
KITN
BSMT
PHCY
TAUN
CENT
COBT
ALFD
Dietary, Steno pool, Receiving
Kitchen, Cafeteria " 7
Combined Basement Floor Units 9
Pharmacy
Laundry
Central Supply
Radiation Therapy, Cobalt
U. S. Public Health Service
Appalachian Health Laboratories
5
5
5
5
5
5
Ground Floor Loading Dock
Basement Floor Incinerator Room
Loading Area Refuse Truck
Consecutive and Non-
Consecutive days
43
43
92
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STATION
Table II-2 Basic Science* station: and sampling frequency
(24 Hour Samples)
LOCATION
UNIT
41
42
31
32
21
22
23
11
12
Gl
G2
G3
G4
G5
4th Floor
it
3rd Floor
ii
2nd Floor
n
"
1st Floor
it
Ground Floor
n
ii
n
ii
Offices
Laboratories
Offices
Laboratories
Offices
Laboratories
Library
Offices
Laboratories
Offices
Laboratories
Animal Quarters
Repair Shops
Cafeteria
FREQUENCY
CObSECUTIVE DAYS
NON CONSECUTIVE DAYS
Hospital Incinerator Room
Hospital Loading Dock
Basement
Ground Floor
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
Consecutive
and
43
43
Non Consecutive
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18
waste was generated. For the remainder of the study, the chute was taped shut
from 11:30 P.M. to 7:00 A.M. the following morning and a sign was placed on the
door asking that refuse be placed in containers provided. There was excellent
cooperation by the hospital staff in doing this. The refuse collected at night
was tied up and labeled by a sample collector at 7:00 A.M. before he moved to a
new sampling station. Collectors worked in convenient but continuous shifts from
7:00 A.M. to 11:30 P.M. during the study period.
Bagged and tagged refuse was picked up from the hospital at least twice daily
and transported 1.7 miles to the Engineering Building where laboratory facilities
were available. The Civil Engineering International Travelall was used for most of
the transportation with private cars used only when no other vehicle was available.
Refuse from food preparation and dishwashing areas was not collected for
laboratory analysis. It was felt that this refuse had little pathogenic contamination
and was similar to other hospital food preparation refuse. Refuse produced from
food preparation and food scrapping operations was weighed and measured prior to its
discharge into food grinders, sewer, or storage containers. Pood waste from iso-
lation patients was collected in paper sacks, sealed and weighed without separating
prior to disposal.
In addition to the series of samples collected for laboratory analysis, each
station was sampled for weight and volume of refuse produced concurrently with the
quantity of refuse produced by the entire hospital. To obtain additional information,
i
generation from several sampling stations was analyzed by measuring weights and
volumes from individual rooms or offices during a consecutive 5 day period. This
required 4 weeks to accomplish.
Total weights and volumes reaching the incinerator room were measured for at
least 43 separate 24 hour periods using a Fairbanks Morse and Company 1000 ib.
capacity platformjcale. Total weights and volumes reaching the refuse storage
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19
area at the loading dock were measured prior to placement in bulk storage containers.
Weights from at least 43 separate 24 hour periods were recorded using a model 2430
Howe Scale Company platform scale. In addition, the refuse collection truck was
weighed 92 times before and after pickup, by using two Type-A Hi-Way Load-Ometer
20,000 Ib. portable truck scales borrowed from the West Virginia Department of
Highways.
Weights of soiled linen reaching the laundry were recorded each day by laundry
personnel. An average of 7,830 pounds of linen were processed each day during 1968
and 1969. Data for specific study periods and monthly for the years of 1968, 1969
are shown in Table A-6 Appendix A.
Basic Sciences Sampling Procedures
Total refuse generated for a 24 hour period was collected from each of the
Basic Sciences sampling stations on each of five days (Monday through Friday) of
separate weeks. In addition, weights and volumes originating in each room or
laboratory were measured for a 24 hour period on each of five consecutive days.
One week was needed to sample each station once or 10 weeks total for the collection
of these samples. This sampling was carried out over an 18 month period to include
possible seasonal variation.
The standard procedure for collecting samples was for a sample collector to
accompany each custodian as he made his rounds and intercept waste by placing it
in size 9, 3 mil thick polyethelene bags. When full, bags were tied shut and
identified with a tag showing date and point of origin. Bags were then collected
and transported to the Engineering laboratories for analysis. Extra liners were
used for samples containing large quantities of glass, wood, metal, or other heavy
objects to prevent spillage of refuse.
-------
During the time that quantities were not retained for laboratory analysis,
sample collectors weighed the refuse in a plastic container suspended from a Model
8910 Hanson portable spring scale. Volume of refuse was determined by its level in
the container and then the refuse was emptied into carts for transportation to
either the incinerator or refuse storage area.
Refuse generated from the student cafeteria was handled similarly to that from
the hospital food preparation area. It was intercepted, weighed and measured and
then allowed to follow its usual course for disposal.
Waste from the animal quarters was not handled by the study personnel but was
handled by animal quarter personnel. The number and weights of animals incinerated
and amounts of ash removed were weighed, measured, and recorded for the project by
these personnel.
Anatomy wastes, autopsy wastes, and surgical wastes such as amputations and
organs removed, were auto-claved and then weighed and placed in a special "Human
Destructor" incinerator for disposal. Ash from this operation was weighed and
recorded for the project by the mortician in charge. Project sample collectors
did not handle this type of waste.
Initial Sample Preparation
Laboratory personnel in the Engineering laboratories were required to wear
laboratory coats, surgical face masks, and rubber gloves while sorting, weighing
or grinding. Laboratory personnel were urged to shower immediately after working.
The laboratory coats were commercially laundered, and the laboratory was cleaned
after each day's sorting and sanitary conditions were observed.
New brown paper from a 54" wide roll was placed on the sorting table at the
beginning of each day's work or as often as needed to maintain clean conditions.
Bags of refuse were weighed on a Howe Richardson Model 54 XL platform scale and
the emptied onto the table for sorting into plastic bins in the categories shown
on Table IV-6.
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21
After sorting, totals of each category were weighed on a Pennyslvania Scale
Company Model 1-10 table scale and recorded. The sum of the categories was then
checked against the original sample weight as a precaution. One twentieth (5
percent) by weight of each grindable category (all categories except glass, metal,
wood, rubber, and hard plastic) was recombined in a plastic bag, tagged and saved
for further processing. Exclusion of certain categories of waste was partly due
to laboratory restrictions, lack of grinding capability during the initial phase of
the laboratory work and sample size necessary for the different chemical and bio-
logical tests. The remainder of the refuse was placed in a large plastic container
and hauled to the refuse storage area for mechanical pickup by the university
packer truck. A 2-1/2 cubic yard Truxmore metal bulk container was purchased and
placed at the Engineering Sciences Building to handle the increased waste load
caused by this investigation.
The grindable portions saved were then processed thru a "Davis-Built"
granulator machine to reduce the size of sample particles to less than 1 inch. A
special burlap filter was designed and employed to retain the processed particles.
The sample was then fine ground through a Standard Model 3 Wiley Mill to pass a
2 mm sieve. The effluent from the mill was thoroughly mixed and approximately
100 gms retained in a 24 oz. deep-form seamless closed tin box for chemical and
physical analysis. The boxes were labeled as to date and origin of the sample.
Duplicate samples were retained when possible.
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22
III. SOLID WASTE GENERATION BY MEDICAL CENTER AND INDIVIDUAL UNITS
Introduction
One of the main objectives of this study was to determine waste generation
rates for the various units of a medical care institution. This information was
lacking but through this study effort, data is now available to assist architects,
designers, administrators and others who need to know types, quantities and sources
of waste generation. Since waste handling is basically a materials handling
problem, generation information is necessary to adequately design materials flow
systems, especially with ever increasing quantities of single use items in health
care facilities.
An analysis of total waste production from the two major sections of this
institution precedes the analysis of waste generation by hospital units in this
chapter. All of the data is presented in pounds. Classification of the waste
components, volumes, and densities are subjects handled in a subsequent chapter.
Statistical Procedures
Information obtained during the data gathering operations for use in determin-
ing waste generation was punched onto IBM data cards for ease 'of analysis and
manipulation on the University's IBM 360/75 computer. Means, standard error of
the mean, 95 percent confidence intervals and sample totals were computed and
listed for most of the results.
The use of the computer allowed analysis of data to be performed that would
have been extremely laborius and time consuming if done manually.
A special stepwise regression analysis, DMD OZR BIOMED, on file at West
Virginia University's Computer Center was used to help determine the best variables
for the prediction equations.
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23
Programming and statistical assistance was provided by personnel of the
University's Department of Statistical and Computer Science.,
Results and Discussion
Total Wastes Generated
The total daily generation of solid wastes from the West Virginia University
Medical Center was determined from measurements taken over a two year study
period. For this, three sets of separate data were compared., One set consisted of
data generated during seven consecutive days, another set was made up from each
of seven weekdays from different weeks, and the third consisted of totals of eight
different weeks, each made up of seven consecutive days* Total quantities for tlie.
first two sets of data were obtained by adding the amounts of waste generated b>
individual sources (units described on Table III-l and Table III-2 and totaled for
Hospital and Basic Sciences portions of the Medical Center» The third study
included only wastes reaching the general purpose incinerator and the loading dock.
The summarized results of this study are shown en Table II] L where the data
are given under headings representing the twc main generation sources, the Hospital
and Basic Sciences. For comparative puruoses, this table includes the high daily
value observed in each study and a theoretical high, equal to the sum -A al] K>igh
values for each unit. These nigh values can be used for determining total expected
loads.
Comparing values of means obtained for the three separate studies shows a
maximum difference of 256 pounds (or 7 percent between means) for the Hospital,
181 pounds (or 12 percent) for the Basic Sciences and 437 pounds (or 9 percent)
for the total Medical Center complex. Thus, as a whole the data obtained were
consistent and can be considered reliable for the different set of conditions
observed.
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Table III-l Daily solid waste generation totals
UNIT
HOSPITAL
Mean
High
Theore-
tical
High*
B. S. B.
Mean
High
Theore-
tical
High*
TOTALS
Mean
High
Theore-
tical
High*
STUDY 1
CONSECUTIVE
DAYS
3475.2
3863.4
4567.9
1475.0
1595.3
1850.6
4950.2
5458.7
6418.5
STUDY 2
NON- CONSECUTIVE
DAYS
3228.0
3863.4
4567.9
1389.8
14^0.9
1804.6
4617.8
5304.3
6372.5
STUDY 3
INCINERATOL AND
LOADING DOCK
3219.1
4033.0
4915.0
1294.4
1554.6
2609.0
4513.5
5587.6
7524.0
TO LOADING
DOCK ONLY
1290.8
1614.9
2095.0
763.2
919.2
1682.0
2054.0
2534.1
3777.0
TO INCINERATOR
ONLY
1928.3
2418.1
2820.0
531.2
635.4
927.0
2459.5
3053.5
3747.0
* Theoretical High = Sum of all Indiv: dual Unit Highs
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Table III-2 Comparison of solid waste generation rates
HOSPITAL MEDICAL LOS ANGELES STUDY (32)***
ONLY CENTER LOW VALUE HIGH VALUE
Bed Patients
Disposable Wastes
lb=./Bed Patient
Ibs. /Person - Gross Pop.*
Ibs. /Capita - Equiv.Pop.**
Reusable Wastes
Ibs. /Bed Patient
Ibs. /Person - Gross Pop.*
Ibs. /Capita - Equiv.Pop.**
Total Wastes
Ibs. /Bed Patient
Ibs. /Person - Gross Pop.*
Ibs. /Capita - Equiv.Pop.**
402
3,300 Ibs.
8.2
1.6
4.0
9,630 Ibs.
24.0
4.5
11.7
12,930 Ibi.
32.1
6.1
15.7
402
4,700 Ibs-
11.7
1.1
3.6
10,140 Ibs.
25.2
2.4
7.8
14,840 Ibs.
36.9
3.6
11.4
144
732 Ibs.
3.6
0.9
3.1
1,720 Ibs.
11.9
2.6
8.1 !
/
2,452 Ibs.
17.0
3.7
11.3
2018
23,200 Ibs.
16.7
1.8
5.6
54,500 Ibs.
29.6
4.1
10.2
77,700 Ibs.
46.3
5.4
15.3
* Sum of all patients, outpatients, paid staff,
doctors and volunteers
** An average 8 hour population census counting the
number of outpatients at onu half
*** Low and high values from a study of seven hospitals
to
Ul
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It should be noted that figures in Table III-l include only wastes which
require disposal. Other wastes studied but not included in this table are wastes
that are reusable and are normally recycled, such as soiled linen, (see Table A-6,
Appendix A) dinnerware and patient care items.
To further test the validity of data reported in Table III-l, waste production
or generation rates were calculated and compared to data obtained from a study of
seven hospitals in Los Angeles, California (61) ranging from' a bed patient occupancy
of 144 to an occupancy of 2,018. Wastes are compared in three categories: disposable
reusable and total. Refuse production rates based on number of bed patients, total
or gross hospital population and equivalent population are recorded for all three
categories on Table III-2. Calculations and data used to obtain these figures are
recorded on Table A-4, Appendix A.
A comparison of data shows that values obtained in this study are in agreement
and within the ranges recorded for the Los Angeles study. The figure of 8.2 pounds
of disposable waste per bed patient per day for the Hospital and 11.7 pounds per
day for the total Medical Center are also in agreement with most reports reviewed.
It is important to note that the Los Angeles study contained two teaching
hospitals where their reported populations included students, teachers, researchers
and supporting personnel comparable to the population of this institution. Thus,
the validity of the comparison is further enhanced and results could, therefore,
be considered as typical or expected from institutions of this nature.
It is interesting to note variation between different rates of waste pro-
duction, and within each particular rate. When reporting rates based on a bed
patient basis, values ranged from 3,6 to 16.7 pounds per patient for disposable
wastes in the Los Angeles study. This institution had a value of 11.7 pounds but
other studies reported rates as high as 19 to 20 pounds per patient (68,69,81,84).
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27
When using the very same quantities of waste from the same hospitals to calculate
rates based on the institution's total or gross population, values ranged from
0.9 to 1.8 pounds per capita in the Los Angeles study and were calculated to be
1.1 pounds per capita in this study. While variation between the different rates
is due largely to the method of reporting, variation within any particular rate
is due mostly to the inability of that method to reflect differences in the type
or amount of care given to each patient at the various institutions studied.
With this great amount of unpredictable variability, these two methods of report-
ing waste generation are very unreliable for design purposes. Rates reported on
these two bases are confusing, misleading and should not be used.
In order to overcome differences in reporting waste rates and to equate
institutions giving different types and amounts of care, the American Public
Health Association study (85) and the Los Angeles County study (61) proposed
that wastes should be calculated in terms of an "equivalent population." This
"equivalent population" is defined by the Los Angeles study as the average 8 hour
population census over a seven day week, counting the outpatients at one half
value. In addition to patients, this method includes staff and others who are
contributing to the daily wastes but are not considered when reporting on a per
patient basis. This method is also different from gross populations in that
patients who are present 24 hours a day are valued at more than someone there for
a part of the 24 hour period. The total number present during the 24 hour period
is averaged into an 8 hour shift, which is then used to calculate the daily waste
production rate.
Following this definition, the rates calculated are also reported in Table I1I-2.
In the Los Angeles study, these rates vary from 3.1 to 5.6 pounds per capita for
disposable wastes and have a calculated mean value of 3.8 pounds per capita. The
-------
28
value of 3.6 pounds per capita obtained for this Medical Center is very close to
the Los Angeles study mean. Equivalent populations rates for total wastes vary from
11.3 to 15.3 pounds per capita in the Los Angeles study, but if these same quantities
of wastes are used to calculate rates on a bed patient basis, they vary from 17.0
to 46.3 pounds per patient.
This equivalent population method for computing total waste generation appears
to be more reliable than any other method so far devised. Use of this method should
enable designers to anticipate total quantities of refuse from various types of
institutions from calculations based on the equivalent population of that institution,
This will help determine total quantities from an entire institution; however, prior
to this study, no one has developed generation equations for the individual units of
an institution.
Unit Wastes Generated
Based on the hypothesis that different types of patient care units would
produce different quantities and possibly different characteristics of wastes, each
unit of the Hospital and Basic Sciences was sampled individually. Tables III-l
and III-2 list the units, type of activity performed in each unit and frequency
of sample collection. Each unit represents a particular type of patient care
particular nursing station, with basically similar care being given to patients
within any unit.
The mean daily weight, high day's weight, standard error of the mean and 95
percent confidence interval for each unit are listed on Table III-3 for the
Hospital and on Table I1I-5 for the Basic Sciences. Values for supplemental studies
that were conducted to provide additional information are listed on Table I1I-4 and
Table TII-6 for Hospital and Basic Sciences respectively.
-------
Table III-3 Solid waste generation by hospital units
(initial stutly)
SAMPLING
STATION
83
62
8th Floor
72
71
7th Floor
62
61
5th Fleer
52
51
5th Floor
40
32
31
36
37
3rd Fi.-or
•. nd Fl .-;-r
UNIT
Metabolic
Psychiatric
General
Medicine
General
Medicine
Pediatrics
Gynacology
Surgical
Surgical
Maternity
(4th Floor)
Orthopedics
Orthopedics
Operating
Room;.
Intensive Care
MEAN
DAILY
WEIGHT*
24.6
27.1
51.7
88.9
76.9
165.8
95.8
80.0
17:. s
193.2
167.8
361.0
96.4
69.5
91.2
191.3
103. 3
4.55.3
34,.. .
HIGH
DAY'S
WEIGHT*
39.4
34.8
73.2
107.9
115.0
222.9
181.6
150.2
231.8
288.1
310.3
598.4
133.7
96.0
122.9
260.3
140.3
619.5
388 . :<
STANDARD
KRROR
01' MEAN
3.7
3.0
4.9
5.0
..0.8
.3.6
.4.9
1.3.4
::3.o
::2.5
:-6.3
'.0.9
8.0
6.6
0.2
.'»!. 5
.3.0
'-4.7
:,.«
95% CONFIDENCE
LOW
WEIGHT*
15.4
19.8
39.6
76.6
50.4
132.7
59.2
47.3
1^1 o <;
138.1
103.5
260.8
76.8
53.3
66.3
127.4
73.5
29^.2
'•'•'•"
INTERVAL
HIGH
WEIGHT*
33.8
34.3
63.8
101.2
103.4
199.0
132.3
112.8
232.1
248.2
232.1
1461.1
115.9
85.6
116.2
255.2
13S.1
512.3
385.6
* Al I «- .gi-.i- in y.., ,d>
N5
VD
-------
Table III-3 (continued)
CO
O
SAMPLING
STATION
11
12
13
14
15
1st Floor
GO
G2
Ground Floor
Basement Floor
Colunn Totals
t »\»T m
ursix
Emergency
Rooms
Operating
Clinics
MEAN
DAILY
WZIGIIT*
30.8
66.4
Administration 65.3
Coffee Shop
Gift Shop
Dietary
Receiving
Kitchen -
Cafeteria
Statistical Totals
24.7
13.3
200.5
168.3
1309.0
1477.3
149.7
3475.2
3228.0
HIGH
DAY'S
WEIGHT*
44.7
81.4
109.0
30.0
35.0
300.1
197.0
1515.0
1712.0
187.0
4567.9
3863.4
STANDARD
ERROR
OF MEAN
3.7
3.1
12.8
1.8
3.8
25.7
13.2
75.2
97.6
15.1
- -
29'+. 2
95% CONFIDENCE
LOW
WEIGHT*
21.7
43.9
33.9
20.4
4.1
116.2
131.7
1122.4
1200.7
105.1
2686.6
2508.2
INTERVAL
HIGH
WEIGHT*
39.9
88.9
96.6
29.0
22.5
246.8
204.9
1495.6
1678.3
194.3
4363.4
3947.9
* All weight in pour.ds
-------
Table III-4
Solid waste generation by hospital units
(supplemental study)
SAMPLING
STATION
21
22
23
24
25
26
MEAN
DAILY
UNIT WEIGHT*
X-ray
Blood Analysis
Regional Medical
Ears, Nose, Throat
Card io- Pulmonary
EMG
77.0
231.1
11.1
8.8
33.6
1.7
HIGH
DAY'S
WEIGHT*
110.0
254.5.
12.0
13.0
42.0
3.0
STANDARD
ERROR
OF MEAN
3.8
9.8
3.4
1.7
2.4
3.4
95% CONFIDENCE INTERVAL
LOW HIGH
WEIGHT* WEIGHT*
52.8
203.9
9.9
4.0
26.9
1.0
101.4
258.3
12.3
13.6
40.3
2.8
Total 2nd Floor
363.3
434.5
13.4
Total Ground
54.5
2.2
Total Basement
191.2
251.4
19.3
312.3
137.7
414.3
13
GO
Gl
Administrative
Area
Ground Floor
Dietary
75.7
24.6
15.7
88.0
32.0
24.5
7.6
4.2
2.6
54.5
12.7
8.5
96.9
36.5
22.9
46.4
Bl
B2
B3
B4
B5
Pharmacy 30.4
Laundry 41.7
Central Supply 98.3
Radiation Therapy 5.1
Appalachian Health
Laboratory 15.8
38.7
82.9
127.2
9.5
37.0
3.0
11.7
11.7
1.1
5.8
21.9
9.1
65.7
2.0
1.0
38.8
74.3
130.8
8.2
31.9
244.8
* All weight in potnds
-------
CO
ro
Table III-5
Solid waste generation by Basic Sciences units
(initial study)
SAMPLING
STATION
41
42
4ch Floor
31
32
3rd Floor
21
22
23
2nd Floor
11
12
1st Floor
Gl
G2
G3
G4
G5
Ground Ficor
UNIT
Offices
Laboratories
Offices
Laboratories
Offices
Laboratories
Library
Offices
Laboratories
Offices
Laboratories
Animal Quarters
Repair Shops
Cafeteria
Ccl-jinn Totals
Statistical
Total.s
MEAN
DAILY
WEIGHT*
83.3
64.5
147.8
56.3
62.9
119.2
44.5
122.8
16.7
184.0
59.9
161.0
220.9
69.9
59.7
304.2
11.6
272.4
717.8
1389.7
1389.8
HIGH
DAY'S
WEIGHT*
124.8
96.0
220.8
75.0
100.3
175.3
74.4
137.0
19.8
231.2
81.0
219.8
300.8
114.8
95.3
336.8
24.6
305.0
876.5
1804.6
1440.9
STANDARD
ERF.OR
OF IE AN
1:>.9
3.5
14. 1
6.7
14.2
17.5
9.6
6.5
L.4
15.2
10.4 -
17.4
12.3
16.2
11.6
13.0
3.4
12.7
19.0
32.3
957. CONFIDENCE
LOW
WEIGHT*
47.4
40.8
108.6
37.7
23.3
70.7
17.9
104.7
12.8
141.8
31.0
112.8
186.7
24.9
22.0
259.9
2.1
237.1
664.9
974.4
1300.1
INTERVAL
HIGH
WEIGHT*
119.2
88.2
187.1
74.9
102.4
167.7
71.1
140.8
20.5
226.1
88.9
209.1
255.2
115.1
97.3
348.5
21.1
307.7
770.7
1804.8
1479.5
A? 1
"* "i ^M t "* **"* pCMT^ds
-------
Table III-6
Solid waste generation by Basic Sciences units
(supplemental study)
SAMPLING
STATION UNIT
41 Offices
42 Laboratories
4th Floor Totals
31 Offices
32 Laboratories
3rd Floor Totals
21 Offices
22 Laboratories
23 Library
2nd Floor Totals
11 Offices
12 Laboratories
1st Floor Totals
Gl Offices
G2 Laboratories
G3 Animal Quarters
G4 Repair Shops
G5 Cafeteria
Ground Floor Totals
Column Totals
Sta-'istio.ai Totals
MEAN
DAILY
WEIGHT*
82.2
94.4
176.6
34.8
67.1
105.5
62.3
45.0
16.7
124.0
94.3
201.4
295.7
65.9
107.3
304.2
23.9
272.4
7/3.7
14:-.!
14/5.0
HIGH
DAY'S
WEIGHT*
89.0
144.0
233.0
44.5
95.5
140.0
91.5
51.0
19.8
162.3
107.5
226.5
334.0
119.5
173.5
336.8
46.5
305.0
981.3
1850.6
1595.3
STANDARD
E&ROK
OF 14EAN
2.5
37.9
20.5
2.6
8.2
10.1
8.5
2.4
1.4
8.9
3.8
8.0
10.2
36.0
18.0
16.0
8.5
12.7
8.3
- -
25.7
957, CONFIDENCE
LOW
WEIGHT*
75.1
44.6
119.8
32.6
44.2
77.5
38.6
38.5
12.8
99.4
83.7
179.1
267.5
21.4
57.4
259.9
1.0
237.1
750.8
1126.0
1375.8
INTERVAL
HIGH
WEIGHT*
89.3
144.2
223.4
44.2
90.0
133.5
85.9
51.5
20.5 * *
148.5
104.9
223.7
323.9
110.4
157.1
348.5 * *
47.6
307.7 * *
797.0
1824.7
15/4.2
* All weight in pounds
* * Values from iritial study
UJ
10
-------
In this institution, patient care units are located on floors three to eight
inclusive; outpatient units (clinics) and emergency rooms are located on the first
floor, and support units (all others) are located from basement to second floor.
Patient care units contributed 37.6 percent, outpatient units and emergency rooms
combined contributed 2.8 percent and the support units contributed 59.6 perdent
of the mean daily weight. It is significant to note from these data that the
hospital kitchen, cafeteria and coffee shop combined contributed 38.4 percent of
the mean daily hospital weight or an amount exceeding that of the combined patient
care areas. This waste from the kitchen includes all of disposable material produced
there including single use dinnerware used for meal service to all isolation patients
Meals were served to all other patients on china service during the period of study.
The proportion of wastes produced by all food service and food preparation units of
the entire Medical Center accounted for 33 percent of the total combined weight,
however.
Although outpatient care areas contributed a relatively small portion of wastes
generated when measured by individual units, it should be noted that in this parti
cular institution, outpatient care units generate 15 percent of clinical laboratory
work, 42 percent of X-ray examinations and an unaccountable amount of administrative
work. Wastes from these additional activities are included in support unit totals.
The remaining portion of the Medical Center was studied in terms of both
activity and Personnel classifications in order to better understand the waste
4
generation processes. Table III-7 lists personnel classifications and room use
categories used in this study. Tables A-l, A-2 and A-3 in Appendix A list the
population census for each personnel classification for both Hospital and Basic
Sciences units.
-------
35
TflMc TTT-7
ol rl .nsm' f irzt ior>« and room "se
CLASSIFICATION
1.
2.
3.
4.
5.
6.
7.
PERSONNEL INCLUDED
Patients, outpatients
Doctors, administrators, directors
supervisors, dentists, chiefs
Secretaries, clerks, cashiers,
office support personnel
Laboratory assistants, technicians,
graduate assistants, maintenance men,
laborers
Registered nurs-is, licensed practical
nurses, practical nurses, nurse!s aids,
orderlies
Janitors, maids, housekeeoers. floor
Volunteers, students
CATEGORY
A.
B.
C.
D.
E.
F.
G.
ROOM USE
Offices, nursin;; station headquarters
Laboratories, work areas, shops
Restrooms, lock;r rooms, dressing
rooms
Classrooms, conference rooms,
libraries
Supply rooms, s :orage areas
Lounge areas, wiiting areas
Patient care roxns, examination
rooms
-------
36
Using this system, a laboratory technician in a laboratory would appear under
the same heading as a mechanic in a repair shop but the room use category would be
different. A doctor in a patient care area would be different from a doctor shown
in an office where his main function might be related to paperwork. Doctors,
administrators, supervisors, directors and dentists were put together in the same
classification because it was felt that in an office they would most likely
produce about the same amount of waste, while in another room category their function
might be different. This provided a good basis for determining room usage within a
unit or between units. Since each unit was studied separately, there was no conflict
between categories or classifications.
The first step towards obtaining a relationship between the quantity of waste
produced and the people who produced it was to divide the amount of waste per unit
by the number of patients per unit. The values obtained varied considerably not
only within units but between units as well. The gross population was then used
as a divisor to obtain weight per capita per day. As with values for total generation
these unit values varied widely. Next, the equivalent population for each unit was
computed and divided into the amount of waste produced per unit but still no
meaningful equations were produced. The equivalent population method that worked so
well for total waste quantities from the entire institution did not work well for
individual units. This is due, perhaps, to the fact that for the entire institution.,
all of the wastes from patient care and support activities are combined, as are
population totals. On a unit basis, however, wastes come only from one particular.
unit and support activities, are not included. Thus on a unit basis, there is no
overlapping or compensation to provide a balance. These calculated values are listed
in Table A-5, Appendix A.
-------
Quantities of waste produced per unit per day were then correlated against
numbers of people in each classification or in combinations of classifications for
that day to see if there were any meaningful relationships. The weight was held
as the dependent variable and the numbers in each classification, their squares,
square roots, cubes, cube roots and combinations of various classifications were
used as independent variables in a stepwise regression analysis that selected the
best of the independent variables and calculated prediction equations using these
variables. Means, standard deviations, analysis of variance, F ratios, R values,
R squared values, predicted weights and residuals were computed by the University
Computer Center for all units studied,
Each unit study produced its own best prediction equation based on the
independent variables selected by statistical analysis. It was felt that a
coefficient times the cube root of the number of nurses plus another coefficient
times the square of the number of housekeepers for example, would not be a practical
equation for any general use. The number and type of independent variable was then
restricted to whole numbers or combinations of whole numbers in an attempt to obtain
an equation of only one best variable that would be easy to apply and yet still be
reliable. As expected, each unit had a different coefficient for every independent
variable selected in the analysis. For a designer to use a different coefficient cr
equation for each unit did not seem very practical, especially with no other data
from other institutions to verify the values. It was observed that certain patient
care areas had coefficients that were similar in quantity and tended to group them-
selves into two main divisions. Each division was composed of units giving approxi-
mately the same type of care. Patient care units such as the operating rooms,
intensive care area, maternity and newborn infant care, surgical care and orthopedic
care, all produced heavy quantities of waste and had large staffs. Patient care units
such as metabolic research, psychiatric care, general medicine, pediatric care,
gynecology, ear-nose-and-throat, and neurology all produced lighter amounts of waste
-------
38
and had smaller staffs. The data for units in each division were then pooled and
analyzed to find the best overall correlation and corresponding prediction coef-
ficient and equation. Fortunately the same independent variable turned out to be
best in each division but with a new coefficient. The best independent variable
found for each division was a summation of the total paid staff for a 24 hour
period minus the number of doctors. This variable did not include the number of
patients nor the number of non-paid volunteers or students. To determine why the
doctors and volunteers were excluded, the data were further analyzed. It was observed
that the number of doctors varied considerably for the same unit on different days
as did the number of students and volunteers. Doctors were also counted at more
than one unit as they made their rounds. This would not appear when calculating
the equivalent population from the entire hospital but would dhow up on a unit basis.
The paid staff of nurses, aids, clerks, orderlies, housekeepers, and maids of a unit
remained more constant and paralleled the amount of waste produced. This is probabh
why the best variable included only paid staff minus all of the doctors. Values for
coefficients, prediction equations, R square and standard errors obtained from tVe
analysis are listed in Table III-8.
When support activities were analyzed it was found that u*nits dealing mostly
LH paper work produced similar quantities of waste, while waste from other support
activities, such as the kitchen-cafeteria, was better equated to the number of meals
served than to the staff or combinations of staff classifications. The best indep
endent variable for all support activities, except certain special ones, turned out
to be the number of paid staff minus the number of supervisors or administrators
(sum of classifications 3 through 6) times a coefficient. These values are also
shown on Table III-8.
