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Research and testing laboratories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
World at work: Research and testinglaboratoriesR J Emery, G L Delclos. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spotlight on a diverse industry
Manufacturing facilities typicallyfocus on the creation of a finitearray of products in large
volumes. Consequently, the potentialhazards inherent to these workplacesare limited in scope, although they maybe high in output. On the other hand, aresearch and testing laboratory performstesting and diagnostic evaluation ofsamples, a setting not typically withinthe production line sequence; hence, thelikelihood of exposures to large volumesof potentially hazardous agents isusually much lower. However, thesophisticated analytical procedures con-ducted in laboratory settings ofteninvolve the use of a variety of exoticand potentially hazardous agents. It isthis array of hazards, combined withdifferences among potentially exposedindividuals, that makes the laboratorysetting a unique working environment.
TASKS OF THE JOBLaboratories are ubiquitous in today’sworld, are designed to fulfil variousroles, and can vary markedly in size,from that of a small closet area tomultiple floors in large buildings.Commercially operated laboratories pro-vide analytical testing services for pro-ducts, such as processed food, or areinvolved in the research and develop-ment of new products. Governmentsoperate laboratories for quality controlpurposes to ensure product integrity andperformance. Governments also operateforensic laboratories for the identifica-tion of evidence in crimes or to deter-mine cause of death. Healthcarefacilities maintain medical, clinical,and/or veterinary laboratories to accom-modate the processing of clinical speci-mens for medical diagnoses, whereasuniversities house laboratories directedat research endeavours. Based ondata from the United States Bureauof Labor Statistics, in 2003 there weremore than 430 000 persons employed inmedical, diagnostic, veterinary, and/ortesting laboratories—that is, approxi-mately 0.3% of the civilian workforce(http://www.bls.gov/oes/2003/may/oessrci.htm).
Regardless of their purpose or setting,all laboratories share certain character-istic tasks. In a broad sense, the tasksinherent to laboratory work includesome or all of the following: develop-ment of testing protocols and samplingstrategies; instrument calibration andinternal quality assurance; product sam-pling and collection; transport anddelivery of samples to the laboratory;receipt and recording of sample entry;sample preparation; sample analysis;calculation and reporting of results;and waste disposal. Of these tasks, thoseof greatest concern for potentially hazar-dous exposures involve sample collec-tion, preparation, and analysis.
All laboratories perform analysesusing equipment and techniques thatsubject samples to extreme physical,chemical, radiological, and/or biologi-cal conditions, often simultaneously. Inturn, these procedures represent poten-tially hazardous exposures to workersin and around these settings. Effectiveimplementation of controls and protec-tive measures for these workers requiresan in-depth appreciation of the com-plexities of the laboratory workenvironment.
In addition to the various potentialhazards that may be present in thelaboratory work setting, it is importantto consider the diversity of the potentialat-risk population. First are the labora-tory workers themselves. These indivi-duals are recruited, hired, trained, andreceive direct compensation for theirefforts; their adherence to acceptedwork practices can be a condition ofcontinued employment or annual per-formance evaluations. However, thesekinds of administrative controls maynot extend to other individuals whocan spend time in a laboratory, includ-ing students, volunteers, and visitingscholars. Because of the cyclical natureand variable duration of such exchangesand visits, these persons may not besubjected to the same surveillancemeasures, workplace monitoring,hazard awareness training, safety per-formance assessment, controls, orexpectations afforded to usual labora-tory employees.
HAZARDS OF THE JOB AND INTHE WORKPLACEThe potential hazards present in alaboratory environment can be classi-fied, from a pragmatic standpoint, intofour main categories: chemical, physical,radiological, and biological. Each agentclass exhibits a unique set of concerns,warranting specialised attention.
