III. THE ENVIRONMENT
There are many physical, chemical, and
biological factors which may influence experimental animals and thus modify
the results of the investigations (Melby, 1983; Small, 1983). The experimental
results obtained are, in principle, only valid for the conditions under
which they were obtained and only useful for comparison if all the relevant
information concerning experimental conditions is made available.
Among the environmental factors which should
be recorded for possible inclusion in scientific reports are: temperature
(C and range), relative humidity (% and range) and whether or not these
are regulated; air exchanges/hour, proportion of fresh and recirculated
air, and gas or particle concentrations in the air; lighting (natural and/or
artificial, photoperiod, and intensity); water type, quality, and pretreatment;
bedding type, quality, and pretreatment; housing density; housing equipment;
and physical measures to protect microbiological status. The microbiological
status of the animal should be reported [conventional, Specific Pathogen
Free (SPF) for stated pathogens, or gnotobiotic with microorganisms specified]
(WCBCLA, 1985).
A. CLIMATE CONTROL
Environmental requirements vary with the
species and the experimental protocol. Environmental parameters are usually
measured at the level of the room. More important, however, is the microenvironment
established at the cage level, since the conditions between the two may
differ dramatically (Woods, 1980; Corning and Lipman, 1992). A summary
of some environmental parameters for individual species is given in Appendix
I.
The design of the animal facility should
permit adjustment of environmental controls to meet the needs of the species
and the experimental protocol. Ideally, each animal room would be controlled
independently. In facilities not originally constructed with this capability,
this ideal could be approached through proper management and the installation
of ancillary automatic light timers, rheostats, thermostatically controlled
exhaust fans, humidifiers, and air conditioning units.
1. Temperature
Published data on optimal temperatures
for housing laboratory animals are variable (CCAC, 1984; Clough, 1984;
NRC, 1985). All these were considered when the guidelines of the Council
of Europe were formulated (European Convention, 1986).
It is essential that emergency equipment
be available to maintain environmental temperatures, particularly in rooms
housing small laboratory animals, fish, and non-human primates (NHP).
In special cases, for example, when housing
very young or hairless animals, higher room temperatures than those indicated
may in Appendix I be required.
Animal room temperatures should be monitored
daily, preferably by continuous recording. A less-costly alternative is
the use of a maximum/minimum thermometer which is examined and re-set daily;
however, this does not indicate how long the room was held at a particular
temperature, knowledge of which is extremely important (McSheehy, 1983).
If the experimental protocol or management practices require that an animal
be housed at temperatures outside the recommended range, an adequate time
should be given for adaptation to occur (Baker, Lindsey and Weisbroth,
1979). The temperature of the microenvironment should also be monitored.
Factors affecting temperature in the cage include the type of cage and
bedding or nesting material, the use of filter covers, age, sex, strain,
species, and housing density (Woods, 1980; Corning, 1992).
Environmental temperatures and variability
can affect animal research and testing, influencing an animal's response
to drugs, susceptibility to infectious disease, fertility, production,
feed and water intake, growth curves, and hematologic parameters (Baker,
Lindsey and Weisbroth, 1979; Lindsey, 1978; Yamauchi, 1981). Occasionally,
optimal temperature for the research animal is not the most comfortable
for personnel; however, human preferences should not compromise the experimental
requirements or the health and comfort of the animal.
2. Humidity
Most laboratory animals prefer a relative
humidity around 50%, but can tolerate a range of 40-70% as long as it remains
relatively constant and the temperature range is appropriate (Clough, 1987).
Discomfort results when humidity levels adversely affect the animal's ability
to maintain thermal homeostasis. In facilities where humidity is difficult
to control within an acceptable range, dehumidification or humidification
devices may need to be installed.
Humidity levels can affect experimental
results by influencing temperature regulation, animal performance, and
disease susceptibility.
3. Ventilation
Ventilation influences temperature, humidity,
and gaseous and particulate contaminants in the animal cage and holding
room. The design of the building ventilation system should permit the maintenance
of these parameters within acceptable limits. The actual ventilation rate
required varies with age, sex, species, stocking density, frequency of
cleaning, quality of incoming air, ambient temperature and humidity, and
construction of primary and secondary enclosures, among other factors.
Draft-free air exchanges in the range of 15-20 per hour are commonly recommended
for rooms containing small laboratory animals under conventional housing
conditions (Clough, 1984). Achieving these rates does not guarantee adequate
ventilation at the cage level, particularly if filter-tops are used (Keller,
White, Sneller
et al. 1989). Laminar flow units and rooms provide
good ventilation with an unidirectional airflow having few eddy currents.
These systems may effectively isolate cages within them, controlling the
spread of odours and airborne pathogens (Phillips and Runkle, 1973; McGarrity
and Coriell, 1976).