It should be noted that these coefficients and equations will estimate average
daily solid waste quantities. An upset, extra patients, special treatment requirements
-------
Table III-8 Solid waste generation equations
UNITS
COEFFICIENT
EQUATION
STANDARD
ERROR
Metabolic, Psychiatric, General Medicine 2.77
Pediatrics, Gynecology, Neurology, Ears-
Nose-Throat
Heavy Care Units
General Surgery. Neurosurgery, 4.47
Cardiovascular, Urology, Eye,
Chest, Burn, Patients, Maternity, New
Born; Orthopedics, Operating Rooms,
Intensive Care, Recovery
2.77(s)=lbs. waste/day .92 0.127
4.47(s)=lbs. waste/day .89 0.231
Support Units
Administrative Offices, Gift Shop, Dietary 2.21
Offices, Laundry, Pharmacy, Receiving,
Regional Medical Program, Appalachian
Respiratory Diseases Lat>«
2.21(s)»lbs. waste/day .89 0.134
Soeciai Units
X=Rav, Radiation Therapy^ Emergency 0.48
Rocm, Central Supply
Clinical Laboratories, Out Patient Clinic 0.19
Kitchen. Cafeteria 1.5
(s) - Sum of the paid staff during a 2i-
doctors (categories 3-6)
(n) « Number of patients treated, order
or patient meals served
C,48(n)=lbs. waste/day .68 0.079
0.19(n)=lbs. waste/day .71 0.035
1.5(n)='Jbs. waste/day .76 0.173
•nour period, not including
baskets filled, tests run
-------
or any number of unexpected occurrences may cause waste quantities to fluctuate
above and below estimated daily values. Anticipated increases in the use of disposal
items may necessitate increasing the value of coefficients sufficiently to accommcxUti
the additional weight and volume. For example, disposable sheets weigh about 25
percent of the weight of linen sheets. If a total conversion to throw-away linen
were undertaken at the institution studied, the increased weight would be approxi-
raately2,000 pounds per day. That would be an additional load of almost 43 percent
on the total waste handling system but would represent an increase of 81 percent on
the portion going to the general purpose incinerator. Conversion to total disposable
food service items would add about a pound and a half of waste per meal served. This
would amount to about 1,800 pounds per day at this institution. (The purpose of the*
examples is not to discredit the use of disposable articles but only to illustrate ttii
need to anticipate their usage when planning waste handling and disposing facilities)
The prediction equations listed on Table III-8 should be useful in the design of
new facilities or in the remodeling of those in existence. Engineering practice
would apply a factor of safety to these values to provide for peak loads. At this
institution, the total peak load exceeded the total mean load by 15 percent. A sum
of all the unit peak loads exceeded the total mean load by 36 percent. See Table:
II1-1. It is unlikely that all units would peak at the same time except in the case
of a disaster. Increased waste quantities will result from current hospital trends
toward the increased use of disposables. The weight of anticipated increases can be
added to weights derived from these general equations to form a reliable basis of
waste generation for future time periods. The time of day that these quantities
reached the incinerator room and loading dock are recorded on Table IV-2.
-------
41
Waste Disposal Practices
Both volume and weight of solid wastes generated are of great importance in
handling, storing or disposing operations. Increased labor costs, building costs
and disposal costs necessitate volume and hopefully weight reduction practices
wherever possible.
Incineration is one method of volume reduction commonly used in hospitals.
At this institution, approximately 66 cubic yards of refuse per day (2600 pounds)
are reduced to approximately 1/2 cubic yard of ashes weighing about 200 pounds.
This represents a 99 percent reduction in volume and a 92 percent reduction in
weight at the incinerator room. Part of the 2400 pounds of waste that leave
through the chimney is converted to carbon dioxide or other gases and dispersed to
the atmosphere. Unfortunately enough is converted to fly ash and soot to cause
problems with cooling towers, air conditioners and surrounding property. Without
proper air pollution control devices, incinerators remove waste from containers
where it can be managed and distribute it over the country side where it cannot
be managed.
Residue from the incinerator and most non-combustibles are taken to the load-
ing dock for storage until picked up and removed by the University refuse truck
each morning. Figure III-l is a flow chart showing the path taken by most of the
wastes from this institution. Solid lines represent existing routes and dashed
lines represent proposed routes discussed in the chapter on recommendations. As
can be seen from this diagram, all waste eventually requires ultimate disposal in
a location away from the Medical Center. For this institution, most of the waste
is taken to the municipal landfill by university owned vehicles.
Small portions of the total waste from this institution do not follow the
normal course but are handled in a special manner. These special wastes require
special precaution and disposal operations and consequently have not been included
-------
Figure III-l Solid waste flow chart
Disposable Waste
Soiled Linen
Source
Source
I
I
Grav
i
r— Clean up -.
tty Chute
f
\
— '
f
Cart
\
— _ "\
\
1
1
1
r
Elevator
r Incinerator— .
Rot
1
1
/"TubeX
/ or \
VConveyory
1
>
?m
Separation
4
Cart
V
Incinerator
1
Cart
I
y)n Site Storage ^ —
y
. — Cart o
f
Gravity Chute ^ A
> f
Elevator 5
i 1 A
Pneumatic
Tu>>o
^_
-*p Separation^ 7
1
/ ^ Storage 8
1
i Laundry 9
\
Re-use 10
I
(Loading Dock)
Transport
4
Disposal
(Mu
nicin
Away
Site
aT>
12
Ex
isting Routes
13
Proposed Routes
-------
43
in the totals to either the loading dock or the general purpose incinerator.
Surgical trimmings, placentae, pathological wastes and autopsy wastes are
autoclaved, refrigerated during storage, and then incinerated when quantities
accumulate to make a load., Approximately eight loads (175 pounds per load) are
cremated each year in a special "Human Destructor" type incinerator. At this
institution, cadavers used for instruction in anatomy classes or for other work in
the School of Medicine are also cremated in this special purpose incinerator,,
After use in the laboratory, approximately 35 bodies, averaging 135 pounds per
body, are cremated each year. This adds to a total of 6,125 pounds disposed per
year (20 pounds per day) resulting in about 404 pounds of ashes.
Experimental animals used for research at this institution are also handled
and disposed separately from the general refuse. An average of 178°9 pounds of
animals are cremated in a destructor type incinerator each working day. This
weight is made up of an average of 4.6 dogs, 2.4 cats, 68.6 rats, 21.6 mice,
1.1 hamsters, 0.3 opposums, 0.2 monkeys, 1.9 rabbits, 0.9 guinea pigs, and is
reduced to 7.8 pounds of ash per day. The ash and an estimated 150 pounds of corn
cob bedding from the animals are taken to the loading dock each working day.
(This weight is included in the totals from the loading dock).
Another special waste category requiring separate handling is volatile liquids.
All flammable or dangerous chemicals, liquids or toxic compounds are stored in a
separate room in the Basic Sciences area and are hauled away to a land disposal
site and buried. No reliable estimations of the quantities handled each year
was available.
Radioactive materials used for research or treatment are handled as prescribed
by the Atomic Energy Commission under the license granted to the University Medical
Center. Most radioactive wastes are discharged to the sewer after proper dilution.
Solid particles are buried at a prescribed location and items of high activity are
-------
retained in protective containers until they decay sufficiently to allow disposal.
Total quantities of radioactive wastes requiring disposal were considered insignifi-
cant.
Waste handling personnel reported receiving numerous punctures from disposable
needles protruding from plastic waste sacks. One or two were pricked while attempt--
ing to compact refuse into sacks containing disposable needles. Minor cuts were
reported from handling broken glass, and splinters have resulted from disposing of
wooden crates and boxes. While no one has reported contracting disease or serious
infection from these hazards, the potential still remains. Regulations require
that needles and syringes must be thrown away in a condition that will not cause
injury to someone or provide for their reuse if they should be removed from the
waste at a later time. Crushers, ovens and containers are available for properly
disposing of these hazardous items.
There were no reports of anyone scavenging in the waste for partly used or
out-dated bottles of medicines or narcotics that may have been thrown away. What
happens to such bottles at the municipal waste disposal site is not known. The
contents of bottles that have a potential illegitimate reuse are properly flushed
to the sewer if a hospital has control over the method of disposal.
Fire hazards exist in the incinerator room and in the refuse chute and there
have been reports of fires in the chutes; but a sprinkler system installed at the
top is usually able to control such incidents. The incinerator room and the refuse
chute are separated by a fire door. There have been reports of smoke in the
incinerator room but no reports of a serious fire.
-------
45
Conclusions and Recommendations
Waste Generation
1. The institution studied is considered to be typical in its generation of
refuse quantities. This conclusion is based on a comparison of generation
rates for total refuse quantities with rates from other studies which
contained institutions of similar function.
2. The existing trend to report total solid waste generation rates from
hospitals on a pound per bed patient or pound per gross population basis
was found to be inaccurate, unreliable and misleading.
Hospital generation rates should be based on a common parameter that
will allow comparison of hospitals of different types, functions or sizes.
An "Equivalent Population" such as one defined by the American Public
Health Association (6) and used in a comprehensive study of hospital wastes
conducted in Los Angeles, California (1) is the most reliable basis found
to date and should be used to report waste generation of total hospital
solid wastes. An equivalent population is defined as an average 8 hour
population census, counting outpatients at one half value. The average is
based on a seven day week.
3. The prediction or reporting of waste quantities for individual units of a
hospital was found to be unreliable and misleading when based on number of
bed patients or gross population of that unit.
The same unreliability was found when attempting to use the Equivalent
Population as a prediction parameter. It was observed that doctors and
volunteers or students were counted at more than one unit during the same
day because of their mobility. Inclusion of doctors was found to bias
the equivalent population figures for units while it did not affect the
equivalent population figures for the total institution.
-------
1*6
4. This study found that equations based on the total 24 hour paid staff minus
the number of doctors was very reliable for predicting the quantity of refuse
generated from patient care units and from certain support units of the
institution studies. Prediction equations for other units were reliable
when based on number of meals served or x-rays taken. All equations and
their statistical reliability are listed on Table III-8.
Since the institution studied was found to be typical in total generation
quantities, it can be assumed that the unit rates are also typical.
5. The equations derived from this study should provide a reliable basis for
reporting or predicting waste quantities for individual hospital units. Such
equations had previously not been available. Designers and architects should
find these equations useful in designing or remodeling waste handling systems
in hospitals.
6. The equations developed include units grouped into three main divisions;
1) units dealing in heavy or extensive patient care; 2) limits dealing in
light or moderate patient care; 3) units dealing in support activities. A
statistical analysis of the data supports the assumption that these equations
will be usable for other institutions but this assumption requires verification.
These equations are to be verified by: Selecting at another similar institu-
tion, three units in each of the three main divisions; calculating the
population by summing the total paid staff minus the doctors of administrators
for each unit; collecting the waste produced for at least three separate 24
hour periods for each unit; and comparing the observed results with those
calculated from the equations suggested. If individual results are found
to be scattered, pool the data for the three observations on each unit and
compare average values with the calculated averages.
-------
47
7- The equations developed in this study are empirical in origin and provide
only an estimate of current mean daily quantities. They do not include all
variables known to influence refuse generation, and should be adjusted in
value to account for known or anticipated changes in waste handling practices
at any institution. Peak loads at this institution ranged from 15 to 35 percent
higher than mean daily quantities. Current trends in hospitals are toward
increased use of disposable or throw-away items. The outcome of these trends
must be anticipated and then added to base line values of current waste
production derived from direct observations or calculated from the equations
offered in this study.
8. Of the total waste generated in the hospital, only 25 to 30 percent can be
considered potentially dangerous. This is due to its origin from patient care
units treating communicable diseases or because of its association with surgical
operations, autopsy wastes, body discharges, or pathogenic organisms. By
keeping these wastes separate from all other wastes the remaining wastes need
not receive the same type of treatment that is advocated for contaminated or
pathogenic wastes. If all wastes are mixed together they must all be con-
sidered contaminated and treated as such.
9. Support services contributed almost 60 percent of the total weight of wastes,
while the remaining 4Q percent was generated by the patient care areas. The
largest single producer of waste is the food service area which accounts for
over 38 percent of the total wastes generated by Medical Center as a whole.
Waste Handling
1. Proper operation of a refuse incinerator in a hospital is mandatory. Hospital
incinerators not equipped with adequate air pollution control devices should
not be used.
-------
2. Additional studies are needed in the area of anticipated changes in materials
used in hospitals. Medical personnel, administrative personnel, equipment and
materials designers, producers of disposable items, and all others concerned
with health care now and in the future should be researched in order to
prognosticate waste generation information for the future. These studies should
not only include physical parameters, such as quantities and weights, but
should also investigate social, economical and legal parameters.
3. Additional studies on the impact of mechanical waste handling devices are
needed. With available waste generation data and an estimate of anticipated
increases in waste production, systems approach procedures must be investigated
and the components of such systems evaluated. New systems must be devised to
economically handle increased quantities.
Facilities - Operational Recommendations
1. To reduce the exit of contaminated dust from the refuse a'nd laundry chutes
into the corridors, exhaust fans should be installed near the top of each
chute to create a slight negative pressure. If the doors are kept closed on
the chutes, this should have little effect on the air conditioning system of
the hospital.
2. Refuse should be bagged at the point of generation wherever possible, and the
bags should remain closed in order to reduce the possible spread of contamination
The contents of bags should never be dumped from one container to another or
down the chute.
3. Soiled laundry should be contained in bags until it reaches the laundry area.
The opening of bags in the corridor and the stuffing of individual sheets
into the laundry chute has been proven to be a source of airborn contamination.
Laundry should be handled with precautions similar to those used to handle
refuse.
-------
49
4. Clean or sanitary items should never be placed on the same trays or conveyances
that are used to handle wastes without properly sanitizing the trays or convey-
ances. Infractions of this rule were observed during the course of the study.
5. Disposable syringes and needles should be made inoperative prior to disposal.
This can be accomplished by cutting, crushing, melting, or sealing them in a
container. Usable needles and syringes reached the loading dock almost daily.
Since the hospital has no control over the municipal refuse disposal operation,
it has no control over possible reuse of these devices unles they exercise
proper handling procedures prior to disposal.
6. Radioactive wastes should be handled in a safe manner. Compliance with Atomic
Energy Commission regulations will insure continuance of a non hazardous
operation.
7. Volatile liquids must be handled with continual care. Separate storage and
disposal is mandatory and should be continually maintained.
8. Care should be exercised over the disposal of unused or outdated medicinals,
especially narcotics. Where there is no control over disposal operations, wastes
must be handled so that there is no opportunity for them in a usable form to
reach the public.
9. Reminders of safe waste-handling rules and techniques must continually be
given to all staff and professionals through in-house training and information
bulletins. Employees were often observed to practice unsafe and unsanitary
procedures in the disposal of wastes that they generated or helped to generate.
Too often people get in a hurry or become forgetful and neglect basic rules
that should always be observed.
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50
IV. PHYSICAL AND CHEMICAL COMPOSITION
OF MEDICAL CENTER SOLID WASTES
Introduction
The waste generation from the units of the Medical Center was analyzed to
determine physical and chemical properties. It was felt that these analyses would
give better insight into the difficulties of an possible solutions to waste handling
and disposal problems.
Physical analyses performed include: weight, volume, bulk density, and separa-
tion of waste into component categories.
Chemical analyses include: moisture content (really a physical parameter but
was performed as part of the chemical investigations), volatile solids content, ash
residue, gross calorific value (British Thermal Unit), sulfur content, phosphorus
content, nitrogen content, carbon content, and hydrogen content.
Physical Analyses
Sample Preparation
Sample collection and preparation for physical analysis was described in
detail in Chapter II. Basically, preparation consisted of manually sorting the
waste into predetermined categories and weighing the total for each category. A
flow diagram of sample preparation is shown in Figure IV-1.
Volume determinations were made by: a) measuring the size of the bulk containers
at the loading dock and calculating their volumes, b) measuring the size of the
waste cart in the incinerator room and calculating its volume, c) measuring the
number of gallons of water it took to fill the plastic sampling and weighing contain-
ers, and d) measuring the dimensions of individual piles of waste and computing their
volumes. When a container was only part full, the sampler would estimate the volume
based on a relationship of what the volume would be if the container was full.
-------
Waste from
Medical Center
1
Refuse Bag
Storage Area
_J
Excess Waste
Container
To Waste
Waist-High
Sorting Table
Can Storage
Table
Grinder—^J
Sampling Table
Shredder
Figure IV-1 Physical analysis process
-------
52
Estimates were spot checked periodically to determine accuracy. The samples were
able to stay within 5 to 10 percent accuracy limits.
Solid Waste Densities
Density values were calculated from the measured weights and volumes. Densities
at best were all relative. If the sampler or housekeeper compressed more waste into
a given container by pushing with his hands or feet, the density increased accordingly,
Throughout the study, a concentrated effort was made to measure the waste "in situ" as
it was being handled by Medical Center personnel without manipulating it or changing
existing practices.
Weights and volumes of refuse reaching the general purpose incinerator room and
loading dock from both the Hospital and Basic Sciences Building were recorded for
eight separate weeks during the study period. The densities (ratio of weight to
volume) were computed from the data and statistical analyses were run to determine
the reliability of the relationships. The density values obtained are listed on
Table IV-1, complete with R squared values and standard errors. The time of day
that these quantities reached the incinerator room and loading dock are recorded on
Table IV-2.
Waste from the Hospital to the incinerator room comes mainly from patient care
areas and includes very little glass or metal. The waste is loosely packed in
plastic bags and takes up considerable volume, often accumulating in the chute up to
the first floor (30 feet above). The waste is mainly paper or plastic and con-
sequently has a low weight to volume ratio (low density). The refuse from Basic
Sciences to the incinerator is also composed predominately of paper products but
contains more office paper, magazines and heavier articles. Since this waste is
picked up in carts and wheeled to the incinerator room, the janitor who collects it
often compacts his load into the cart to get more in per trip and this increases the
density. This partially explains the difference of density between th.e two sources.
-------
Table IV-i Weight-volume relationships
SOURCE OF WASTE
Hospital
Hospital
Hospital
Basic Sciences
Basic Sciences
Basic Sciences
Medical Center
Medical Center
Medical Center
DESTINATION
Incinerator Room
Loading Dock
(Combined Total)
Incinerator Room
Loading Dock
(Combined Total)
Incinerator Room
Loading Dock
(Combined Total)
DENSITY
LBS/CILYD.
36.7
111.2
40. 1
64.2
86.2
74.2
37.2
100.7
4J.4
R2
0.991
0.915
0.841
0.964
0.857
0.865
0.979
0.879
0.874
STANDARn
ERROR
1.290
12.601
4.482
4.573
12.781
7.489
1.394
9.531
3.437.
Medical Center
(Refuse Truck
Weights)
Medical Center
(Storage
Container
Weights)
Disposal Site
Disposal Site
149.1
216.1
-------
Table TV-2 Mean hourly solid waste generation totals
(weight ir. pound:;)
UNIT
Hospital
TIME
0-6 A.M.
6-8 A.M.
8-10 A.M.
10-12 noon
12-2 P.M.
2-4 P.M.
4-6 P.M.
6-8 P.M.
8-10 P.M.
10-12 P.M.
TO LOADING
DOCK
0.0
13.4
234.1
172.4
233.1
125.3
55.7
249.1
80.6
127.0
TO INCINERATOR
ROOM
TOTAL
1290.8
173.4
1928.3
TOTAL
0.0
215.4
219.2
249.8
187.4
431.2
156.5
114.9
180.5
0.0
228.8
453.3
422.2
420.5
556.5
212.2
364.1
261.1
300.4
3219.1
Basic
Sciences
0-6 A.M.
6-8 A.M.
R-in A M
10-12 noon
12-2 P.M.
2-4 P M.
4-6 P.M.
6-8 P.M.
8-10 P.M.
10-12 P.M.
0.0
77.7
/, q 3
f -* n
HU.U
71.0
127.7
51.6
190.3
90.7
63.8
TOTAL
758.0
531.3
1289.3
Medical
Center
0-6 A.M.
6-8 A.M.
8-10 A.M.
10-12 noon
12-2 P.M.
2-4 P.M.
4-6 P.M.
6-8 P.M.
8-10 P.M.
10-12 P.M.
0.0
73.0
268.8
203.1
287.5
223.3
95.3
395.2
150.2
176.0
TOTAL
1872.5
2336.0
4208.5
-------
55
Since the Hospital contributes the major portion of the waste taken to the incinerator
room, the value listed for the total Medical Center is closer to that of the Hospital.
Wastes from the Hospital to the loading dock are composed of glass, metal, food
wastes, and other items not easily burned. Densities of waste to the loading dock
are about three times that of the waste to the incinerator room. The difference is
not so great coming from Basic Sciences because there, is less glass, metal and other
heavy items, and more empty boxes in this waste. Values of density for the entire
Medical Center give volumes greater than anticipated from review of other investigations
in the literature. If the total volume is divided by the number of bed patients, the
volume production rate is 0.21 cubic yards or 5.71 cubic feet per patient. If the
equivalent population values are used, this rate reduces to 1.75 cubic feet per
patient as opposed to 0.5 to 1.0 cubic feet often quoted.
Volumes and weights froir 92 observations of the refuse truck picking up waste
from the loading dock resulted in another value for density. The mean density value
from these observations was 149 pounds per cubic yard. These observations often
included large quantities of empty boxes occupying extensive volume prior to loading
into the packer mechanism of the refuse truck. Densities of the waste in the containers
along averaged 216 pounds per cubic yard. Waste in the containers was composed mostly
of ashes, glass, metal, casts and other items that were not combustible.
Waste Classification
Solid wastes originating from hospitals have been classified in many different
ways by equally as many different individuals. They are broadly classified as food
wastes (garbage), combustible material, and non-combustible material, and handled
accordingly. Most wastes coming from patient care areas are classified as infectious
while wastes originating from patients in isolation are normally classified as highly
infectious. Often the total wastes become mixed and many authorities have chosen to
-------
56
Table IV-3 Hospital areas generating wastes and
their typical waste products (30)
Area
Administration
Obstetrics department
including patients'
rooms
Emergency and surgical
departments, including
patients' roors
Laboratory, ;norgue,
rooms
Isolation rootrs
other than regular
patients' rootrs
Nursing stations
Service areas
Waste Products
Paper goods
Soiled dressings; sponges; placentas; waste
fmpules, Deluding silver nitrate capsules;
needles and syringes; disposable masks; dis-
posable drapes; sanitary napkins; disposable
blood lancets; disposable catheters and
colostomy bage; disposable enema units; dis-
posable diapers and underp*ads; disposable
gloves; etc.
Soiled dressing:;; sponges; body tissue
including amputations; waste ampules; dis-
posable masks; miedles and syringes; drapes;
casts; disposable blood lancets; disposable
emesis basins; T/'.vine tubes; Catheters;
drainage sets; :olostomy bags; underpads;
Contaminated glassware, including pipettes,
specimen slides; body tissue; organs; bones.
Paper goods containing nasal and sputum dis-
charges; dressings and bandages; disposable
masks; leftover food; disposable salt and
pepper shakers; , including tin cans, drums,
including food containers,
">, and pharmaceutical bottles;
lie and patient rooms, including
owcrs, etc.; waste food materials
L and floor kitchens; wastes
:
-------
Table IV-4 Additional Hospital areas generating wastes
and their typical waste products (30)
57
Area
Service areas
Teaching and
research areas
Food preparatiDn
areas
Waste l"_rod_ucts_
Dust and purticulatc matter from heating and
ventilation equipment; soiJ.ed linens and
uniforms; lint from washing and drying cycles;
empty detergent, bleach, and disinfectant
containers; etc.
Paper; bottles; dry rubbish; infectious
wastes (mostly animal remains including car-
casses and organ:;) ; cadavers and organs from
surgery; ashes from crematories; etc.
Wooden crates; cardboard and plas'.:ic cartons
containing food; food trimmings; cans; bottles;
aluminum and pla-.tic containers; paper tray
covers; disposable eating utensils; food
wastes; etc.
-------
58
Table IV-5 APWA Classification of refuse materials
Kind or
Ch-rc-cr
Competition or Nature
Origin or Source
C<3, v.c.
Large auto parts, tires
Stoves, refrigerators, ofner large cpplicnces
Furniture, large crates
Trees, branches, palm fronds, stumps, flotage
•
Leuves
Cctch bcsin dirt
Contents of litter rccepfcctes
Small animals: ccts, dc;s, poultry, etc.
Lcrge cnimols: horses, ccws, etc.
Automobiles, trucks
Construction ; LuT.ber, roofing
& Demolition ; Rubble, broken
wastes ; Conc'uif, pioe,
Industrial
refuse
Special
wastes
, ond s'reathir.j scrcps
concrete, plaster, etc.
wire, insulation, etc.
Solid wastes resulting r'ro.Tn indusrriol
processes and manufccturing opcrcfions,
such as: fcoo-procc'.sirg wcitcs, Lcilcr
house cinders, weed, plastic, anj metal
' scrcos ond '-.'lavi^a;, etc.
Hazardojs w;sto;- oc!r- ologicol wastes,
explosives, radloccSvo mato.-iols
Security v/j',fjs.- csnfidc.Ttial documents,
negotiable pcners, etc.
Anincl and
Ajriculi urcl . Mcnures, crcp rc.idues
WCStcS j
Scwc^c
Ircat.-icr I
rclid jcs
Coorso screcnir-,, ^rit, Septic IG-.S ilud-e,
acwotcred sfuije
From:
households,
institutions,
ond commercial
concerns s^ch
as:
hotels,
stores,
restaurants,
markets, etc.
From:
streets,
sidewalks,
olleys,
vacant lott, etc.
From:
factories,
power plants,
etc.
Households,
hospitals,
institutions,
stores,
industry, etc.
Forms,
feed lots
Sewage treat-
ment plonts,
septic tanks
SOUKCc: AP.VA - A^rdSc CC.UCTIG, - r'.WCTICES
-------
Table IV-6 Medical Center classification of refuse materials
(APWA Classification)
GARBAGE FOOD:
(Study Classification)
Coffoo Ground H
RUBBISH (conbustible)
PAPER:
RUBBISH
(non-combustible)
ASHES
DEAD ANIMALS
CONSTRUCT!ON»
DEMOLITION WASTE
SPECIAL WASTES
ANIMAL, AGRICULTURAL
WASTE
PLASTICS:
FILM:
CLOTH:
Office
Carbon
Newspaper, magazine
Towels
Sacks
Cardboard
Cups
Candy, cigarette wrappers
Other
Hard
Foam
Bags
X-ray plates
Gotten
\~>ui_L.\jLi
Gauze
RUBBER:
WOOD:
DUNNAGE:
GLASS:
METALS:
MOLDS, CASTS:
ASHES:
EXPERIMENTAL ANIMALS;
CONSTRUCTION W^STE:
RADIOACTIVE, PATHOLOGICAL, AUTOPSY, SURGICAL
ANIMAL DROPPINGS
-------
Office Paper
Carbon Paper
Newspapers , Magazines
Paper Towels
Paper Sacks
Cardboard
Paper Cups
Candy, Cig. Wrappers
Other Paper
TOTAL PAPER
Hard Plastic
Form Plastic
Plastic Bags Etc.
TOTAL PLASTIC
Glass
Rubber
Metals
Cloth, Gauze, Cotton
Food
Coffee
Film, X-ray Plates
Molds, Casts
-------
Table IV-.7 (continued)
Office Paper
Carbon Paper
Newspaper,Magazines
Paper Towels
Paper Sacks
Cardboard
Paper Cups
Candy, Gig. Wrappers
Other Paper
TOTAL PAPER
Hard Plastic
Form Plastic
Plastic Bags Etc.
TOTAL PLASTIC
Glass
Rubber
Metals
Cloth, Gauze, Cotton
Food
Co f f ee
Film. X-ray Plates
Molds, Casts
Wood
Dunnage
Ashes
Animal Droppings
Other
TOTAL
2ND
ER
CLIN
ADMIN
CAFE
GIFT
GRND
BASE
HOSPITAL
TOTAL
7.0
1.5
5.7
8.0
2.1
15.0
2.8
0.5
0.0
47.6
11.4
0.3
2.7
14.4
25.8
3.0
3.1
6.0
0.8
0.1
0.5
0.0
0.3
1.6
0.5
0.0
'. 3
6.9
0.1
5.7
17.6
6.5
7.2
5.0
1.6
0.2
50.8
3.8
0.0
2.7
6.5
13.4
2.8
1.3
16.6
2.1
0.0
0.0
3.1
1.0
0.0
0.7
0.0
1 Q
15.1
0.1
2.9
25.9
6.6
8.7
3.8
0.8
1.0
64.9
2.4
0.0
2.3
4.7
3.2
1.7
2.5
13.2
1.8
0.0
0.0
1.8
1.6
0.0
0.0
0.0
4.4
44.3
6.4
21.9
7.6
2.8
9.3
1.0
0.9
0.2
94.2
1.1
0.1
1.9
3.1
0.1
0.0
0.6
0.5
0.8
0.0
0.1
0.0
0.0
0.0
0.5
0.0
0.1
2.5
0.0
1.8
19.3
2.7
26.2
23.5
6.7
0.4
83.1
1.9
0.0
3.6
5.5
0.1
0 4
0, S
2.1
5.;
1.^
O.C
O.C
O.C
O.C ,
l.i
O.C
O.C
4.4
0.4
4.0
7.4
1.6
57.0
8.8
2.2
0.4
86.2
2.6
0.0
2.6
5.2
0.0
0.0
0.9
1.4
2.7
0.0
0.0
0.0
0.0
0.5
1.1
0.0
2.1
11.2
0.9
2.4
19.8
2.0
42.2
1.9
1.7
0.1
82.2
3.2
0.0
1.5
4.7
1.6
0.1
1.3
- 1.3
3.7
0.0
0.0
0.0
0.2
0.0
0.7
0.0
4.1
4.
1.
1.
12.
4.
23.
1.
0.
0.
49.
2.
0.
2.
5.
3.
9.
1.
24.
1.
0.
0.
0.
0.
0.
0.
0.
4.
9
0
8
0
6
0
3
6
1
3
8
0
3
1
7
2
4
9
1
0
0
0
1
3
1
0
8
5
0
4
12
5
10
5
1
0
46
5
0
4
9
18
2
1
15
1
0
0
0
0
0
0
0
2
.9
.6
.3
.9
.0
.4
.7
.0
.6
.4
.4
.2
.0
.6
.4
.1
.9
.6
.6
.4
.1
.3
.9
.2
.4
.0
.8
BSB
TOTAL
13.7
0.6
12.3
21.0
3.'J
13.5
1.7
0.0
0.3
67.8
2.4
0.2
1.3
4.4
10.7
3. I
4.7
1.3
2.1
0.5
0.1
2.3
0.2
0.2
0.4
0.3
1.8
100 100
100
100
100
100
100
lOO
100
100
-------
62
consider all waste originating from hospitals as infectious and require special
disposal techniques (incineration) even though wastes originating in administrative
areas or from central receiving departments are no different than wastes from other
institutions (schools, office buildings) in a community.
Tables IV-3 and IV-4 show general classifications of waste products from hospitals
and the areas of generation as outlined by Oviatt (30). Segregation in such detail
was not considered necessary for accomplishing the objectives of this study but the
classification system was considered sufficiently informative jto include with the
report.
Table IV-5 shows the American Public Works Association CAPWA) classification for
all refuse materials. Table IV-6 shows the classification system used during this
project and its relationship to the APWA system. The categories used in this study
were chosen for ease of identification, facility in sorting, and use In later analyst!
Quantities of waste generated in each category by each unit of the hospital are shewn
later in this chapter.
The 24 hour accumulations of waste from each of the units were separated into the
designated categories and each category was weighed. The mean daily percentages for
t jr.h category from each Hospital unit are listed on Ta°ble IV-7. Paper, in vari".>s
s- b~categories was high from all units arid accounted for 46 percent of the total
Hospital weight. Either glass or cloth-gauze-cotton categories were second >• Lgnest
depending on the particular unit source. Note that paper towels alone account f>-r
13 percent of the total hospital waste by weight but account for a much higher percent1
l>y volume. Plastic percentages were not significant weightwise, but a plastic bottle
takesup just as much volume as a glass bottle and can be more difficult to dispose.
An increased use of plastics could decrease total weights while increasing total
volumes.
-------
63
The mean percentages for each day of the week in each category are shown for
the Hospital on Table IV-8 and for the Basic Sciences on Table IV-9. It is important
to nnce that these percentages do not include food preparation or food scrapping
wastes nor do they include experimental animals or pathological wastes. Table IV-10
shows the mean percentages for the Hospital (except kitchen and cafeteria), main
kitchen and cafeteria, Hospital total, Basic Sciences (except kitchen, Basic Sciences
kitchen, Basic Sciences total, and Medical Center total. This table gives a more
realistic overview of percentages of waste (by weight) by each of the various cate-
gories.
The figures in the preceding tables reflect the percentages by weight of the
various categories of waste. Table IV-11 shows the actual weights for each of the
categories measured for the main kitchen of the Hospital. This information is
significant since approximately one third (by weight) of all the refuse generated
in the Hospital comes from the main kitchen. Table IV-11 is divided into food
preparation and food scrapping activities. The wastes generated by these activities
are indicated for each of the days sampled.
