Share thisDeal with noise and vibration issues during planning, design, and construction to avoid costly corrections.
When planning and designing animal research facilities careful consideration should be given to control noise and vibration to avoid disturbing laboratory animals. Excessive noise and vibration can potentially disrupt sleep and contribute to stress, as well as alter animal breeding cycles and other activity patterns.1,2,3
While the effects of noise and vibration on animals are difficult to quantify, the potential risk of contaminating research data is ever-present. Determining with confidence that ambient noise and vibration may be the cause of spurious data is virtually impossible, and for that reason proper facility planning, design, and construction is necessary to avoid later corrections that may not be practicable.4
To minimize noise and vibration as a research variable, qualified design and construction professionals should conduct interviews with user groups to establish appropriate facility requirements including appropriate noise and vibration design criteria, resolve site constraints and proper space layouts for programmed uses. This article discusses key steps in dealing with noise and vibration during planning, design and construction of animal research facilities.
Facility Requirements and Selection of Design Criteria
Clearly defining facility requirements at the start with the users and key stakeholders will enable the design team to identify and consider segregating areas of high noise and vibration (cage wash and bedding dispenser equipment, sterilizers, large animal holding rooms, mechanical equipment rooms, loading docks, etc.) and areas that are sensitive to noise and vibration (animal holding rooms, behavioral testing suites, microscopy and imaging suites).
For facilities that house several animal species, it is imperative that very noisy animals such as canines, swine, and non-human primates be strictly segregated from mice and rodent populations. This is extremely challenging and requires detailed design coordination to avoid incompatible adjacencies and develop occupant circulation paths and ventilation schemes that provide the appropriate acoustic and vibration environment in the completed facility.
After careful review of facility requirements and discussion with researchers, acoustic and vibration criteria must be verified for all interior spaces. Such criteria for animal holding areas can vary between facilities, as industry standards are not well established. For example, the Guide for the Care and Use of Laboratory Animals states that “exposure to sound louder than 85dB (linear) can have both auditory and non-auditory effects”; however little is known about the effects of prolonged exposure to lower levels of noise with varying frequency content. Further studies are warranted to more appropriately develop acoustic sensitivities for various animal species.5
When determining the background noise criteria for different animal research spaces (holding rooms, behavioral testing suites, etc.) the frequency content must also be considered, as laboratory animals can hear frequencies above the range of human hearing (20Hz to 20kHz), and are generally less sensitive to low-frequencies (below 500Hz).6,7
Furthermore, most noise criteria typically used in building design are based on human comfort and may not reflect animal sensitivities.8 Designing for frequencies above the range of human hearing creates new challenges, from having sound level meters that measure ultrasonic frequencies (above 20 kHz) to obtaining valid sound data from equipment manufacturers and materials used in building construction to carry out the requisite level of analysis.
In addition to acoustic noise, vibration sensitivities for different animal species should also be used to establish vibration design criteria. The threshold of human vibration perception (4,000micro-inches/sec or 100micro-meters/sec) is commonly used as the floor vibration criterion for vivarium projects with some institutions allowing higher or lower limits depending on past experiences and anticipated future research activities.
Vibration criteria for research spaces typically range between 1,000micro-inches/sec and 4,000microinches/ sec with the exception of areas with high-end microscopy and imaging equipment that require lower vibration levels. The selection of appropriate vibration criteria can have a profound effect on structural costs and ought to be considered from the outset of the project. There are no data to confirm that this level of vibration performance is also acceptable for various animal species, so studies should be undertaken to establish thresholds of vibration perception to animal species.
Vibration design for structural systems is based on limiting floor vibration due to footfall excitation. There are standardized methods for structural vibration design that use standard walking paces that range from “slow” (50 paces/min) to “moderate” (75 paces/min) to “fast” (100 paces/min), or even higher.9 The walking pace should be selected for each area based on space layout and circulation paths, and needs to be explicitly defined in the analysis as this has a profound effect on the results. The same vibration criteria must also be met by the building mechanical equipment as well as external sources of vibration such as street traffic and trains.
Site Selection
For new or existing facilities, site evaluation should include ambient noise and vibration surveys to determine compatibility and identify constraints to be taken into account during space planning and building design. Such feasibility studies should be conducted before commitments to a particular site have been made, as some sites, at least partially, may not be suitable for all research uses.
For new buildings, ground vibration surveys are useful for identifying specific areas of the site suitable for vibration-sensitive uses. Vibration exposure maps based on these surveys should be developed and used to properly locate vibration-sensitive areas. Ambient noise surveys should also be undertaken, especially for urban sites, or sites near major roads, highways, airports, or industrial facilities.
For renovation projects, surveying existing noise and vibration conditions is even more important and would also depend greatly on the sensitivity of planned uses. For example, if behavioral testing or imaging suites that require low noise and vibration levels are planned inside an existing facility, ambient conditions need to be monitored and used to determine how such uses can best be accommodated.
It is also beneficial to review zoning in the area and inquire with local agencies about current and future development plans for the project vicinity, as some uses may not be compatible with animal research facilities. Establishing research districts that clearly outline acceptable uses and construction methods is an effective method for avoiding potential issues with future developments.
If buildings in the area will be constructed after the facility is operational, zoning restrictions and conditions of project approval should be sought with local authorities to ensure that noise and vibration levels are limited to acceptable levels and kept in check throughout construction. Certain high energy construction activities such as pile driving, excavation, and demolition on neighboring properties can have adverse impacts on laboratory animals and ought to be properly taken into consideration or avoided.
Facility Planning
Planned future expansions and/or renovations should be carefully reviewed during the design of each animal research facility. To minimize noise and vibration exposure to animals in an existing facility during expansion and renovation, tasks that involve heavy construction should be completed as part of the base-building. Some construction activities and equipment may not be suitable and alternative methods should be evaluated with regards to noise and vibration and associated cost and schedule implications. Provisions to temporarily relocate animals or to provide upgraded constructions should be options to explore.
An important first step in designing animal research facilities is to define how spaces should be laid out. By not locating noisy or vibration producing areas next to or near spaces sensitive to noise and vibration, many design conflicts can be avoided. It may seem trivial, but the decision to locate certain spaces on an elevated floor versus on a concrete slab that is in contact with the ground (e.g. on-grade slabs) is important to consider during space planning. In general, spaces with activities that produce substantial noise and vibration, and spaces that are sensitive to noise and vibration, can be most easily accommodated on thick on-grade concrete slabs or in basements.