Differential pressures can be used to inhibit
the passage of pathogenic material between rooms. Higher pressures are
used in clean areas relative to dirty or biohazardous ones, in order to
minimize contamination (Hessler and Moreland, 1984). In facilities where
containment or exclusion of airborne microorganisms depends in part on
differentials in air pressure, inclined manometers or magnehelic gauges
can be used to measure the difference between the high and low pressure
areas in millimetres of water. Generally, 2.5-5.0 mm (0.1-0.2 in.) differential
is
maintained (Small, 1983).
The design of the ventilation system should
take energy conservation into account (Besch, 1980). Although total air
exchange systems are preferable, they are not always economical, especially
in regions experiencing temperature extremes. Recirculating air systems
must be equipped with effective filters (and scrubbers, if necessary) to
avoid the spread of disease and to remove particulate and gaseous contaminants
(e.g., NH3) (Hessler, 1984).
4. Lighting
The three characteristics of light which
can influence laboratory animals are intensity, quality, and photoperiod.
The lighting should provide good visibility and uniform, glare-free illumination.
Previous recommendations of 807-1345 lux (75-125 fc) at 76 cm from the
floor have been shown to cause retinal degeneration in albino rats (Belhorn,
1980; NRC, 1985; Semple-Rowland and Dawson, 1987). The recommended level
of 323 lux (30 fc) approximately 1.0 m above the floor has proved sufficient
for the performance of routine animal care duties and does not cause rodent
phototoxic retinopathy (Belhorn, 1980). A level of approximately 200 lux
does not appear to cause retinal damage and has been shown to be adequate
for reproduction and normal social behaviour among most rodents (Weihe,
1976). At this level, an additional light source on a separate switch is
needed to enhance illumination during caretaking activities.
The intensity experienced by animals housed
close to the source may differ markedly from that experienced by those
farther away, because light intensity is inversely proportional to the
square of the distance from its source. Additionally, light intensity within
a cage is dependent upon cage type and construction, position of the cage
on the rack, and type of rack, and may vary markedly from front to back
(McSheehy, 1983). Light intensity can influence aggressiveness and the
incidence of cannibalism in rodents (Weihe, 1976; Fall, 1974). Gradual
changes between dark and light periods allow time for behavioural adjustment
and the expression of crepuscular behaviours. Fish and amphibians may take
thirty minutes to make intra-ocular adjustments to changing light intensities
(Allen, 1980).
There are few studies on the effect of
light quality, or spectrum, on laboratory animals. It has been stated that
animal room illumination should duplicate the characteristics of sunlight
as closely as possible. There is some disagreement over the necessity for
this in every case (Belhorn, 1980; Small, 1983). Among laboratory rodents,
a light spectrum that differs markedly from sunlight may reduce breeding
efficiency, cause behavioural abnormalities, and enhance spontaneous tumour
development (Weihe, 1976). High levels of ultraviolet (UV) light can induce
cataracts in laboratory mice (Belhorn, 1980). The wavelength to which guppies
are exposed influences fecundity and affects development and sex ratios
in offspring (Mulder, 1971). Exposure to UV light may cause epithelial
damage in some species exposed to photosensitizing agents. Electromagnetic
waves outside the visible spectrum may influence behaviour and activity
of laboratory rats (Mulder, 1971). Light tubes which imitate the spectrum
of sunlight are commercially available.
Photoperiod is probably the most influential
of light characteristics on laboratory animals. Photoperiod influences
the circadian rhythms seen in biochemical, physiological, and behavioural
aspects of the animal - patterns stimulated and synchronized through the
neuroendocrine pathway. The circadian cycle can affect the animal's response
to drugs or resistance to inoculated infectious organisms (McSheehy, 1983).
The light/dark ratio can affect reproductive performance and sexual maturity.
It is suggested that, if a change occurs in an animal's photoperiod, no
experiments be conducted with that animal for at least a week (Davis, 1978).
If the light phase is interrupted by dark, there are few significant effects;
however, if the reverse occurs, endogenous rhythms can be significantly
skewed (Davis, 1978). This is one reason why automatic timers should control
light cycles in all animal rooms. Timer function should be monitored or
hooked into an alarm system. Additionally, any windows in an animal room
should be occludable.
Differences in light, temperature, and
airflow between locations on a cage rack can affect experimental results
and should be minimized by either rotating cages through different positions
on a rack, or by assigning animals to cages based on a table of random
numbers.
B. OTHER ENVIRONMENTAL
FACTORS
1. Noise
The effects of noise on laboratory animals
are related to its intensity, frequency, rapidity of onset, duration and
characteristics of the animal (species, strain, noise exposure history).
Species differ in their auditory sensitivity and susceptibility to noise-induced
hearing loss. Prolonged exposure to high levels of noise can cause auditory
lesions in animals. Although a maximum background noise of 85 db has been
recommended (Baker, 1979), adverse changes have occurred in rats exposed
to intermittent noise at 83 db (Gerber, Anderson and Van Dyne, 1966). Exposure
to uniform stimulus patterns may lead more readily to hearing loss, whereas
exposure to irregular patterns may be more likely to cause disorders due
to repeated activation of the neuroendocrine system (Peterson, 1980).