Conclusions
It is estimated that if the Hospital converted to total disposable food
service items (including trays) it would add approximate.!/ [,800 pounds per dav to
the waste load. This would more than double present waste quantites from the main
kitchen. Since most of the disposable items are low in weight per unit volume, this
•wculd add very high volumes of vaste to be handled and require some type of on-site
compactor or volume reduction device to accommodate the loads«, T^e pioportimi of
paper and plastics would greatly increase if such a conversion were to take place
It is estimated that if the Hospital converted to disposable linen the increased
weight of refuse requiring disposal would be approximately 2,000 pounds. This is
-------
Table IV-8 Daily Hospital refuse generation by category
(values in percent of weight)
•MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY SUNDAY WEEKLY
Office Paper
Carbon Paper
Newspapers ,
Magazines
Paper Towels
Paper Sacks
Cardboard
Paper Cups
Candy, Cig.
Wrappers
Other Paper
Hard Plastic
Foam Plastic
Plastic Bags,
Etc.
Glass
Rubber
Metals
Cloth, Gauze,
Cotton
Food
Coffee Grounds
Film, X-ray
Plates
Molds, Casts
Wood
Dunnage
Ashes
Animal Droppings
Other
6.95
0.83
5.21
14.21
5.06
9.63
5.62
0.88
2.42
4184
0.14
2.83
18.30
1.47
1.85
14.12
1.99
0.25
0.35
0.09
0.33
0.00
0.32
0.00
2.26
TOTAL 100.00
7.07
0.74
5.59
13.10
5.10
7.72
6.33
0.78
0.40
6.21
0.37
4.46
19.18
2.40
2.31
11.07
1.58
0.41
0.06
0.47
0.27
0.00
0.47
0.00
3.91
100.00
7.55
0.57
2.76
12.35
4.70
12.50
3.75
0.83
0.60
4.20
0.46
8.43
14.74
2.80
1.80
16.02
1.32
0.44
0.00
0.00
0.15
0.00
0.33
0.00
3.70
100.00
4.80
0.41
3.74
12.41
5.34
17.13
4.66
1.00
0.06
5.76
0.10
2.90
15.11
2.35
1.80
15.75
1.55
0.73
0.02
1.29
0.18
0.00
0.32
0.00
2.59
100.00
4.97
0.65
4.21
12.23
4.79
8.46
6.01
0.96
0.26
6.40
0.06
2.13
22.34
1.82
1.57
16.81
1.57
0.09
0.04
0.09
0.16
1.26
0.46
0.00
2.66
100.00
4.74
0.00
4.01
13.99
5.15
8.16
8.46
1.37
0.10
4.78
0.00
2.82
18.67
1.54
1.67
20.25
2.01
0.30
0.00
0.00
0.11
0.00
0.52
0.00
1.35
100.00
3.73
0.23
4.50
12.34
4.84
5.80
7.54
1.12
0.29
5.69
0.00
3.83
23.07
2.16
2.07
17.97
1.55
0.32
0.10
0.00
0.14
0.05
0.53
0.00
2.13
100.00
TOTAL
5.9
0.6
4.3
12.9
5.0
10.4
5.7
1.0
0.6
5.4
0.2
4.0
18.4
2.1
1.9
15.6
1.5
0.4
0.1
0.3
0.2
0.2
0.4
0.0
2.8
100.0
-------
Table IV-9 Daily Basic Sciences refuse generation by category
(values in percent of weight)
MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY WEEKLY 95% CONFIDENCE INTERVAL
Office Paper
Carbon Paper
Newspapers ,
Magazines
Papec Towels
Paper Sacks
Cardboard
Paper Cups
Candy, Cig.
Wrappers
Other Paper
Hard Plastic
Foam Plastic
Plascic Bags,
Etc.
Glass
Rubber
Metals
Cloth, Gauze,
Co -ton
Food
Coffut: Grounds
Film,. X-ray
P:.ates
Moldn, Casts
Wood
Dunnage
Ashe:3
Animal Droppings
Other
TOTAL
15.9
0.6
11.9
18.8
3.7
13.3
1.9
1.1
0.2
2.9
0.1
0.9
12.7
3.6
5.0
1.2
1.8
0.5
0.0
1.4
0.2
0.1
0.3
0.1
1.8
100.0
13.4
0.7
7.5
24.3
4.4
17.2
2.1
0.6
0.0
2.8
0.4
0.9
12.1
0.3
3.8
1.3
1.5
0.7
0.0
1.3
0.1
0.3
0.2
0.2
3.9
100.0
18.3
0.4
16.6
22.7
1.8
9.5
1.8
0.8
0.2
1.9
0.1
0.7
10.3
0.3
5.1
1.5
2.9
0.2
0.1
3.3
0.3
0.1
0.4
0.1
0.6
100.0
8.9
0.6
.0.8
:2.3
4.8
13.0
1.4
0.7
0.4
2.8
0.2
5.2
5»8
9.0
5.8
1.7
2.3
0.4
0.0
2.2
0.1
0.3
0.4
0.2
0.7
K'0.0
12.8
0.7
15.1
17.7
4.6
14.3
1.5
0.8
0.6
1.5
0.3
0.9
12.8
1.2
4.0
0.9
2.2
1.0
0.3
3.3
0.2
0.2
0.7
0.1
2.3
100.0
TOTAL
13.7
0.6
12.3
21.0
3.9
13.5
1.7
0.8
0.3
2.4
0.2
1.8
10.7
3.1
4.7
1.3
2.1
0.6
0.1
2.3
0.2
0.2
0.4
0.1
2.0
100.0
LOW LIM
10.6
0.5
9.1
18.6
2.9
11.1
1.5
0.6
0.1
1.8
0.1
0.1
8.2
-0.2
4.0
1.0
1.7
0.3
-0.0
1.4
0.1
0.1
0.2
0.1
0.6
74.9
UP LIM
16.8
0.7
15.4
23.5
5.0
16.0
2.0
1.0
0.5
2.9
0.3
3.5
13.3
6.3
5.5
1.6
2.6
0.9
0.2
3.2
A n
w • -/
0.3
0.6
0.2
3.1
125.7
V.1
-------
-------
Table IV-11 Sampling dita for the Main Kitchen.
Weights In Pounds
Monday Tuesday Wednesday Thursday Friday Saturday Sunday
4/7/69 3/25/69 2/26/69 1/30/69 11/15/69 10/26/69 4/20/61.
Food preparation
paper
food
cans & bottles
food scrapping
170
518
84
152
313
88
143
37)
115
106
351
117
260
432
119
117
443
108
97
251
108
paper
food
Totals
229
518
1519
212
655
1420
22/
523
137}
315
514
1403
265
282
1358
205
331
1204
214
236
906
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68
based on non-woven disposable sheets weighing about 25 percent of what a linen
sheet weighs. If such a conversion were to take place, the proportions of paper
and/or plastics would increase significantly.
The quantities of waste generated in each of the categories reflects the type
of materials used and to a degree, the type of service given by the particular unit
of the Hospital. Any significant change in the types or physical characteristics
of the materials used in the units will naturally be reflected in the wastes. Paper
and plastics together comprise well over half of the total waste load (by weight).
Since most of the wastes from the Hospital are low density wastes, (41 Ibs/cu.ft.)
the volumes generated are very high (about 2-1/2 cu.yds./lOO Ibs). Consequently
most hospitals have volume reduction equipment in the form of incinerators or on-site
compactors. Without some method of reducing the volume, the storage requirements
would be extremely high.
The design of refuse handling facilities and equipment should reflect the
physical nature of the waste and provide the necessary volume storage or volume
reduction capacities. Automatic waste handling equipment is being developed to
process the large quantities of materials that flow through hospitals. Materials
handling expertise is being directed toward the problems in hospitals but without
information such as that presented in these tables, it could well be misdirected.
Hospitals which are required to pay for waste disposal on a volume basis shcjjd
use every means available to reduce the volume while those hospitals which pay on
a weight basis, may not be as concerned about volume reduction.
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69
CHEMICAL ANALYSIS
Sample Preparation
Sampling procedures and initial sample preparation were discussed in detail
in Chapter II. Any additional preparation necessary prior to chemical analysis
IT described as part of the specific test procedures for each chemical test. For
most analyses the procedures outlined in Appendix B of Municipal Refuse Disposal
(91) were followed. Where modifications to these analyses were required or where
procedures were used that are not contained in Appendix B of Municipal Refuse Disposal,
such deviations or additions are mentioned in addition to the standard procedure for
each chemical analysis. That is listed in Appendix B of this report.
The samples taken from the covered tin containers were systematically analysed
in order to obtain maximum efficiency of equipment. The tests conducted were as
follows in order of testing; Moisture content, Volatile solids content, ash
residue, Gross calorific value (B.T.U.) Sulfur content, Phosphorus content,
Nitrogen content, Carbon content and Hydrogen content.
Statistical analyses were run on all chemical data to increase the degree cf
reliability for the results and conclusions. Means, standard deviations, standard
error of this means, and ninety five percent confidence intervals were the statis-
tical analyses used for this portion of the study.
Moisture Content
The true moisture content of the solid waste as generated from the Medical
Center is not reflected by this data as shown in Table IV-12. The sample preparation
process was not conductive to moisture retention. The separation into categories
rough grinding through the "Davis-Built" grandulator and fine grinding through the
Standard Model 3 Wiley Mill all allowed the samples to be in contact with the air
and tc dry out.
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70
Table IV-12 Moisture content
(Percent of Total Weight)
Location
Hospital
Basic Sciences
Total Medical Center
No. of
Observations
76
101
177
Mean
5.054
5.455
5.283
Standard
Deviation
0.149
0.166
0.115
95%
C.I.
5.351
5.784
5.508
No tests were run on the "as received" refuse to determine actual moisture
percentages but visual observations on wastes coming from the kitch laboratories,
maternity, intensive care, surgery and areas where burn patients are cared for
confirmed that wastes were often very moist.
Since over half of the waste was paper, much of the moisture was absorbed
in the waste handling process. Only when partially filled containers were
dumped did moisture seep from the refuse.
The true moisture content is important for incinerator operation and heat
reclamation. Moisture adds to the weight of refuse for disposal and can increase
disposal costs where weight is the parameter for cost determination.
Since the moisture content of the refuse will vary significantly from one
hospital unit to another, it was not felt necessary to obtain "as received"
moisture values. This should be done on an individual hospital basis if it is
required. Excessive moisture content will lower the effective heating value of
the refuse if heat recovery operations are anticipated.
Volatile Solids Content
The values for volatile solids content are calculated on the portion of the
sample that was ground. Excluded are the metal, wood, glass, rubber and hard
plastic components of the waste. Since glass and metal make up approximately 20
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71
percent of the total waste by weight the mean value listed in Table IV-13 for
the total Medical Center should be reduced to approximately 76 percent.
Table IV-13 Volatile solids content
(Percent of Total Weight)
Location
Hospital
Basic Sciences
Total Medical Center
No. of
Observations
76
101
177
Mean
96.372
95.576
95.917
Standard
Deviation
0.211
0.246
0.168
95%
C.I.
96.794
96.062
96.246
Glass and metal are normally excluded from the waste that is incinerated,
consequently these values are not too different from what occurs in actual
practice. Approximately 92 percent by weight of the waste incinerated leaves
through the chimney leaving an ash residue of about 8 percent. The refuse
incinerator at the Medical Center is not equipped with after burners or air
pollution control devices and consequently all the material that leaves the
stack has not volatized. Fly ash, unburned particles and products of incomplete
combustion shower the neighborhood making the 92 percent apparent weight reduction
seem better than it really is.
The volatile solids content of the samples does show that with proper in-
cineration, the wastes can be significantly reduced in both weight and volume.
This is primarily due to the high percentages of paper, plastic, cloth, and other
materials that are combustible.
Ash Residue
The ash residue represents that portion of the waste which is not volatile.
Because of this relationship, most of what was discussed under Volatile Solids
content is applicable for ash content, but with inverse results. The values
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72
listed in Table IV-14 are low because of the exclusion of glass and metal from
the samples. Adjusted values would range closer to 24 percent by weight.
Table IV-14 Ash Residue - Volatile solids test
(Percent of Total Weight)
No. of Standard
Location Observations Mean Deviation
Hospital 76 3.627 0.206
Basic Sciences 101 4.423 0.242
Total Medical Center 177 4.081 0.166
Carbon train test
Hospital 76 2.707 0.222
Basic Sciences 101 3.651 0.300
Total Medical Center 177 3.246 0.198
95%
C.I.
4.038
4.902
4.407
3.151
4.245
3.635
Gross Calorific Value
The gross calorific value of the refuse provides a measure of its heating
potential. Incinerators are designed around the heat value of the fuel to be
used when heat recovery or heat dissipation are of prime importance. Knowing
the calorific value of hospital refuse, expressed in B.T.U.'s per pound of
refuse, provides design engineers with a helpful tool. The B.T.U. value allows
us to compare one fuel with another.
The calorific value for municipal refuse varies from about 5,500 BTU/pound
to 10,000 BTU/pound. The values obtained for this refuse averaged around 8,000
BTU/pound and did not vary much over 500 BTU/pound above or below this mean
value. Having a fuel with a reliable heating value is an important factor.
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73
The figures in Table IV-15 do not include the non-grindable metal, glass,
wood, rubber and hard plastic. The metal and glass would not add to the BTU value
but wood, rubber and hard plastic would. The values in Table IV-15 were obtained
from samples having low moisture contents. A higher moisture content would
decrease the BTU value per pound of refuse. It is assumed that the low moisture
content is offset by the lack of wood, rubber and hard plastic which could tend
to cancel each other out.
Table IV-15 Gross calorific value
(Values in B.T.U./pound)
Location
Hospital
Basic Sciences
Total Medical Center
No. of
Observations
76
101
177
Mean
8381.391
7612.477
7942.508
Standard
Deviation
112.537
98.512
79.327
95%
C.I.
8606.461
7807.527
8097.988
Coal has BTU per pound values ranging from 10,000 to over 14,000 with a high
percentage of coals having around 13,000. Hospital refuse at 8,000 BTU per
pound is not as good as coal but since it must be disposed of anyway and since
it contains possible pathogenic organisms that can be killed by heat, it makes
good sense to incinerate where air pollution control regulations can be satisfied
both in equipment and operation.
Sulfur Content
The sulfur in refuse can react to form sulfur dioxide (SCL) when incinerated,
This gas can then add to air pollution problems if sufficient quantities are
generated. In certain areas of the country coal with a sulfur content over 2
percent is banned because of the sulfur dioxide that is released. Coal is con-
sidered low sulfur coal when the sulfur content is 1 percent or less.
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74
The sulfur content of this refuse was about 0.2 percent or one fifth that of
a low sulfur coal. Since it would take almost twice as much refuse as coal to
give the same B.T.U. value it would be more realistic to figure twice as much
sulfur liberated or about 0.4 percent when comparing refuse to coal. Even at
this figure, the sulfur content of refuse does not appear to be a serious problem
during incineration as seen in Table IV-16.
Table IV-16 Sulphur content
(Percent of Total Weight)
Location
Hospital
Basic Sciences
Total Medical Center
No. of
Observations
76
101
177
Mean
0.211
0.199
0.204
Standard
Deviation
0.018
0.014
0.011
957.
C.I.
0.247
0.226
0.226
If the refuse is landfilled and anaerobic conditions occur, the sulfur in
the refuse can be reduced to hydrogen sulfide (H S) which can be quite odiforous.
Other than that, there should be no problems with sulfur in waste disposal opera-
tions.
Phosphorus Content
The phosphorus content of the refuse is very low, 0.03 percent. Phosphorus
content of municipal refuse ranges from 0.12 to 0.70 percent as shown on Table
IV-17
The phosphorus content of this refuse is considered to be inconsequential.
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75
Table IV-17 Phosphorus content
(Percent of Total Weight)
Location
Hospital
Basic Sciences
Total Medical Center
No. of
Observations
76
101
177
Mean
0.025
0.026
0.026
Standard
Deviation
0.033
0.002
0.002
95%
C.I.
0.030
0.030
0.029
Nitrogen Content
The nitrogen content of the refuse sampled is low (0.33 percent) but this
compares with the low end of the values for municipal refuse that are shown in
Table IV-18.
Table IV-18 Nitrogen content
(Percent of Total Weight)
Location
Hospital
Basic Sciences
Total Medical Center
No. of
Observations
73
97
170
Mean
0.343
0.318
0.329
Standard
Deviation
0.017
0.015
0.011
95%
C.I.
0.377
0.347
0.351
The nitrogen content is not considered important in incineration but could
play a small role in composting or decomposition in landfills. The nitrogen
content of this refuse is not considered significant.
Carbon Content
The high carbon content reflects itself in high BTU values and high volatile
solids values. It also indicates a high organic content in the samples. These
values would be lowered somewhat if metal and glass were added to the total from
which the percentages were calculated. Comparing the values obtained in this
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76
study with those listed in Table IV-19 for municipal refuse shows this refuse
to be on the high side.
Table IV-19 Carbon content
(Percent of Total Weight)
Location
Hospital
Basic Sciences
Total Medical Center
No. of
Observations
76
101
177
Mean
45.840
43.149
44.304
Standard
Deviation
0.334
0.277
0.236
957.
-C.I.
46.508
43.699
44.767
Both incineration and biological decomposition can benefit from large carbon
contents in the refuse. Carbon dioxide (C02) is the final product desired from
the carbon in any waste.
Carbon-nitrogen or carbon-hydrogen ratios can be easily calculated from
the data in these tables.
Hydrogen Content
The hydrogen content of this hospital's refuse is slightly above that
expected in municipal refuse as shown in Table IV-20. Quantities of plastics
larger than normally found in municipal refuse could explain part of this. A
large hydrogen content is not considered bad and consequently the amount contained
in this refuse should not be detrimental to any waste disposal practices.
Table IV-20 Hydrogen content
(Percent of Total Weight)
Location
Hospital
Basic Sciences
Total Medical Center
No. of
Observations
76
101
177
Mean
7.376
6.803
7.049
Standard
Deviation
0.061
0.049
0.044
95%
C.I.
7.498
6.899
7.134
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77
Table IV-21 Chemical test comparisons
(Ranges of values containing 68%
of test means)
Chemical Test
Moisture
Volatile Solids
Ash
B.T.U.
Sulfur
Phosphorus
Nitrogen
Carbon
Hydrogen
Range
4.0 -
95 -
2 -
7,000 -
0.09 -
0.009 -
0.25 -
41 -
6.3 -
6.5
98
5
8,500
0.30
0.040
0.45
48
7.7
Comparison*
8.8 -
53 -
4 -
5,475 -
0.08 -
0.12 -
.3 -
76 -
4.2 -
575
95
38
10,000
0.6
0.70
1,74
48
6.4
Comparison**
15 -
50 -
-
3,000 -
0.07 -
-
0.2 -
15 -
2 -
35
65
6,000
0,1
1.5
30
5
* Ulmer, N. S., "Physical and Chemical Parameters and Methods for
Solid Waste Characterization," Division of Research
and Development, Open File Progress Report #RS-03-68-17
PHS - HEW, 1970.
** DeMarko, J. et al., Incinerator Guidelines - 1969, U. S. Dept. of
Health, Education and Welfare, Public Health Service
Publication No. 2012, p. 6.
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78
V. BACTERIOLOGICAL AND VIROLOGICAL STUDIES
Introduction
The bacteriological studies were conducted in three phases; (1) a general
approach at selected wastes to determine types and quantities of organisms present
through the use of selective media and total population counts, (2) a more detailed
examination for specific organisms from each of the generating units of the institution,
and (3) a study of airborne bacteria that are generated during waste handling and
pathways by which such bacteria can be disseminated within the hospital environment.
The virological studies consisted mainly of determining the length of time that
viral agents persisted at room temperature on solid waste materials recovered from
the Hospital, the efficiency of their recovery and some of the factors which might
influence their survival or recovery. Isolation and identification of virus from raw
refuse that had not been artifically contaminated was not attempted during this study.
PHASE 1 Bacteriological Studies
The increased production of solid waste has lead to an increased possibility of
contamination of persons from pathogenic microorganisms in refuse. The presence of
tliese organisms in the refuse has been verified and correlated with some of the
current diseases of today (17,92). Some of the diseases that may be contacted
through environmental association with the refuse from a hospital are: salmonellosis,
tuberculosis, amebic dysentery, staphlococcal infections, streptococcal infections,
typhoid, urinary tract infections, hepatitis, and diphtheria.
The increasing potential of infection by pathogenic microorganisms can only be
controlled by proper environmental safeguards. Contact with the disease-related
organisms in the refuse may result from direct handling of the wastes or indirect
contact with some inanimate object that had been infected. It is important that a
thorough investigation of waste be made and pathogens that are related to man and
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79
his diseases be identified. Their distribution throughout the institution and possible
routes of communication should also be established.
Before this can be accomplished, it is necessary to provide some guide lines
regarding what are organisms of importance and what means are available to correctly
identify them. This will include, the sampling techniques that are presently being
employed and the media that are used to culture these organisms.
The main objective is the correlation of the total bacterial count per gram of
sample. This includes the total aerobic and anaerobic counts, plus the use of
selective media for the counts for streptococci, staphlococci, coli, fungi, molds,
and others. The endeavor today is to relate all of these pathogenic species (only
a few species are pathogenic in each of the above groups) to their association with
man and how, through environmental control, their virulence can be decreased.
Methods and Materials
All samples were taken from pre-determined stations established by other
researching personnel. Each sample was checked for:
(1) Total Count - Standard Plate Count Agar, incubated at 37°C for
24-48 hours.
(2) Total Anaerobic Count - Standard Plate Count Agar, incubated at 37°C
for 72-120 hours.
(3) Aerobic Sporeformers - Heat sample to 80°C for 30 minutes - use
Nutrient Broth.
(4) Anaerobic Sporeformers - Heat sample to 80°C for 30 minutes - use
Thioglycollate Broth.
(5) Coliform Count - Violet Red Bile Agar, MacConkey Agar
(6) Pathogenic Staphlococci - Mannitol Salt Agar
(7) Beta-Hemolytic Organisms - Blood Agar Plates
-------
80
(8) Fungi - Cooke's Rose Bengal Agar
(9) Streptocci & Enterococci - Mitis Salivarius Agar
The Agars, Broths, Mediums and Preparations used to perform these analyses
are listed in Appendix C.
Collection and Preparation of Samples
In the beginning of this study, all samples were taken from the incinerator
room in the basement of the University Hospital. These samples were taken on a
biased basis, avoiding all refuse that appeared to be an administrative level, and
restricting the collection of samples to those of an obvious medical nature.
It was presumed that the refuse from the administrative offices was of a low
micrcbial count and that it was important in the beginning to determine what were
the real, potential pathogens that were to come from the medical wastes. In the
latter part of this study sampling began on a total hospital basis to verify the
previous assumption.
The collectors of the samples were always equipped with a disposable mask,
rubber gloves, and a white laboratory coat. These precautions were taken because
sorting through this refuse, the collector was subject to contamination from many
infectious agents.
The sample was collected in large (10 gal.) plastic bags from the designated
station and then tagged, identifying the station number, date, and the time the
sample was picked up.
F.ach sample was picked on a random basis throughout the station area. The
sample was then brought back to the laboratory for separation and grinding. It
was also, necessary to sort from the refuse all plastic, such as utensils, plastic
bags, syringes, etc., and metal items, such as scissors, needles, clamps, wire;
because this material would break the grinders being used.
-------
81
To decrease the initial bulk load on the smaller grinder, each specimen was
pre-ground on a large Wisconsin grinder- The specimen was ground to the 2 mm size
and then placed in sterilized metal container (1 pint) and identified by date, time
and station number.
Analysis
Equipment:
(1) Dial-0-Gram Ohnus Balance, Weigh: 1600 gm capacity
(2) Beaker, Sterile, 50 ml
(3) Phosphate Peptone Buffer Solution
(4) Agar Plates (100 mm Diameter)
(5) Dilution Tubes (20 ml)
(6) Broth Tubes (20 ml)
(7) Incubator @ 37°C + 0.5°C
(8) Brewer Anaerobic Jar
(9) Large, Glass Desiccator
(10) Small Candles
(11) Tube racks
(12) Sterile pipets - in 10 ml size - in 1 ml size (disposable)
(13) Sterile Cotton
(14) Bent Glass Rod
Steps in Analysis:
(1) All steps required strict aseptic conditions - Weigh 50 ml sterile
beaker on balance.
(2) Add exactly 1 gm of ground sample with sterile tongs to beaker while
still on balance.
(3) Add 9 ml of phosphate peptone buffer solution to beakered sample
with a sterile pipet.
-------
oo
ro
Figure V-l
FLOW DIAGRAM FOR BACTERIOLOGICAL EXAMINATION
1 Gm Sample + 9 Ml
0.5% Peptone Bro :h Soln (PBS)
80° C @ 30
Spore Formers
Aerobic
Anerobes
Isolates
Thioglycollates
Broth
Nutrient Broth
(1) EMB Agar
— 1 —8
Dilutions in PBS (10 - 10 )
\
Total Count in Duplicate
- Aerobic
-Anaerobic
STD. Plate Count Agar
Coliforms (lO"1 - 10~8)
VRB Agar
- Mannitol Salt Agar - (Staphlococci)
- MacConkey's Agar (Gram. (-) )
- Mitis Salivarius Agar
(Streptococci Enterococci)
- Blood Agar Plates (B-Strepto~occi)
v
- Cooke's Rose Bengal Agar (Fungi)
Colored Colonies
E. Coli.
Enterobacter
Klebsiella
Colorless Colonies
Proteis
Pseudcnnnas
Herrella
_Sali!ior e lla
ShigeUa
-------
83
(4) Follow this dilution scheme:
Original 1 gm •»- 19 ml = 10"1'
2 ml (10'1'3) + 8 ml = 10~2
1 ml (10~2) + 9 ml = 10~3
1 ml (10~3) + 9 ml = 10~4
1 ml (l(f4) + 9 ml = 10"5
1 ml (10~5) + 9 ml = 10~6
1 ml (10~6) + 9 ml - 10"7
1 ml (10~7) + 9 ml - 10~8
(5) Innoculation of Agar Plates and Broths - Each plate was
Innoculated with 0.1 ml of the dilutioned sample - and then
spread evenly over the stirtace wicn a Dent glass roa.
Dilution Range No. of Plates
—3 —8
(a) Aerobic: Plate Count Agar 10-10 2
(b) Anerobic: Plate Count Agar 10"3 - Iff8 2
(c) Violet Red Bile Agar 10"1 - 10"6 1 Each
(d) MacConkey Agar 10*"1 - 10~6 1 Each
(e) Mitis Salivarius Agar 10"1 - 10~6 1 Each
(f) Blood Agar 10** - 10~6 1 Each
(g) Cooke's Rose Bengal Agar 10" - 10~ 1 Each
(h) Mannitol Salt Agar 10"1 - 10~6 1 Each
Then all dilutions were heated :.n water bath for 30 minutes
@ 80-82°C and then inoculated U/dilution into thioglycollate
broth and nitrient broth.
-------
(6) Incubation: All samples inverted during incubation
(a) "True" Aerobic Incubation - Plates placed in incubator
(b) Brewer Anaerobic Jar in incubator
(c) (d) (e) (f) (h) All incumbated "Microaerophillically"
in glass disiccator in the presence of C0_ + 0_. C0_
environment is established by placing a small candle
inside disiccator with plates in side, lighting it,
close and incubate flame burns off a major portion of
0- environment.
All samples incubated at 37°C + 0.5°C for 24 hours
except (6) Cooke's Rose Bengal Agar for fungi which is
t i ._ . . f\ »r-O /* i nO r* j . .. .. „_». 3
^kllt-UUO UWkA ^ i.^ w • A. S* , .k • C. • A.W04U wt^M*^* «_•. w*.wMfc w ^«»»«»
read 48-72 hours.
(7) Counting - All colony counts were made on a Qubec. Colony
Counter. The only plates that were recorded were those in
which the colonies numbered between 30-300.
(8) Computation of number of organisms per gram of refuse.
-------
85
Results and Discussion
A complete test journal plus histograms for test bacterial counts are contained
in Appendix C.
TEST #0
ORIGIN: Incinerator Room
-4 6
10 : 4.4 x 10 /gm
DATE: July 14, 1970
PGA...AEROBIC:
mostly Bacillus, various types
5-10% Staphylococcus 5-10% Corynebacterium
PGA... ANAEROBIC 10~4: 2.6 x 106/gm
similar to aerobic plates
B.A. 10~4: 5.1 x 106/gm
most Bacillus, 3 Staphylococcus, 4 Corynebacterium
no hemolytic colonies
10"4: 9.0 x 105/gm
MSA
M-S
VRB
MacC
Staphlococcus-like, overgrown with Bacillus
-1
10"2: 3.8 x 104/gm
all Enterococcus,
10
12 possible mitis
10
-2
CRB
2.5 x 10H/gm coli
6.0 x 104/gm total
no E. coli confirmed
10"2: 2.7 x 104/gm coli
4
6.7 x 10 /gm total
also Streptococcus, no E. coli confirmed
10"1'3: 1.2 x 104/gm
molds: 1.0 x 10
-------
86
yeast: 1.4 x 10
1.9 x 103 total of fumigatus. Alternaria. phycomycetes
penicillin types, yellow Aspergillus
THIO. KPN: 1.5 x 104
N.B. MPNt 9.3 x 10
Station No. 0
Incinerator Room
The original sample taken from this station was biased for, it was compulsory
to know which types of organisms were to be found in the "dirtiest" area of the
hospital. As far as total count is concerned, Bacillus organisms were the most
significant colonies present. Staphylococcus organisms comprised 5-107., and
Corynebacterium 5-10%.
Although there were many colonies of cocci-form bacteria present on the VRB
and MacConkey Agars, none of these passed the confirmed test (BGBLB) for the
presence of E^ coci. CRB Agar presented a wide variety of molds and fungi,
including phycomycetes, Aspergillus. and penicillin types.
Sporeformers from the thioglycollate and Nutrient Broth verified the high
populations that are present in the refuse.
Actually because the sample was biased it can only be used as an indicator
and not for total colony comparisons.
TEST #1
DATE: July 21, 1970 ORIGIN: Blood Bank
PGA...AEROBIC 10"3: 9.9 x 105/gm
mostly mixed Bacillus, 5% Staphylococcus
-------
87
PGA...ANAEROBIC
B.A.
MSA
M-S
VRB
MacC
CRB
THIO.
N.B.
-3 5
10 : 2.2 x 10 /gm
mostly Bacillus
10"3: 1.0 x 106/gm
predominantly slow growing (48 hr.) small gram negative
rods; dry, medium size, mat colonies, some with lacy margins,
no hemolytic colonies.
10"2: 1.3 x 104/gm
Staphylococcus-like, overgrown with Bacillus
1 O O
10 : 4.6 x 10 /gm Enterococcus
1.4 x 103/gm S. mitis
10'1'3: 2.6 x 103/gm coli
1.3 x 104/gm total
£_._ coli confirmed (BGBLB)
10'1'3: 4.8 x 103/gm coli
1.9 x 104/gm total
E. Coli confirmed
10
-1.3.
8.4 x 10J/gm
o 3
molds: 4.4 x 10 yeast: 4.0 x 10
Aspergillus, yeasts, very varied green velvet
MPN: 9.3 x 10 /gm
MPN: 4.3 x 105/gm
Station No. 1
Blood Bank
The station had a complete flora of the microorganisms under present observation.
The most significant colonies were Bacillus, which predominated on the Aerobic
Anaerobic, B.A., MSA plates. On both the VRB and MacC plates, cocci-form were present
and these were both positive for E. coli on BGBLB.
-------
88
E^ coli, Fecal coliform, should not be present in this area and further testing
should decide whether this is a abnormal condition or if normal, what is its main
route entry.
TEST #2
DATE: July 21, 1970 ORIGIN: Incinerator Room
PGA...AEROBIC 10~4: 9.3 x 106/gm
PGA...ANAEROBIC 10~4: 7.6 x 106/gm
similar to aerobic growth
B.A. 10"4: 7.7 x 106/gm
predominantly B. cereus-like. hemolytic
MSA 10"3: 3.3 x 106/gm all Staph. like
M-S 10"1'3: 3.4 x 103/gm
all enterococcus, no mitis seen
VRB 10"1'3: 2.6 x 103/gm coli
1.0 x 10 /gm total
E^ coli confirmed (BGBLB)
Mi- 10"1'3: 2.6 x 103/gm.....coli
1.1 x 10 /gm total
E. coli confirmed
CRB 10"1'3: 3.6 x 104/gm
molds: 2.2 x 10 yeasts: 1.4 x 10
Aspergillus, yeasts, very varied green velvet
THIO. MPN: 4.3 x 105/gm
N.B. MPN: 2.3 x 105/gm
-------
89
Sample #2
Incinerator Room
All organisms found at this station are similar to the finding on Sample No. 0
on a previous date. The total count is approximately the same with the Bacillius
organisms dominating the total count.
