HOSPITAL
WASTES
-------
COVER PHOTOGRAPH, showing one of
the many special waste handling practices
necessary in hospitals, is courtesy of the
American Hospital Association.
This summary report (SW-129) is based
on studies made by the University of
Minnesota under grant no. EC-00261, by
the University of West Virginia under
grant no. EC-00265, and by the County
of Los Angeles under grant no. EC-00164.
It was written for the Federal solid
waste management program
by IRENE KIEFER
U.S. ENVIRONMENTAL
PROTECTION AGENCY
1974
An environmental protection publication (SW-129) in
the solid waste management series.
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402
-------
HOSPITAL WASTES
Phenomenal progress has been made in
methods and equipment for the care of
hospital patients. Hundreds of single-
service items have been marketed to re-
duce the possibility of hospital-acquired
infections. Yet hospitals generally have
been slow to improve their techniques for
handling and disposing of waste materials,
which are increasing in quantity as a re-
sult of more patients and higher per-
patient waste loads. Present disposal sys-
tems tend to be costly, outdated, and
poorly designed and operated; they re-
quire large staffs and repeated handling of
wastes.
What the effect has been on health and
safety has not been measured, but with-
out proper management, wastes contain-
ing contaminated materials, dangerous
chemicals, or discarded needles are a po-
tential hazard to millions of patients,
employees, and visitors. Furthermore, the
health of the entire community can be
jeopardized if wastes are temporarily but
inadequately stored outside the hospital,
hauled through the streets without proper
precautions, or thrown onto open dumps.
The potential hazards of hospital
wastes, their growing volume and chang-
ing characteristics, and the generally in-
-------
amcricaii hospitals are big business
7,061 HOSPITALS
WITH
1,550,000 BEDS
DDD
ODD
ODD
ODD
ODD
DDD
nan
DDD
DDD
ODD
ODD
nan
DDD
DOD
2.7 MILLION
EMPLOYEES
AND 33.3 MILLION
PATIENTS A YEAR
ASSETS OF
$43.2 BILLION
AND EXPENSES OF
$32.7 BILLION A YEAR
Source: American Hospital Association, 1972 figures.
-------
sanitary and expensive methods now
used to handle them call for action from
hospital designers and administrators,
government agencies, and the community
at large. Included in the body of informa-
tion that can help guide that action are
studies funded by the U.S. Environmental
Protection Agency (EPA) and conducted
by the University of Minnesota, West
Virginia University, and the County of
Los Angeles.
EPA
studies
The University of Minnesota's School of
Public Health surveyed 80 hospitals in 37
States to gather information on the kinds
and amounts of wastes hospitals discard
and how the wastes are handled and dis-
posed of. Conducted from 1966 to 1970
by Albert F. Iglar and Richard G. Bond,
the study covered nongovernmental, non-
profit general hospitals, which account
for a large percentage of U.S. hospital
admissions. The smallest hospital had 50
beds, the largest 1,226. Over 40 percent of
the hospitals were originally constructed
more than 50 years ago. However, 54
percent had undergone major alteration
or expansion since 1965. Funding for the
study came from EPA's Office of Solid
Waste Management Programs.
The County of Los Angeles study, con-
ducted by Esco-Greenleaf (a joint venture
of Engineering Service Corporation, Los
Angeles, and Greenleaf/Telesca, Engi-
neers and Architects, Miami), focused on
improved solid waste techniques adapt-
able to hospitals and other types of multi-
story buildings. This study covered only
-------
seven hospitals, but it covered them in
more detail than was possible in the 1-day
visits made in the University of Minnesota
study. The seven Los Angeles hospitals
ranged in size from the 2,300-bed Los
Angeles County-University of Southern
California Medical Center, one of the
largest teaching hospitals in the country,
to the 232-bed hospital of the Mira Loma
Rehabilitation and Detention Facility.
The Mira Loma Hospital specializes in
providing medical care for tuberculosis
patients but also offers generalized hos-
pital care to nearby communities. Funds
for the 1968 69 Los Angeles study were
provided by the Office of Solid Waste
Management Programs.
The 3-year study of the West Virginia
University Medical Center, a 438-bed
teaching hospital and research institution,
examined in detail the kinds and amounts
of wastes discarded. The study was con-
ducted from 1968 to 1971 by Jerry C.
Burchinal of West Virginia University
with funds provided by EPA's Office of
Research and Development.
waste
& kind*
The sources of solid wastes in hospitals
are many—nursing floors and stations;
dietary facilities; laboratory, X-ray, and
surgical departments; pharmacy; emer-
gency room, offices, and service areas. In
the hospitals surveyed by the University of
Minnesota, dietary facilities account for
about 50 percent of the total wastes, fol-
lowed by general nursing stations with 20
percent; surgery and maternity, about 4
percent each; and offices and laboratories,
-------
dietary facilities
account for half of hospital wastes
DIETARY
FACILITIES 49%
Percents refer to weight.