Intense noise can cause alterations in
gastrointestinal, immunological, reproductive, nervous, and cardiovascular
systems, as well as changes in development, hormone levels, adrenal structure,
blood cell counts, metabolism, organ weights, food intake, and behaviour
(Agnes, Sartorelli, Abdi et al. 1990; Bailey, Stephens and Delaney,
1986; Fletcher, 1976; Kraicer, Beraud and Lywood, 1977; Nayfield and Besch,
1981; Pfaff, 1974; Gerber and Anderson, 1967). Sudden intense sound can
elicit startle responses and can precipitate epileptiform seizures in several
species and strains of laboratory animals (Iturrian, 1971; Pfaff, 1974).
Ultrasound emissions can cause behavioural disturbances in a variety of
species (Algers, 1984). Although firm criteria for noise tolerance have
not been established for laboratory animals as for humans (Falk, 1973;
Welch and Welch, 1970), unnecessary and excessive noise may be assumed
to be an important experimental variable and a possible health hazard.
Noise can be controlled in an animal facility
through proper facility design and construction, thoughtful selection of
equipment, and good management practices. Naturally noisy animals should
be located where they minimally disturb quiet, noise-sensitive species.
Fire alarms which operate at low frequencies are audible to humans, but
do not disturb mice and rats. Telephones should not be placed in animal
rooms. Many noise sources in an animal facility emit ultrasound (Sales,
Wilson, Spencer et al. 1988). These include running taps and squeaking
chairs. Efforts should be made to identify and correct or shield these
sources.
Noise can also disturb or harm animal care
staff, researchers, and other nearby personnel. It may be necessary to
provide ear protectors in some areas such as dog, pig, or monkey rooms,
or the cage-washing facility.
2. Chemicals
Chemicals in the environment can adversely
affect the laboratory animal in a variety of ways. Inherently toxic compounds
or toxic metabolites can have local and/or systemic effects on virtually
every system. Although most chemicals found in animal facilities exert
their major effect by altering hepatic microsomal enzyme activity, immune
function, or behaviour, allergens, mutagens, teratogens, and carcinogens
have also been detected. Their ultimate effect is modulated by the interplay
between chemical factors (concentration; physicochemical properties; duration,
frequency, and route of exposure; interaction with other agents) and host
factors (species, age, sex, strain, nutritional status, immune function,
disease status) (Baker, Lindsey and Weisbroth, 1979).
Chemicals arrive in the microenvironment
through air, water, food, bedding, and contact surfaces. Common air pollutants
include dust and bedding particles, ammonia, disinfectants, pheromones,
organic solvents, volatile anesthetics, insecticides, and perfumes or deodorants.
The most common air contaminant in animal
facilities is ammonia (NH3) resulting from the decomposition
of nitrogenous waste. Ammonia causes irritation of the respiratory epithelium
and increases susceptibility of rodents to respiratory mycoplasmosis (Broderson,
Lindsey and Crawford, 1976; Lindsey, Connor and Baker, 1978). Sub-clinical
pathological changes in the respiratory tract due to ammonia complicate
inhalation toxicity studies in laboratory rodents (Gamble, 1976). In humans,
25 ppm is the level below which there are no harmful effects from an 8
hr/day, 5 day/week exposure [American Conference of Government and Industrial
Hygienists Threshold Limit Value (TLV)]. The human odour detection threshold
for ammonia is 8 ppm. In comparison, the TLV is 17 mg/m3.
The animal's microenvironment must be checked
as well as the room, because conditions often differ significantly between
the two (Corning and Lipman, 1992). Ammonia levels build up when production
components (species, sex, housing density, bedding) exceed elimination
components (cage design, air exchange, frequency of cleaning) (Serrano,
1971). Filter covers, which reduce air exchange at the cage level, can
rapidly lead to detrimental concentrations of NH3. Controlling
NH3 within safe levels requires constant attention to stocking
density and to frequency of cage cleaning.
Perfume and deodorants should never be
used to mask ammonia or other animal odours in lieu of proper husbandry.
These substances may be harmful to the animals (Baker, Lindsey and Weisbroth,
1979; Pakes, Lu and Meunier, 1984). Volatile anesthetics should be used
only with proper scavenging equipment.
Chemicals can enter the animal's environment
through the water. Other than checking for bacterial contaminants, water
quality is rarely monitored except for aquatic animals. Chlorinated municipal
water sources are commonly used. Over 700 organic compounds have been isolated
from such sources - 90% are natural decomposition products. These may react
with chlorine to produce chloroform (Pakes, Lu and Meunier, 1984). Inorganic
solutes, particularly copper (from copper pipe) and chlorine are especially
hazardous to aquatic organisms.