There is a good normal flora of staph., strep., and coliform microbes. The
only variation from No. 0 sample is that this sample is positive for E. cqpi and
this is quite understandable for this area.
CRB Agar had a high population of molds and yeasts.
TEST #3
DATE: July 24, 1970 ORIGIN: General Medicine (71)
PCA AEROBIC 10"2: 1.4 x 104/gm
5 bright yellow colonies, gram (-) rods
3 pale yellow colonies, gram (-) rods
PCA ANAEROBIC 10~2: 9.0 x 103/gm
same as aerobic
B.A. 10""1-3: 2.0 x 104/gm
bright yellow colonies, few Strep.,
Corynebacterium,
Bacillus, no hemolytic col.
10'1'3: 1.0 x 103/gm all Staph. like
MSA
M-S
VRJ3
MacC
10
-1.3
10
,-1.3
10
.-1.3
1.2 x 10 /gm
all enterococcus, no mitis seen
3.4 x 10 /gm coli
no coli confirmed
3.2 x 10 /gm coli
no coli confirmed
-------
90
CRB
THIO.
N.B.
1 1
10: no significant colonies
MPN: 9.3 x 10 /gm
No growth
Sample #3
General Medicine (71)
The most significant colonies present were Bacillus and these accounted for
approximately 90 percent of the total colonies seen. B.A. had a few no-Hemolytic
Strep, and cocci-organisms. Staphylococcus colonies were dominating on the MSA.
This sample was representative of the total spectrum of colonies under observation
except for the CRB Agar which had no significant growth. This is a good indicator
that the spore dispersal in the environment was quite low.
The total count is much lower than previous counts and this is due most
probably to the disinfection procedures that are carried out.
This station is the adjacent hall to the Station (71) of the Sample No. 4.
If these two samples are compared, it is worthy to note how the change occurred
between them. This is another reason for more testing of Station (72).
DATE: July 24, 1970
TEST #4
ORIGIN: General Medicine (72)
PGA....AEROBIC
PGA....ANAEROBIC
B.A.
MSA
M-S
VRB
MacC
-2 4
10 : 5.8 x 10 /gm all the same yeast
10"2: 6.3 x 104/gm yeast
9 /
10 : 8.9 x 10 /gm yeast, no hemolytic colonies
10"1'3: no Staph.-like
-1.3
10 : no growth
10 : no growth
in'1'3
10 : no growth
-------
91
-2 4
CRB 10 : 6.4 x 10 /gm
all yeast, no significant molds
THIO. MPN: 4.0 x 102/gm
N.B. No growth
Sample #4
General Medicine (72)
The only significant colonies that appeared in this test were yeast cultures.
On the MSA, M-S, VRB, MacC, and Nutrient Broth there was no growth on the lowest
-1 3
(10 ) dilution which is a good indicator that the sample was taken from an area
in which there was little contamination. It is possible that in this hospital
section that they have a high degree of aseptic conditions through the use of
disinfectants and germicides.
It is also possible the sample was not representative. The sample was taken
from the total section and ground according to established procedures.
A method to overcome this is to take several more samples from the section and
to compare the results.
Conclusions
From the preceding analysis of the initial data, it is concluded that:
1. Bacillus organisms make up 80-90 percent of all microbes under observa-
tion.
2. Staphylococcus organisms comprise 5-10 percent of the population .
3. Streptococcus organisms comprised 5-10 perdent of the population.
4. Mannitol Salt Agar was not selective enough for Staphylococcus organisms
Bacillus grew too well, and a new Agar should be substituted, such as
Staphylococcus 110 Agar.
5. The background count from the present 2-grinding technique is too high and
a new method should be incorporated. A possible alternate is a Waring
Blender.
-------
92
6. Representative samples must be taken at least twice, or three times when
possible, for good comparison of results.
PHASE 2 Bacteriological Studies
In order to assess the potential health hazard associated with refuse, a
thorough bacterial examination of the refuse from each nursing station was necessary.
This initially required a decision regarding what organisms yould be of greatest
concern in a general survey and by what methods they could be most readily identified,
The specific organisms chosen to be examined were Escherichjia coli. Pseudomonti,
fungi, yeasts, molds, staphylococci, and streptococci. Selective and differential
medias for these organisms were chosen accordingly. Attempts were made to identify
other dominant organisms. In addition to the specific counts, total colony counts
of aerobic and anaerobic bacteria were performed.
The main objectives of this research project were (1) to determine what types
of bacteria are most prevalent in the refuse (2) to obtain an estimation of the
relative numbers of organisms, and (3) to investigate the possibility of existing
trends between the numbers and types of organisms and the particular Hospital Units.
Collection of Samples
During the course of five months between September and February, 15 nursing
stations at West Virginia University Hospital were each sampled three times. The
total of 45 samples were taken at a random basis with four samples taken each week.
The source of the refuse was from the waste receptacles in the bathroom and by the
patient's bed. Several rooms from each wing were sampled in order to obtain a
representative sample from the respective station.
The various types of stations included in the research were outpatient clinic,
orthopedic, operating room, intensive care, general surgery, maternity, gynecology,
pediatrics, general medicine, metabolic unit and emergency room.
-------
93
The samples were usually collected between the hours of 1:00 P.M. and 3:00 P.M.
Due to the nature of this work, the investigator was required to wear gloves and a
white coat while collecting the samples.
Analysis
After the samples are collected, they are taken back to the laboratory for
analysis. The laboratory used in this project is located in West Virginia University
School of Engineering Building in Room B-33. The time interval between sampling and
analysis never exceeded five hours. Aseptic techniques were stressed throughout all
phases of the operation to minimize contamination and erroneous results.
All bacterial counts are listed in terms of bacterial counts per gram of sample.
It should be noted that this number applies to the sample analyzed which includes
only paper products and those items which the blender can accommodate. Other items
in the refuse, such as plastics, metals, and fibrous materials had to be excluded
from the analysis.
A. Media
1. Cooke Rose Bengal Agar (0703)
2. Blood Agar Base (0045)
3. MacConkey Agar (0075)
4. Mitis Salivarius Agar (0298)
5. Tellurite Glycine Agar (0617)
6. Plate Count Agar (0479)
7. Pseudosel Agar (11554)
8. Fluid Thioglycollate Medium (0256)
9. Lactose Broth
10. E E Broth
11. Brilliant Green Bile 2%
12. Azide Dextrose Broth
13. Phosphate Peptone Buffer Solution
14. Nutrient Agar
-------
The following references were used for the selection of the proper media
(110,111,112,113,114,94)
B. Equipment and Supplies
1. Brewer Anaerobic Jar
2. Disposable Agar Plates (100 mm diameter)
3. Dial-0-Gram Balance
4. Erlenmeyer Flasks, 500 ml
5. Dilution tubes (18 x 20 mm)
6. Broth tubes (20 ml)
7. Tube Racks
8. Incubator
9. Sterile Cotton
10. Large Plastic Bags
11. Water bath
12. Refrigerator
13. Sterile pipets, 1 ml and 10 ml
14. Waring Commercial Blender
15. Penicillin
16. Streptomycin
17- Kanamycin
18. Syringe (2 cc)
19. Gas Pak (R) BBL
20. Stock Cultures of Bacillus subtilis and E^ coli.
21. Sterile Filter Paper Discs
C. Analysis Steps
1. Weigh 10 grams of sample (excluding metals, plastics and other
material which is unacceptable to the blender.
2. Add 490 mis of sterile peptone buffer solution to a Waring Blender
container.
3. Transfer the 10 gram sample to the blender container. (This yields
a 1:50 dilution).
4. Blend the sample for approximately 60 seconds.
5. Follow this dilution scheme:
5 mis of 1:50 dilution + 5 ml = 10"2
1 ml (10~2) + 9 ml = 10~3
1 ml (10"3) + 9 ml = 10"4
1 ml (10~4) + 9 ml = 10"5
6. Inoculation procedure:
The lowest dilution plates are inoculated with 0.5 mis of the
1:50 dilution to yield a plate dilution factor of 10~2- All other
inoculations are made with 0.1 ml of the dilutions ranging from
10Ie to 10 ™s wil1 yield Plate dilution factors of 10~3 to
10 . After inoculation, the liquid inoculum is spread evenly across
the plates and allowed to dry.
-------
95
ytfedium
a. Cooke's Rose
Bengal Agar
b. Mitis Salivarius
Agar
c. Pseudosel Agar
d. Blood Agar
e. Blood Agar + Kanamyctn
(concentration 100
microgram/ml)
f. Anaerobic Plate Count Agar
g. Aerobic Plate Count Agar
h. Tellurite Glycine Agar
Dilution Range
-2 -6
10 - 10
- ID
'6
ID'2 - !0-6
ID"2 - ID'6
-2 -3
10 - 10
ID'2 - ID'4
ID'2 - ID"6
ID'2 - ID'6
Selectivity
molds & yeasts
Streptococcus
Pseudomonas
Not selective
Strict Anaerobes
Not selective
Not selective
Staphylococcus
7. All dilution tubes are then placed in the water bath at 80°C for 30
minutes. This is considered sufficient time to kill all vegetative
bacterial cells leaving only the viable spores. Then 1 ml of each
dilution is inoculated into the thioglycollate broth tubes using
three tubes per dilution.
8. Incubation:
All plates are inverted during incubation to prevent moisture from
condensing and falling upon the medium.
a. Anaerobic plate count agar plates and blood + kanamycin agar plates
are first placed in Brewer Anaerobic Jar with an activated Gaspak
and then into incubator at 37°C.
b. Cookers Rose Bengal Agar which is used for fungi is incubated at
room temperature.
c. All other media are placed in the incubator at a temperature of 37"C.
9. Colony Count Determination:
Colonies were read on the Quebec Colony Counter. Most counts were
recorded in the optimum counting range of 30 - 300 colonies. In some
cases, however, other counts were used because optimum counts were not
available - for example, less than 30 colonies on the lowest dilution
and no colonies at higher dilutions. The Cooke's Rose Bengal Agar plates,
the anaerobic plates and the Thioglycollate broth were read after five
days. All other agar plates were read at two and five day intervals.
Counts of spore forming organisms in the Thioglycollate broth were deter-
mined using a table of most probable numbers. (See Standard Methods for
the Examination of Water and Wastewater, 1965, p. 608).
-------
96
10. Computation of the number of organisms per gram of refuse. This computation
is made by multiplying the number of colonies per plate times the plate
dilution factor.
11. Test for Inhibitory Agents:
Two pour plates were prepared using molten nutrient agar at 45°C and
one drop of a young nutrient broth culture of E. coli and B. subtilis
respectively. A sterile paper disc moisted in the 1:50 dilution was placed
on each plate. The plates were examined and the inhibition of either bacter-
ium was recorded as positive for antibacterial activity.
12. Identification tests
a. E^ coli
1. Typical pink colonies on MacConky agar.
2. Gas production in lactose broth.
3. Gas production in brilliant green bile broth.
b. Fecal Streptococcus
1. Typical grey black colonies on Mitis Salivarious Agar.
2. Growth with turbidity and mauve sediment in EVA broth.
3. Gram positive cocci.
4. Catalase negative.
5. Ferment glucose in sealed thioglycollate medium.
6. Growth at 10°C, 45°C, and in presence of 6.5% NaCl.
c. Staphylococcus aureus
1. Large flat white, cream, or yellow colonies on plate count or
blood agar or black colonies on tellurite glycine agar.
2. Gram positive cocci.
3. Catalase positive.
4. Fermentation of glucose in a sealed thioglycollate medium.
5. Coagulase positive by the slide test.
d. Candida albicans
1. Budding yeasts.
2. Produces pseudohyphae and chlamydiospores when growing on rice
corn meal agar.
e. Pseudomonas aeruglnosa
1. Growth on media containing 0.037» cetrimide.
2. Does not ferment glucose in a sealed thioglycollate medium.
3. Produces cytochrome oxidase.
4. Growth at 42°C.
5. Produces blue green pigment.
f. Other organisms were identified as far as was practicable using
generally recognized tests and criteria. The following references were
used for identification (115,116,117,118,119).
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97
Results and Discussion
Presentation of test data
Microbial counts of the various organisms in the refuse constituted the majority
of the test data. These counts, expressed as the Login Per 8ram °* refuse, were
recorded in Tables V-l - V-4.
Table V-l lists the total colony counts, as well as the counts of the specific
organisms for which the selective medias were chosen. The following list provides
the explanation of columns 1 - 11 in Table V-l.
Column
1. Number of the nursing station (Hospital units) sampled.
2. Number of the test at the respective stations.
3. Total bacterial count on the medium which gave the highest count.
4. The medium from which the total count was taken.
5. Coliform count on MacConkey Agar except at very low levels where
growth in EE broth indicated a Iog10 count of 1.0.
6. Fecal Streptococcus on Mitis Salivarius Agar except at very low
levels where growth in Azide Dextrose broth indicated a login count
of 1.0.
7. Count of Staphylococcus aureus, on Blood Agar, Plate Count Agar,
or Tellurite Glycine Agar.
8. Candida albicans count on Cooke Rose Bengal Agar.
9. Pseudomonas count on Pseudosel Agar.
10. Most Probable Number of heat resistant spores grown in fluid
thioglycolate medium.
11. Antibacterial activity at a 1:50 dilution.
-------
10
ao
Table V-l Total and individual counts
(Logi())
Fecal
Strepto- StaDhylo- Candida
Nursing Sample Total
Station Number Count
(1) (2) (3)
11 1
2
3
12 1
2
3
31 1
2
3
32 1
2
3
36 1
2
3
33 1
2
3
41 1
2
3
3.3
3.0
5.9
3.9
3.6
2.6
4.2
7.7
6.7
2.7
/ .9
7.2
2.5
<2.0
3.5
7.0
6.3
6.9
5.8
5.7
5.2
Coliform coccus coccus
Medium Count
(4) (5;
BA 1.0
BA 1.5
BA <1.0
BA <1.0
PCA <1.0
PCA <1.0
PCA(AN) 2.9
PCA 4.3
BA <1.0
PCA <1.0
PCA
-------
Table V-l (Continued)
Nursing Sample Total
Station Xuzber Count
(1) (2) (3)
51 1
2
3
52 1
2
3
61 1
2
3
62 1
2
3
71 1
2
3
72 1
2
3
7.2
6.4
5.4
6.8
7.3
2.0
3.0
7.8
5.3
«.i
7.7
9.0
6.0
5.5
6.7
6.4
6.1
6.7
Medium
(4)
BA
BA
BA
PCA
BA
PCA
PCA
BA
PCA
bA
PCA
MS &
MacC
BA
BA
PCA (AN)
FCA
BA
PCA
Coliform
Count
(5)
<1.0
1.5
<1.0
6.1
1.5
<1.0
<1.0
<1.0
<1.0
5.0
7.7
8.6
<3.8
<2.0
<4.0
3.4
<1.0
1.0-5.0
Fecal
Strepto
coccus
Count
(6)
<1.0
1.5
4.9
6.8
1.5
<1.0
<1.0
7.1
1.5
8.0
1.5
7.0
<1.0
<1.0
«1.0
<1.0
<1.0
1.5
'- Stao.-tylo- Candida Psuedo-
cocsv.s
Coun':
(7)
7.1
<2.0
<3.0
4.0
<4.0
<2.0
<2.0
<2.0
<3.0
3.3
<2.0
5.7
<2.C
<4.C
<2.C
<2.C
<5.C
<3-C
albicans monas
Count
(8)
<2
<2
<2
3
<2
<2
<2
<2
<2
,;£
<2
<2
<2
<2
<2
<2
2
<2
.0
.0
.0
.8
.0
.0
.0
.0
.0
. u
.0
.0
.0
.0
.0
.0
.3
.0
Count
(9)
4.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
^4.0
<2.0
3.7
3.9
<2.0
<2.0
6.4
<2.0
<4.0
Spore Inhibitory
Count Agent Tes'..
(10) (11)
5
.8
.0
.2
.5
.4
.0
.5
.0
>5
.6
.5
j_
-
—
_
-
-
_
_
-
_
-
-
_
+
-
_
_
_
-------
Table V-l (Continued)
o
o
Fecal
Strepto- St.aphylo- Candida
Nursing Sample
Staticn Number
(1) (2)
82 1
2
3
33 1
o
3
Tote1 Colifom coccus
Count
(3)
7.7
8.5
4.5
6.1
5.8
2.7
Medium
(4)
BA
PCA
PCA
BA
BA &
PC A (AN)
PCA
Count
(5)
5.9
5.4
<1.0
4.4
1.5
<1.0
Count
(6)
5.3
5.3
<1.0
1.5
<1.0
<1.0
arccus
Count
7)
•'•: .0
< .0
i .1
*: .0
; .6
•:', .0
Pseudo-
albicans monas
Count
(8)
<2.0
3.5
<2.0
<2.0
<2.0
<2.0
Count
(9)
4.3
8.4
<2.0
<2.0
<2.0
<2.0
Spore Inhibitory
Count Agent Test
(10) (11)
2.4
3.4
1.6
2.0
1.6
1.6
-------
Table V-2 Microbial counts of organisms in Groups I-V
Outpatient
0. R.
36
I.C.U.
33
Surgical
31
32
1
2
3
1
2
3
1
2
3
1
2
3
1
2
"3
6.3
6.3
6.8
A. 3
1.5
1.5
3.2
<2.0
2.6
<2.0
<2.0
2.7
6.5
2.3
2.8-4.0
<2.0
4.5-6.0
6.6
<2.0
<2.0
7.2
Group III
Cour t
<2.0
2.6
4.5
<3.0
3.6
<2.0
<2.0
<2.0
<2.0
<6.0
<5.0
6.1
4.1
7.5
4.2
<2.0
7.7
<7.0
Group IV
Count •
<2.0
2.6
4.5
3.2
3.6 •
2.6
<2.0
<2.0
2.7
6.7
6.3
6.9
4.2
7.5
6. 6
<2.0
7.7
<7.0
Group V
Count
3.3
2.8
5.9
3.7
<2.0
<2.0
2.5
<2.0
3.5
6.5
3.2
<2.0
<2.0
3.0
5.5
2.7
7.4
<2.0
-------
Table V- 2 (Contir ued)
Nursing
Station
Surgical
Cent .
51
52
61
Medical
71
72
83
Sample
Number
1
2
3
I
2
3
1
2
3
1
- 2
3
1
2
3 -
1
2
3
Group I
Count
<1.0
1.5
4.9
6.8
1.5
<1.0
<1.0
7.1
1.5
3.8-4.6
<1.0
4.0
3.4
<1.0
1.0-5.0
4.4
1.5
<1.0
Group II
Count
7.1
<2.0
<3.0
4.2
<4.0
<2.0
<2.0
<2.0
<3.0
3.9
<4.0
<2.0
6.4
2.3
<4.0
<5.0
5.6
<2.0
Group III
Count
2.3
6.4
4.8
3.5
7.1
<2.0
<2.0
7.2
5.3
4.6
5.5
6.7
2.3-5.0
6.1
4.4
5.8
5.5
2.7
Group IV
Count
7.1
6.4
5.2
6.8
7.1 •
<2.0
<2.0
7.4
5.3
4.8
5.5
6.7
3.4
6.1
4.4
5.9
5.8
2.7
Group V
Count
6.5
5.3
5.0
<2.0
6.7
2.0
3.0
7.5
<2.0
6.0
<2.0
4.0
<2.0
3.2
6.7
5.7
<2.0
<2.0
-------
Table V-2 (Continued)
Nursing
Station
Pediatrics
62
Sample
Number
1
2
3
Group I
Count
8.0
7.7
8.6
Group II
Count
3.7
<2.0
5.7
Group III
Count
<7.0
<7.0
8.7
Group IV
Count
8.0
7.7
9.0'
Group V
Count
6.0
2.3
6.0
Psychiatrics
82
1
2
3
6.0
5.8
A.3-6.0
8.4
4.1
6.9
<5.0
3.7
6.9
5.8
4.3
7.6
7.8
4.1
Maternity
41
1
2
3
2.0
5.7
2.7
<4.0
5.0
5.7
4.7
5.7
5.7
4.7
4.7
<2.0
o
U)
-------
o
-p
Table V-3 Counts of specific organisms in Groups III and V
Nursing
Station
12
11
36
33
31
32
Sample
Number
Counts of Organisms
Isolated in Group III
Counts of Organisms
Isolated in Group V
1
2
3
1
2
3
1
2
3
1
2
Bacillus sp. (3.7)
Staphylococcus epidermidis (3.6)
Xanthomonas (3.3)
S. epidermidis (2.6) Candida sp. (2.8), Enterobacter (2.0)
S. epidermidis (4.0), Respiratory Corynebacterium sp. (5.9)
Streptococcus (4.1)
. Corynebacterium sp. (3.5)
Corynebacterium like, catalase (-) (6.5)
Candida sp. (3.2)
S. epidermidis (6.1), Torulopsis
glabrata (3.1)
Anaerobic cocci (4.1), Bacteroida s
(2.8)
S. epidermidis (-6.3), Respiratory Proteus mirabilis (3.0)
Strep. (7,4)
Torulopsis glabrata (4.2) Micrococcus sp. (5.4), Lactic Strep. (4,9)
S. epidermidis (7.7) Micrococcus sp. (7.4), Unidentified
Yeast (3.1)
-------
Table V-3 (Continued)
Nursing
Station
Sample
Number
Counts of Organisms
Isolated in Group III
Counts of Organisms
Isolated in Group V
51
52
61
71
1
9
1
2
1
2
Anaerobic Gram (+) Cocci (2.3)
S. epidermidis (3.1), Respirator^
Strep. (6.4)
S. epidermidis (4.3), Respiratory
Strep. (4.6)
Corynebacterium sp. (6.5)
Catalase (-) Staph. (5.1),
Aerococcus (4.7)
Micrococcus sp. (5.0)
Clostridium perfringens (3.5)
Respiratory Strep. (7.1), Acinetobacter (6.7),, Klebsiella (4.2)
S. epidermidis (4.6)
Corynebacterium sp. (2.0)
Corynebacterium sp. (3.0)
Respiratory Strep. (7.2), Micrococcus sp. (7.0), Corynebactorium
Fusobacterium (3.5) (7.3), Candida sp. (3.2)
S. epiderT.idis (A.6), Respirator^
Strep. (5.2)
S. epidermidis (4.6) Unidentified enterobacteria (5.5)
Micrococcus sp. (5.8)
S. epidermidis (5.5)
Respiratory Strep. (3.8)
Bacteroides (5-9) Corynebacterium (4.0)
Anaerobic non-sporeforming Grain (+)
Rods (6.6),
S. epidermidis (4.0)
-------
Table v-3 (Ccntinued)
o
CT)
Nursing
Station
Sanple
Nunber
Counts of Organism
Isolated in Group III
Counts of Organisms
Isolated in Group V
Anaerobic Gram (+) Cocci (4.5)
Respiratory Strep. (4.9)
Respiratory Strep. (5.7)
Bacteroides (3.1)
S. epidermidis (4.7)
Lactic Strep. (4.6)
Unidentified Yeast (3.9)
Bacillus sp. (5.1), Penicilliuai (3.1)
-------
Table V-3 (Continued)
.•.ursing
Station
Sample
Number
Counts of Organisms
Isolated in Group III
Counts of Organisms
Isolated in Group V
72
83
62
32
1
2
3
1
2
3
2
3
S. epiderinidis (2.3)
S. epidermidis (3.9), Respiratory Lactobacillus (3.2)
Strep. (3.4)
S. epidermidis (4.4) Alcaligenes (6.1), Pseudomonas sp. (6.0)
Unidentified Enterobacteria (5.9)
Xanthomonas (5.8), Corynebacterium sp.
(6.1), Large Pleomorphic Gram (+)
Rods (6.0)
S. epidermidis (5.8), Corynebacterium sp. (5.7), Candida sp.
Bacteroides (4.5) (3.0), Lactobacillus (2.8)
Bacteroides (4.4), Anaerobic non-
sporeforming Gram (+) Rods (5.5}
Respiratory Strep_. (3.2)
S. cpidcrmidic (2.7)
Catalase (-) Staphylococcus (4.8)
Pseudomonas sp. (6.0)
Proteus vulgaris (2.3)
Respiratory Strep. (8.7) Catalase (-) Staphylococcus (6.0)
S. epidermidis (6.9) Corynebacterium sp. (7.4), Lactic JBtre_p_.
(7.3), Unidentified Yeasts (2.0)
Proteus mirabilis (7.8)
Respiratory Strep. (3.7) Acinetobacter (3.5), Pseudomonas sp. (3.9)
-------
o
oo
Table V-4 Geometric mean oE bacterial counts
Nursing
Station
11
12
36
33
31
32
51
52
61
71
72
83
62
82
Al
Total
Count
A.I
3. A
2.5
6.7 ;
6.2
5.9
6.3
5. A
5. A
6.1
6. A
A. 8
8.3
7.0
5.6
Group I
Count
1.0
<1.0
<1.0
6.5
2.8
1.3
2.5
3.1
3.2
2.9
3. A
2.3
8.1
A. 3
1.3
(Log10)
Group II
Count
2.7
2.6
2.2
<• A. 3
A. A
A. 6
A.O
3.1
<2.0
2.9
A. A
3.8
3.8
6.1
A. 2
Group III
Count
3.0
2.9
<2.0
5.5
5.3
A. 8
A. 5
A. 2
A. 8
5.6
A. 3
A. 7
7.6
5.3
5.1
Group IV
Count
3.0
3.1
2.2
6.6
6.1
5.5
6.2
5.3
A. 9
5.7
A. 6
A. 8
8.2
5.7
5. A
•
Group V
Count
A.O
2.6
'2.7
3.9
3.5
3.7
5.6
3.6
A. 2
3.3
A.O
3.2
A. 8
6.5
2.9
-------
109
In order to facilitate interpretation of data, all identified organisms were
placed in one of five groups. The data contained in Table V-2 represents the summationf
of counts of the individual organisms in each group. The criteria for the grouping
of the organisms is as follows:
Group I contains the combined counts of the Coliform and fecal Streptococcus
organisms. This group is designed to serve as an index of fecal contamination.
Group II contains the combined counts of Staphylococcus aureus, Candida albicans.
and Pseudomonas. These organisms are known to be secondary pathogens. They will be
discussed in greater detail later in this paper-
Group III contains the combined counts of all microorganisms known to be of
human origin other than Staphylococcus aureus and Candida albicans.
Group IV contains the total of all the identified microorganisms which are
known to be of human origin. This important group actually is the summation of
Group III and the counts of Staphylococcus aureus and Candida albicans. This group
is useful in that it serves as an indicator of human contamination.
Group V contains all organisms which are not necessarily of human origin, that
is they are commonly found outside the human body. For example, many of these
bacteria are commonly found in the soil.
Table V-3 is designed to list the individual species of bacteria in Groups III
and V and their respective counts. It gives an indication of the rather sporadic
frequency with which the various organisms appear in the different samples.
Table V-4 lists the geometric means of counts of organisms in Groups I - IV
for each station. These numbers represent the maximum possible values. For
example, in many cases at least one of the three counts had to be recorded as a
number less than two. This was the limit of the sensitivity of our test. In these
cases, the number two would be used in the computation of the mean value. Another
problem arises when an organism similar in appearance to the one to be counted
-------
110
occurs In large numbers. This makes counting of the specific organism virtually
impossible. All that can be recorded is that its colony count is something less
than the total.count on the plate. When this occurred, the uncertain number was
ignored in the computation of the sample mean.
Figures C-7 - C-12 in Appendix C are histograms which provide a graphic presenta-
tion of the data from Table V-4. They present a visual comparison of microbial
counts of the 15 respective nursing stations involved in this study.
See Appendix C for a list of nursing stations, their functions, and the dates
at which the samples were taken.
Total Counts
The repetitive sampling of the 15 nursing stations makes possible some interestinj
comparisons. As expected, many of the stations had total bacterial counts which varied
over several orders of magnitude. This could have been due to a number of factors.
Probably the most important variable is the condition of the patient in the rooms.
Sometimes the period of time which elapsed between two repetitive tests was several
weeks. During this period of time, one may expect a complete turnover of patients.
Another factor is simply that the degree of contamination varies from day to
day, even among the same patients. This is probably due to variable personal habits.
A third factor to be considered is that the total counts do not represent the
entire population in the refuse but only the bacterial population in the sample.
It should be mentioned again that the sample tested contained only those materials
which were acceptable to the blender. Unfortunately, some apparently grossly
contaminated items necessarily had to be omitted from the analysis.
In spite of these variables which would tend to bring about differences in total
counts, one should note that seven of the fifteen stations Numbers 12, 33, 41, 51,
62, 71, and 72 exhibited three total counts which differed from each other by a facto
-------
Ill
of less than 100. There ware several stations among the others which had two total
counts that were very similar.
Two explanations may be postulated to account for the low variability among the
three total counts per station. One would be the similarities in the condition and
type of the patients at the particular stations. For example, the poor condition of
patients confined to Intensive Care Unit, Station 33, would suggest the appearance
of a high degree of contamination in the refuse. Likewise, in Pediatrics, Station
62, one would expect a high degree of fecal contamination from soiled disposable
diapers. This naturally leads to very high total colony counts.
Another explanation could be based upon the methods by which the wastes are
handled. Thus, one would expect consecutively low bacterial counts from station?
which segregated their contaminated waste from the uncontaminated. Such is the case
with Operating Room, Station 36. In this case only the uncontaminated waste was
available to be sampled. For this reason, Station 36 had the lowest total count.
Another important factor would be that at this station, there is much greater
demand for an aseptic environment.
Stations 12 and 11 offered the second and third lowest total counts, respectively.
Emergency room, Station 11, is frequented by a great variety of people and one might
expect higher total counts. However, the presence of agents inhibitory to bacterial
growth in two of the three samples taken might account for this low population.
Outpatient Clinic, Station 12, offers many of the same possibilities for contamination
as Emergency Room. The low counts are probably due to diluting effects of large
quantities of apparently uncontaminated paper products. The presence of inhibitory
agents is also a plausible explanation.
Stations 33 and 62 had the highest total colony counts. Reference has previously
been made to the possible explanations. Station 82 had two very high total counts.
This is a psychiatric ward. The reasons for the high counts are not readily apparent
but differences in personal hygiene may partially be responsible.
-------
112
See Figure C-7 for a graphic comparison of total colony counts.
Coliform and Fecal Streptococcus Counts
Coliform counts were highest at stations 62, 33, and 82, respectively. The
explantions for these high counts are the same as those given for the high total
colony count. Coliform counts indicate fecal contamination. These counts should
serve as an index to assess the hazard of pathogenic enteric bacteria such as Shigelh
and Salmonella typhosa. Fecal Streptococcus, as expected, occurred with approximately
the same frequency as the coliforms but at lower growth levels.
Group I Counts
Group I consists of the combined counts of coliform and fecal Streptococcus.
Figure C-8 illustrates the significant fecal contamination in the refuse of stations
62, 33, and 82. Also illustrated is the notable absence of these organisms at
stations 11, 12, and 36.
This absence might be explained by the fact that these stations have no living
quarters; and, therefore, the probability of this type of contamination is somewhat
reduced.
Staphylococcus Aureus Counts
Staphylococcus aureus is one of the most important pathogens in nosocomial
cross infection. It is easily spread in dust particles. Therefore, its presence
in refuse is particularly significant. It is notorius as the cause of suppurative
(pus forming) condition; boils; carbuncles, infantile impetigo, and internal abscesses
in men and women.
S. aureus appeared at all stations except stations 32, 61, 71, and 72. The
greatest frequency of occurrence (two of three samples) occurred at stations 62, 41,
33 and 12. The highest average count occurred at station 62 with the highest single
count appearing at station 51.
-------
113
Candida Albicans Counts
Candida albicans is a pathogenic fungus which is commonly found on the skin, on
oral or vaginal mucous membranes or in the feces of normal individuals. This species
can cause a number of serious infections in man, especially of mucous membranes
(thrush and vulvovaginitis), the skin (cutaneous candidiasis) and lungs (pulmonary
candidiasis).
This organism was found at stations 31, 33, 52, 72 and 82. Its frequency of
appearance was quite low (one of three samples). The highest count was observed
at station 31.