Chemical hazardsGiven their large number, a detaileddiscussion of individual chemical agentsused in laboratory settings is beyond thescope of this article. However, analysisof laboratory samples typically involvesa series of elaborate processes that allowthe isolation of a specific characteristicof a compound. In the processing andanalysis of these samples, a wide arrayof exotic hazardous chemicals may beused, which can be broadly classified bythe health and safety risks inherent intheir use. These risk categories includecarcinogens, toxic or highly toxic agents,reproductive toxins, irritants, corrosives,sensitisers, hepatotoxins, nephrotoxins,neurotoxins, haematopoietic systemtoxins, and agents which damage thelungs, skin, eyes, or mucous mem-branes.1 The most likely routes ofexposure are inhalation and absorptionthrough skin or mucous membranes.
In comparison to private industry as awhole, where trends in the incidence ofboth work related skin disorders andacute toxic inhalations have beendeclining steadily since 1998, rates inlaboratory settings have either fluctu-ated or increased (table 1).
Physical hazardsIn addition to the hazards representedby the intrinsic toxicity of a chemicalagent, its physical state may also pose ahealth hazard (for example, combustibleliquids, compressed gas, explosive, flam-mable, pyrophoric compounds, andcompounds that are unstable or waterreactive).
From an ergonomic standpoint,laboratory analytical techniques canrequire long periods of standing on hardfloors or sitting in one position, togetherwith the performance of repeated tasks,increasing the chances of low back painand other musculoskeletal discomfort.Work surfaces not matched to theworker’s height and inadequate tasklighting in the work area can also causework discomfort. Repetitive proceduressuch as opening and closing vial caps,pipetting (fig 1), and sample sortinghold the potential to result in repetitivemotion injuries or other cumulativetrauma. Similar concerns exist whenprolonged periods of data entry or othercomputer based work are required. Inselected laboratory settings, such as
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animal research work areas, chronicexposure to noise may also be anadditional physical hazard of concern.
A review of occupational illness ratesin the United States in private industry,for the years 1998 to 2001 (mostrecently available data), indicates thatthe incidence of cases due either tophysical agents or repetitive trauma inmedical and dental laboratories areconsistently higher than those forindustry as a whole (table 1).
Radiological hazardsSources of both ionising and non-ionis-ing radiation are commonly employed inlaboratory analytical procedures, mostnotably in government and universityresearch settings. For example, almost80% of all biochemical research fundedby the US National Institutes of Healthincludes use of radiation in some formor fashion, and the evaluation of 90% ofall new pharmaceutical drugs approvedby the US Food and Drug Admini-stration involves radionuclide basedtesting.2 Ionising radiation sources inthe form of radionuclide tracers are usedto label chemical compounds to deter-mine their fate in various systems. Theamount of activity used in such tracerexperiments is typically small, measuredin the microcurie to megabecquerelrange, so the potential for acute biolo-gically significant whole body doses isquite low. However, since the materialused in radiotracer experiments is oftenin an unsealed form, the possibilityexists for internal organ exposurethrough inhalation or ingestion.
Higher activity sources of encapsu-lated radioactive materials, with dosesin the curie to gigabecquerel range, maybe used to irradiate products. Forexample, blood banks may irradiatewhole blood products to decreasechances of a graft-versus-host reactionin immunosuppressed patients. In suchoperations, the sources are typicallyhoused in a specially designed devicethat precludes direct accessibility to theradioactive source.