Food may be contaminated with heavy metals
(e.g., lead, arsenic, cadmium, nickel, mercury), naturally occurring toxins
(e.g., mycotoxins, ergot alkaloids, pyrrolizidine alkaloids, estrogenic
compounds), agricultural chemicals (e.g., herbicides, pesticides, fertilizers),
and additives (e.g., antibiotics, colouring, preservatives, flavourings,
unintentionally incorporated drugs) (Baker, Lindsey and Weisbroth, 1979;
Pakes, Lu and Meunier, 1984; Silverman and Adams, 1983).
Chemicals found on contact surfaces include
cleaning agents such as soaps, wetting agents, detergents, solvents, and
disinfectants (Burek and Schwetz, 1980). Unless otherwise specified as
safe according to the manufacturer's instructions, these substances should
be thoroughly rinsed from surfaces which will contact animals. The efficacy
of the rinse cycle of the cage-washer should be checked periodically.
Bedding materials, particularly wood products,
may introduce naturally occurring volatile oils, herbicides, pesticides,
and preservatives into the animal's microenvironment. Other possible contaminants
include PCB's and antibiotics (Silverman and Adams, 1983). Volatile hydrocarbons
in cedar and pine shavings can induce hepatic microsomal enzymes (Weisbroth,
1979).
3. Bedding
The choice of bedding materials and cage
flooring profoundly affects the microenvironment of small rodents. In most
circumstances, contact bedding is recommended. Most species should be provided
with solid flooring and bedding prior to parturition. Some desirable characteristics
of contact bedding are listed below.
Bedding material should always be taken
into consideration in designing an experiment and should be uniform throughout
the study because of its influence on behavioural and physiological responses
and on toxicity and carcinogenesis studies.
DESIRABLE CRITERIA FOR RODENT CONTACT BEDDING
(Kraft, 1980)
Moisture absorbent
Dust free
Unable to support bacterial growth
Inedible
Non-staining
Non-traumatic
Ammonia binding
Sterilizable
Deleterious products not formed as a result
of sterilization
Easily stored
Non-desiccating to the animal
Uncontaminated
Non-nutritious
Non-palatable |
Unlikely to be
chewed or mouthed
Non-toxic
Non-malodorous
Nestable
Disposable by incineration
Readily available
Relatively inexpensive
Fire resistant
Remains chemically stable during use
Manifests batch to batch uniformity
Optimizes normal animal behaviour
Non-deleterious to cage-washers
Non-injurious and non-hazardous to personnel |
Unsterilized materials are a possible source
for the introduction of disease into rodent colonies. Wild rodents enjoy
nesting in packages of bedding, and cats will defecate in loose bedding
(Newman and Kowalski, 1973). Recommended bedding materials for each species
are discussed in Volume 2 of this Guide.
4. Population Density
and Space Limitations
Population density and group size influence
the physiological and psychological state of the animal and can profoundly
affect experimental responses (Baer, 1971; Clough, 1976). Productivity,
growth, and behaviour of laboratory mice may be seriously altered by variations
in floor space alone. Infant growth and survival, as well as maternal behaviour,
may be adversely affected by excessive floor space. Infant mortality in
large cages can occur from failure of females to nurse their young due
to inhibition of mammary development. Nest-building behaviour in rats is
adversely affected in densely populated pens, leading to an increasing
tendency to ignore the pups and to infant death. Housing density can affect
efficiency of feed utilization and the incidence of skin lesions (Les,
1968, 1972).
Isolation stress may result in increases
in nervousness, aggression, susceptibility to convulsions and certain drugs,
metabolism, and adrenocortical activity (Balazs and Dairman, 1967; Hatch,
Weiberg, Zawidzka et al. 1965; Moore, 1968). As much as possible,
housing type and densities should be kept uniform throughout a study. Further
details on appropriate housing (see also Laboratory Animal Facilities).
Individual species requirements are discussed in Volume 2 of this Guide
(see also Social and Behavioural Requirements of Experimental Animals).
Recommended housing densities are listed in Appendix I.
C. MICROBIOLOGICAL
CONTROL
The effects that microbiological agents
can have on experimental results and the health of laboratory animals have
been widely documented (Baker, Lindsey and Weisbroth, 1979; Lindsey, Connor
and Baker, 1978; Pakes, Lu and Meunier, 1984). Control of the microbiological
status of the experimental animal and its environment is necessary for
valid scientific results and animal well-being. The sources of microbial
contamination include vermin, experimentally infected and spontaneously
ill laboratory animals or their tissues or tumours, air, food, water, bedding,
ancillary equipment, and personnel. Good facility management practices
and constant surveillance are necessary to minimize the introduction of
unwanted microbes. Insect and rodent vermin should be strictly controlled
or excluded from the facility (Small, 1983).
Whenever possible, the health status of
all animals should be ascertained before the animal is brought into the
facility. Animals having an unknown health status should be quarantined
and tested before being admitted to the facility (Loew and Fox, 1983).
Additionally, all tumour and cell lines should be tested before being introduced
(Small, 1984). Research on contagious diseases must be carried out in appropriate
containment facilities (see 3. below).