Pseudomonas Count
The genus Pseudomonas contains several species which are responsible for a number
of types of infections. They cause urinary tract infections, as well as secondary
infections of burn patients. They can also be responsible for outbreaks of diarrhea
in children's wards.
The greatest frequency of occurrence (two of three samples) was at station 82.
Pseudomonas also appeared at stations 32, 33, 51, 62, 71 and 72. Station 82 had the;
highest average, as well as individual counts of Pseudomonas.
Group II Counts
Group II consists of the combined counts of S. aureus. Candida albicans, and
Pseudomonas. These three organisms are "opportunists;" that is, they take advantage
of a patient whose resistance to infection has been lowered by some other illness,
From Figure C-9, it will be observed that the Group II counts cover a broad
spectruiL and are evenly distributed among the 15 nursing stations. It is interesting
to note that the only station at which these microorganisms failed to be detected was
station 61. Station 36 also exhibited a very low count. One of the three samples
taken from this station contained these organisms in very low numbers. On the other
end of the spectrum are the counts from station 82. This station had the highest
single count, as well as the largest average count of Pseudomonas.
-------
114
Group III Counts
Group III contains all organisms considered to be of human origin, excluding two
of the more common species - S. aureus and Candida albicans. The exception of these
two organisms is designed to give an indication of the magnitude of the count contri-
buted by less notorious organisms of human origin.
The only station at which this organism failed to appear was station 36.
Station 12 also exhibited a very low count of these bacteria. All of the stations
showed a significantly high count in at least one of the three samples taken. The
highest individual count came from station 62.
Group IV Counts
Group IV is the most important group because it contains the combined counts
of all organisms of human origin. It, therefore, serves as an indicator of human
contamination. The various species of these organisms are found in Table V-3.
From Figure C-ll we see that at least some of these organisms were detected at
all 15 nursing stations. The lowest count by far was observed at station 36. The
organisms were detected in only one of the three samples taken from this station.
Stations 11 and 12 showed low counts relative to those of the remaining stations.
The greatest average, as well as single count of these microorganisms, occurred at
station 62. The counts from all three of the samples taken at this station were
greater than any of those taken from the other stations. Other stations exhibiting
high counts were stations 33, 31, 51, 71, and 82.
Group V Counts
Group V consists of bacteria which are not necessarily of human origin. There-
fore, the detection of these organisms does not imply any human contamination, Tne
various species of these identified bacteria are enumerated in Table V-3. The
inclusion of this group in the report is intended to give some indication of the
fraction of the total colony counts contributed by organisms of non-human origin.
-------
115
From Figure C-12 it can be seen that bacteria from this group appeared at all
15 nursing stations. The two lowest counts were observed in the samples taken from
stations 12 and 36. The highest count was observed at station 82. Station 51 also
had a high number of these organisms in its refuse.
Sporeforming Organisms Count
Bacterial spores are partially resistant to heating and drying and other methods
of sterilization. Therefore, their relative abundance and distribution in the hospital
would be of concern with regard to sterilization procedures.
The only station which failed to yield any sporeforming organisms was station
11. Stations 12, 36, 41, 52, and 72 also showed a low frequency (one out of three
samples). Stations 82, 31, and 83 showed the highest frequency of sporeforming
organisms. Station 82 had the highest average spore count and also the highest
individual count.
Inhibitory Agents
Inhibitory agents such as bactericides, fungicides and antibiotics will occas-
ionally be discarded into the refuse. The extent of the antibacterial action that
it exerts would depend upon how thoroughly it is combined with the refuse. During
I
the blending phase of the analysis, inhibitors are completely mixed. Therefore,
the presence of an inhibitory agent might result in a count substantially lower than
what is actually present in the refuse container.
Seven of the 15 stations at one time had refuse which contained inhibitory agents.
The only station which exhibited this twice was Emergency Room. There appears to be
no significant difference between counts (total and of likely human origin) between
samples with and without inhibition. In one case, the inhibition was almost certainlv
due to the high count of Pseudomonas aeruginosa which is known to produce an anti-
biotic.
-------
116
Conclusions
From the preceeding analysis of the data, we make the following general con-
clusions:
1. Pathogenic bacteria can be present in hospital refuse in significantly
high concentrations. These concentrations may be much higher if the
organisms are located where organic substrate is present. Also, the
additional time between collection and incineration may allow further
multiplication of the microorganisms leading to higher counts than
those observed in the tests.
2. Trends do exist between the number of microorganisms present and the
respective nursing stations. From the previous discussion of results,
it was observed that certain stations, such as station 36, exhibited
consecutively low bacterial counts in their refuse. Other stations
produced consistently high counts such as stations 33, 62, and 82.
3. Certain types of bacteria are more prevalent in the refuse of some stations
than others. This is most probably due to source and type of waste
generated.
From Table V-l and Figures C-7 - C-ll, we draw the following specific con-
clu:. ions:
1. S. aureus is by far the most predominant pathogen in the refuse. It is
most unfortunate that the true numbers of this pathogen were often un-
obtainable due to the high growth of S.. epidermidis on the selective agar
plates.
2. The high coliform counts from stations 33 and 62 suggest that these stations
would be the ones most likely to generate refuse containing enteric pathogeni.
3. Sporeforming organisms are not present in sufficient numbers to pose a
potential hazard providing that the accepted methods of sterilization are
utilized.
-------
117
4. The substantial number of organisms of human origin relative to those not
of human origin would suggest the presence of some of the more virulent
pathogenic bacteria and viruses living on the refuse in undetected numbers.
5. The recurring high counts of organisms in groups I - V in the refuse of
stations 33, 62 and 82 would indicate that the refuse from these stations
is the most likely to be contaminated by pathogenic microorganisms.
PHASE 3 Bacteriological Studies
There is a growing concern about the microbiological hazards of hospital refuse
handling. Several authors have expressed their concern about the possibility of
pathogenic organisms escaping from the hospital refuse chute and into the hallways.
At the present time there have been only a few studies of airborne bacteria from
hospital refuse. It is difficult to compare data from different studies because
there are no standard methods for air sampling of this type.
Many of the articles on this subject make recommendations to minimize the
problem of air contamination from the refuse chute. Several of them are summarized
below:
1. Design the chute so that air cannot back up into the hospital corridors
and provide doors which are leakproof.
2. Separate refuse so that only uncontaminated materials are thrown into
the chute.
3. Empty the chute often enough so that refuse does not back up in the
chute and block the doors.
4. Autoclave all materials before they are thrown into the chute.
5. Increase the use of plastic liners for cans so that the refuse is wrapped
before being thrown into the chute.
6. Wash the chute regularly with antiseptic.
7. Minimize waste transfer operations.
-------
118
Some of these methods are very difficult and would be impractical because of the
high cost involved. One of the easier methods to implement is the plastic bag system.
The use of plastic liners to minimize air contamination has become increasingly populir
and there are several articles in hospital magazines which make unsubstantiated claim
of effectiveness.
The purpose of this phase was to evaluate the sanitation of a hospital refuse
chute with respect to airborne bacteria. The study attempted to measure the dispersal
of viable airborne bacteria from the handling of refuse in the chute closet area.
The effect of wrapping the refuse in bags was evaluated. Recommendations were made
for methods to reduce the number of bacteria escaping from the chute and entering the
hallways.
Solid Waste Handling
The hospital studied had a refuse chute which is 118.2 feet high and 24 inches
in diameter. The total volume is 372 feet. The effective storage capacity is the
volume up to the bottom of the first door which is 69.4 cubic feet. The chute is
fitted at the top (eighth floor) with a sprinkler head which is used for fire control
and for washing twice a week with an antiseptic solution. The chute has a door on
each floor and empties into a closet provided with a metal door.
The refuse is emptied from the chute into a cart and is taken to a larger room
which contains a multi-chambered incinerator. The larger room has a fan mounted on
one wall which draws air from the hallway into the room. All or part of the air
drawn into the room can follow these alternative pathways; 1 - pass through the
priraiy combustion chamber, 2 - pass through the chimney damper, 3 - go up the chute
closet vent, 4 - go up the chute itself, or 5 - out the door and vent to the hallway.
The fan is usually on when someone is in the room.
-------
119
In practice the refuse stays in the chute several hours at a time and has
occasionally backed up as far as the third floor of the hospital according to the
engineering staff of the hospital. This refuse is comprised of "floor refuse" such
as paper, trash, and food wastes from the wards; pathological wastes, including
dressings, syringes, and other disposable equipment; and some kitchen wastes. It
is of interest that the first door immediately above the chute closet is the door
to the kitchen. The refuse packs against this door and could be a source of food
contamination in the kitchen. Air temperatures in the chute closet averaged in the
low 80's and the relative humidity was in the 55-65 percent range.
Methods and Materials
A. Bacterial Studies
Quantitative sampling of airborne bacteria was carried out with Andersen samplers
(93) and petri plates made with Difco Blood Agar Base mixed with 5 percent defibrinated
sheep blood (94). Samples were taken for periods of one minute at a sampling rate of
1.0 cubic ft/min. After exposure, the plates were incubated aerobically at 35°C for
24 hours and the number of colonies per plate were counted with a Quebec colony counter.
This resulted in a count of aerobic organisms/cu.ft. which was broken down into six
aerodynamic sizes. According to the original research carried out on the Andersen
sampler (93), the instrument has essentially no loss due to adherence to the walls,
and captures essentially all of the organisms by the sixth stage ( ;> 99 percent).
According to the Difco Manual (94) the blood agar media will grow most bacteria
including many fastidious pathogenic organisms. The bacteria usually grow luxuriantly
and the hemolytic types exhibit clear zones of hemolysis. Previous research (95) has
shown that the total anaerobic airborne bacteria constitute a very small part of the
total count and may be disregarded in studies of this type.
-------
1.
2.
3.
A.
5.
6.
7.
8.
9,
10,
11,
12,
Refuse chute
Chute closet
Chimney
Chimney damper
Incinerator
Fan
Door to hallway
Vent to hallway
Cart sampling point
Push cart to incinerator
Empty cart on floor
Sweep refuse into
incinerator
Figure V-2 Incinerator and Chute Closet Area
-------
121
I STAGE NO.
JET SIZE
JET VELOCITY
STAGE i
O.O465" OIA.
3.54 FT/SEC
STAGE 2
0.0360" OIA.
5.89 FT/SEC
STAGE 5
0.0280" DIA.
9.74 FT/SEC
STAGE
0.0210" DIA.
17.31 FT/SEC
STAGE 5
0.0135" DIA.
41.92 FT/SEC
STAGE 6
O.OIOO" DIA.
76.40 FT/SEC
Figure V-3 Andersen Sieve Sampler
-------
122
Samples were taken on random days of the week and at random times of the day
between 8:00 A.M. and 5:00 P.M. The sampler was placed at a height of three feet
and a distance of four feet from the chute in the chute closet. Samples were taken
of loose refuse and of refuse wrapped in plastic bags as it was transferred from
the chute to the trash cart.
Results a.nd Discussion
The results of these tests are expressed as the number of colonies of bacteria
per cubic foot of air samples and are shown on Tables V-5 and V-6 for loose and
bagged refuse respectively.
Air Movement Studies
The air moving out of the chute into the hallway was measured with an Alnor
velometer, type 3002. This instrument measures the velocity and pressure of air
with a mechanical system utilizing an aluminum vane in a calibrated air chamber.
Velocities are in feet per minute and the area of the opening is in square feet.
The air flows computed are given in cubic feet per minute.
2
The area of the chute opening is 1.54 feet x 1.54 feet = 2.37 feet , when the
chute door is wide open. Tests were made on the flow from the chute door while no
other chute doors were open with the following average values:
Floor Number 8-55 ft/min or 124 cubic ft/min
7-50 " 111
6-40 " 95 "
5-40 " 95 "
4-40 " 95 "
These values fluctuated approximately + 5 ft/min when all other chute doors
were closed.
-------
Table V-5 Airborne bacterial counts from loose refuse
(No. Colonies/cu.ft.)
o>
1
2
3
4
5
6
7
8
9
10
11
12
13
" 14
O ie
r-l 15
«V . .
•a AU
« 17
•S 18
19
20
21
22
23
24
25
26
27
28
29
30
1
5
23
22
14
27
23
44
23
29
35
34
31
31
34
36
1 35
30
38
28
39
38
47
51
69
42
57
54
84
136
192
2
4
4
11
14
6
15
7
15
13
17
13
14
21
15
23
A5
15
21
23
16
26
24
23
18
22
24
33
40
73
68
3
1
4
9
13
9
10
5
13
14
13
9
9
11
12
10
4 ..
3
0
6
8
10
7
4
9
5
1
8
3
7
12
4
5
3
0
1
1
1
4
4
5
2
1
2
5
3
3
4
O.O H J
14
16
31
26
11
13
14
14
20
23
33
31
51
81
13
9
4
10
15
9
13
6
18
13
21
16
24
46
7
3
3
0
5
2
2
1
9
2
3
4
7
12
6
1
1
0
1
1
0
0
0
2
. 0
3
0
2
0
0
Total
17
32
49
51
54
59
64
.65
65
67
69
70
75
76
77
G |j 77
1
0
0
1
1
3
1
0
1
0
1
0
0
3
80
87
89
92
96
98
104
108
112
119
145
175
291
402
-------
12H
Table V-6 Airborne bacterial counts from bagged refuse
(No. Colonies/cu.ft.)
Stage Number
1
2
3
4
5
6
7
8
9
10
1 13
a 14
« 15
16
17
•2- i?
| 20
5 21
22
23
24
• 25
26
27
28
29
30
1
1
2
2
3
1
3 '
1
2
4
3
2
4
3
3
3
4
6
4
i
2
1
1
1
0
3
2
1
1
0
1
1
1
2
1
3
2
1
2
3
1
0
1
0
1
0
1
1
1
0
2
1
0
2
1
2
0
2
4
0
0
0
0
0
0
0
1
1
1
0
1
0
0
1
1
0
0
i
5
0
0
0
0
0
0
1
0
0
2
2
]
2
1
0
0
1
1
6
0
0
0
1
0 .
0 .
2 ,
1 i
o ;
o ,
0
0 4
1
1
1 ,
0
1 •
0
Total
3
3
4
4
5
5
6
6
6
7
7
8
8
8
9
9
9
9.
2 j 2 | 4 j 2 j C j 0 , ji .10 i
7
8
3
9
7
6
9
10
9
6
20
2-
1
1
0
1
1
2
1
1
2
2
1
1
3
1
1
3
0
1
1
4
2
0
0
0
0
2
1
1
1
0
3
1
0
0
3
0
0
0
0
0
2
2
2
0
0
1
1
0
1
0
0
1
5
1
10
10
11
11
11
12
12
13
14
22
29
-------
125
Next, the flow of air was determined when other chute doors were open. The
velometer was placed at the 6th floor chute door and the 4th floor chute door was
opened. The rate of flow at the 6th floor immediately increased to 150 ft/min or
355 cubic ft/min.
Then, the fourth floor chute door was closed and the eighth floor chute door
was opened. The velometer immediately pinned to the zero mark.
From these results it appears that the air in the chute will exhaust onto the
highest floor level available. If only one door is open, the flow of air is limited
to 55 feet/min or less. The magnitude of flow is usually greater on the upper floors.
For example, when the sampler was placed on the eighth floor chute door and the sixth
floor chute door was opened, the flow through the chute door was greater than 300
feet/min. or 710 cubic feet/min.
By comparison, the Hurst study (34) found that when one of the upper floor
chute doors in a 16-story hospital was opened, as much as 30 to 60 cubic feet of
air was released in five to ten seconds. This is approximately the same flow as in
this ^hospital.
Statistical methods were used to compare the effects of loose and bagged refuse
on dispersal of airborne bacteria. An examination of the frequency distribution of
total colonies per cubic foot (Table V-7) indicates that the data is essentially
normally distributed. Thus, a parametric test of the mean is justified. In this
case, the variances of the two populations are considerably different. The ordinary
"t" test will tolerate considerable inequality between the two population variances
without appreciable change in the probabilities of errors of Type I and II (96).
However, Cochran and Cox suggest a modified "t" test (97) which takes into account
the differences in variance.
The result of this test indicates that the mean population of airborne bacteria
from loose refuse and bagged refuse, under the conditions of the experiment, are
-------
126
Table V-7 Vrc'.r,'er.cy di£trib.'l:ion of ti'tal colonies
ot bagged and loose refuse
Frequency dir-tii/ibuticn oi: total colonies - I/K•••;.• v.?t\t?.ti
y.ColojviLfts, 'Kreranrcy -A'-.'.»::^ vo _Krg
0-25 1 O.Ui'i
25-50 2 0,;;c7
50-75 «; c.jco
75-100 ID O.i33
100-125 4 C.133
125-150 1 0.033
150-200 1 0.033
200-300 1 0.033
300-350 1 _PtM3_.
30 f. 000"
Freauencv distrLbuti c,- of" f-.ot?. 3 r.n'tti.-\i.(>.# - ^c.o«ri re. !"<>«*«
Har.ge
tfColonies Frequency Relative Frequency
0-2 0 0.00
2-4 2 0.067
4-6 4 0.133
6-8 5 0.167
8-10 '/ 0.233
10-12 6 0.200
12-14 3 0.100
14-16 J. 0 033
16-25 I 0.033
25-30 _i_ Q.Q33
2f> 1.000
-------
127
not equal. We accept the alternative hypothesis which may be stated as: we are
99 percent certain that refuse wrapped in bags generates fewer airborne bacteria
than loose refuse, under the conditions of the experiment. Presumably, the difference
between the two systems would be even greater if the refuse was wrapped in completely
leakproof bags.
An examination of the size distribution of the samples (Table V-8) indicates
that there is a wide variation in the magnitude of bacteria in all size classifications.
The majority of the bacteria in all samples were concentrated in the larger particle
size ranges (Figure V-4 and V-5).
Previous research (93) has shown that particles 5 microns and larger are retained
in the upper respiratory tract. This fraction of the particles is collected on the
first two stages of the sampler. Respiratory tract penetration increases with
decreasing particle size (93). Particles 1 micron and smaller were retained in the
alveoli of the respiratory tract (98), and it is these particles which are the more
significant in the causation of respiratory tract infection (99). These smaller
particles are found on the two lower stages of the Andersen sampler. An evaluation
of the health significance of airborne bacteria, then, should take into account the
sizes of the particles on which the bacteria are carried, as well as the total
number of bacteria involved.
Thus, if a refuse handling system is designed to remove airborne bacteria, it
is especially important to remove the smallest particles which may penetrate the
respiratory tract. The smaller particles, however, were found to be more difficult
to remove than the larger particles. The least-squares line of Figure V-6 indicates
that as the total number of colonies decreases, the proportion of colonies on stage
#6 increases..
The result of this phenomenon is that we might reduce the total number of
organisms from 100 to 10 and still have the same number of organisms which are
impinged on stage #"6. Thus, the respiratory tract hazard is not reduced in direct
proportion to the reduction of total bacteria.
-------
i
40-
C
o
o
o
30-
ZO-
fO-
Colony size distribution - loose refuse
-------
So-
40
o
•*4
c
S 30
0
c
Q»
O
M
(!)
FU
Figure V-5 Colony size distribution - bagged refuse
3
Stage Nun'>er
-------
CO
o
0.05 -
Figure V-6 Scatter diagram of stage 6 organisms per
total organisms per cubic foot of air.
(Cross indicates the origin for deviations
of Least Squares Line)
0.04 -
sO
00
(0
4J
CO
c
o
m
0)
T*
O
0.03
0.02 -
l-l
§•0.01
Least Squares Line
Y « 0.016560 - 0.000057 X
0.00 ~
50
100
Total Colonlea/en.ft.
-------
Loose
Refuse
Bagged
Refuse
Table V-8 Distribution of colonies from loose and bagged refuse
on Ar.darsen Sampler stages
(per c-j. ft.)
Andersen S.a pier Stage Number
2345
X
7.
Range
s_
X
i
44.9
45
5-192
36.7
21.2
21
4-73
15.6
1
1
1
1
Total
9
1
6
10.3
11
3-A6
8.8
3.5
4
3-12
2.6
0.8
1
1-3
0.9
96.5 .
100
17-402
78.7
Total
X
%
Range
s_
X
4.9
52
1-20
3.9
1.3
15
0-3
0.8
1.1-
1.5
0-*
1.1
0.4
4
0-3
0-9
0*7
8
0-2
9.0
0.6
6
0-5
1.0
9.4
100
3-29
5.3
Legend
x = Maan
7,
Percent
of total
: Standard
Deviation
-------
132
Conclusions
From the preceding analysis of the data we conclude:
1. Airborne bacteria are generated in the handling of this hospital's
refuse.
2. Placing the refuse in bags reduces the total number of airborne bacteria
generated.
3. The smaller particle sizes which can penetrate the respiratory tract
are not removed as easily as the larger particles.
From the velometer studies of airflows we conclude:
1. The possibility exists for viable organisms to be transmitted t;o other
parts of the hospital by way of the refuse chute.
2. The air in the chute tends to flow upward with a tendency to flow out
into the hallways. If two or more chute doors are open at the same time,
the air flows through the highest open door at a rate several times the
flow if only one door was open.
3. The doors do not fit tightly so there is a constant leakage of air into
the hallway.
4. There is a hazard presented by the backing up of refuse in the chute,
packing refuse against the chute doors. This is especially dangerous
because the first chute door above the chute closet is in the kitchen
area.
-------
133
Virological Studies
Introduction
The dissemination of microorganisms by various waste materials has been
recognized for many years. To develop controls and preventive measures, a greater
knowledge of the basic factors causing the problem is necessary. Significant
results have been obtained with bacteria, but little is known about the persistence
of viruses on these materials. It is for this reason that the following work was
undertaken.
In this work the persistence of coxsackievirus A«9, poliovirus type I, influenza
virus PR-8 and vaccinia virus on various solid waste materials was studied. Samples
artifically contaminated with the viruses were held at room temperature until tested.
Attempts were made to evaluate the efficiency of recovery, some of the factors which
might influence the efficiency, and the duration of infectivity of virus adsorbed
to various solid wastes.
Methods and Materials
Viruses
Coxsackievirus A type 9, the PR-8 strain of influenza virus A, the Sabin strain
of poliovirus type 1 and vaccinia virus used in this work were laboratory strains
passed an undetermined number of times in various tissue culture systems. All
stock virus was prepared in GMK bottle cultures by inoculating them with 1.0 ml of
undiluted virus. Culture fluids from the bottles showing complete cytopathogenic
effect (CPE) or, as with the influenza virus, a high degree of hemadsorption (HAd),
on or before the fifth day of inoculation were pooled. The fluids were centrifuged
for clarification and dispensed in 10 ml aliquotes in sterile screw-cap vials to
be stored at -70 C. Before harvesting the influenza virus, cultures were frozen and
thawed two times.
-------
134
Culture' Media
African green monkey kidney (GMK) and HeLa cells (derived from a human cervical
carcinoma) were obtained from Flow Laboratories, Rockville, Maryland. All cell
cultures were grown in Eagle's minimal essential medium (E-MEM) containing Eagle's
salts, glutamine (2 mole/ml), NaHCO-j (1.4 mg/ml) and calf serum. The GMK bottle
cultures were grown using 2% calf serum, whereas the roller tubes were grown in a
10% concentration. Both bottle cultures and roller tubes of HeLa cells were grown
in 10% calf serum and 10% tryptose phosphate broth (TPB). Maintenance medium for
GMK cells was E-MEM supplemented with 0.5% calf serum, whereas the maintenance
medium for HeLa cells contained 2% calf serum in E-MEM. All media contained 100
units of penicillin, 100 ^ g of streptomycin and 25^e/g of Fungizone (E. R. Squibb
& Sons, New York) per ml.
Cell Cultures
Confluent monolayers of GMK and HeLa cells were grown in 4 oz. prescription
bottles with 10 ml of growth medium. Twenty-five roller tube cultures (16 x 125 mm)
were prepared per bottle of GMK cells after 5-7 days of growth in bottle culture.
HeLa cell roller tubes were also prepared, 25 tubes per bottle culture, after 3 days
of growth.
The HeLa cell line was monitored for Mycoplasma at each transfer by plating en
Chanock'a medium (100). These plates were incubated anaerobically at 37°C for
2-3 weeks before discarding as negative. Cells contaminated with Mycoplasma were
not used.
Virus Titrations
All viruses were titered in GMK cells except polio-virus type 1 which was
titered Ln HeLa cells. Hemadsorption was used as an index of infection with
influenza virus, whereas CPE was used for all others. Serial tenfold dilutions of
-------
135
the viruses were made in maintenance medium and for each dilution, five roller tuves
were inoculated with 0.2 ml of that dilution. The titration endpoints were calculated
by the method of Reed and Muench.
Solid Waste Extraction Medium
Except where noted, the following medium, based on that used by Sidwell et
al. (87), was used to recover virus from artifically contaminated samples of solid
waste.
Eagle's salt solution (10X) 100 ml
MEM amino acids8 (SOX) 20 ml
Sodium hydroxide (IN) 4 ml
Sodium bicarbonate (2.8%) 50 ml
MEM vitamins* (100X) 10 ml
Glutamine (100X) 10 ml
Gamma globulin-free calf seruma 50 ml
Chick embryo extract* 5 ml
Penicillin5 (100,000 units/ml) 5 ml
Streptomycin15 (100, OOO^g/ml) 5 ml
Amphotericin Bc (5 mg/ml) 1.0 ml
Double distilled water (q.s.) 1000 ml
Selection and Preparation -of. Solid Waste Samples
Solid waste was collected from strategic points in the West Virginia University
hospitals refuse disposal system. These samples were sorted into arbitrary cate-
gories and weighed individually. The criteria used in determining which materials
were to be tested were the following: the item should be found in a large proportion
of the random samples taken and be present in significant percentages therein; the
item should have an object-to-person or interperson frequency which would make them
potential threats; and the item should be relatively easy to test. From the above
criteria came the following categories:
Grand Island Biological Company, Grand Island, N. Y.
Eli Lilly & Company, Indianpolis, Indiana
°E. R. Squibb & Sons, N. Y.
-------
136
A. Office papers Including typing paper, envelopes,
carbon paper, newspaper and magazines 50%
B. Laboratory paper towels, Kleenex and wrapping
paper 20%
C. Cloth including rags, facemasks and elastic items 17%
D. Surgical tapes, gauze and bandages 8%
E. Paper and plastic cups 5%
The approximate percentages of each category as it was found in the refuse disposal
system is given after its description. A representative sample was then prepared
which expressed these percentages. The representative sample and each of the above
were pulverized in a Wiley Mill (Arthur H. Thomas Co., Philadelphia, Pa.)
The following items were chosen to be tested in the unpulverized state:
1. Gauze 3. Paper towels
2. Cotton balls 4. Paper cups
5. Cotton cloth
Treatment of Pulverized Materials
Except where noted, all categories of the waste including the representative
sample, were tested in the following manner. One-half gram samples of the pulver-
ized materials were placed in culture tubes (25 x 100 mm), autoclaved and allowed
to dry for one day. Each sample was then contaminated with 0.4 ml/ of a known amount
ot virus and incubated at room temperature. Virus titers were determined for each
sample at various intervals of time until no virus could be detected.
Treatment of Unpulverized Materials
Except where noted, the unpulverized materials were cut into 3x3 inch piences,
placed in Petri dishes and autoclaved. After drying for one day, they were con-
Laminated with 0.4 ml of a known amount of virus and incubated at room temperature.
Virus titers were determined for each sample at various intervals of time until no
virus could be detected.
-------
137
Recovery of Virus from Samples
Throughout this work, 0.4 ml of a known amount of virus has been added to each
sample. To recover the virus in each tube, samples were mixed with 15 ml of extract-
tion medium adjusted to pH 7.2. Mixing was carried out on a Super-Mixer (Lab-Line
Instruments, Inc., Melrose Park, Illinois) run at speed setting 6 for 15 seconds.
After settling for 5 minutes, the fluids were removed and centrifuged at 4°C at
15,000 rpm's for 15 minutes to remove suspended materials. The virus titers of the
supernatant fluids were determined by assay in GMK or HeLa cells grown in roller
tube cultures.
Those samples not autoclaved before testing were allowed to settle for 30 minutes
after mixing and were centrifuged for 30 minutes at 15,000 rpm's to remove bacteria
and fungi.
The materials tested in the unpulverized state were macerated with 15 ml of
extraction medium in a Sorvall Omnimix homogenizer (Ivan Sorvall, Inc., Norwalk,
Conn.) run at full speed for 30 seconds (87). Centrifugation and virus assay were
carried out as described for the pulverized samples.
All samples taken in this work were stored at -20°C until tested except the
influenza virus samples which were stored at -70°C.
Results and Discussion
Throughout this work, control samples, uncontaminated with virus, were assayed
with the experiment. In no instance did control materials damage cell cultures.
Effect on Virus Recovery of Autoclaving and Pulverizing Solid Haste Samples
Prior to Contamination
To each of 5 sterile, pulverized and 5 sterile, unpulverized samples was added
0.4 ml of either poliovirus type 1, vaccini virus or coxsackievirus A-9. In addition,
5 unsterile, pulverized and 5 unsterile, unpulverized samples were similarly con-
taminated. Virus titers were determined after 2 hours at room temperature. In this
experiment, 10 ml of extraction medium was used.
-------
138
Table V-9 shows that neither autoclaving nor pulverizing had an affect on virus
recovery. In addition, most of the virus added to all samples was recovered at that
tine period. Based on these results, waste samples used throughout this work were
autoclaved.
Effect of the pH of the Extraction Medium upon the Recovery of Virus from Solid
Waste Samples
To pulverized samples of cotton, gauze and paper was added 0.4 ml of either
vaccinia virus, poliovirus type 1, coxsackievirus A-9 or influenza virus PR-8.
Virus titers were determined after 24 hours using extraction medium adjusted to
either pH 2.5, 5.0, 7.0 or 9.0.
In nearly all instances, the efficiency of virus recovery waa greater when the
pH of the extraction medium was 7.0 (Table V-10). For the remainder of this work,
the extraction medium was adjusted to pH 7.2.
Recovery of Virus from Solid Waste Suspended in Distilled Water
A 4 gram aliquot of the representative sample was suspended in 500 ml of
distilled water, autoclaved, allowed to cool and dispensed in 15 ml quantities in
culture tubes (25 x 100 mm). Each tube was contaminated with 0.4 ml of a known
amount of either poliovirus type 1 or coxsackievirus A-9. In addition, some of the
suspension was centrifuged at low speed and the resulting supernatant fluid was
contaminated with virus. This would detect possible toxic properties of the extract
for the viruses or the tissue culture systems in which they were assayed. Tubes
were incubated for 2 hours at room temperature or in a 4°C water bath.
In Table V-ll, no difference in virus recovery was seen between the contaminated
suspension and the contaminated extract. Those tubes held at room temperature
showed no significant variation from those kept at 4°C. Thus, the extract had no
apparent toxicity for the viruses or the tissue culture systems.
-------
Table V-9 Effect of virus recovery of autoclaving and pulverizing solid
waste samples prior to artificial contamination with vaccinia
virus, Poliovirus 1 or Coxsackievirus A-9
Virus
-
Polio 1
(6.27)c
,
Vaccinia
(5.78)
Coxsackie
A-9
(6.05)
Sample*3
A
B
C
D
E
A *
B
C
D
A
B
C
D
E
Virus
Autoclaved
Pulver-
ized
6.20
6.27
6.07
5.96
5.87
5.75
5.75
5.61
5,75
_» . U J-
6.00
6.05
6.01
6.27
5.80
Un-
pulver-
ized
6.16
6.00
6.20
5.87 •
5.88
5.75
5.70
5.70
5.61
J .0^
6.05
5.81
5.98
5.81
5.91
titcr3
Unautoclaved
Pulver-
ized
6.26
6.29
6.20
6.00
6.07
5.75
5.60
5.61
5.69
D.OU
6.10
5.80
5.91
6.01
5.98
Un-
pulver-
ized
6.18
6.17
5.98
6.16
6.27
5.70
5.69
5.65
5.69
s.bb
6.01
5.98
5.74
5.81
5.90
a
L°9lO T^ID50 Per 0.2 ml.
Sample A = mixture of B-E; Sample B = office papers;
Sample C = paper towels and tissues; Sample D = paper
and plastic cups; Sample E = surgical tape, gauze and
bandages.
c The titer of virus contained in each sample after the
addition of 10 ml of extraction medium. (Login
per 0.:> ml) . u
-------
Table V-10 Effect of the pH of the extraction medium upon the recovery
of virus from autoclaved, pulverized samples of solid waste
artifically contaminated 24 hours previously with vaccinia
virus, Foliovirus i, Coxsackievirus A-9 and Influenza virus
PR-8
Sample
Cotton
GAU*«
Paper
PH
2.5
5.0
7.0
9.0
2.5
5 .0
7.0
9.0
2.5
5.0
7.0
9.0
Vaccinia
(4.91)b
2.37
2.64
3.00
3.00
2.49
?.??