Source: University of Minnesota study
GENERAL
NURSING STATIONS 20%
SURGERY 4.5%
MATERNITY 3.8%
LABORATORIES 2.1%
ADMINISTRATIVE
AND OTHER OFFICES
1.6%
MIXED, OTHER,
AND UNKNOWN 19.0%
-------
2 percent each. These figures generally
agree with those for the West Virginia
University Medical Center hospital, al-
though the dietary facilities there account
for only 40 percent of the wastes.
The composition of the wastes is typical
of wastes produced by the community in
general. Combustible rubbish accounts
for about 50 percent of the total weight
of wastes in the hospitals surveyed. Gar-
bage (including estimates of the weight of
food waste discharged via garbage grind-
ers) accounts for approximately 28 per-
cent, followed by noncombustible rubbish
at about 9 percent.
At most hospitals, combustible rub-
bish is probably associated with at least
small amounts of microbiological and
chemical contamination. Food wastes, on
the other hand, are not necessarily con-
taminated, although they can putrefy and
attract insects and rodents. Both com-
bustible rubbish and garbage can be
handled easily by municipal-type disposal
facilities.
Some hospital wastes result directly
from diagnosing and treating patients. Al-
though they constitute quite small frac-
tions of the total, such wastes are fre-
quently hazardous and require separate
handling and treatment. Hazardous
wastes include biological, radioactive, and
chemical wastes, plus sharp items such as
disposable needles. Hospital staffs try to
keep hazardous wastes separate from
other wastes, but these attempts often fail.
Therefore, with few exceptions (for ex-
ample, administration office wastes, which
are physically separated from patients),
all hospital wastes must be considered
potentially contaminated. People with
access to most areas of the hospital—in-
-------
half of hospital waste is combustible
COMBUSTIBLE
RUBBISH 50%
Percents refer to weight.
Source: University of Minnesota study
GARBAGE 28%
NONCOMBUSTIBLE
RUBBISH 9.2%
MIXED, OTHER,
AND UNKNOWN 12.8%
-------
eluding patients, doctors, nurses, techni-
cians, orderlies, aides, maids, janitors,
laundry workers, volunteers, and visitors
—may come in contact with these wastes.
Special bacteriological and virological
studies were made in the West Virginia
study. Results indicate that pathogenic or-
ganisms may be present in hospital solid
waste in significantly high concentrations.
Bacillus organisms made up 80 to 90 per-
cent of all microbes observed, with staphyl-
ococci and streptococci each composing
between 5 and 10 percent of the popula-
tion. Staphylococcus aureus was by far the
most common pathogen detected.
The number of airborne bacteria in-
creases during handling of the solid
wastes. Proper handling, including placing
the wastes in bags, can markedly reduce
the total number of airborne bacteria. The
possibility exists that viable organisms
may be transmitted to other parts of the
hospital by way of the chutes or open
carts. Virus-survival studies indicate that
almost all materials found in hospital solid
wastes can become vehicles for transmis-
sion of viruses.
amounts
of wastes
The amounts of wastes generated by
American hospitals vary widely, depend-
ing on their facilities and the kind of serv-
ice they provide. In 1950, 7 pounds per
patient per day was a commonly quoted
figure; by 1970, the figure had risen to
about 10 pounds per patient per day. The
increases have been due in large measure
to increasing popularity of single-use
items, single-patient items, unit-dose and
8
-------
unit-serving packages, and similar prod-
ucts. These "disposable" items are seen
as a measure to minimize risk of the spread
of infection, but their increasing use is an
important cause of the increase in hos-
pital operating costs in recent years. Ac-
cording to a National Sanitation Founda-
tion conference on single-use items, the
need for economy is being subordinated
to such factors as increasing affluence and
growing difficulty in staffing hospitals, as
well as demands for safety, comfort, and
convenience. The result can be higher
hospital costs and grossly overloaded
waste handling facilities.
The wastes generated in the 80 general
hospitals surveyed by the University of
Minnesota ranged from 4.7 to 16.2
pounds per patient per day. The mean
figure is 8.7 pounds. The volumes gener-
ated range from 1.0 to 4.0 cubic feet per
patient per day, with the mean being 2
cubic feet. While both weight and volume
are primarily related to bed capacity,
they are also significantly related to a
number of other factors:
Community Characteristics. Hospitals in
larger communities and those in Standard
Metropolitan Statistical Areas tend to
generate more wastes.
Presence of Specialized Facilities and Serv-
ices. Pathology laboratories, cobalt ther-
apy, radioisotope utilization, laboratory
research, a hospital-controlled school of
nursing, and a psychiatric inpatient clinic
—all tend to increase wastes per patient
per day.