The laboratory animal veterinarian should
be consulted about regular monitoring of the health status of animals within
a facility, as it is important to verify the microbiological standing for
publication of experimental results and to minimize cross-contamination
between areas (Baker, Lindsey and Weisbroth, 1979). The use of sentinel
animals is one proven, sensitive, and practical component of an animal
health surveillance program (Loew and Fox, 1983). Health monitoring programs
should consider the source and species of animal, husbandry practices,
the nature of research carried out in the facility, and the association
of personnel with laboratory animals in other locations. The efficacy of
cage and equipment sanitation should be tested periodically by culturing
for microorganisms, as well as by checking physical indicators (Baker,
Lindsey and Weisbroth 1979; Small, 1983). Feed, water, and bedding should
also be sampled and cultured periodically. The frequency and intensity
of microbiological monitoring programs will be dependent upon husbandry
practices, the level of confidence desired, associated risk factors, and
economics, in addition to the factors mentioned above (Small, 1984).
Personnel must be instructed in the precautions
they must take to avoid introducing diseases into the facility. The specific
precautions will vary between areas and facilities, depending upon the
nature of the facility, the status of the animals, and the type of research
being conducted. The co-operation of all staff working with animals, in
both caretaking and experimental activities, is essential to maintain facility
and scientific standards.
1. Conventional Facilities
A conventional room or facility is one
which is not especially designed for isolation procedures. An isolation
unit could operate conventionally if isolation management practices are
not employed. The following practices reduce the probability of contamination
in a conventional facility:
- Personnel should wear
clean clothing and outer protective garments in animal rooms.
- Personnel should wash
their hands upon entering and leaving a room.
- There should be no
movement of personnel and equipment between rooms which house animals
of different
microbial
status without proper precautions.
- Animals entering shared
facilities, such as laboratories, surgery, irradiators, etc., should not
be returned to
the holding room
unless the shared room and equipment therein have been disinfected between
groups of
animals.
- Cleaning and sanitation
practices as outlined in Laboratory Animal Care should be followed.
2. Barrier Facilities
Gnotobiotes, SPF breeding colonies, aging
study colonies, and immunodeficient or immunosuppressed animals require
a higher level of control of the microbial environment than practised in
conventional housing (Hessler and Moreland, 1984). Barrier housing prevents
infectious agents from entering and infecting animals inside the barrier.
Barriers can be established at the room level as in large-scale commercial
production of disease-free rodents; around groups of cages as for gnotobiotes
or breeding colony nuclei in free-standing flexible film isolators; or
at the level of the individual cage as in microisolation cages.
Closed barrier systems employ variations
of the following principles:
- The room, isolator,
or isolation cage is sterilized chemically or physically prior to entry
of animals, supplies,
or equipment.
- Animals enter through
ports from isolators or transport containers which prevent contamination.
- All other materials,
supplies, and equipment are sterilized before entering the barrier.
- Effective entry and
exit systems include pass-through autoclaves, sterilized double-door transfer
chambers,
or germicidal
dunk tanks.
- Exits from large barriers
may be through airlocks with powerful exhaust coming from the inside of
the unit.
- Personnel must shower,
dress in sterile garments, and don head covers, masks and Gloves before
entering
a large barrier.
- The interior of smaller
isolators is accessed through rubber or neoprene gloves sealed to the isolation
unit.
- Incoming air is filtered
with high-efficiency particulate air (HEPA) filters and air pressures are
carefully
balanced to consistently
prevent backflow into the barrier.
- Water is sterilized
through filtration, UV light, acidification, or autoclaving.
- Feed and bedding are autoclaved
or irradiated before entering the barrier. Special enriched diets must
be
used if the feed is
to be autoclaved (Hessler and Moreland, 1984).
Microisolation cages are generally used
to protect animals in otherwise conventional rooms. With laminar flow cage-changing
stations and special management procedures (sterilization of feed, bedding,
water, etc.), highly disease-susceptible animals such as thymus deficient
and Severe Combined Immune Deficiency (SCID) mice may be successfully maintained
in a conventional room. Rigorous microbiological monitoring is necessary
to maintain and verify the health status of animals kept in barrier-sustained
systems.
3. Biohazard Containment
Containment is required for animals exposed
to known infectious microorganisms. Required containment and management
procedures vary with the biohazard classification of the microorganism,
based on the degree of risk to man and other animals (HWC/MRC, 1990). Personnel
may be required to shower before leaving the containment unit. All cages
and materials are sterilized upon leaving the area. Air pressures are balanced
so that the highest pressure is outside the containment area. Air exiting
the facility is diluted with clean air, filtered, or incinerated. Because
it is hazardous to staff and animals, UV light is not generally recommended
for routine disinfection of laboratory air. The infectious disease unit
should be segregated as much as possible from the rest of the animal facility.