3.37
3.16
1.00
2.17
3.00
2.67
Virus
Polio 1
(5.33)
4.94
5.00
5.26
5.16
4.43
\ . 17
5.30
4.50
4.50
4.30
4.83
4.62
titera
Coxsackie
A-9
(5.18)
4.83
5.10
5.10
4.78
5.15
A 01
4 . W ~*
5.00
5.15
5.00
4.16
5.18
4.80
Influenza
PR-8
,(6.07)
6.00
5.96
6.00
6.00
.5.48
f A A
6.00
5.95
5.84
6.00
6.00
6.16
Log1Q TCID50 per 0.2 ml.
The titcr of virus contained in each sample after the
addition of 15 ml of extraction medium. (Login TCIDcn
per 0.2 ml). 10 50
-------
141
Table V-ll Recovery of Poliovirus 1 and Coxsackievirus A-9 from artifically
contaminated solid waste suspended in distilled water
•
Treat-
ment
Tubes
incu-
bated
2 hrs
4°C.
Tubes
incu-
bated
2 hrs
Room
Temp.
Experi-
ment
number
•
1
2
3
4
Mean
5
6
7
8
Mean
Vii."us Li
Supernatant fluid
from
contaminated
suspension13
Polio
(5.33)
5.03
5.16
5.30
5.20
5.17
5.20
5.12
5.00
5.25
5.14
1 Coxsackie
A-9
d (5.18)
5.10
5.05
5.00
5.11
5.06
5.93
5.00
5.10
5.16
5.04
ter"
Supernatant fluid
extracted before
contamination0
Polio 1
(5.33)
5.20
5.00
4.93
5.10
5,06
5.00
5.30
4.90
5.00
5.05
Coxsackie
A-9
(5.18)
5.10
5.15
5.20
5.00
5,12
c; r\ f\
5.15
5.10
5.11
5.09
a
Log1Q TCID50 per 0.2 ml,
The contaminated suspension was centrifuged and the
supernatant fluid tested for virus.
The sterile suspension was ccntrifuged and the super-
natant fluid was contaminated an3 tested for virus.
The titer of virus contained in each sample after
dilution to final volume.
-------
142
Persistence Studies
The next five experiments were carried out on unpulverized materials by contam-
inating them with 0.4 ml of either vaccinia virus, poliovirus type 1, coxsackievirus
A-9 or influenza virus PR-8. Virus titers were determined at zero time, 1, 2, 3, and
5 days and thereafter once a day until ho virus could be detected.
Persistence of Virus on Cotton Balls
Influenza virus PR-8 persisted on this material until the eighth day after
contamination. Vaccinia virus and poliovirus type 1 were undetectable at 7 days,
Tjhile coxsackievirus A-9 survived 3 days (Table V-12). No general trend of virus
inactivation could be seen. Virus loss for one day ranged from 0.2 to 2.0 log units
in most cases. The fastest loss was recorded for the period 1-3 days during which
time coxsackievirus A-9 lost 4 log units.
Persistence of Virus on Paper Towels
The results (Table V-13) show that vaccinia virus and poliovirus type 1 were
again undetectable after 7 days. Coxsackievirus A-9 persisted for 3 days, while
influenza virus PR-8 survived until the seventh day. Coxsackievirus A-9 again lost
4 log units in 2 days as compared to 0.2 to 2.0 logs for the other viruses.
Persistence of Virus on Cotton Cloth
Table V-14 shows that on this material, poliovirus type 1 and coxsackievirus
A-9 persisted for 3 days, while vaccinia virus and influenza virus PR-8 survived
until the fifth day. No pattern of inactivation could be seen for any of the viruses,
although each lost between 3-4 log units in 2 days.
-------
Table V-12 Persistence of vaccinia virus, Poliovirus 1, Coxsackievirus A-9
and Influenza virus PR-8 on cotton balls at room temperature
Incubation
time
(days)
0
1
2 .
3
5
7
Virus titera
Vaccinia
(4.91)*5
4.40
3.48
2.50
1.62
0.75
0.00
Polio 1 Coxsackie
A-9
(5.33) (5.18)
5.25
5.00
4.26
3.16
1.71
0.00
5.00
4.83
2.62
0.50
0.00°
0.00
Influenza
PR-8
(6.07)
5.83
5.00
4.50
3.25
2.16
0.50
Log10 TCID5Q per 0.2 ml.
The titer of virus contained in each sample after the
addition of 15 ml of extraction medium. (Logm TCIDcn
per 0.2 ml). ' 1U 50
No virus detectable in 0.2 ml of undiluted fluid.
-------
144
Table V-13 Persistence of vaccinia virus, Poliovirus 1, Coxsackievirus A-9
and Influenza virus PR-8 on paper towels at room temperature
Incubation
time
(days)
0
1
2
3
5
7
Virus titera
Vaccinia
(4.91)b
4.36
3.83
2.62
1.62
0.75
0.00
Polio 1 Coxsackie
A-9
(5.33) (5.18)
5.00
4.37
3.50
2.00
0.50
0.00
5.00
4.83
2.33
0.83
0.00°
0.00
Influenza
PR- 8
(6.07)
6.00
5.50
4.56
4.00
2.05
0.00
a
Log1Q TCID5Q per 0.2 ml,
The titer of virus contained in each sample after the
addition of 15 ml of extraction medium. (Log,n
per 0.2 ml). 10
No virus detectable in 0.2 ml of undiluted fluid.
-------
145
Table V-14 Persistence of vaccinia virus, Poliovirus 1, Coxsackievirus
A-9 and Influenza virus PR-8 on cotton cloth at room temperature
Incubation
time
(days)
0
1
2
3
5
7
Virus titera
Vaccinia
(4.91)b
4.41
2.68
1.83
1.30
0.83
0.00
Polio 1 Coxsackie
A-9
(5.33) (5.18)
5 .28
4.37
3.30
1.80
0.00C
0.00
4.83
1.83
1.00
0*.83
0.00
0.00
Influenza
PR-8
(6.07)
5.75
4.56
3.00
1.96
0.75
0.00
a
Log1Q TCID50 per 0.2 ml.
The titer of virus contained in each sample after the
addition of 15 ml of extraction medium. (Log,ft TCIDCrt
per 0.2 ml). 10 50
c No virus detectable in 0.2 ml of undiluted fluid.
-------
Persistence of Virus on, Surgical Gauze
Vaccinia virus could not be detected after 3 days, while poliovirug type 1,
coxsackievirus A-9 and influenza virus PR-8 were recovered on the fifth day (Table
V-15). A loss of 1 log unit was recorded for vaccinia virus at zero time and was
considerably higher than that observed for the other viruses.
Persistence of Virus on Wax Coated Paper Cups
Table V-16 shows that all viruses persisted until the fifth day after contamina-
tion. Influenza virus PR-8 lost 5 log units from zero time to 3 days, while the
others lost between 3 and 4 log units. No pattern of loss could be seen with any
of the viruses.
Studies on Pulverized Materials
One-half gram samples of the waste were contaminated with 0.4 ml of either
vaccinia virus, poliovirus type 1, coxsackievirus A-9 or influenza virus PR-8.
Virus titers were determined at zero time, 2, 6, and 9 hours and thereafter once
a day until no virus could be detected.
Persistence of Virus on the Pulverized Representative Sample
Vaccinia virus persisted until the fifth day, whereas poliovirus type 1 and
influenza virus PR-8 survived until the seventh day (Table V-17). Coxsackievirus
A-9 was undetectable after 6 days. Almost no virus was lost in the first 9 hours
after contamination. Thereafter, losses ranged from 0.1 to 1.5 log units per day
for each virus.
Persistence of Virus on Pulverized Office Papers
Table V-18 shows that poliovirus type 1 persisted up to the sixth day, while
the other viruses lasted until the seventh day. No pattern of inactivation could
be seen for any of the viruses. Losses ranged from 0.1 to 1.5 log units per day
fui each virus.
-------
147
Table V-15 Persistence of vaccinia virus, Poliovirus 1, Coxsackievirus A-9
and Influenza virus PR-8 on surgical gauze at room temperature
Incubation
time
(days)
0
1
2
3
5
7
Vaccinia
(4.91)b
3.90
2.37
1.16
0.50
0.00C
0.00
Virus titer
Polio 1
(5.33)
5.30
5.16
4.30
1.50
0.50
0.00
a
Coxsackie
A-9
(5.18)
5.10
5.00
2.62
1.62
0.75
0.00
Influenza
PR-8
(6.07)
6.00
5.50
3.28
1.79
0.62
0.00
Log1Q TCID50 per 0.2 ml,
The titer of virus contained in each sample after the
addition of 15 ml of extraction medium. (Logm T
per 0.2 ml).
c No virus detectable in 0.2 ml of undiluted fluid.
-------
148
Table V-16 Persistence of Vaccinia virus, Poliovirus 1, Coxsackievirus A-9
and Influenza virus PR-8 on wax coated paper cups at room
temperature
Incubation
time
(days)
0
1
2
3
5
7
Vaccinia
(4.91)b
4.80
3.25
2.62
1-.83
0.50
0.00°
Virus titer
Polio 1
(5.33)
5.21
4.98
3.21
2.50
0.50
0.00
a
Coxsackie
A-9
(5.18) ,
5.06
4.16
2.83
1'.62
0.75
0.00
Influenza
PR-8
(6.07)
5.95
4.65
3.00
1.00
0.60
0.00
Log1Q TCID5Q per 0.2 ml.
The titer of virus contained in each sample after the
addition of 15 ml of extraction medium. (Log,A TCIDCft
per 0.2 ml). 10 50
No virus detectable in 0.2 ml of undiluted fluid.
-------
149
Table V-17 Persistence of Vaccinia virus, Poliovirus 1, Coxsackievirus A-9
and Influenza virus PR-8 on an autoclaved, pulverized solid waste
mixture at room temperature
Incubation
time
(hours)
0
2
6
9
(days)
1
2
3
4
5
6
7
8
Vaccinia
(4.91)b
4.21
4.00
4.00
3.85
3.00
2.62
2.00
1.75
0.50
0.00C
0.00
0.00
Virus
Polio
(5.33
5.31
4.83
4.78
4.73
4.62
3.62
2.83
2.50
2.37
2.17
1.35
0.00
titera
1 Coxsackie
A-9
) (5.18
5.00
4.90
4.85
4.00
3.41
2.*n
2.00
1.62
• i.oo
0.81
0.00
0.00
Influenza
PR-8
(6.07)
5.97
5/90
5.41
5.35
4.83
4 71
3.52
2.82
2.17
1.62
0.83
0.00
-Log10 TCID50 Per
b The titer of virus contained in each sample after the
addition of 15 ml of extraction medium (Log-i n TCIDco
per 0.2 ml). 10 50
0 No virus detectable in 0.2 ml of undiluted fluid.
-------
150
Table V-18 Persistence of Vaccinia virus, Poliovirus 1, Coxsackieyirus A-9
and Influenza virus PR-8 on an autoclaved, pulverized sample of
office papers at room temperature
Incubation
time
(hours)
0
2
6
9
(days)
1
2
3
4
5
6
7
8
Vaccinia
(4.91)b
4.50
4.25
4.12
4.00
3.62
3.34
3.12
2.54
1.89
1.75
0.62
0.00
Virus
Polio
(5.33)
5.16
4.62
4.59
4.58
4.20
•>. «•*
2.62
2.17
1.45
0.75
0.00°
0.00
titera
1 Coxsackie
A-9
(5.18)
4 '.98
4.98
4.58
4.40
4.12
3 °°
3.21
2.81
2.12
1.62
0.50
0.00
Influenza
PR-8
(6.07)
6.00
5.51
5.21
5.00
4.27
n /*•*
*^ • wy
3.05
2.50
2.17
1.21
0.50
0.00
'JCID50 per
The titer of virus contained in each sample after the
addition of 15 ml of extraction medium (Log,A TCIDert
per 0.? ml) . 10 50
No virus detectable in 0.2 ml of undiluted fluid.
-------
151
Persistence of Virus on Pulverized Paper Towels. Tissues and Bags
Influenza virus PR-8 was detected until the seventh day, while poliovirus type
1 was detected until the eighth day (Table V-19). Vaccinia virua was also recovered
until the seventh day. No significant losses were recorded in the first 9 hours
after contamination. Losses per day were approximately 0.5 to 1.0 log unit for
each virus.
Persistence of Virus on Pulverized Paper and Plastic Cups
The initial zero time isolation with vaccinia virus showed a loss of 0.8 log
units (Table V-20). Vaccinia virus persisted for 6 dayo on the material, coxsackie-
virus A-9 and poliovirus type 1 survived until the seventh. Influenza virus PR-8
lasted the longest by persisting until the eighth day.
Persistence of Virus on Pulverized Surgical Tape. Gauze and Bandages
Influenza virus PR-8 persisted for 5 days, while poliovirus type 1 lasted 6
days (Table V-21). Vaccinia virus and coxsackievirus A-9 also persisted for 5
days. The greatest loss of the three was recorded for coxsackievirus A-9 when it
lost 4 log units in 3 days.
Effect on Virus Recovery of Pulverizing Paper "Bowels After Contamination with Virus.
Transmission of Virus from Contaminated to Uncontaminated Paper Towels by Direct
Contact
Paper towel samples (5x5 inches) were contaminated with 0.4 ml of a known
amount of either vaccinia virus or coxsackievirus A-9. Each sample was placed in
a plastic bag containing three additional uncontaminated towels. After three hours
at room temperature, the towels were individually pulverized and tested for virus
survival.
Virus was recovered from one of the towels contaminated indirectly (Table V-22).
No virus was recovered from towels in contact with coxsackievirus A-9. From the
towel contaminated with vaccinia virus, 1.0 log unit was recovered, whereas 2.S log
units of coxsackievirus A-9 were recovered.
-------
152
Table V-19 Persistence of Vaccinia virus, Poliovirus 1, Coxsackievirus A-9
and Influenza virus PR-8 on an autoclaved, pulverized sample of
paper towels, tissues and bags at room temperature
Incubation
time
(hours)
0
2
6
9
(days)
1
2
3
4
5
6
7
8
Virus titer3
Vaccinia
(4.91)b
4.62
4.50
4.00
3.81
3.75
2.75
2.12
1.86
1.12
0.62
0.00°
0.00
Polio 1 Coxsackie
A-9
(5.33) (5.18)
5.26
5.16
5.00
4.86
4.83
3.R3
3.53
2.37
2.17-
1.75
0.50
0.00
5.00
5.00
5.00
4.83
4.21
3.83
2.62
2.17
1.85
1.00
0.50
0.00
Influenza
PR- 8
(6.07)
,
5.84
5.75
5.21
5.00
4.50
4^.00
3.16
2.41
2.00
1.15
0.00
0.00
a
Log1Q TCID5Q per 0.2 ml
b The titer of virus contained in each sample after'the
addition of 15 ml of extraction medium (Log,A TCIDcn
per 0.2 ml). ^10 50
No virus detectable in 0.2 ml of undiluted fluid.
-------
153
Table V-20 Persistence of Vaccinia virus, Poliovirus 1, Coxsackievirus A-9
and Influenza virus PR-8 on an autoelaved, pulverized sample of
paper and plastic cups at room temperature
Incubation
time
(hours)
0
2
6
9
(days)
1
A
C.
3
4
5
6
7
8
Vaccinia
(4.91)13
•
4.12
4.00
4.00
3.86
3.62
J . 4U
2.83
2.12
1.75
0.50
0.00C
0.00
Virus titer
Polio 1
(5.33)
5.30
5.27
5.27
5.15
5.00
•»./_>
3.62
2.62
1.50
0.65
0.50
0.00
a
Coxsackie
A-9
(5.18)
5.10
5.00
5.00
5.00
4.62
• « *K
n * JLV
3.55
2.62
1.59
1.07
0.83
0.00
Influenza
PR-8
(6.07)
5.89
5.89
5.61
5.50
5.21
•S • JL V
5.00
4.35
3.21
1.62
1.00
0.50
TCID50 per 0.2 ml.
The titer of virus contained ir each sample after the
addition of 15 ml of extraction medium (Log1n TCJDcn
par 0.2 ml). 1U 50
So virus detectable in 0.2 ml of undiluted fluid.
-------
154
Table V-21 Persistence of Vaccinia virus, Poliovirus 1, Coxsackievirus A-9
and Influenza virus PR-8 on an autoclaved, pulverized sample of
surgical tapes, gauze and bandages at room temperature
Incubation
time
(hours)
0
2
6
9
(days)
1
^
i.
3
4
5
6
7
8
Vaccinia
(4.91)b
4.86
4.75
4.62
4.62
4.00
- Tr
j . 75
2.83
1.12
0.83
0.00C
0.00
0.00
Virus tit
Polio 1
(5.33)
5.26
5.16
5.00
5.00
4.83
.) . 0 J
2.50
2.00
1.62
0 = 83
0.00
0.00
era
Coxsackie
A-9
(5.18)
4.83
4.75
4.62
3.83
2.83
j. . _>i
1.00
• 0.83
0.50
0,00
0.00
0.00
Influenza
PR-8
(6.07)
5.83
5.50
5.21
5.00
4.75
• /s ^
1 • V W
3.21
2.16
1.00
0.00
0.00
0.00
Log10 TCID50 per
•Tho tJ cer of virus contained i'i each sample after the
addition of 15 mJ of extract-ion medium (Log,Q
per 0.2 ml).
No virus detectable in 0,2 ml of undiluted fluid.
-------
Table V-22 Effect on virus recovery of pulverizing paper towels after
artificial contamination with Vaccinia virus and Coxsackievirur.
A-9. Transmission of virus from contaminated to uncontaminated
paper towels by direct contact
Sample
towels
Con-
taminated
Uncon-
taminated
1
2
3
Virus
Vaccinia virus
(4.28)b
1.00
•
o.ooc
0.83
0.00
i
titera
Coxsackievirus A-9
(4.83)
2.50
•
0.00
0.00
0.00
Log1Q TCID5Q per 0.2 ml.
The titer of virus contained in each sample after the
addition of 15 ml of extraction medium (Login TCIDcn
per 0.2 ml) . ' J'U 50
'.No virus detectable in 0.2 ml of undiluted fluid.
-------
156
Conclusions
Before undertaking control and preventive measures for stopping the spread of
microorganisms by fomites, an understanding of the factors influencing the conta.nl:.
ation of the materials and the factors influencing the survival and Infactivity ut
the microorganisms on the materials is needed. This work has supplied additional
information on virus stability to the limited amount available today.
Maximum recovery of virus was obtained when the medium used for extraction vas
adjusted to pH 7.0. In addition to maximum recovery at this -pH, none of the
harmful effects for the virus that were exhibited at the lower pH levels were
observed.
It was thought that the pulverizing or autoclaving might be exerting an
influence on the recovery of virus. However, virus was recovered from treated
materials with little difference in efficiency from those that were not autoclaved
or pulverized. To facilitate testing, most samples were autoclaved before being
used.
To find if these materials had any properties toxic for viruses or for tissue
cultures, an extract of a representative mixture of solid wastes was tested. No
toxic substances could be shown in the materials that were used. But in much of
the solid waste generated in a hospital exists toxic chemicals and disinfectants
which could be virucidal in nature. Viruses are apparently susceptible to inactive
tion by a number of chemical substances. (Reviewed by Dunham (101) and by Klein
and DeForest (102). In this study, the materials were tested as they were found
in the refuse disposal system where they posed the greatest threat to the greatest
number of people. If present, the chemical agents had no adverse effect on the
tissue cultures used. This could be due to the autoclaving which would change the
compound significantly or to their removal by the clarification centrifugation.
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The use of chemical agents for the sanitizing of fabrics from bacteria has been
extensively used since the days of the Roman Empire, but to date no attempts have-
been made to use this process to render fabrics refractory to viruses. If effect :ve
chemicals can be found that have significanc activity against a br-.-ad speetium of
viruses, fabrics could be treated with the agent, particularly in areas suspected
of being contaminated with the susceptible viruses.
Persistence of viruses on the materials tested seemed to vary with the virus
used and the type of waste. Since no pattern of loss of virus on coctuii materials
or paper items could be seen, it was assumed that the factors influencing the surviva-1
on the various materials were peculiar to the individual item or group of items
being tested. In this study, cotton cloth was the only fabric studied, but suf t Lc:iet! i
information already exists to indicate that other types of fabrics can disseminate
viruses.
Differences in the fibrous structure of waste materials may have some effecf on
their retention of virus. Cotton fibers are flattened, twisted cellulose tubes wiM.
a small amount of pectins and waxes in the outer wall, whereas the paper products
consist of polyester and cellulose in various concentrations depending on the itt •
being studied. The paper fibers are laid down either randomly, parallel <->r at. < i >v »
angles. In laboratory paper towels there is more polyester than cellulose. T^e
natural water content of cotton materials is about 77,,, whereas for paper items it
is less. Approximately 20-417, of the cotton material is unoccupied space, whereas
paper has less space. The possibility exists that viruses might be held more tightiy
on one type of fiber than on another depending upon which offers the most protection,
thus allowing recovery of virus to be higher from one material than from another.
Virus clumping could also prevent their release from the fibers. However, since the
virus titer decreased in most cases at a steady rate with increasing time the
implication is that the agent lost its viability upon incubation. Relative humidity
(RH) has been shown to be an important factor in the survival cf viruses (103,104, ''.)•>,
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106,107,108). Due to evaporation after addition of the virus suspension, the moistui
content slowly decreased. At least at one point in the drying process, the humidity
within the samples reached levels that should have favored survival of the virus.
Perhaps on a material that held its moisture less readily, as with cotton cloth in
Table V-14, the enteric viruses lost their viability sooner than the vaccinia and
influenza viruses. These results would be in accordance with the findings of other
investigators (87,103,105,109). However, this could not account for other results
which are believed to be caused by individual variation.
Viruses persisted on the pulverized materials slightly longer than on those thit
were unpulverized. In Table V-19, all viruses persisted on pulverized paper towels
for 6-7 days, whereas on regular paper towels, they lasted for 3-5 days (Table V-13),
This again could be due to the rate of water loss and/or the fiber construction after
pulverization, but these results are hard to interpret.
To determine the effect of pulverizing after contamination, samples of paper
towels were tested. Another question was answered by this experiment; do viruses
contaminating one object contaminate another one by coming in contact with it? Vlrue
was recovered from only one towel that was originally uncontaminated. This shows
that contamination of viruses can be spread from one object to another merely by
mixing the two. Most of the virus that was originally placed on the towels was lost
during the pulverizing process, which could probably be attributed to the heat
generated in the pulverizing mill.
The results presented in this work support the thesis that almost all solid was«
materials found in the refuse disposal system at West Virginia University hospital
could be possible vehicles of transmission of viruses. To insure public safety froo
exposure to possible contamination by infectious agents harbored on these materials,
refuse containers should be designed which allow the least contact between person
and waste. Plastic bags have met with relative success, but in many cases were
easilv torn open by sharp objects with which they came into contact. These containers
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would be employed in all areas of the hospital since all areas generate materials
capable of retaining infectious microorganisms. At regular collection times, the
containers would be sealed and carted away to be disposed of in a way that is
effective yet minimizes possible pollution of air and water. Possibly, high risk
areas could be decided upon so that special precautions could be taken in handling
the waste generated there.
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VI. SAFETY PRECAUTIONS, COSTS AND RECOMMENDED SAMPLING PROCEDURE
As the title of this chapter indicates this is a compilation of some studieg
which evolved as a result of the overall study.
Safety Precautions
Concern here is for certain steps which were considered necessary for the
personnel who were working on the project and some additional recommendations for
the personnel whose job it is to handle the wastes in the institution.
Most of the concern for personnel working on the project pertained to work
in the laboratory. They were required to wear laboratory coats, surgical face
masks and rubber gloves while sorting, weighing and grinding. In addition,
goggles were required during the grinding operation. They were urged to shower
after working. The laboratory coats were commercially laundered and the lab-
oraboty was cleaned after each days sorting.
New brown paper was placed on the sorting table at the beginning of each
days work or as often as needed to maintain clean conditions.
Bags of refuse known to contain pathogenic organisms were weighed only and
not sorted.
The following recommendations although partially applicable to personnel
working on this project apply mainly to waste handlers in the institution.
1. Disposable needles and syringes are a hazard to waste handlers.
Some system to crush, melt, break or otherwise incapacitate these
devices should be a part of each health care facility that uses them.
2. Unused portions of certain medicines, narcotics or other drugs used
in health care facilities should be poured down the drain, crushed
or otherwise made unusable prior to disposal.
3. A comprehensive investigation of sickness or disease rates of refuse
handlers in hospitals should be conducted.
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4. Radioactive wastes should be handled and disposed of according to
methods prescribed by the U. S. Atomic Energy Commission.
5. Separate storage and disposal should be required for flammable or
dangerous chemicals, liquids and toxic compounds.
Solid Wastes Handling Costs
Although this was not a specific aim in this study of the handling of solid
wastes at the Center it arose and was carried cut.
The following factors were considered in estimating costs of the Basic
Sciences Building and the Teaching Hospital:
1. Personnel
2. Salaries of personnel
3. Time spent by personnel in the handling of solid wastes
4. Equipment and supplies
5. Maintenance and replacement of equipment
6. Utilities
7. Other related factors
Personnel included custodians, maids, kitchen help and special service help.
Other related factors include periodic cleaning of air filters, removal of
fly ash and so forth.
Exact costs on many items were difficult to determine and hence some of the
figures shown beiow represent our best estimate of cost.
Basic Sciences Building - Annual Costs
1. Physical Plant - Medical Center Department
Personnel - Custodians, maids, etc. $ 28 030
2. Physical Plant - University Personnel - Truck driver, etc. 3 035
3. Purchasing and Supply Department 980
4. Kitchen Cafeteria and Snack Shop 725
5. Animal Quarters - Including Incineration 2,594
6. Human Waste Incineration 1 220
7. General Refuse Incineration 430
8. Radioactive Waste 216
Total Annual Cost $ 37,230
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Teaching Hospital - Annual Costs
1. Housekeeping Personnel $ 28,483
2. Physical Plant - University Personnel 4,430
3. Physical Plant - Medical Center Department Personnel. 115
4. Kitchen, Cafeteria, and Coffee Shop 5,594
5. General Refuse Incineration 1,075
6. Chute Maintenance 60
7. Laundry Wastes ±11
Total Annual Cost $ 40,050
General refuse incineration costs are prorated between the Basic Sciences
Building and the Teaching Hospital and include depreciation.
The total c^st of refuse handling and disposal thus comes tc $77,280 per year
and using a rough approximation of 1,000 tons of refuse generated per year this
gives a cost of handling and disposal of $77.28 per ton.
Recommended Sampling Procedures
A number of factors arose during the course of this study pertaining to
sampling procedures such that it is felt that some general recommendations can
be made which should assist other investigators in further studies.
1. A sufficient number of stations should be selected so that wastes from
a particular unit may be isu.'ated and identified as being from that
particular unit.
2. Samples must be collected tr:ugh times from an; sampling station so that
the effect c.f diurnal -_r seasonal variation can be detected if it is
present.
3. Periodic cnecks of weights from individual sampling stations should be
compared to t.tal production from the facility to verif> the validity
of station sampling.
4. Twenty-four hc^ur attendance at sampling stations may be necessary.
5. If wastes are handled in such a way that certain hours are peak hours
at a disposal vr, int additijnal study personnel may be required during
that peri/d.
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6. The amount of waste which can be sorted, ground and analyzed Is usually
a limiting factor and is another justification for having a series of
stations in the facility being studied-
7. If ths sample sorted is relatively large 50 to 100 pounds of a
representative portion must be selected for chemical and bacteriological
analysis. The procedure used in this study was to take a 5 to 10
percent sample by weight of each item trom the physical separation and
grind these together for the chemical analysis.
Some idea of the time required for sorting, sampling and grinding may be
seen in Table VI-1.
Table VI-1 Labor efficiencies for refuse sorting, sampling
and grinding
Pounds of refuse sorted, sampled
and ground
Pounds of refuse sorted only
Labor hours spent in sorting
sampling and grinding
Labor hours spent in sorting cnly
Pounds per labor hour for sorting,
sampling and grinding
Pounds per labor hour fcr sorting
only
Hospital
3528
666
324
52
10.89
12.86
Basic
Sciences
3704
8405
351
752
10.54
11.16
Total
7232
9073
675
804
10.69
11.02
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VII. SUMMARY
The specific aims which were initially listed for this project are given
below.
1. To determine the physical and chemical composition of the solid wastes
from one medical school and hospital referral complex.
2. To determine whether bacteria and viruses are present to any
significant degree and to do some isolation and identification.
3. To provide a classification basis and obtain quantity values for the
waste from the significant floors and departments.
4. To establish a safe procedure for studies on potential pathogenic
wastes.
5. To provide information about solid wastes on a waste producing unit
basis that can be used by designers in establishing waste handling
procedures and facilities for hospitals and other medical complexes.
6. To develop a sampling procedure which could be used in future solid
waste studies including statistical analysis of the data to determine
the percent errors and confidence in the sampling procedure.
It is the primary purpose of this chapter to pc-int out where in the main
body or the report the information can be found which will satisfy or partially
satisfy the initial specific aims.
Number one can be found in Chapter IV
Number two can be found in Chapter V
Number three can be found in Chapter III
N'umber four can be found in Chapter VI
Number five can be found in Chapter III
Camber six can be found in Chapters II and VI
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It was considered more convenient to list the conclusions with the chapters
that dealt with that particular topic.
Cost, which were not included as part of the specific aims are discussed
in Chapter VI.
Although all pertinent references are listed in the Bibliography a list is
also provided here of all papers which were written pertaining to this study. If
more detail is desired on any topic discussed in this report these papers are
on file with Solid Waste Research, Office of Research and Monitoring, Environmental
Protection Agency, Cincinnati, Ohio and with the Department of Civil Engineering,
West Virginia University, Engineering Sciences Building, Morgantown, West Virginia
26506.
1. Armstrong, David Harold, "Hospital Refuse - Chute Sanitation," Unpublished
problem report, W.V.U., Morgantown, '". Va. 1969.
This report deals with the general problem of hospital refuse chute
sanitation and the specific problem of the effect of putting hospital
refuse in plastic bags. The study shows that airborne bacteria are
generated during waste handling and that there are pathways by which they
may gain entrance to hospital floors. Plastic bagging of the refuse signi-
ficantly reduced the number of airborne bacteria generated.
2. Cleveland, Elmer G., "Sampling Data and Procedures Used in the Medical Center
Solid Waste Program," Unpublished class report, W.V.U., Morgantown, W. Va.
1968.
This report deals with the design of the sampling and weighing procedure
in order to obtain weights, volumes, types and generation origins of solid
wastes within the Medical Center complex. Collection of samples, laboratory
procedures and safety precaustions are discussed. Preliminary data as to
physical breakdown and quantities are presented.
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J. DiNicola, Thomas A., "Persistence of Viruses -n Hospital Solid Wastes,"
Unpublished masters thesis, W.V.I)., Motgantown, W. V*. 19t>9.
This thesis reported on contaminating hospital solid wastes with vaccinia
virus, policvirus type I, coxsackie virus A-9 and influenza virus PR-8.
The length of time these agents persisted at room temperature on such
materials was determined. Generally, viruses persisted for 3 t.. f> days
on cotton balls and sheeting and frr 3 t, 8 days on paper items.
4. Galli, Alfred A., "Chemical Analysis of Solid Wastes from a Teaching Hospital,"
Unpublished problem report, W.V.U., Morgantcwn, W. Va. 1971.
This problem report is a study of the chemical c ,nstit<-fcnts fround in solid
wastes. After a physical separation into 25 categories a chemical analysis
which included moisture, volatile solids and ash, BTU value, sulfur and
phosphorus was performed. Data obtained during one year rf sampling was
processed in a computer which provided rt.&di uts. Other chemical tests were
added after the completion of this revort.
5. Morris, Ronald Lee, "Preparation and Operatic:, of Combustion Trains for
Carbon and Hydrogen Analysis," Unpublished pr' blew report, TT.V.U.,
Morgantown, W. Va. 1969.
This report focuses en the construction and method of operation of coicbustiop
trains for the anal/sis of carbon and .Vvdregen it the cnei!.leal analysis of
solid wastes at the Medical Center Complex.