Utilization of Hospital. Patient census on
the day of the survey, as well as the number
of surgical procedures, outpatient visits,
and live births affect waste generation.
-------
Employees and Trainees. The larger the
staffs, the more waste is generated per
patient per day, especially if housing is
provided.
State License, and Accreditation by the
Joint Commission on Accreditation of Hos-
pitals. Both tend to correlate with increas-
ing quantities of wastes.
The Minnesota study team developed
an equation that includes the most im-
portant of these variables for use in esti-
mating solid waste poundages for specified
conditions. This equation provides better
estimates of solid wastes per patient per
day than is possible using bed capacity or
patient census alone.
The quantities of wastes discarded by
the seven Los Angeles hospitals are dis-
tributed in an even wider range than the
hospitals in the Minnesota study. The Los
-------
Angeles County-University of Southern
California (LAC-USC) Medical Center
discards 11.6 pounds per day per patient,
and another hospital affiliated with a medi-
cal school discards 16.7. At the lower end
is the Mira Loma Hospital (5.1) and a ge-
riatrics center (3.6). The latter type of
patient care requires limited bed space, sup-
plies, staff, and support personnel, as op-
posed to the Medical Center, which pro-
vides a comprehensive range of medical
care for all age groups.
This extremely wide range of waste
generation indicates the unreliability of
the traditional pounds-per-patient-per-day-
figure for designing solid waste systems. A
figure is needed that allows estimating
waste generation rates for hospitals of
different sizes and different types of medi-
cal care. Such a figure may be the "equiva-
lent population"—that is, the average
population present for each 8-hour shift
over 24 hours a day and 7 days a week,
counting outpatients at one-half value. The
range of the seven Los Angeles hospitals
reduces to 2.08-5.57 pounds per capita
per day on this basis. The wastes gener-
ated by the West Virginia University
hospital are in the same range—in three
sets of measurements made over a 2-year
period, the hospital was discarding 4.0
pounds per day per capita of equivalent
population.
The equivalent population method thus
appears to permit hospital designers to
predict the amounts of wastes generated
for various types of institutions. However,
it cannot predict wastes for the individual
units of the institution. Location of the
units with regard to supply and disposal
points markedly affects material handling
costs and consequently is an important
11
-------
consideration in design and operation of
hospitals.
The West Virginia study derived a
series of simple mathematical equations
that predict wastes for units within hos-
pitals. The main variable for most patient-
care units proved to be the total paid staff
for a 24-hour period, not including doc-
tors. Doctors are excluded because the
number varies considerably for the same
unit on different days. Furthermore, doc-
tors would be counted at more than one
unit as they made their rounds. The paid
staff of nurses, aides, clerks, orderlies,
housekeepers, and maids of a unit remains
constant and parallels the amount of
wastes produced. Patient-care units group
themselves into two main divisions. Units
such as surgery, maternity and newborn,
and intensive care have large staffs and
produce large quantities of wastes. Units
handling, for example, psychiatric, pedi-
atric, and neurology patients have smaller
staffs and produce smaller amounts.
Support activities dealing mostly with
paperwork produce similar quantities of
wastes, with the main variable being total
number of paid staff, excluding super-
visors or administrators. A number of spe-
cial units producing considerably smaller
quantities of waste depend on other
variables.
The equations are empirical in origin
and statistically reliable; they provide,
however, only an estimate of mean daily
quantities. Unusual circumstances in the
hospital, community epidemics or disas-
ters, peak loads, increased use of dispos-
ables, and similar variables can produce
quantities of waste that exceed the aver-
age. During the study period, peak loads
from units in the West Virginia University
12
-------
estimating waste
Generated by Individual Units of West Virginia Medical Center
"
'H>31*V£*'; -*T
4^J***V !'V«^
T :^T f^^Kv^.\'W^^^f^ #W "v'"'-3>— --
. **
^ ^r^j
|F%C>«¥'^ \ i". ^;"* ,^ar^,i« ^54-
^n't*- 41 *- ^4^^/«
^«^
^
*
-------
hospital ranged from 15 to 35 percent
higher than mean daily quantities.
more
disposables
Increased use of disposables could have
a dramatic effect on the amounts of
wastes discarded by hospitals. The West
Virginia University hospital, for example,
handled 4,700 pounds of disposable
wastes a day and 10,140 pounds of re-
usable wastes (those processed in the
laundry). Assuming that, on the average,
disposable items will be one-third the
weight of reusable items, an additional
3,300 pounds of disposable wastes could
be generated by the hospital, and the exist-
ing solid waste management system would
have to be almost doubled. With solid
waste management costs at the hospital
averaging $100 per ton, a significant new
expense would be involved.