Specific requirements will differ with the degree of risk. Depending on
the hazard, containment of small groups of animals may be accomplished
with flexible film isolators or microisolation cages. The use of laminar
airflow racks to prevent cross-contamination between cages should be carefully
evaluated as the transfer of certain pathogens may be enhanced in some
instances (Clough, 1973). Infectious disease units should be disinfected
immediately following use. Recommendations for control of biohazards can
be found in Laboratory Biosafety Guidelines (HWC/MRC, 1990)
and elsewhere (Barkley and Richardson, 1984). Biological safety cabinets
approved for the appropriate biohazard level must be used for experimental
manipulations. These cabinets must be inspected and tested annually by
trained personnel (HWC/MRC, 1990).
Persons working in infectious disease units
should be protected with a comprehensive occupational health and safety
program.
D. CHEMICAL AND RADIOISOTOPE
UNITS
In Canada, laboratory use of radioisotopes
is regulated by the (federal) Atomic Energy Control Board (AECB), in accordance
with the Atomic Energy Control Regulations. The AECB issues licences to
the institution for the possession of radioactive material. When radioisotopes
are used in animals experimentally, Standard Operating Procedures (SOPs)
to ensure that related hazards are minimized should be defined and enforced;
these SOPs are considered by the AECB when it issues the Radiation Licence.
As well, the AECB recommends that the institution's Radiation Safety Officer
sit on the Occupational Health and Safety Committee in an ex-officio
capacity.
The Workplace Hazardous Materials Information
System (WHMIS) is regulated by federal and provincial health and safety
authorities. It legislates labelling requirements, availability of Material
Safety Data Sheets (MSDS), and training programs required for personnel
to work safely with certain hazardous materials.
The chemical and radiation hazard area
should be separated from other animal housing and work areas. The hazardous
area must be clearly posted and entry restricted to necessary personnel.
Contaminated cages should not be transported through corridors. Safe transport
equipment and procedures should be developed if necessary. Laminar flow
cage-changing stations are recommended to protect the staff from aerosolized
contaminants (Hessler and Moreland, 1984) (see also Occupational Health
and Safety).
E. REFERENCES
AGNES, F., SARTORELLI, P., ABDI, B.H. and
LOCATELLI, A. Effect of transport loading or noise on blood biochemical
variables in calves. Am. J. Vet. Res. 1990; 51: 1679-1681.
ALGERS, B. A note on behavioural responses
of farm animals to ultrasound. Appl. Anim. Behav. Sci. 1984; 12: 387-391.
ALLEN, D.M. A device providing gradual
transitions between light and dark periods in the animal room. Lab. Anim.
Sci. 1980; 30: 252-254.
BAER, H. Long-term isolation stress and
its effects on drug response in rodents. Lab. Anim. Sci. 1971; 21: 341-349.
BAILEY, K.J., STEPHENS, D.B. and DELANEY,
C.E. Observations on the effects of vibration and noise on plasma ACTH
and zinc levels, pregnancy and respiration rate in the guinea pig. Lab.
Anim. 1986; 20: 101-108.
BAKER, H.J., LINDSEY, J.R. and WEISBROTH,
S.H. Housing to control research variables. In: Baker, H.J., Lindsey, J.R.
and Weisbroth, S.H., eds. The laboratory rat. Toronto, Ont.: Academic Press,
1979(1): 169-192.
BALAZS, T. and DAIRMAN, W. Comparison of
microsomal drug-metabolizing enzyme systems in grouped and individually
caged rats. Toxicol. Appl. Pharmacol. 1967; 10: 409-410.
BARKLEY, W.E. and RICHARDSON, J.H. Control
of biohazards associated with the use of experimental animals. In: Fox,
J.G., Cohen, B.J. and Loew, F.M., eds. Laboratory animal medicine. Toronto,
Ont.: Academic Press, 1984: 595-602.
BELHORN, R.W. Lighting in the animal environment.
Lab. Anim. Sci. 1980; 30: 440-450.
BESCH, E.L. Environmental quality within
animal facilities. Lab. Anim. Sci. 1980; 30: 385-406.
BRODERSON, J.R., LINDSEY, J.R. and CRAWFORD,
J.E. The role of environmental ammonia in respiratory mycoplasmosis of
rats. Am. J. Path. 1976; 85: 115-127.
BUREK, J.D. and SCHWETZ, B.A. Considerations
in the selection and use of chemicals within the animal facility. Lab.
Anim. Sci. 1980; 30: 414-421.
CANADIAN COUNCIL ON ANIMAL CARE. Guide
to the care and use of experimental animals. Vol. 2, Ottawa, Ont.: CCAC,
1984.
CLOUGH, G., HILL, A. and BLACKMORE, D.K.
Evaluation of a filter rack for laboratory rodents. Lab. Anim. 1973; 7:
149-159.
CLOUGH, G. The immediate environment of
the laboratory animal. In: McSheehy, T., ed. Control of the animal house
environment. Laboratory animal handbook 7. Buckden Huntington, Cambs.,
U.K.: Laboratory Animals Ltd., 1976: 77-94.