Lasers have become a common sourceof non-ionising radiation used in labora-tories. Laser systems are classifiedaccording to the possible threat theyrepresent to key organ systems such asthe eye and skin, ranging from class I,which does not present harm duringuse, to class IV, which can producesignificant eye and/or skin damage.3
Other sources of non-ionising radiationin laboratories include radio frequency,microwave, and infrared radiation.Although acute health effects such asburns or localised heating from expo-sure to non-ionising radiation are wellrecognised, the possibility of chroniceffects is still being evaluated.4
Biological hazardsPotentially infectious agents may beencountered in laboratories, such asmicrobiology laboratories, when analys-ing samples derived from humans,plants, or animals, and risks associatedwith handling such specimens aredependent on the specific microorgan-ism and the pathway of exposure. Ahallmark series of elegant surveys con-ducted many years ago by Sulkin andPike on laboratory acquired infectionsshowed that laboratory acquired infec-tions paralleled the prevalent infectiousdiseases at the time, and were mostlikely transmitted via procedures thatresulted in the creation of aerosols.5 6 Onthe other hand, infectious agents suchas human immunodeficiency virus,hepatitis B, and hepatitis C viruses areprimarily transmitted in the laboratorysetting via percutaneous transmission orcontact with mucous membranes ornon-intact skin; in these cases, the mostcommon vehicles of transmission areneedles and cutting sharps. Morerecently, occupationally acquired infec-tions caused by ‘‘new’’ microorganisms,such as West Nile virus, have beendocumented in laboratory workers.7
Simultaneous exposuresCompounding the diversity of potentialhazards present in the laboratory settingare situations involving simultaneousexposures, which can be commonplace.For example, it is not unusual toencounter a laboratory environmentwhere individuals work in a building(with its concurrent physical hazards),and perform extractions on potentiallyinfectious biological materials usingchemical solvents and radioisotope tra-cers. The appropriate design and imple-mentation of safety measures to controlsuch simultaneous exposure situationswarrants a sound understanding of therisks and associated controls for eachtype of agent on both the part of theworker and the occupational healthprofessionals supporting the operations.
Table 1 Trends in incidence rates* of occupational illness for all private industryand research/testing laboratories, United States, 1998–2001
Occupational illnesscategory Year
All privateindustry
Medical and dentallaboratories Testing services
Overall 1998 1.9 4.3 0.21999 1.7 11.1 2.22000 1.5 2.5 1.72001 1.6 8.1 0.6
Skin disorders 1998 6.0 4.4 2.21999 4.9 3.9 3.12000 4.6 6.7 4.32001 4.3 3.6 5.3
Toxic inhalations 1998 2.0 2.0 1.41999 1.8 4.9 2.52000 1.6 1.4 4.62001 1.6 2.9 4.2
Physical agents 1998 1.9 4.3 0.21999 1.7 11.1 2.22000 1.5 2.5 1.72001 1.6 8.1 0.6
Repetitive trauma 1998 28.5 33.0 22.81999 27.3 35.2 25.12000 26.3 30.7 15.12001 23.8 42.0 22.9
*Cases per 10 000 full time employed workers.Source: US Bureau of Labor Statistics, www.bls.gov.
Figure 1 Repetitive tasks, such as pipetting,are common in research and clinicallaboratories.
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Thus, a laboratory procedure involvingthe manipulation of potentially infec-tious agents may require the use of anenclosure device such as a biologicalsafety cabinet, but if the processinvolves an ignition source and poten-tially flammable chemicals with lowervapour pressures, gases could accumu-late in the safety cabinet enclosure andcause an explosion. Likewise, personalprotective equipment intended for onehazard may not provide adequate pro-tection against a second agent. A classicexample would be the use of latexgloves, which provide protection againstthe transmission of infectious agentsthrough breaks in the skin, but couldallow permeation of certain chemicals.
OCCUPATIONAL HEALTH ANDSAFETY MANAGEMENTThe protection of workers in laboratoryenvironments requires a combination ofclear management commitment, appro-priate facility design, engineering con-trols, worker training, personal protectiveequipment, routine surveillance, periodicaudits and inspections, and effectivecommunication. Ultimately, though, aneffective health and safety programmedepends most critically on upper manage-ment support and commitment. Whenupper management clearly articulates itsdedication to maintaining a work envir-onment that is safe and healthy, theremaining necessary protective measuresbecome easier to implement.