The West Virginia study points up the
need for hospital administrators to look
carefully at how each single-use item will
affect the operations and costs of the hos-
pital before they approve its use. Purchas-
ing, receiving, storing, distributing, collect-
ing, processing, and disposal should be
considered, not just safety, acceptance,
and convenience for the patient and staff.
waste
storage
Hospital wastes are stored in many kinds
of receptacles—wastepaper baskets, gar-
bage cans, empty oil drums, laundry
hampers, carts, buckets, and even on the
14
-------
fe
-------
floor. Plastic containers are coming into
widespread use. They are easier to lift and
clean than metal containers, and the
bases and sides are impermeable to in-
sects, since they do not rust, bend, or
dent.
Use of disposable liners for waste con-
tainers has substantially increased sanita-
tion of solid waste handling in hospitals.
The bulk of the solid waste is unbagged in
only 16 percent of the hospitals in the
Minnesota study. This usually means that
wastes are stored loose in containers and
have to be transferred to other receptacles,
increasing the risk of spreading infectious
agents. The study found that 79 percent
of the hospitals visited use plastic bags
for most of their solid waste. Paper bags
are used as the primary means of en-
closure in only a few of the hospitals.
Paper bags, especially waterproof ones,
are frequently used to enclose relatively
small amounts of wet or contaminated
material. Because a hospital uses bags
does not guarantee, however, that the bags
would be used effectively or at all times.
The surveyors noted numerous instances
of bags leaking because they were torn
or not tightly closed, endangering the
persons handling the wastes, as well as
others in the hospital.
Central storage of solid wastes is
usually outdoors, even though such areas
are accessible to children and other un-
authorized individuals. In addition, the
storage areas at many of the hospitals are
unsightly, highly soiled, and accessible to
insects and rodents. Various types of con-
tainers are used: bulk receptacles (57 per-
cent of the hospitals visited) and small
cans or improvised receptacles (53 per-
cent), and even storage without recep-
16
-------
tacles (6 percent). A majority of the hos-
pitals visited have more than one central
storage location.
waste
handling
An unusual feature of hospital waste man-
agement is that wastes are generated con-
tinuously around the clock, but they are
collected sporadically at fixed intervals
during the day shift. The housekeeping
department usually has primary responsi-
bility for collection within the hospitals
surveyed, although a number of other
departments have regular responsibility
for other facets of waste collection. Gen-
erally, only minimal qualifications are
required for persons collecting wastes.
Most of the hospitals surveyed use
manually propelled carts of some variety
to collect waste materials. The most fre-
quently used carts (40 percent of the hos-
pitals) have rigid walls made from wood,
metal, or other materials. Flat carts are
used as the primary means in 26 percent
of the hospitals. Carrying waste by hand
is the primary means in only 8 percent of
the hospitals, but it is used to at least a
small extent at nearly every hospital. More
sophisticated mechanical systems are
found at only a few hospitals.
Hospital carts are frequently con-
structed in such a way that sanitizing
them is impossible, thus providing sur-
faces where bacteria can multiply. The
routing of carts into and through areas
where freedom from contamination is
critical and near clean equipment and
supplies increases the probability of con-
tamination from wastes. In addition, per-
17
-------
sons collecting wastes are repeatedly ex-
posed to chemical and microbiological
contamination and other hazards, but
have minimal knowledge, skill, or equip-
ment to protect themselves.
Gravity chutes are a simple and inex-
pensive means of transferring wastes verti-
cally and are an important method at 32
percent of the institutions visited by the
University of Minnesota study team.
Chutes are found more frequently and in
larger numbers at hospitals with higher
bed capacities. However, the chutes are
seldom constructed with mechanical ex-
hausts, interlocking charging doors, or
other systems for preventing the spread
of microbiological contamination. In
several instances, linen chutes are reserved
for conveying solid wastes during certain
times of the day—another potential way
of spreading contamination.
18
-------
Chute usage has additional drawbacks:
fire hazards, spilling of wastes during
loading, blockages, difficulties in cleaning,
and odors. Proper design and construc-
tion can help to prevent some of these,
especially the fire hazard and cleaning
problems. Others can be avoided by ex-
cluding certain wastes, especially grossly
contaminated articles, and by exercising
more care in use of chutes.
The problems associated with gravity
chutes are well illustrated in the West
Virginia University hospital. The chute
there receives combustible wastes from all
10 floors and terminates in a room ad-
jacent to the incinerator room. The wastes
include "floor refuse" such as paper, trash,
and food wastes from the wards; patho-
logic wastes, including dressings, syringes,
and other disposable equipment; and some
kitchen wastes. Air temperatures in the
chute closet average in the low 80's and
the relative humidity is in the 55-to-65-
percent range. In practice, wastes can re-
main in the chute for several hours and
occasionally back up as far as the third
floor of the hospital. The first door im-
mediately above the chute closet is the
door to the kitchen. The waste packs
against this door and could become a
source of food contamination.