6. Proden, Leonard, "Tentative Methods and Procedures ft-r c-.etnUai and Bacter-
iological Analysis of Institutional Solid Wastes," Ur.iuhiished revert.
W.V.I)., Morgantown, W. Va. 19b8.
This report lists suggested procedures t,. be followed in chemical and
bacteriological analysis of hospital s^lid wastes. It also discusses some
safety and sanitary precaustions to be followed as» well a* suggestions on
ways of enhancing the quality of the work being perf-rmed.
7. "••ir-., Richard J., Ill, "Bacteriological E-aor-ination of Institutional Solid
Wastes, Unpublished problem recort, W.V.U., Me rfeant.,wn, W. Va. 1970.
This re-ort deals with t!-.e method , f e»a*ir*ti. n t. b*. -^sed i-. the analysis
f *=steb containing pathogenic mic r u..rgar. i°ms. S..•**• i-rfci i«r it;&t / data are
presented.
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8. Trigg, Jere A., "Microbial Examination of Hospital Solid Wastes," Unpublished
problem report, W.V.U., Morgantown., W. Va. 1971.
Building on reference number six this report gives a detailed explanation
of analysis materials and procedures for tie determination >..f the raicrobial
counts in hospital refuse. Insight is obtained into the question of the
types of microorganisms most commonly associated with hospital refuse.
From the data on the 15 nursing stations conclusions are drawn on the type
of station most likely to generate potentially pathogenic solid wastes.
9. Usmiani, John 1., Part I., "Estimate of Cost Factors Involved in Solid Waste
Handling and Disposal at West Virginia University Medical Center", Part 2,
"Personnel Involved in Solid Waste Production at West Virginia University
Medical Center," Unpublixhed class report, W.V.U., Morgantown, W. Va. 1968.
This report attempts to take into account all factors which contribute to
the cost of handling and disposing of solid wastes at the W.V.U. Medical
Complex. Part 2 is an effort to correlate these c.sts with the personnel
who are contributing to the production of the solid wastes in the Complex.
10. Wallace, Lynn Pyper, "Solid Waste Generation by the Units of a Teaching
Hospital," Ph.D. Dissertation, W.V.U., M&rgantown, ". Va. 1970.
After the determination the weights and volumes <;f so!id waste generated
by a modern teaching hospital these quantities were correlated the
number of patients, the number of paid empLj/ees (nurses, doctors, aides,
administrative and operational personnel) and t'-e number of non-paid
personnel (volunteers and students) who ;>r educed the refuse. The results
show that the quantity of refuse generated by ^capital units can be pre-
dicted from tbe 24 hour staff on ditty in that i.-at.
11. Zepeda, Francisco, "Statistical Analysis of Institutional Solid Wastes,"
Unpublished problem report, W.V.U., Morgantown, W. Va. 1969.
This repr.rt is a study of the percentages ;.-f the difft.-ent /i/steal con-
stituents of institutional solid wastes. The analysis consisted in the
physical separation of the refuse into 25 categories aad in obtaining the
percentage by weight of each.
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168
Data obtained during one year of sampling were processed in a computer
and the results obtained shoved the quantity of solid waste generated in
each section and the percentage by weight of each constituent.
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' <\
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170
17. Bond, R. G. and G. S. Michaelsen, Bacterial Contamination from Hospital Solid
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83. "Hospital Refuse Destructor: Successful Application of Gas Firing," Hospital
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84. Groce, R. B., "Disposable Items Add to Hospitals' Waste Disposal Problems,"
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-------
175
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1964, pp. 1054-1055.
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-------
176
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biologists; Part B.. Academic Press, London and New York, 1968.
-------
177
APPENDIX A
Appendix A consists of data tables and calculation tables used in obtaining
values for certain tables in the main body of the report.
-------
Table A-l Mean hospital ut.it population
(24 HOUR PERIOD)
UNIT PATIENTS
MONDAY
FRIDAY
META.
PSYC.
GMED.
GMED.
FED.
GYN.
SURG.
SURG.
OB.
ORTH.
ORTH.
OR.
1C.
X-RAY
BLAB..
REGM.
ENT.
CP.
EMG.
ER.
CLIN.
ADMIN.
CAFE.
GIFT
GRND.
DIET.
10
24
43
47
41
44
46
46
15
21
38
19
8
0
0
0
0
0
0
65
311
0
0
0
0
0
DOCTORS
ADMINISTRATORS
SUPERVISORS
7
11
21
33
41
36
18
24
17
8
11
34
22
10
7
6
13
12
2
16
85
21
1
1
3
4
SECRETARIES
CLERKS
0
1
2
2
2
2
2
2
1
2
2
1
0
11
9
5
2
6
0
1
4
41
0
1
12
4
TECHNICIANS
LAB ASS'T
2
1
2
2
3
1
3
2
0
0
0
4
0
13
26
1
5
9
2
0
9
0
5
0
8
17
NURSES
AIDS
8
13
24
26
24
20
25
25
17
16
23
36
18
0
3
0
0
1
0
9
14
0
0
0
0
0
HOUSEKEEPING TOTAL VOLUNTEERS
MAINTENANCE STAFF STUDENTS
2
2
4
4
5
4
4
4
2
2
4
4
3
1
1
0
0
1
0
3
1
4
0
0
2.
2
19
28
53
67
75
63
52
57
37
28
40
79
43
35
46
12
20
29
4
29
113
66
6
2
25
27
3
9
2
2
12
3
1
2
9
3
4
0
1
22
16
0*
2*
5
0
1
19
20
0
6
0
0
-------
Table A-l (continued)
UNIT
KITN.
PHCX-
1AUN,.
CENT.
COBT.
ALF.
PATIENTS DOCTORS
ADMINISTRATORS
0
0
0
0
0
0
SUPERVISORS
7
2
2
1
1
6
SECRETARIES
CLERKS
0
0
0
1
1
7
TECHNICIANS
LAB ASS'T
64
6
20
7
4
7
NURSES HOUSEKEEPING TOTAL VOLUNTEERS
AIDS MAINTENANCE STAFF STUDENTS
ORDERLIES
0
0
0
0
0
3
2
0
3
0
1
I
73
8
25
9
7
24
0
0
0
0
0
0*
TOTALS 778 483
Includes 376 Outpatients
124
223
305
66
1201
142
*Administratively Part Of The Basic Sciences Building
-------
00
o
~a')le \.-2 Mean hospital unit reputation
(24HOUR PERIOD)
UNIT PATIENTS
DOCTORS
ADMINISTRATORS
SUPERVISORS
META.
PSYC.
GMED.
GMED.
FED.
GYN.
SURG.
SURG.
OB.
ORTH.
ORTH.
OR.
1C.
V-RAY
BLAB.
REGM.
ENT.
CP.
EMG.
ER.
CLIN.
ADMN.
CAFE.
GIFT.
GRND.
DIET.
KITN.
7
18
41
45
42
45
45
43
28
20
32
3
10
n
0
0
0
0
0
65
0
0
0
0
0
0
0
8
4
17
20
36
24
11
17
6
5
10
7
19
1
3
0
0
0
0
4
0
3
1
1
0
2
6
SECRETARIES
CLERKS
0
1
1
1
1
1
1
1
0
1
1
0
0
1
2
0
0
0
0
0
0
8
0
0
0
3
0
TECHNICIANS
LAB ASS'T
1
1
1
1
3
3
2
2
0
0
0
1
0
3
13
0
0
0
0
0
0
0
6
0
0
12
• 60
NURSES
AIDS
ORDERLIES
6
9
25
23
24
18
22
25
18
14
21
4
14
0
1
0
0
0
0
8
0
0
0
0
0
0
0
SATURDAY AND SUNDAY
HOUSEKEEPING TOTAL VOLUNTEERS
MAINTENANCE STAFF STUDENTS
2
2
3
2
5
4
4
3
2
1
2
1
1
0
0
0
0
0
0
3
0
2
0
0
0
1
1
17
17
47
47
69
50
40
48
26
21
34
13
34
5
19
0
0
0
0
15
0
13
7
1
0
18
67
0
2
0
0
2
0
1
0
0
0
0
0
0
0
0
0
0
0
0
2
0
22
0
5
0
0
0
-------
Table A-2 (continued)
UNIT
PHCY.
LAUN.
CENT.
COBT.
ALF.
TOTALS
PATIENTS
0
0
0
0
0
379
DOCTORS
ADMINISTRATORS
SUPERVISORS
1
1
1
0
0
208
SECRETARIES
CLERKS
0
0
0
0
0
23
TECHNICIANS
LAB ASS'l
3
6
4
0
0
122
NURSES
AIDS
ORDERLIES
0
0
0
0
0
232
HOUSEKEEPING
MAINTENANCE
0
1
0
0
0
40
TOTAL
STAFF
4
8
5
0
0
625
VOLUNTEERS
STUDENTS
0
0
0
0
0
34
65 Outpatients
-------
Table A-3 Mean basic sciences unit population
(24 HOUR PERIOD)
MONDAY — FRIDAY
STATION
41.
42
TOTAL
31
32
TOTAL
21
22
23
TOTAL
11
12
TOTAL
Gl
G2
G3
G4
G5
TOTAL
Building
Total
DOCTORS
PROFESSORS
SUPERVISORS
69
30
99
35
48
83
35
33
1
69
43
72
115
14
20
6
1
2
43
409
SECRETARIES
CLERKS
25
0
25
8
2
10
15
1
2
18
42
2
44
7
0
0
0
0
~7
104
TECHNICIANS
LAB ASS'T
0
32
32
4
26
30
42
55
9
106
12
37
49
24
36
22
12
18
112- -
329
NURSES
AIDS
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
1
JANITORS
MAIDS
1
1
2
1
1
2
1
1
0
2
3
4
7
1
1
2
0
0
4
17
TOTAL
STAFF
95
63
158
48 .
77
125
93
90
12
195
100
116
216
.46
57
30 '
13
20
L66
960
VOLUNTEERS
STUDENTS
34
164
198
74
154
228
136
76 .-.
-
212
164
216
380
15
36
-
.
„
51
1069
-------
Table A-4 Mean daily waste production
HOSPITAL
Mon-Fri. Sat.-Sun.
BASIC SCIENCES
Mon.-Fri. Sat.-Sun.
MEDICAL CENTER
Mon.-Fri. Sat.-Sun.
Bed Patients
Out Patients
Professional & Staff
Volunteers & Students
Gross Population*
Average 8 Hour**
Population Census
402
376
1201
142
2121
912
Equivalent Population***
Disposable Waste
Ib./Bed Patient
Ibs. /Person-Gross
Ibs . /Capi ta-Equiv
Reusable Wastes
Ibs. /Bed Patient
Ibs. /Person-Gross
Ibs . /Cam" t--Fmiiv.
Total Wastes
Ibs. /Bed Patient
Ibs. /Per son- Gross
Ibs./Capita-Equiv
Pop.
. Pop.
Pop.
Pnn.
Pop. '
. Pop.
8.2
1.6
24.0
4.5
32.1
6.1
379
65 K'.O
625
34
1103
609
825
3300
4.0
9630
11 -7
12930
15.1
8
3
25
8
34
11
.7
.0
.4
.7
.1
.7
8(.0
10(>9
23'-9
61.3
473
1400
..
37
3.0
510
•
0.2
1 .1
1910
..
39
4.0
402
496
2061
1211
4170
1575
11
1
25
2
36
. 3
.7
.1
.2
.4
.9
.6
1298
4700
3.6
10140
7.8
14840
11.4
379
65
625
34
1103
609
12.
4.
26.
9.
39.
13.
4
3
7
2
2
5
* Sum of Patients, Out Patients, Doctors, Staff an<; Volunteers
** Sum of Patients plus 1/3 (sum of staff, volunte^t, and 1/2 out patients)
*** Equivalent Population Equals 5/7 M-F census plus 2/7 S-S census
Formulas Based on Los Ang2 es County Study (32)
00
-------
oo
Table A-5 Solid waste production rate calculations
(Monday-Fr .day)
UNIT
MATA.
PSYC.
8th
GMED.
GMED.
7th
FED.
GYN.
6th
SURG.
SURG.
5th
OB.
ORTH.
ORTH.
OR.
1C.
3rd.
MEAN
WEIGHT
25.2
29.4
54.6
93.2
89.8
183.0
103.7
90.2
193.9
203.5
179.1
38? -6
96.2
74.8
94.2
191.3
110.0
470.3
PATIENTS
10
24
34
43
47
90
41
44
85
46
46
92
15
21
38
19
8
86
PAID
STAFF
19
28
47
53
67
120
75
63
138
52
57
109
37
28
40
79
43
190
VOLUNTEERS
STUDENTS
3
9
12
2
2
4
12
3
15
1
2
3
9
3
4 ;
0
1
8
GROS:;
POPULATION
32
61
93
98
116
214
128
110
238
99
105
204
61
52
82
93
52
284
EQUIVALENT
POPULATION*
17.3
36.3
53.7
61.3 -
60.0
121.3
70.0
66.0
136.0
63.7
65.7
129.3
30.3
31.3
53.7
45.3
22.7
153.0
LBS.PER
PATIENT
2.5
1.2
1.6
2.2
1.9
2.0
2.5
2.1
2.3
4.4
3.9
4.2
6.4
3.6
2.5
10.0
13.8
5.5
LBS.PER
GROSS POP.
0.8
0.5
0.6
1.0
0.8
0.9
0.8
0.8
0.8
2.1
1.7
1.9
1.6
1.4
1.1 -
2.0
2.1
1.7
LBS.PER
EQUIV. POP.
1.5
0.8
1.0
1.5
1.5
1.5
1.5
1.4
1.4
3.2
2.7
3.0
3.2
2.4
1.8
4.2
4.8
3.1
-------
Table A-5 Continued)
UNIT
X-RAY
BLAB.
REGM.
ENT.
CP.
EMG.
2nd
ER.
CLN.
ADMN.
CAFE.
GIFT.
1st
GRND.
DIET.
KITN.
GRND.
PHCY.
LAUN.
CENT.
COBT.
ALF.
BASE.
MEAN
VEIGHT
77.0
231.1
11.1
8.8
33.6
1.7
363.3
32.5
66.4
82.8
25.0.
14.4
223.1
128.0
40.3
1412.0
1580.3
30.4
41.7
98.3
5.1
15.8
191.2
PATIENTS PAID
0
0
0
0
0
0
0
65
311
0
0
0
376
0
0
402
402
0
0
0
0
0
0
Equivalent
STAFF
35
46
12
20
29
4
146
29
113
66
6
2
216
25
27
73
125
8
25
9
7
24
73
Population
VOLUNTEERS
STUDENTS
22
16
0
2
5
D
45
1
19
20
0
6
46
0
0
0
0
0
0
0
0
0
.. 0
= patients -
GRCS
> EQUIVALENT
POPULATION ' POPULATION*
57
62
12
22
34
4
191
95
443
86
6
8
638
25
27
73
125
8
25
9
7
24
73
1/2 ou
f
19.0
20.7
4.0
JZ-3
11.3
1.3
63.7
20.8
95.8
278.7
2.0
2.7
150.0
8.3
9.0
426.3
443.7
2.7
8.3
3.0
2.3
8.0
24.3
LBS.PER
PATIENT
0
0
0
0
0
0
0
0.5
0.2
0
0
0
0.6
0
0
3.5
3.9
0
0
0
0
0
0
LBS.PER
GROSS POP.
1.4
3.7
0.9
0.4
1.0
0.4
1.9
0.3
0.2
1.0
4.2
1.8
0.3
5.1
1.5
193.4
12.6
3.8
1.7
10.9
0.7
0.7
2.6
LBS.PER
EQUIV. .POP.
4.1
11.2
2.8
1.2
3.0
1.3
5.7
1.6
0.7
2.9
12.5
5.3
1.5
15.4
4.5
3.3
3.6
11.3
5.0
32.8
2.2
2.0
7.9
-.patients + paid staff + volunteer
3
»-•
CO
en
-------
186
Table A-6 Soiled linen quantities
Weight in pounds
DATE
1968
June 24
June 25
June 26
June 27
June 28
June 29
June 30
Total
Mean
July 22
July 23
July 24
July 25
July 26
July 27
July 28
Total
Mean
Mar. 10
Mar. 11
Mar. 12
Mar. 13
Mar. 14
Mar. 15
Mar. 16
Total
Mean
WEIGHT
10,750
6,345
7,520
7,128
6,555
5,250
43,548
7,258
9,950
8,360
7,200
8,700
8,780
6,970
49,960
8,327
10,890
6,737
6,631
8,795
7,945
6,792
47,790
7,965
DATE
1968
June 1
June 2
June 3
June 4
June 5
June 6
June 7
Total
Mean
July 29
July 30
July 31
Aug. 1
Aug. ?
Aug. 3
Aug. 4
Total
Mean
Apr. 28
Apr. 29
Apr. 30
May 1
May 2
May 3
May 4
Total
Mean
WEIGHT
8,400
6,600
6,100
9,300
7,250
37,650
7,530
10,215
7,687
8,075
7,955
8.045
6,045
48,022
8,004
11,650
7,100
8,036
8,410
7,705
6,327
49,228
8,205
DATE
1968
July 8
July 9
July 10
July 11
July 12
July 13
July 14
Total
Mean
Feb. 10
Feb. 11
Feb. 12
Feb. 13
Fob. 1.4
Feb. 15
Feb. 16
Total
Mean
May 5
May 6
May 7
May 8
May 9
May 10
May il
Total
Mean
WEIGHT
10,035
7,850
7,835
8,000
6,635
5,570
46,235
7,706
10,725
7,790
7,150
8,332
7.QIA
7,550
49,461
8,244
.'10,285
6,780
7,189
7,470
7,222
6,710
45,656
7,609
-------
Table A-6 (continued).
187
DATE
WEIGHT
DATE
WEIGHT
Jan. 68
Feb. 68
Mar. 68
Apr. 68
May 68
June 68
July 68
Aug. 68
Sep. 68
Oct. 68
Nov. 68
Dec. 68
192,692
188,612
208,543
211,488
212,569
183,801
208,712
208,156
190,562
210,604
196,227
177,597
Jan. 69
Feb. 69
Mar. 69
Apr, 69
May 69
June 69
July 69
Aug. 69
Sep. 69
Oct. 69
Nov. 69
Dec. 69
204,292
195,166
202,454
206,594
194,163
189,222
211,103
199,373
197,723
206,957
181,777
196,295
Total
2,389,563
Total
2,385,069
-------
188
APPENDIX B
Appendix B consists of the Chemical Test Procedures
-------
189
TEST FOR MOISTURE
(Oven Drying Method)
Equipment;
Drying oven
Large glass desiccator (250mm sufficient)
Sample containers (covered aluminum cans)
A balance (graduated to 0.1 grams sufficient)
Procedure;
1. Preheat drying oven to 103°C.
2. Duplicate samples of 50 - 100 grams of freshly ground refuse are
placed in tared sample containers and immediately cover. (1) Remove
and discard inorganic materials such as glass, metal, and ceramics
before grinding; (2) Do not pack the material.
3. Weigh the samples to the nearest decigram (0.1 gm) within one hour.
4. Dry the material to a constant weight being sure to have the
container lid cocked off. Note: the oven temperature should be
75°C, unless removal of volatile constituents such as ammonia-N
and liquids are desired, in such case the oven temperature should be
raised to 103°C.
5. Allow samples to dry for 48 hours.
6. Cool samples in dry area or desiccator and then weigh.
Calculation;
100 (loss in weight)
Percent moisture (wet basis) = (net wet welght)
-------
190
VOLATILE SOLID AND ASH TEST
Equipment:
Drying oven
Analytical balance
Desiccator
Procelain crucibles (high form)
Muffle furnace with indicating pyrometer and rheostat
temperature control
Procedure:
1. Transfer 3 to 6 grams of dried and ground sample to a previously
ignited and tared crucible.
2. Re-dry samples for 2 hours at 75°C and weigh to nearest centrigram
(0.01 gm)
3. Place the crucibles in a cold muffle furnace and gradually bring
the temperature to 600°C with door raised about 1/2 inch.
4. Muffle at 600°C for 2 hours.
5. Cool in a desiccator and weigh.
Calculations:
(a) Percent ash =
100 (tared sample left after firing)
(net dry weight)
(b) Percent volatile solids = 100 - percent ash
-------
191
TEST FOR GROSS CALORIFIC VALUE
Equipment;
Parr oxygen bomb calorimeter (adiabatic calorimeter)
Parr oxygen double valve bomb
Parr automatic electric water heater
Parr ignition unit (transformer type)
Parr metal combustion capsules
Support stand for oxygen bomb heads
Parr oxygen filling connection
Oxygen cylinder (standard commercial or medical grade whichever
is more convenient)
Analytical balance
Pressure regulator (standard commercial)
Reagents:
Distilled water
Sodium carbonate solution, 0.0725N: dissolve 3.84 grams of Na«CO, in
distilled water and dilute to one liter
Sodium hydroxide or potassium hydroxide solutions of the same normality
are acceptable
Methyl orange or methyl red indicator
Procedure;
1. Attach a single length of 10 centimeters of standard fuse wire
between the electrodes of the oxygen bomb head.
*2. Weigh 0.8 to 1.2 grams (never more than 1.5) of the redried sample
directly into a metal combustion capsule. Place the capsule in the
loop holder on the bomb head and bend the center of the fuse wire
down so that it is set slightly above the surface of the material in
the capsule.
3. Put I milliliter of distilled water in the bomb from a pipette; put
the bomb head into the cylinder; Place contact ring above the sealing
gasket; screw the cap down firmly by hand.
4. Attach the filling connection to the bomb inlet valve and slowly
admit oxygen to between 25-30 atmosphere gage pressure at room
temperature. Note: If too much oxygen should accidently be
introduced, do not proceed with combustion, exhaust the bomb.
*5. Fill the calorimeter bucket with 2,000 grams (-1- or - 0.5 grams) of
distilled water, which may be measured volumetrically instead of
weighing if it is always done at the same temperature. Note: The
temperature of water should be 3° or 4° below that of the room.
6. Set the filled bucket in the calorimeter jacket: lower the bomb into the
water, taking care to avoid jarring or disturbing the contents. Attach
the thurst terminal to the bomb electrode and shake back into the
bucket all drops of water adhering to the fingers.
-------
192
7. Swing the cover on the jacket with the thermometer toward the operator.
Lower the cover into position, using care to avoid striking the thermo-
meter against anything. Put on the rubber drive belt and start the
motor. (Should turn at 150 clockwise revolutions per minute; most
motors are pre-adjusted to this speed)
8. Run the motor for 5 minutes to attain thermal equilibrium but do not
record temperatures during this period. Adjust the thermometer read-
ing lens and be prepared to take temperature readings as soon as
equilibrium is indicated by a slow, uniform rise.
9. Then press the botton on the ignition unit to fire the charge at the
start of the sixtieth minute, recording the exact time and temperature
at the firing point.
10. After the period of rapid rise (about 4 or 5 minutes after firing) adjust
the reading lens and record the temperatures to the nearest 0.01°F when
the reading has been constant for 5 minutes. Usually the temperature will
reach a maximum then drop slowly.
11. The net rise is equal to the difference between the initial temperature
at the time of firing and the final maximum temperature developed in
the calorimeter.
12. After completing the readings, stop the motor, remove the belt, and
swing the cover from the jacket; wipe the thermometer bulb with a clean
cloth to remove any water, and set the cover on the support stand;
disconnect the firing connection from the bomb terminal.
13. Lift the bomb out of the bucket and relieve all residual pressure.
14. After all pressure has been relieved, remove the cap, lift out the bomb
head and place it on the support stand. Examine the interior of the
bomb for soot or other evidence of incomplete combustion, and discard
the test if any is found.
15. Wash all interior surfaces of the bomb with a jet of distilled water
and quantitatively collect the washings in a beaker. Titrate with
0.0725N alkali solution, using methyl orange or methyl red. Save the
solution remaining after titration for determining the sulfur content
of the sample.
16. Carefully remove all unburned pieces of fuse wire from the bomb
electrodes, straighten them and measure their combined length in
centimeters. Subtract this length from the initial 10 centimeters,
and enter this value on the data sheet as the net amount of wire
burned.
17. Repeat the same procedure for each succeeding test.
* Indicates changes made in the original testing procedures.
-------
193
tS i S°Uld ^ aVaUable " the --pletion of a
test using the calorimeter.
Time of firing
temPerature "-ch.. 60 percent of
H,» r-a^a f . - °f period (after the temperature rise) in which
the rate of temperature change has become constant.
ta = Temperature at time of firing.
tc = Temperature at time of temperature attaining constant.
rj. - Rate at which temperature was rising during the 5 minute period before
firing (degree F per minute)
r2 = Rate at which the temperature was falling during the 5 minute period
after time C (degrees F per minute). If the temperature was rising
instead of falling after time C, subtract the quantity r0 (c-b)
instead of adding it when computing the correct temperature rise.
Cx = Millilitera of 0.0725N alkali solution used in the acid titration.
C,, = Percentages of sulfur in the sample.
Cj = Centimeters of fuse wire consumed in firing.
W = Energy equivalent of the calorimeter (supplied by the manufacturer)
in calories per degree Fahrenheit. (1356 cal/F°)
m = Mass of sample in grams.
t = tc - ta - r: (b-a) + r2 (c-b)
e^ = GI if 0.0725N alkali was used for titration.
e2 = (14) C2 (n)
e.j = (2.3) (Cg) when using Parr 45C10 nickle - chromium fuse wire or
= (2.7) (C_) when using No. 34 B 6 X gage iron fuse wire.
Hg * Gross calorific value
Hg - tw - e1 - e2 - e3
, calories per
m
calories per gram (1.8) = B.T.U. per pound
-------
194
TEST FOR SULFUR
Equipment:
Parr oxygen bomb calorimeter
Oxygen cylinder (standard commercial)
Pressure regulator (standard commercial)
Steam bath or hot plate
Crucibles
Muffle furnace (600 to 900°C)
Drying oven
Desiccator
Analytical balance
beakers (400 ml and 250 ml)
Filter paper-ashless (Whatman 41 and 42)
Fluted watch glasses
Volumetric pipettes
Reagents:
Wash Water
Methyl orange indicator: one milliliter saturated solution of methyl
orange indicator per liter of distilled water
Concentrated ammonium hydroxide
Concentrated hydrochloric acid
Saturated bromine solution
Barium chloride solution (10 percent)
Procedure:
1. Collect the bomb washings following (see test for gross calorific value)
the combustion of a sample not weighing more than one gram. Note: If
the sample has not been used for a calorimetric test, allow the bomb
to stand in a water bath at least ten minutes after firing.
2. Release the residual gases slowly and at an even rate so that the
pressure is reduced to atmosphere in not less than one minute.
3. Wash all the interior parts of the calorimeter with wash water and
collect the washings in a beaker or Erlenmeyer flask (250 ml is
sufficient). Note: Wash until no further acid reaction is observed
and be sure to add all precipitate to the beaker-
4. Titrate the washings with standard sodium carbonate solution (0.0725N,
see test for gross calorific value) to determine the acid correction.
5. After neutralization, add one milliliter of NH.OH (concentrated
ammonium hydroxide), heat the solution to boiling, and filter through
rapid filter paper (Whatman #41) into a 600 or 400 milliliter beaker.
6. Wash the filter paper and residue with hot distilled water.
-------
195
7. Add sufficient water to the beaker to bring the total volume of solution
to approximately 250 milliliters.
8. Neutralize the solution with concentrated HC1 and add two milliliters
in excess. Note: Approximately three milliliters will be sufficient.
9. Add ten milliliters of saturated bromine water.
10. Evaporate the solution to approximately 200 milliliters on a hot plate
or other source of heat.
11. Add ten milliliters of 10% barium chloride to the solution slowly
while stirring.
12. After two minutes of stirring, cover the beaker with a fluted watch
glass and reduce the volume to 75 milliliters on a hot plate or other
source of heat.
13. Allow the precipitate to settle and cool. Note: Cooling period may be
from one to twelve hours depending on the sample being tested.
14. Filter the barium sulfate precipitate through ashless filter paper
(Whatman #42).
15. Wash the filter paper with warm water until you are sure it is free of
chlorides.
16. Transfer the filter paper containing the precipitate to a previously
dried and weighed crucible.
17. Dry and char the filter paper at low heat without flaming.
18. Place the crucible containing the filter paper in a muffle furnace
and raise the temperature to 600°C.
Note: Allow the crucible to stay in the muffle furnace for 2 hours
after the 600°C temperature has been reached.
19. Cool in desiccator until room temperature is reached.
20. Re-weigh the crucible.
21. Determine weight of the barium sulfate precipitate .
Calculations:
weight of BaS04 X 13.734
Percent Sulfur = —— —•• ,
weight of sample
-------
196
TEST FOR PHOSPHORUS
Equipment:
Micro Kjeldahl flasks
Fume hoods
Volumetric flasks
Spectrophotometer or calorimeter
(equipped with a light filter with maximum transmittance near 625
to 675 millimicrons)
Drying oven
Desiccator
Analytical balance
Columetric pipettes
Reagents:
Sulfuric acid (93 to 96 percent H2S04)
Concentrated nitric acid
*Perchloric acid (70 percent)
Ammonium molybdate solution: dissolve 5 grams of ammoniumi molybdate
in 10 milliliters of concentrated sulfurnic acid and make up to
one liter
Elon solution: dissolve 10 grams of elon in one liter of 3 percent
NaHS03
Standard potassium dihydrogen phosphate solution:
dissolve 1.917 grams of pure dry KH2PO^ in water and dilute to one
liter. (One milliliter of this solution is equivalent to 1 milligram
of P205)
Procedure:
1. Weigh out approximately 0.5 grams of redried sample in, previously
dried and tared sample container.
*2. Transfer the sample to a micro Kjeldahl flask and add about 2 milliliters
of concentrated HN03, 2 milliliters of perchloric acid, and 1 milliliter
of concentrated H2SO,.
3. Heat slowly at first and then strongly until the solution becomes clear.
4. Cool rinse into a flask and make up to 100 milliliters.
5. Pipette 1 milliliter (or any suitable aliquot) of this solution into a
test tube, add 3 milliliters of molybdate solution and 1 milliliter of
elon solution, (5 milliliters total volume)
6. Pipette a measured portion of standard phosphate solution into a test
tube, add the same amount of molybdate and elon solution and dilute
to the mark with water.
indicates changes made in the original test procedures.
-------
197
7- Mix the sample and standard thoroughly and allow to stand for 30 minutes.
8. Read and compare samples in a calorimeter.
Calculations:
Say X ug is the concentration read from the calorimeter.
1 ml. contains X ug
100 ml. 100 ug
This 100 ml. has been extracted from 0.5 grams of sample
0.5 grams contains 100 C ug
100X 100 gms.
0.5 X 106
_ X%
50
-------
198
PROCEDURE FOR CARBON-HYDROGEN ANALYSIS
Equipment:
Carbon Combustion Train - The apparatus consists of the following units
arranged as listed in the order of passage of oxygen from the cylinder.
(a) Coarse Needle Valve -- The coarse needle valve is used to regulate
a rough flow of oxygen through the system.
(b) Oxygen Purifying Train -- The purifying train consists of three
units in the following order:
(1) Preheater -- The oxygen, before entering the combustion tube,
is purified by passing it through a silica tube" filled with
copper oxide (wire form). The correct temperature for the
preheater is 750°C which is controlled by a Steples input
control variac.
(2) Water absorber -- A U-tube filled with drierite is used as an
absorber of water that may exist in the oxygen.
(3) Carbon dioxide absorber — A U-tube filled with ascarite is
used to absorb carbon dioxide in oxygen directly from the
cylinder.
(c) Fine Needle Valve -- A fine needle valve is used for adjustment of
the oxygen flow through the system.
(d) Flow Meter — Used to permit a volumetric measurement of flow of
oxygen during analysis. The flow rates are 50 - 75 nil per minute
or 2 - 3 bubbles per second in the bubbler at the end of the train.
(e) Combustion Unit -- The combustion unit consists of three electrically
heated furnace sections. Each section is individually controlled by
two dials labeled "coarse" and "fine".
Furnace Section 1 — This furnace section, nearest the oxygen
inlet end of the combustion tube, is approximately 12 inches long
and is used to heat the inlet end of the combustion tube and the
sample. It is capable of rapidly attaining an operating temperature
of 850° to 900°C.
Furnace Section 2 — This section is approximately 8 inches in
length and is used to heat that portion of the combustion tube that
is filled with copper oxide. The operating temperature .is 850° + 20°C.