CLOUGH, G. Environmental factors in relation
to the comfort and well-being of laboratory rats and mice. Proc. of LASA-UFAW
(Universities Federation for Animal Welfare) Symposium "Standards in Laboratory
Animal Management" UFAW, 1984(1): 60-64.
CLOUGH, G. The animal house: design, equipment
and environmental control. In: Poole, T., ed. UFAW (Universities Federation
for Animal Welfare) handbook on the care and management of laboratory animals.
6th Ed. Harlow, Essex: Longman Scientific and Technical, 1987.
CORNING, B.F. and LIPMAN, N.S. A comparison
of rodent caging systems based on microenvironmental parameters. Lab. Anim.
Sci. 1992; 41: 498-503.
DAVIS, D.E. Social behavior in a laboratory
environment. In: National Research Council Institute of Laboratory Animal
Resources. Laboratory animal housing. Washington, DC: National Academy
of Sciences, 1978: 44-64.
EUROPEAN CONVENTION FOR THE PROTECTION
OF VERTEBRATE ANIMALS USED FOR EXPERIMENTAL AND OTHER SCIENTIFIC PURPOSES.
Appendix A: Guidelines on accommodation and care. Report No. 123, HMSO,
London 1986.
FALK, S.A. and WOODS, N.F. Hospital noise
levels and potential health hazards. New Eng. J. Med. 1973; 289: 774-781.
FALL, M.W. The use of red light for handling
wild rats. Lab. Anim. Sci. 1974; 24: 686-687.
FLETCHER, J.L. Influence of noise on animals.
In: McSheehy, T., ed. Control of the animal house environment. Laboratory
animal handbook 7. Huntingdon, U.K.: Laboratory Animals Ltd., 1976.
GAMBLE, M.R. and COUGH, G. Ammonia buildup
in animal boxes and its effect on rat tracheal epithelium. Lab. Anim. 1976;
10: 93-104.
GERBER, W.F., ANDERSON, T.A. and VAN DYNE,
V. Physiologic response of the albino rat to chronic noise stress. Arch.
Environ. Health 1966; 12: 751-754.
GERBER, W.F. and ANDERSON, T.A. Cardiac
hypertrophy due to chance audiogenic stress in the rat, Rattus norvegicus
and rabbit, Lepus cuniculus. Comp. Biochem. Physiol. 1967; 21: 273-277.
HATCH, A.M., WIBERG, G.S., ZAWIDZKA, Z.,
CANN, M., AIRTH, J.M. and GRICE, H.C. Isolation syndrome in the rat. Toxicol.
Appl. Pharmacol. 1965; 7: 737-745.
HEALTH AND WELFARE CANADA/MEDICAL RESEARCH
COUNCIL. Laboratory biosafety guidelines. Ottawa, Ont.: Office of Biosafety,
Laboratory Centre for Disease Control, Health and Welfare Canada, 1990.
HESSLER, J.R. and MORELAND, A.F. Design
and management of animal facilities. In: Fox, J.G., Cohen, B.J. and Loew,
F.M., eds. Laboratory animal medicine. Toronto, Ont.: Academic Press, 1984:
505-526.
ITURRIAN, W.B. Effect of noise in the animal
house on experimental seizures and growth in weanling mice. In: National
Academy of Sciences. Defining the laboratory animal. Washington, DC: National
Academy of Sciences, 1971.
KELLER, L.S.F., WHITE, W.J., SNIDER, M.T.
and LANG, C.M. An evaluation of intracage ventilation in three animal caging
systems. Lab. Anim. Sci. 1989; 39: 237-242.
KRAFT, L.M. The manufacture, shipping,
and receiving and quality control of rodent bedding materials. Lab. Anim.
Sci. 1980; 30: 366-376.
KRAICER, J., BERAUD, G. and LYWOOD, D.W.
Pars intermedia ACTH and MSH content: effect of adrenalectomy, gonadectomy
and a neurotropic (noise) stress. Neuroendocrinol. 1977; 23: 352-367.
LES, E.P. Cage population density and efficiency
of feed utilization in inbred mice. Lab. Anim. Care 1968; 18: 305-313.
LES, E.P. A disease related to cage population
density, tail lesions and C3H/HeJ mice. Lab. Anim. Sci. 1972; 22: 56-60.
LINDSEY, J.R., CONNER, M.W. and BAKER,
H.J. Physical, chemical, and microbial factors affecting biologic response.
In: National Research Council/Institute of Laboratory Animal Resources.
Laboratory animal housing. Washington, DC: National Academy of Sciences,
1978: 44-64.
LOEW, F.M. and FOX, J.G. Animal health
surveillance and health delivery systems. In: Foster, H.L., Small, J.D.
and Fox, J.G., eds. The mouse in biomedical research. III. Normative biology,
immunology, and husbandry. Toronto, Ont.: Academic Press, 1983: 83-100.