The West Virginia study establishes the
possibility of viable bacteria being trans-
mitted to other parts of the hospital via
the chute. The doors do not fit tightly,
thus air constantly leaks into the hallway.
The air in the chute tends to flow upward
and outward 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
when only one door is open.
19
-------
processing
& disposal
Hospital wastes are disposed of in a num-
ber of ways, usually by the hospital's
maintenance or engineering department.
Eventually, almost two-thirds of the
wastes leave the hospitals and go out
into the community for disposal. About 35
percent by weight, principally combustible
rubbish and biological materials, are dis-
posed of in hospital incinerators. Non-
combustibles are usually separated and—
along with the incinerator residue—leave
the hospital to be disposed of on the land.
Of the 80 hospitals surveyed in the
Minnesota study, 70 use incinerators to
dispose of some wastes. Usually, the in-
cinerators are operated by persons lack-
ing the necessary skills and knowledge.
At only 39 percent of the hospitals using
incinerators is operation limited to a spe-
cific operator or group of operators. A
more common practice is for the persons
collecting the waste to load it into the
incinerator. The operators lack—or fail
to use—even the most simple personal
protective equipment such as face shields.
About half of the institutions have a
separate room for incinerators, but the
rooms are occasionally uncomfortable and
even hazardous because of heat, smoke,
dust, and danger from exploding aerosol
or ether containers.
In addition to a lack of skilled person-
nel, the hospital incinerators have numer-
ous operating problems. Since they usually
operate intermittently, maintaining ade-
quate combustion temperature is difficult.
Since very pronounced peaks occur in
collection, there are brief periods when in-
20
-------
most hospital wastes go outside
the hospital
INCINERATION
AT THE HOSPITAL;
35.0%
GRINDING 21.0%
SANITARY
LANDFILL
15.0%
Percents refer to weight.
Source: University of Minnesota study
HOG FEEDING
3.7%
MUNICIPAL
INCINERATION
2.9%
MIXED, OTHER,
AND UNKNOWN 1.4%
DUMPING 21.0%
Z
o
u
21
-------
cinerators operate at above their rated
capacity. Both situations can lead to poor
incineration, air pollution, and even to the
escape of infectious agents.
Grinding of garbage and discharging to
public sewers is practiced at 84 percent
of the hospitals, while 27 percent use
grinders to dispose of biological materials
into the sewage system. On the average,
21 percent of hospital wastes is disposed
of by grinding. The method has several
advantages. It reduces opportunities for
insect and rodent infestation and so re-
duces problems both of environmental
sanitation and odor. It reduces labor costs,
since collection need not be so frequent
when food wastes are removed. It also re-
duces the quantities of difficult-to-burn
food wastes sent to incinerators.
Another major method of disposal is on
the land—21 percent of the wastes go to
dumps and 15 percent to sanitary land-
fills. Hog feeding is a minor method, ac-
counting for only about 4 percent. The
Minnesota study team considered it incon-
gruous that institutions established for the
care of the sick should permit hog feeding
at all.
special
problems
of hazardous
The various kinds of potentially hazardous
wastes produced in hospitals pose special
problems. Biological wastes such as human
and animal remains, blood, afterbirths,
bacteriological cultures, and bandages
contaminated with bacteria require spe-
22
-------
cial procedures, with a minimum of
handling, to avoid spreading disease. The
ease with which disease can spread is il-
lustrated by the case of one general hos-
pital where morgue employees had 10
times the incidence of tuberculosis as
other hospital employees.
Incineration is the most frequently used
disposal technique for such wastes among
the hospitals studied by the University of
Minnesota. Some biological wastes are
also ground, buried, hauled away with
other wastes, and—in the case of placen-
tas—sent to drug firms.
More than half of the hospitals visited in
the Minnesota study use radioisotopes for
medical purposes. At 76 percent of the
hospitals, radioactive wastes are first al-
lowed to decay to a satisfactory level, then
disposed of routinely with other wastes. At
17 percent of the hospitals using radioiso-
topes, contaminated waste is incinerated at
the hospital without long-term storage to
reduce radioactivity levels. At one hospital,
radioactive waste is mixed with other waste
and hauled away without benefit of decay,
although the amounts disposed of without
prior decay appear to be small.
Chemical wastes are generally intimately
mixed with other wastes or present as a
contaminant. A common example might be
an organic solvent absorbed in paper towel-
ing. In the course of their visits, the Minne-
sota study team observed several incidents
in which large quantities of a chemical
waste caused problems. At one institution,
for example, about 3 cubic feet of hypo-
chlorite bleaching powder had been
dumped into a bulk waste receptacle, caus-
ing considerable discomfort to hospital per-
sonnel nearby. Since many chemical
wastes are organic materials, they can
23
-------
usually be incinerated, although explosive
or toxic materials may require special pre-
cautions.