Furnace Section 3 -- This section is approximately 4 inches long and
is used to heat that portion of the combustion tube filled with fused
lead chrornate.
-------
199
(f) Combustion tube -- The combustion tube is a high temperature silica
tube packed with copper oxide and fused lead chromate which aid in
the oxidation of gases flowing through the tube. The filling also
contains copper metal.
(g) Combustion Boat -- The boats are approximately 70 x 8 x 8 mm and are
of porcelain material with micro carbon content.
(h) Absorption train -- The absorption train consists of two Nesbitt
absorption bulbs. The first bulb is filled with drierite for removal
of water and the second, ascarite for C02 absorption.
(i) Water Bubbler — A 100 ml. bubbler is connected to the ascarite
Nesbitt bulb. The bubbler is constructed in such a manner that glass
tubing is submerged in water in the bubbler. This gives the operator
some idea of the flow through the combustion train. The average flow
should be 50 to 70 ml. per minute or 2 to 3 bubbles per second.
Reagents and Accessory Equipment:
Tank of highly purified carbon dioxide
Ascarite
Drierite
Analytical Balance
Dessicator
Combustion Rake
Procedure:
To begin a series of analysis, attach all Nesbitt bulbs in correct positions
and regulate the oxygen by adjusting needle valves to the corresponding combustion
train. Adjust the flow of oxygen to 50 - 70 ml./min. or 2 - 3 bubbles per second,
which is the correct flow for analysis.
After regulating the oxygen, energize heater section 2 to 850 + 20°C and
section 3 to 500 + 50&C. It will take about 90 minutes to reach these temperatures.
When the temperatures are reached, they will be maintained throughout the entire
procedure.
Remove the Nesbitt bulbs from the train, wipe them with a clean cloth and
cool them to room temperature. While these are cooling, the sample can be weighed
in the combustion boat and placed in a dessicator. (Refuse samples are weighed
to 0.2 gram). After the Nesbitt bulbs have cooled, open the bulbs for a moment
to allow them to reach atmospheric pressure, weigh them, and replace them to the
correct positions on the combustion train. Transfer the combustion boat containing
the sample to the transparent section of the combustion tube.
A rod called a comb, rake is used to remove the combustion boats and to place
them in their correct positions in the combustion tube. Furnace section 1 is
energized and moved from the left end of the track to cover about half of the boat
containing the sample. If furnace section 1 has been cooling from a previous test,
its temperature should be below 200°C. before another test is started. The temper-
ature is gradually increased to 850 to 900°C. so that the sample burns slowly and
evenly. If the sample is highly volatile cooling to room temperature may be re-
quired.
-------
200
During this time, furnace section 1 is moved slowly toward furnace section
2 until the sample is completely covered by furnace section 1. (This process
takes about 40 to 50 minutes for a refuse sample). After full heat is reached,
hold in this position for 15 minutes. Furnace section 1 is then returned to the
starting position and its temperature is reduced to the starting position and its
temperature is reduced to below 200°C. The oxygen flow is continued for at least
15 to 20 minutes or longer if water vapor exists in the tubing at the end of the
combustion tube. The Nesbitt absorption bulbs are closed under pressure and removed
from the train and placed near a balance for 15 to 20 minutes and then wiped clean
with a lint free cloth. The Nesbitt bulbs are vented momentarily and their weights
are recorded. Calculate the percent carbon and hydrogen. The percent ash can also
be determined by weighing the combustion boat again and calculating the weight of
ash.
**The temperatures and combustion fillings for each combustion section were obtained
from The American Society of Testing Materials, Book of A.S.TlM. Standards, Part
5 (Philadelphia: The Society 1952).
Calculations:
% carbon =
MW of C x 100
wt. increase of C02 absorber x MW of C02
sample weight
wt. increase of CC>2 absorber x 27.29
sample weight
wt. increase of water absorber x
7, hydrogen =
2 xMW of H x 100
MW of H20
7. ash
sample weight
wt. increase of water absorber x 11.17
sample weight
wt. of ash x 100
sample weight
-------
201
PROCEDURE FOR OPERATION OF COLEMAN NITROGEN ANALYZER II
I. Sample Preparation
a. Add the proper amount of sample to a previously weighed combustion boat
and weigh to determine amount of sample. Amount of sample used should
depend on the theoretical yield of nitrogen of sample. Consider 1 mg
nitrogen displaces 1000 microliters in the analyzer. Samples sized to
release between 12-15,000 microliters give best results. Combustion
boat should then be filled with Cuprox fires to give good reagent-
sample mixture.
b. Fill a Quartz Combustion Tube to the top of the trademark with Cuprox,
the trademark being at the end upper. Tap the tube to settle the
Cuprox to the bottom of the trademark.
c. Turn the tube until it is horizontal and carefully insert the loaded
sample boat into the open end. Slide or push the boat without spilling
it's contents, until it reaches the Coleman trademark.
d. After the boat is introduced add enough Cuprox to just cover the combustion
boat. Tap the tube gently to integrate the contents of the combustion
boat and Cuprox.
e. Raise the open end to an angle 60-70° with horizontal and add Cuprox
to within 3/4" from the top of the tube. Tap or vibrate to eliminate
spaces.
II. Machine Preparation
a. Connect the side arm and central capillary tubes to the inlet and syringe
tubing with the spring clamps.
b. Turn the C02 tank valve on, adjust the Regulator to 12 psi and then
open the line. If the pressure gauge on the front panel of the machine
does not read 12 psi, adjust by the regulator gauge.
c. Turn the line switch on and the upper and lower furnace controls to 3;
the post heater control to 10. Allow at least 20 minutes for the furnaces
to warm up. Upper and lower furnaces should read 700°C and the post
heater should read 600°C.
d. Insert the combustion tube by placing the upper end firmly against the
upper tube support and riase the upper support against its spring until
the lower end of the tube can be slipped into the opening of the lower
support. Release of the upper support will firmly clamp the tube in
place.
e Adjust the meniscus level of liquid in the nitrometer to the calibration
mark of the central capillary tube. Great care must be used in doing this
to avoid running the caustic liquid above the o-ring connection to the
syringe. Final adjustment must be made with the manual fine adjust wheel.
It is also imperative that the readout counter never be driven above
50 000 This will permanently damage the syringe. Proper level and counte
reading can be obtained by aid of the vent control. Take the reading on
the counter.
-------
202
f. Record the syringe temperature and the barometric pressure.
g. Turn the combustion cycle control to the start segment line and allow
the automatic combustion cycle to proceed.
h. After the cycle is complete, readjust the causticon level and record
the readout counter setting.
Record the temperature (if the temperature rise is more than .8°C the
test in results are void. This is usually avoided by running 3 to 4
blank cycles at the beginning. The barometric pressure is assured to
remain unchanged during the test run. These are the data used in
calculating the 7. yield.
A blank must be run prior to testing to determine the volume of
unabsorbed gas which appears as a result of a combustion cycle, but
which originates from other sources other than a weighed sample.
NOTE: These are only the basic essentials of operation and do not cover much of
the preparation of the machine and reagents. One should read the instruc-
tion manual to gain full understanding of the machine.
Equipment:
Coletnan Nitrogen Analyzer II
Tank of highly purified C02
Mercury Barometer, accurate and readable to 0.5 mm Hg.
Analytical Balance
Coleman aluminum combustion boats
Coleman quartz combustion tube and quartz postheater tube
Dessicator
Tweezers
Glass rod 7/16" x 15"
Reagents:
Coleman CUPROX or CUPROX Platinum Catalyst
Coleman CUPRIN
Coleman CAUSTICON (KOH)
Mercury
-------
203
F. Calculation
1. Record the observed volume of nitrogen, V0
V.=Obscrved N Volume
Ri=Initial Counter Reading
R2=Final Counter Reading
2. Determine the corrected nitrogen volume, Vc (in
microliters)
Start Finish
V.=V.-(Vb + V.)
Vb=Volume of Blank (,J) Counter readings, Blank 500 fd 524^1
V,= Volume correction for Counter readings, Sample 524 U.207
temperature (pA) tt — 27.5°C
=Ci(tj-tl) t2 -27.7°C
C, from table 1 V0 =17,207-524=16S83/il
(based on final counter rf-ading) y 166S3 — (00°4 + C (t» t )
taandt,In'C(IV,D.4and6) C I16683_ (0024 + 68 X 0.2 /
3. Determine the corrected barometric pressure, Pc = 16646 ^1
fr—fn—(f^ + -p,) P. =750--11
?0=ouicrvecl barometric pressure — • <-•••'
(mmHg) 739 16646
v °' %N= X
Pb=barometric temperature correction 300.7
(TABLE 2) =3.68%
PT=pressure correction for vapor pres-
sure of KOH from TABLE 3
Note: An empirical approximation of (Pb + P,) =
11.0 will be satisfactorily accurate for P0 between
740 and 780 mm Hg and ryringe temperature 25
and 32° C.
4. Calculate % N from the formula:
%N=4j- X -^-X 0.0449
T=Final Syringe Temperature in "Kelvin
(°C + 273)
W=:Samplc weight in milligrams.
Example:
P,=7.50mm Ilg
ung
-------
20U
TABLE 1
Volume Correction for Temperature
Correction Factor
(C.)
(Microlitersper *C)
Final Counter (Ct)
Reading ( Nitrometers with
( Microliters ) check valve )
0 12
5000 29
10000 45
15000 62
20000 79
25000 95
30000 112
35000 129
40000 145
50000 179
Volume correction, V, =Ct ( t2 — ^
TABLE 2 TABLE 3
Barometric Temperature Correction (Pb) Pressv. -e Correction (P,) for Vapor Pressure
P.(minHg) ofKOH
Temperature 700-749 750-780 Temperature °C Pr(mmHg)
15 4.1
10 1-2 1.3 20 57
IS 1.8 1.9 25 7.4
20 2.3 2.5 30 9.6
25 2.9 3.1 35 12.5
30 3.5 3.7 49 16.5
35 4.1 4.3
-------
205
APPENDIX C
Appendix C consists of the Bacteriological and Virological Test Procedures
-------
206
Phase I Analyses
Bacto-Plate Count Agar (0479)
Tryptone Glucose Yeast Agar - This medium is recommended as a general plating
medium for ascertaining bacterial populations. The clarity of the medium and the
increased size of the colonies permit the determination of bacterial counts with
ease.
To rehydrate the medium, suspend 23.5 grams of 1000 ml of cold distilled
water. Heat to boiling to dissolve completely. Sterilize in autoclave for 15
minutes @ 15 psi (121°C).
Bacto- Nutrient Broth (B3)
Bac to-Nutrient Broth is recommended for general laboratory use for the
cultivation of microorganisms that are not exacting in for requirements.
To rehydrate the medium, dissolve 8 grams of Bacto- Nutrient Broth in 1000 ml
of distilled water. Distribute in tubes (10 ml/tube) and sterilize in the
autoclave for 15 minutes at 15 pounds pressure (121°C).
Fluid Thioglycollate Medium (B256)
Bacto-Fluid Thioglycollate Medium is recommended for the sterility test of
biologicals. Also, it has been recommended as a liquid medium fpr the cultivation
of anaerobes. •
To rehydrate the medium, suspend 29.5 grams of Bacto-Fluid Thioglycollate
medium in 1000 ml distilled water, and heat to boiling to dissolve the medium
completely. Then, distribute into tubes, autoclave for 15 minutes @ 15 psi
Violet Red Bile Agar (B12)
Bacto-Violet Red Bile Agar is recommended for the direct plate count of
coliform bacteria in water, milk dairy products and wastes.
-------
207
To rehydrate medium, suspend 41.5 grams of Agar in 1000 ml of cold distilled
water and heat to boiling to dissolve medium completely. Cool to 40-44°C and
pour plates.
Bacto MacConkey Agar (B75)
Bacto-MacConkey Agar is a differential plating medium recommended for use in
the detection and isolation of type of dysentery, typhoid and para-typhoid bacteria
for any material harboring these organisms.
To rehydrate the medium, suspend 50 grams of Bacto-MacConkey Agar in 1000 ml
of cold distilled water and heat to boiling to dissolve the medium completely.
Sterilize by autoclaving for 15 minutes @ 15 pounds pressure (12i°C). MacConkey
Agar inoculated the same day as rehydrated may be used without autoclave steriliza-
tion. Under these conditions the medium need be heated only to boiling to dissolve
it completely before pouring into petri dishes.
Mannitol Salt Agar
Bacto-Mannitol Salt Agar is a selective medium for the isolation of patho-
genic staphylococci. Growth of most bacteria other than staphylococci is inhibited
on this medium. It is recommended for growth at 37°C for 36 hours.
To rehydrate the medium suspend 111 grams Bacto-Mannitol Salt Agar in 1000 ml
cold distilled water, and heat to boiling to dissolve the medium completely,
autoclave for 15 minutes @ 15 psi.
Blood Agar Base (B45)
Bacto-Blood Agar Base is recommended as a base to which blood is added for
use in the isolation and cultivation of mainly fastidious pathogenic organisms.
Colonies of bacteria upon this agar grow luxuriously and the hemolytic types exhibit
clear distinct degrees of hemolysis.
-------
208
To rehydrate the medium, suspend 40 grams of Bacto-Blood Agar Autoclave for
15 minutes @ 15 psi.
If blood Agar is to be prepared immediately, the sterile medium is cooled at
once to 45-50°C., and while still liquid, 5 percent sterile defribrinated sheep
blood is added aseptically with thorough mixing, avoiding incorporation of air
bubbles, and distributing into sterile plates.
Bacto-Cooke Rose Bengal Agar
Cooke Rose Bengal Agar is a selective medium for the isolation of fungi. To
rehydrate the medium, suspend 36 gr. Bacto-Cooke Rose Bengal Agar in 1000 ml
distilled water. Heat to boiling to dissolve the medium completely and sterilize
in the autoclave for 15 minutes @ 15 pounds pressure (121°C).
The selectivity of the medium was increased by the addition of: (1) Penicillin
(1 ml for 500 ml media) and (2) Streptomycin (0.5 ml for 500 ml media). Both of
these antibiotics are added to media after autoclaving with 2 ml syringes.
Hitis Salivarius Agar (B298)
Bacto-Mitis Salivarius Agar is for the isolation of Streptococcus Mitis S.
Salivarius. and Enterococci. The final medium containing Bacto-Chapman Tellurite
Solution, is highly selective for these organisms making possible their isolation
from grossly contaminated specimens such as feces or exudates from different body
cavities.
To rehydrate the medium, suspend 90 grams of Bacto-Mitis Salivarius Agar in
1000 ml cold distilled water and heat to boiling to dissolve the medium completely.
Sterilize in the autoclave for 15 minutes at 15 psi (121°C). Cool to 50-55'C and
just prior to pouring plates add exactly 1.0 ml of Bacto-Chapman Tellurite Solution.
Prepare plates with 25 ml medium per plate. Do not heat the medium after the
addition of the Tellurite Solution.
The preceding discussion of all types of agar is from the Difco Manual. 9th
Edition.
-------
TEST JOURNAL
209
July 14, 1970
Sample: Incinerator Room
Ground to 2 mm
- 1 gm + 9 ml (peptone phosphate diluent)
r Diluted and plated 0.1 ml surface spread
Inoculation: 10~3 - 10~8 4 plates plate count Agar
2 incubated Aerobically
2 Incubated Anaerobically
10"1 - 10~b 1 plate each
Violet Red Bile Agar
MacConkey Agar
MS Agar
Mannitol Salt Agar
Blood Agar
Cooke's Rose Bengal Agar
0.5 gm of ground sample 4- flask of EE Broth
0,5 gm of ground sample + f.Iask of Aride Cactose Broth
All dilutions heated then heated @ 80-82V for 30 minutes and 1 ml
inoculated into each of;
3 ThioglycoJlate Broth
3 Nutrient Broth
All Incubated
Microaerophillicly
-------
210
July 15, 1970
Only those plates were read that had colonies that ranged from
30-300.
Dilution
Aerobic Plates (2)
Blood Agar
MS
VRB
MacConkey
MSA
10
10
-3
-4'
10-1
10-2
ID'2
10-2
10
-4
Total No.
.of Colonies
37. 53
Remarks
10"4, 10-5 (Reincubated)
overgrown with Bacillus
51 4 Coeyne bacterium
No Hemolytic Colonies
Separate Colonies 5. Mjtis
— (12 Colonies)
41 38 Black Colonies
ID'2 (Reincubated)
60 25 large, pink
Bacilli', Some streptococci
67 27 cocci-like
BacilliJ, Some Streptococci
4 Staphylococcl
Too good for Bacilli
Thioglycollate 10'1 - lO'5: 3(+), -10~6; 2(+) l(-), 10"7 1(+) 2(-), 10'8: 3(-)
Nutrient Broth 10'1 - 1Q-5: 3(+), 10~6 2 (+) l(-), 10~7: 3(-), 10~8: 3(-)
EE Broi:h to VRB and MacC
Azlde lactose Broth to MS and BA
-------
211
July 15, 1970
t
Pink colonies picked (2) from MacC and (2) from VRB to start for
confirmation
Poss. Coci
Less Poss. coci
Poss. coci
Less Poss. coci
Poss. entejcocci
Poss. Streptococci
Staphylococci
Mac
VRB
MS
1
2
3
4
5
6
BAP
Rram
MS:
Black Colonies
Deep Blue Colonies,
Small
Large Pale Blue
Colonies
oval and (+) cocci ? Enterococci
Round and Var. Sizes
email and cocci
short chains
? Staph/Strep
BAP Very small grey
Med. White, flat,
smooth, round
Round, shiny, flat,
yellowish
PCA Large, Dull, flat
white
Large, dull, flat,
grey
small, irreg.(-l-)
rods
round (+) cocci
large (+) rods
very reg. width
large (+) rods,
var. length
long (+) rods
? Corynebact erium
Staph +1
- Bacillus
Bacillus
-------
212
Juicy and Medium
Very diffuse
Very, reg. large
Med. wrinkled
Mod. size, reg. (+) Bacillus
rods
Mod, size, very reg (-)
rods ?
Mod.size, (+) rods Bacillus
(+) and (-) rods and "
filamentous reg. width
Therefore, Total Count - Mostly Bacillus
5-10% Staphylocoecus
5-10% Corym-bacterium
Julv 16. 1970
Anaerobic plates 10~4 look like aerobic CBacillus and Staph.)
Aerobic plates overgorwn and discarded
Plates for EE Broth and Azide Lactose Broth are (+) cocci and fecal
Strep. (Entracoccus)
CRB 10'1'3 Total 59
19 ? Fumigatus
7 Yeast
July 20, 1970
Standard anaerobic counts 7-14-70
10"4 28.23
XMoglycoilate HT5: 3(+) 10~6:
<-) 10~7: l(+) - 1.5 x l<)6/gm
Nutrient Broth 10~5: 3(+) 10"6: 2^) 10~7: 0 - 9.3 x 105/gm
Fungus - Alternaria, Phytomycetes
Blue-Green Aspcrgillis. Pencillin Types
Yellow-Green Aspergtllus
-------
213
July 21, 1970
Samples (2)
1. Blood Bank
2. Incinerator Room
Set up same as 7-14-70 except 1 anaerobic plate and no flasks of
EE Broth and Azide Cactrose Broth
Total No.
Dilution of Colonies
Aerobic
Sample No. 1(2) 10~3
No. 2(2) 1(T4
87, 110
94,92
MacC
VRB
MS
BAP
10"! Pink
24
Total 97
Except Bacillus
lO"1 Pink
13
Total 64
10"1 23 Black
7 Blue
104 very mixed
looked like
Enterococcus
10
-4
Remarks
Mixed Bacillus with 5%
Staphylococcus reincubated
(10"J + 10-4)
Mostly, regular flat mat
colonies: Bacillus
2
13
53
13
52
17 Black
0 Blue
77 Predominate colonies
greenish and Hemolytic
BA
MSA
Prciled colonies
to lactose broth
13 Staph like
(1)
33 Staph like
MacC 8
VRB 9, 10
-------
214
(2) MacC 11, 12, 13
VRB 14, 15, 16, 17
(1) N. Broth 10~4 3(+) 10~5 2(+) 1(T6 0(+)
Thloglycollate 10"5 3(+) 10~6 2(+) 10~6 0(+)
(2) N. Broth 10"* 3(+) 10~5 2(+) 10"6 0(+)
Thiogljcollate 10~5 3(+) 10~6 1(+) 10"7 0(+)
-------
215
July 23, 1970
Anaerobic Counts Dilution Colonies
(1) 10-3 16
• (2) ID'4 71
Rose Bengal (1) HT1 noid: 22
yeast: 20
(2) 10"1 mold: 110
yeast: 69
Colonies picked to Lactose Broth on July 22, Read on July 24
10. 11.
12. gas...BGBLB + 13. Little gas... BGBLB +
14. 15. gas...BGBLB +
16. 17.
Colonies picked from July 14, all lactose Bro'th (-)
Triple Sugar Iron(TSI)
1. Acid & gas/butt & slant 2. Alkaline slant,butt no
3. as 1 4. as 2
1. M-S Black colonies N.A. slant f 18 &19
2. M"S Black colonies N.A. slant 0 20 & 21
]. B.A. ? Staph. N.A. slant 9 22
B.A. ? Staph. citrius N.A. slant 9 23
? B. cercus N.A. slant 6 24
-------
216
July 25, 1970
Aerobic Counts (after 15 hours)
(3)
(A)
dilution
10
r2
10
-2
10
-3
Colonies
10, 12
66
8
M-S
MSA
MacC
VRB
B.A.
(3)
10
10
10
10
-1
no
-ino
-1
-1
growth
growth
17
25
10
10
ID
(4)
-1
-1
-1
lo-1
no
no
no
no
growth
growth
growth
growth
10
25
10
81
July 27, 1970
Cooke's Rose Bengal from July 21
(1) Yeasts, phycornycetes, Aspergillus, and green,velvet colonies
(2) Similar to (1)
Cooke's Rose Bengal from July 24
(3) 10" : 2 colonies
(4) 10": 66 colonies
above background
2 as background
(1) Thioglycollate: 10 : 3+, 10"6: 2»-, 10"7: 3-
Nutrient Broth: 10~ : 3+, 10 : 1+, 10~ : 3-
(2) Thioglycollate: 10~5: 3 + , lo"6: 1 +, 10~7: 3 -
Nutrient Broth: 10~ : 3 +, 10 : 3 -
-------
217
Anaerobic PCA
(1) 10~3 22 Bacillus
(2) 10"4 76
(3) ID'2 9
(4) 10~2 63
Aerobic PCA
(3) 10-2
(a)
13+1 mold
5 bright yellow
1 paleyellow
(4) 1(T2 47, 70
(3)
BA 10"1-3
(b)
15+3 molds
6 deep yellow
,5 pale yellow
yeast
MacC
VRB
MSA
MS
10
-1.3
10
10
-1.3
-1.3
10
-1.3
6(?) Strep
19 Deep yellow colonies
7 Corynebacterium, Molds
Few Bacillus and cocci
102 Total
16 Red_
17 Red
5 Staph
6 Black colonies
BA
MAC
VRB
MS
MSA
10
-4
ID'1'3
10-*-3
10"1'3
£9 ? Yeast
No growth
No growth
No growth
as B.A. + "CA.
-------
218
3-1 Mod. Flat shining - bright yellow colonies
PCA, BA Gram Stain very small gm(-) rods
Some on MSA
3-2 Slightly larger than above - pale yellow colonies
PCA, BA Gram Stain very small gm(-) rods
Sone on MSA HAS
3-3 Enterccoccus - Like colonies - slightly green
BA Gram Stain Streptococcus
3-4 Pink colonies Lactos Broth
3-5 VKB
3-6 Pink colonies Lactose Broth/ MacConkey
3-7 Pink colonies Lactose Broth/MacConkey
3-8 Pink Colonies Lactose Broth/MacConkey
3-9 Black Colonies MS NAS
4-1 Yeast like colonies on: PCA, BA, MSA, CRB •
GM Stain Budding Yeast
NAS
July 28, 1970
Lactose Broth
3-4 through 3-8 all negative
-------
219
PCA jj
A3R«. f i
fr
PCA
ANA.
B
•A. ||
KSA
1
M-5 «V
VRB
MacC.
•iff
CRB
4
r
THIC. J?,
N.B.
COI-OWY COUNTS ( lo£, .)
HCT«5feaffl£5EJa»«fi^ffiSSO^
TOJCi*nl>rmLynjTBfv'-ifVfl
Figure C-l
HISTOGRAM FOR BACTERIAL COUNTS TEST 0
-------
2t(C
COLONY COUNTS ( I°g10)
»-• ro VH .P- v/) o> *J
*4»<*l^
-------
221
PCA
PCA
ANA.
ii
B.A. iy
KSA
M-S
VRB
THIC
N.B.
:lt
(U
'•••
COLONY COUNTS (
Vx *- \j\
y*i*>3
• 1
c* r
4
tB i
F
1
AU
y&xrS
w» Vt
ft
'j
\ '
. ft .
Figure C-3
HISTOGRAM FOR BACTERIAL COUNTS TEST 2
-------
222
-PCA
ASS. 3
B.A.
I
M_e V
VRB H
MacC.
CRB
COLONY COUNTS ( I°g10>
VM •*- W C
*^^
PCA jj
ANA. $j
; i
* *
~ :#'
y~
h
i
i
Figure C-4
HISTOGRAM FOR BACTERIAL COUNTS TEST 3
-------
223
Figure C-5
HISTOGRAM FOR BACTERIAL COUNTS TEST 4
-------
224
Brewer Anaerobic Jar
Baltimore Biological Laboratory, Inc.
Division of Becton, Dickinson and Company
Use with Hydrogen
Hydrogen is an explosive gas and all precautions must be taken
to avoid laboratory accidents.
1. After closing and sealing with suitable material, the jar
is attached to the source of hydrogen by means of a rubber tube.
2. The hydrogen is admitted at a pressure of 1 to 2 pounds per
square inch. No preliminary evacuation is necessary.
3. Using Cite cord fuiuis'ufed, couuectiuu is made uitectiy to
110-volt AC or DC current.
4. Maintain the hydrogen supply and the electrical connection
for a period of thirty (30) minutes.
5. Pull out electric plug, tighten clamp on rubber tubing,
disconnect it, and place the jar in the incubator.
-------
225
I rPlafinized catalyst
*-L ^Heating element" sealed
in solid brass tube
\
5P°c*rn
for uu
IB
Wire safefy J \\ !
'Rubber tube
-Plasticine goskz-f
BREWER ANAEROBIC JAR
Figure C-6 Brewer Anaerobic Jar
-------
ISJ
ro
CD
Table C-l
Hospital Stations and Sampling Dates
Station
Nunber
11
12
31
32
33
36
Sample
Number
1
2
3
1
2
3
1
2
3
2
3
1
2
3
1
2
3
Date of
Sample
10/5/70
10/14/70
10/19/70
11/16/70
1/18/71
1/25/71
10/19/70
10/21/70
10/28/70
9/30/70
10/26/70
11/9/70
9/30/70
11/2/70
2/8/71
10/5/70
11/11/70
12/9/70
function of Location
Station of Station
Emerge:ic y Rooms 1st Floor
Outpat:L« nt Clinics 1st Floor
Orthopec ics , Neurosurgery 3rd Floor
Orthopedics 3rd Floor
Intensive Care Unit, Recovery 3rd Floor
Operatirg Rooms 3rd Floor
-------
Table C-l (Continued)
Station
Nunber
41
51
52
61
62
71
Sample
Number
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
Date of
. Sample
11/16/70
11/18/70
12/2/70
10/14/70
10/21/70
11/4/70
10/7/70
11/18/70
12/9/70
10/12/70
11/4/70
12/7/70
12/2/70
12/7/70
1/12/71
11/9/70
11/11/70
1/28/71
Function of
Station
Maternity
Surgery, Cardio Vascular
Cart. Urology, Eye, Chest,
Burr Care
General Surgery
Gyuecology, Neurology,
Ears, Nose, and Throat
Pediatrics
General Medicine
Location
of Station
4th Floor
5th Floor
5th Floor
6th Floor
6th Floor
7th Floor
to
-------
Table C-l (Continued)
to
ro
oo
Station
Number
72
82
83
Sample
Number '
1
2
3
1
2
3
1
2
3
Date of
Sample
10/7/70
1/21/71
1/28/71
10/26/70
10/28/70
11/2/ 70
10/12/70
1/21/71
1/25/71
Function of
Station
Seneral Medicine
Psychiatric Care
tetabolic Care
Location
of Station
7th Floor
8th Floor
8th Floor
-------
Bacterial Counts ^^«.^-j-J--;..-^:^J--_^^lA/-J-^L'.--rA a-/^---~. M*f_: J
83 -
62
82
•
3
10
II
Figure C-7 Comparison Of The Total Microbial
Counts For 15 Nursing Stations
-------
230
Bacterial Counts
in
u
-------
231
«A
fe
JO
c
0
iu
CO
CO
in
=>
z
CL
(A
Bacterial Counts (Log|Q>
3 4 5 6 7 •
« ^i^flq
51 -i
II
12
36
35
31
__ .1. ,11,-,,.:,._.i-.,w,_^iiiV ™
-^ . i-.i i t -t^-n-i n-r a- 'I*'--*-- "•-''"T"
AJh^f J tMl'"fai'l"frt' Vri'^ 'II I'll ^/B
52.
61 ^
71 -
83
62
82
4! '
L i <• iVa
I. t tW^TWT-'
9 .
10
II
_J
5
8
10
Figure C-9 Comparison Of The Group II Rnctcri;il
Counts For 15 Nursing Slat Ions
-------
232
10
tu
.0
3
C
O
n>
*-•
c/1
O>
C
•r™
in
3
•r-
O.
(SI
O
363
33
31'
32
51
52
61.,
71
72
83J
62TI
82,
Bacterial Counts
4567
- .- .^..r-^-^T^»y>,.l, ....y,^,.,^,,
4 I . —h-» -•r'l-i • V- lf~ ' -M-frfa •I'lU'l-irr a-j
8
10 n
T
4
7
8
10 n
Figure C-IO Comparison Of The Group III Bacterial
Counts For 15 Nursing Stations.
-------
233
Bacterial Counts
4 5 6 7
8-9 10 II
•
•
V)
0)
£
z
+-
CO
O)
10
D
Z
—
t'
V)
£
II "
12
36 :
33 .
31 .
32
C 1
7 1
P^
61
7 1
/ 1
72 1
OJ
C*) -
62
82 '
41 •
f
^'SSSS
*"' ..'.'?i~<5^j
!
-^>I5^^V,^i'-?i7'^2ft7r^,/ri,c.tf7i^'1i^^^
<^r' '" i.',"'''-2^S^ ' i^Tr"1i;f'S]?Iii?S''"?Ur'^'i':i'1^3
T^Tj .^'ii3'7\'^.Tiij-K-^r;ir'a^i'^"^}/5l
'.'JSt'/^Mi.T.'.i^lt ,^-'>.'>T*SSSi'.i.J52ri"i 'Sli
._.„ , , ,. -,.-y«,^ .i..™. ,-j.«,,,.,4_,j
^Jt; i^Tjl'M.'wj'L'4 rJ!""i?J:.^:SI
^iiz. j^u^w^ij^j^^iLii^l
•-, u il-,^-e,-..2,,.-,-J.:y:js<^.-"^J-':^«ii>--J«-,l»-H^-»^'-1Trt«l .W.llirtKMiH
> 3 4 ' 5 ' 6 7 8 9 10 ||
. 'Figure C-ll Comparison Of The Group IV Baclorlal
Counts For 15 Nursing Stations
-------
234
Bacterial Counts (Log10)
to
t-
5.
to
0
o:
23 4 5 6 7 89 10 11
___., , i i 1 1
12;
33.
31;
32'
szgal
i i™" i "-rif yj'l ir'l vffSfl
~-^L'>~' • il^.l^J
i :'S i •'• i'^-":? -M?
52
6i :
~* 1 »
71
72^
83;
62 ;
82 I
41 ;
*
;. Y^-.t'..^ J.vi.<.,d
ISSH!SI2Z2SI
•'••""'• "V *]Vr irS
---' J.f J1f-'i-,iiIIi'3i!3
_1""^i^; }nf Ti
• ~'\ '•'• . .* • , ,^~ .'•_' -»al
"* g ~,T-~--.-f ^"ty'" »u'"m»?""'-^7l'»'»iiff^«i
•
I ; 1 : I i 1 1 1-; 1
? 3 4 5 6 7 89 10 11
Figure c-12 Comparison Of The Group V Bacterial
Counts For 15 Nursing Stations
------- |