MCGARRITY, G.J. and CORIELL, L.L. Maintenance
of axenic mice in open cages in mass airflow. Lab. Anim. Sci. 1976; 26:
746-750.
MCSHEEHY, T. Overview of the state-of-the-art
in environmental monitoring. In: Melby, E.C. Jr. and Balk, M.W., eds. The
importance of laboratory animal genetics, health, and the environment in
biomedical research. Toronto, Ont.: Academic Press, 1983; 161-182.
MELBY, E.C. JR. and BALK, M.W., eds. The
importance of laboratory animal genetics, health, and the environment in
biomedical research. Toronto, Ont.: Academic Press, 1983.
MOORE, K.E. Studies with chronically isolated
rats: tissue levels and urinary excretion of catecholamines and plasma
levels of corticosterone. Can. J. Physiol. Pharmacol. 1968; 46: 553-558.
MULDER, J.B. Animal behaviour and electromagnetic
energy waves. Lab. Anim. Sci. 1971; 21: 389-393.
NATIONAL RESEARCH COUNCIL. Committee on
Care and Use of Laboratory Animals of the Institute of Laboratory Animal
Resources, Commission on Life Sciences. Guide for the care and use of laboratory
animals. NIH Publication No. 85-23. Bethesda, MD: United States Department
of Health and Human Services, Public Health Service, National Institutes
of Health, 1985.
NAYFIELD, K.C. and BESCH, E.L. Comparative
responses of rabbits and rats to elevated noise. Lab. Anim. Sci. 1981;
31: 386-390.
NEWMAN, E. and KOWALSKI, J.J. Fresh sawdust
bedding - a possible source of Klebsiella organisms. Am. J. Vet. Res. 1973;
34: 979-980.
PAKES, S.P., LU, Y.S. and MEUNIER, P.C.
Factors that complicate animal research. In: Fox, J.G., Cohen, B.J. and
Loew, F.M., eds. Laboratory animal medicine. Toronto, Ont.: Academic Press,
1984: 649-665.
PETERSON, E.A. Noise and laboratory animals.
Lab. Anim. Sci. 1980; 30: 422-439.
PFAFF, J. Noise as an environmental problem
in the animal house. Lab. Anim. 1974; 8: 347-354.
PHILLIPS, G.B. and RUNKLE, R.S. Biomedical
applications of laminar airflow. Cleveland, OH: CRC Press, 1973.
SALES, G.D., WILSON, K.J., SPENCER, K.E.V.
and MILLIGAN, S.R. Environmental ultrasound in laboratories and animal
houses: a possible cause for concern in the welfare and use of laboratory
animals. Lab. Anim. 1988; 22: 363-375.
SEMPLE-ROWLAND, S.L. and DAWSON, W.W. Retinal
cyclic light damage threshold for albino rats. Lab. Anim. Sci. 1987; 37:
289-298.
SERRANO, L.J. Carbon dioxide and ammonia
in mouse cages: effects of cage covers, population, and activity. Lab.
Anim. Sci. 1971; 21: 75-85.
SILVERMAN, J. and ADAMS, J.D. N-nitrosamines
in laboratory animal feed and bedding. Lab. Anim. Sci. 1983; 33: 161-164.
SMALL, J.D. Environmental and equipment
monitoring. In: Foster, H.L., Small, J.D. and Fox, J.G., eds. The mouse
in biomedical research. III. Normative biology, immunology, and husbandry.
Toronto, Ont.: Academic Press, 1983: 83-100.
SMALL, J.D. Rodent and lagomorph health
surveillance - quality assurance. In: Fox, J.G., Cohen, B.J. and Loew,
F.M., eds. Laboratory animal medicine. Toronto, Ont.: Academic Press, 1984:
709-723.
WEIHE, W.H. The effect of light on animals.
In: McSheehy, T., ed. Control of the animal house environment. Laboratory
animal handbook 7. Buckden, Huntingdon, Cambs., U.K.: Laboratory Animals
Ltd., 1976: 63-76.
WEISBROTH, S.H. Chemical contamination
of lab animal beddings: problems and recommendations. Lab. Animal Nov.-Dec.
1979: 24-34.
WELCH, B.L. and WELCH, A.S., eds. Physiological
effects of noise. New York, NY: Plenum Press, 1970.
WOODS, J.E. The animal enclosure - a microenvironment.
Lab. Anim. Sci. 1980; 30: 407-413.
WORKING COMMITTEE FOR THE BIOLOGICAL CHARACTERIZATION
OF LABORATORY ANIMALS/GV-SOLAS. Guidelines for specification of animals
and husbandry methods when reporting the results of animal experiments.
Lab. Anim. 1985; 19: 106-108.
YAMAUCHI, C., FUJITA, S., OBARA, T. and
UEDA, T. Effects of room temperature on reproduction, body and organ weights,
food and water intake, and hematology in rats. Lab. Anim. Sci. 1981; 31:
251-258.
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