Disposable needles and syringes con-
stitute a significant safety hazard to person-
nel handling wastes in 69 percent of the
hospitals surveyed. The hospitals generally
have policies providing for the safe disposal
of sharp wastes. In a typical case, the policy
calls for replacing the sheath on the needle,
bending the needle or breaking it, and seal-
ing it in a disposable container. Policies
are often disregarded, however, and dis-
posable needles are found mixed with other
wastes and even protruding from bags of
waste. The possibility of danger beyond the
hospital should also be considered, since
sharp wastes are hauled away without in-
cineration at 45 percent of the hospitals
surveyed.
hauling
& disposal
away from
hospital
More than 40 percent of a hospital's solid
wastes end up being transported on public
streets and disposed of within the surround-
ing communities. Wastes are hauled away
from every hospital visited by the Minne-
sota study team, with more than one-third
of the hospitals being served by two or more
haulers. Private haulers serve the largest
number of hospitals, followed by municipal
agencies, the hospital itself, hog farmers,
and haulers under contract to the hospital.
As hospital wastes move through the streets
and to the disposal site, they lose their
24
-------
identity as hazardous wastes that might re-
quire special precautions. (The same is
true of the medical wastes generated in
doctor's offices, nursing homes, and vet-
erinary clinics.)
When wastes are removed from the hos-
pitals, in 73 percent of the cases they go to
a municipal disposal facility—which is
sometimes an incinerator or a sanitary
landfill, but frequently an open dump. A
dump is a source of air and water pollution
and a breeding place for insects and rats;
when it receives hazardous wastes it adds
a new threat to employees, to any scaveng-
ers, and to the entire community. A well
designed and operated disposal site should
provide for proper disposal of the relatively
small amounts of hazardous wastes re-
ceived from hospitals or other sources in
the community.
evaluation
of total
system
The large amounts of potentially contami-
nated wastes generated by hospitals raise
the possibility that they are a concentrated
source of environmental health problems.
The Minnesota study found that at many
hospitals solid wastes are indeed contribut-
ing to occupational injuries, air pollution,
and insect and rodent infestation, and
pointed out some remedial steps that could
be taken immediately.
The Los Angeles study also examined
the total solid waste management systems
in hospitals. A rating method was de-
veloped for evaluating the systems with
regard to four basic environmental factors
25
-------
steps to improve the systems
— Hospitals, Journal of the American Hospital Association
26
-------
or conditions that affect the health and
welfare of the hospital's occupants and the
general public:
Sanitation: control of all conditions that
contribute to contamination and may per-
mit spread of disease or infection.
Safety: control of all conditions relating
to prevention of accidents.
Security: prevention of unauthorized ac-
cess to waste handling and disposal areas.
Esthetics: acceptability in terms of factors
such as appearance, noise, odors, con-
venience, and workability of the system.
Considering both the capability of the
system or equipment as designed and how it
was operated in practice, the solid waste
management system of each of the seven
hospitals was given a deficiency rating from
0 percent—completely acceptable as is—
to 100 percent—not acceptable for present
use. The ratings ranged from 20 to 58 per-
cent, indicating that even the best of the
seven hospitals needs to improve substan-
tially the quality of its system.
Efficiency and costs of the systems could
also be improved. These systems rely heav-
ily on manual methods, pushing labor costs
up to over 90 percent of total operating
costs. Unit costs vary and depend largely
on physical complexities of layout and
equipment, as well as on the skill and in-
clination of labor.
Most of the hospitals surveyed have com-
prehensive and sound policies on solid
waste management, including specific
directives on segregation and special han-
dling of hazardous materials. But in prac-
tice, the policies break down. Employees
fail to make the right judgments consistent-
27
-------
-------
ly, and stricter supervision is needed to
ensure that employees:
• Maintain proper handling and disposal
of pathologic and sharp wastes.
• Separate disposable wastes from reusable
wastes such as dinnerware and linens.
• Bag materials properly.
• Deposit chute materials promptly.
• Supervise storage, processing, and dis-
posal areas closely; maintain security so
that unauthorized personnel cannot gain
access.
It would be relatively expensive to pro-
vide adequate supervision in the conven-
tional waste systems of larger hospitals,
which rely so heavily on people rather than
mechanized systems. Such supervision is
necessary, however, if the solid waste man-
agement systems are to be upgraded
quickly.
concepts
Long-range solutions to hospital waste
management problems involve devising
methods for conveying wastes from their
source to storage or ultimate disposal areas
with minimum handling and exposure to
occupants of the building and the com-
munity. The Los Angeles study examined
new concepts and equipment preparatory
to designing an integrated system for pos-
sible installation in the LAOUSC Medical
Center.
The problem is essentially one of ma-
terials handling and is adaptable to mech-
anization, although it is now managed
29
-------
predominantly by manual methods largely
built in by the design of the building. It is
common to find, even in the newest hos-
pitals, numerous interim storage points
where wastes are temporarily deposited,
thereby breaking the cycle of movement
and requiring rehandling of the same ma-
terial a number of times. These conditions
continue to exist for several reasons. The
hospital administrator, attuned to "doing
it by hand," ignores the problem, the plan-
ner is unaware of it, and the materials-
handling industry is not sufficiently alert to
a new market. The materials-handling in-
dustry's apparent reluctance is understand-
able, for it is accustomed to working
with objects or substances that are
generally similar if not identical in size,
weight, etc. Hospital wastes, on the other
hand, almost defy description. Not only do
they lack uniformity of size and shape but
they may well be hazardous in various
ways.
Despite the advanced state of develop-
ment of general materials-handling equip-
ment, tried and proven mechanical units
designed exclusively for handling solid
wastes are almost nonexistent, with the
exception of chutes and pneumatic tubes.
The mechanized and automated handling
systems currently being tested and im-
proved are relatively high in capital costs.
However, they will likely provide overall
economy in annual operating costs for
many small and large institutions.
A pneumatic tube system for handling
both soiled linens and disposable wastes
has the greatest potential for use in exist-
ing buildings. For buildings still in the
planning stage, conveyor systems for trans-
ferring sealed containers also merit con-
30
-------
sideration. The conveyor system has the
added advantage of being able to distribute
clean supplies and would probably be
economical only if designed to handle them
as well as disposable and nondisposable
wastes. Both pneumatic tubes and con-
veyors for sealed containers would improve
operating standards since materials move
in a closed system that minimizes exposure
within the hospital and also reduces interim
storage.
In addition to various types of temporary
storage receptacles, hospitals must have
areas where collected wastes and handling
equipment can be stored. Although indis-
pensable, such areas are seldom given ade-
quate consideration by builders and design-
ers. Storage areas that are too small and
badly located create fire and health haz-
ards. Carefully planned as part of the total
solid waste management system, storage
facilities will require less space and elimi-
nate unnecessary and expensive handling
operations.
The space required for waste storage
can be reduced even more by processing
wastes to reduce their volume. Probably
the simplest form of processing is to bag
or encapsulate wastes. Compacting, grind-
ing, shredding, pulverizing, and similar
31
-------
techniques can be used alone or in com-
bination. Another alternative is to dis-
charge pulped materials into the sewers, an
already contaminated channel. The chief
concern with this method is the ultimate
effect on the cost and operation of sewage
treatment plants and on potential reuse of
water from the plants.
The greatest investment and advances in
equipment for hospital solid waste systems
are occurring in handling, storage, and
processing. But perhaps the greatest need
is in processing and final disposal. Incin-
eration is a widely used method of on-site
processing. It is not a final disposal method,
since it leaves a residue that requires dis-
posal.
Both incinerator design and operation
are highly complex. The importance of de-
sign is generally recognized, but the impor-
tance of proper operation—especially the
need for qualified operators—is frequently
overlooked. Industry is capable of design-
ing incinerators to meet strict new air
pollution control standards. In areas where
air pollution is severe, the most sophisti-
cated control devices will probably be
required. However, they may prove too
expensive for smaller incinerators.
Certain indirect benefits with monetary
value can accrue as a result of environ-
mental improvements. People in the hos-
pital—especially those associated with
direct handling of waste materials—are
likely to have fewer accidents and illnesses.
Similarly, the community at large would
have less exposure to wastes in transport
and off-site disposal. The cost of building
maintenance and losses due to fires should
be reduced. Congestion in building corri-
dors would be reduced, allowing other hos-
pital operations to be more efficient.
32
-------
integrated
plan for
medical
center
The new concepts of hospital waste man-
agement identified in the California study
were used in designing a single, closed,
integrated system for possible installation
in the LAC-USC Medical Center. The need
for a closed system rests on the premise that
hospital wastes should be treated as if they
are all contaminated. With closed trans-
port, surveillance could be limited to initial
handling at the ward level and final han-
dling at the processing and disposal sys-
tems. The final step of the proposed system
calls for on-site disposal, or processing to
produce a sterile homogeneous material
that can be safely hauled and disposed of
off site.
Since installation of a system of auto-
mated carts or mechanical conveyors was
impractical, the only alternative handling
system with the required capabilities ap-
peared to be pneumatic tube conveyors.
Although twin-tube systems are preferable
for separate handling of linens and wastes,
a single-tube system was selected for the
plan because it takes less space and is less
expensive. A piping network would connect
the existing chutes to the laundry and the
disposal plant. Accumulated materials
would be evacuated as needed. Linens
would be in one type of color-coded bag,
wastes in another. An interval sensor in
the system would direct each bag to its
proper location without cross-contamina-
tion. The vertical chutes would be placed
under a slight negative pressure to mini-
mize aerosol contamination. This closed
33
-------
system eliminates interim storage and re-
handling of wastes and meets environment-
al standards.
A number of alternatives for processing
and disposal were considered. On-site in-
cineration or pyrolysis and hauling the
residue to a landfill was considered a safe
method that would not contaminate the
community. However, this method has
drawbacks for Los Angeles, where strin-
gent measures must be followed to avoid
air pollution.
A method involving grinding and steriliz-
ing wastes and transporting them to a
landfill was considered. Methods that dis-
charge ground wastes into the sewers could
also meet the basic criteria, but the nature
and quantity of hospital solid wastes may
be a burden to conventional sewage treat-
ment processes. A possible answer is the
use of a method such as wet oxidation to
reduce the quantities of solids. This method
permits handling of the wastes at a much
faster rate than is possible with conven-
tional processes.
From this analysis, four largely auto-
mated systems were identified:
• Pneumatic conveyor system, pulping or
wet grinding, wet oxidation, discharging
to sewers.
• Pneumatic conveyor system, incinera-
tion, transport of residue to landfill.
* Pneumatic conveyor system, pulping or
wet grinding, wet oxidation, dewatering,
transport to landfill.
• Pneumatic conveyor system, pulping,
discharging to sewers.
These systems were then evaluated ac-
cording to the same four environmental
34
-------
criteria—sanitation, safety, security, and
esthetics—used on the solid waste manage-
ment systems in the seven Los Angeles
hospitals. The costs and the economic bene-
fits, if any, were estimated for each system.
On the basis of investment requirements
and annual operating costs, the system in-
volving pneumatic conveyors, pulping of
disposable wastes at a central pulping
station, and discharging to the sewers ap-
peared to have merit. There are still so
many unknowns about the effects of solids
in sewer systems, however, that the pro-
posal that was recommended includes an
experimental sewage treatment plant and
a wet oxidation unit. The solids would be
dewatered, without addition of chemical
coagulants, to a moist solid which would
be nonputrefying, biologically stable, free
of obnoxious odors, and safe for trucking
to a landfill.
Until recently, the solid waste manage-
ment systems of hospitals have been ig-
nored. The hospital administrator was
not aware of his system's cost or how
effectively it was operating. The solution
to the most critical problems will ulti-
mately be in the design of buildings. The
solid waste system must come to receive
the same consideration in preliminary
stages that plumbing, air conditioning,
heating, and other functions now receive.
Until modern systems are widely used,
hospitals will continue to struggle with
mounting waste tonnages, and they will be
forced to use stopgap and piecemeal meas-
ures that are expensive and fail to fully
protect the hospital's occupants and the
surrounding communities.
35
-------
This summary is based on three reports:
Hospital Solid Waste Disposal in Community Facilities, by Albert F. Iglar and Richard G. Bond. 1973.
350 pages. Available as publication No. PB-222 018 from the Department of Commerce, National Tech-
nical Information Service, Springfield, Virginia 22151, at $9 per copy.
Solid Waste Handling and Disposal in Multistory Buildings and Hospitals, by Esco/Greenleaf. 1972. Vol-
ume I, Summary, Conclusions, and Recommendations, is available from the Superintendent of Docu-
ments, U.S. Government Printing Office, Washington, D.C. 20402, at $2 per copy. Volume III, Research
on Systems Development, is also available from GPO, at $ 1.75 per copy, Volume II, Observations of
Local Practices, and Volume IV, Selection and Design of Solid Waste Systems, are available as publica-
tion Nos. PB-213 133 and PB-213 135, respectively, from the Department of Commerce, National Tech-
nical Information Service, Springfield, Virginia 22151, at $3 per copy of either volume.
A Study of Institutional Solid Wastes, by Jerry C. Burchinal and Lynn P. Wallace. 1973. 234 pages.
Available as publication No. PB-223 345 from the Department of Commerce, National Technical In-
formation Service, Springfield, Virginia 22151, at $5.75 per copy.
SEE ALSO:
Hospital Solid Waste, An Annotated Bibliography, by Rexford D. Singer, Alain G. DuChene, and
Nichole J. Vick. 1973. Available as publication No. PB-227 708/AS from the Department of Com-
merce, National Technical Information Service, Springfield, Virginia 22151, for $5.75 per copy.
ya772a
36
------- |