Facili ty design and engineeringcontrolsCentral to the protection of workers isproper planning and design of the
laboratory environment, which hasevolved markedly over the past 30 years.The design should be comprehensive,with attention to areas for storage ofchemicals (fig 2), general and localexhaust ventilation, adequate worksta-tion design and task lighting (fig 3),implementation of appropriate fumehoods and wash basins, disposal oflaboratory waste, and accessible safetyeyewash stations and emergencyshowers. Because laboratories areusually housed within a larger physicalstructure (either permanently fixed ormobile in nature), structural safetyhazard controls such as effective firedetection and suppression, and occu-pant means of egress are essential.1 8
The presence of sophisticated analyticalequipment mandates the availabilityand proper functioning of electricalpower supplies and associated safetyfeatures, such as ground fault circuitinterrupters. For example, gel electro-phoresis units employ high electricalcurrents to separate chemical com-pounds, a procedure performed in thepresence of electrically conductiveliquids, making it essential to incorpo-rate safety systems able to interruptcurrent flow in the event of a systemmalfunction.9 In settings where flam-mable or explosive vapours or gases maybe present, specialised designs for theenclosure of switches and lightingsources may also be needed.
Facilities should be designed withmeans of egress in mind, including clearhallways and proper placement of officeareas to avoid traversing the laboratoryarea in the event of an accidentalrelease. Shutoff valves for gases and
fluids should also be clearly marked,and access to emergency stations keptclear and free of clutter.
Since local exhaust ventilation sys-tems are widely used in laboratorysettings to remove vapours from theworker’s breathing zone or to preventthe release of aerosols, occupationalhealth professionals should pay particu-lar attention to these devices. Laboratoryexhaust hoods draw room air into thehood so that contaminants are pre-vented from entering the breathing zoneof the worker. A variation to this designis when the job task requires protectionof the material in the hood as well, suchas when manipulating biological agentsand tissue cultures. In these cases, abiological safety cabinet must be used,in which room air is first filtered beforepassing over any items inside thecabinet, thus providing both personneland product protection (fig 4). Improperplacement, malfunction or misuse ofeither type of enclosure unit can resultin contaminant release. For example,hoods and cabinets placed too close topedestrian traffic can result in airflowdisruptions and loss of capture velocity.
Worker trainingSpecial attention should be given to thetraining and orientation of all indivi-duals in a laboratory setting, includingvisitors and students, given the com-plexity of potential hazards present.Workers should be thoroughly trainedon the laboratory facility’s features,including proper operation and how toproceed in the event of an emergency.Safety training should cover the properuse and maintenance of fume hoodsand biological safety cabinets, as well asthe proper selection and use of personalprotective equipment, with particularattention to the compatibility of theequipment with the worker (video clip1). For example, cases of both irritantand allergic contact dermatitis asso-ciated with the use of latex gloves arewell described, reflecting an unintendedconsequence of a regulatory measureoriginally intended to protect againstsuch events.10 11
In the USA, the Occupational Safetyand Health Administration (OSHA)requires that laboratories handlinghazardous chemicals have a compre-hensive chemical hygiene plan in place.This written programme, developedand implemented by the employer,addresses procedures, equipment, per-sonal protective equipment, work prac-tices, employee training, and exposurecontrol directed at protecting employeesfrom the health hazards presented byhazardous chemicals.12 Because of thevariety of chemicals and their potentialtoxicities, laboratory workers shouldFigure 2 An example of proper storage of hazardous chemicals.
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receive proper training in the identifica-tion and safe handling of chemicals andhave ready access to information ontheir hazards. Material safety datasheets and other technical informationsheets, often created by chemical pro-duct manufacturers, can provide impor-tant initial safety information regardingspecific risks, and should be readilyavailable in the workplace.
Training of employees in the handlingof radioactive sources and biologicalagents, the latter emphasising the useof universal (standard) precautions,addresses radiological and biologicalhazards. In the USA, worker trainingin these areas is mandated under theNuclear Regulatory Commission andthe OSHA Bloodborne PathogensStandard.13 14
Surveil lance and safety committeesBecause the laboratory environment isinherently dynamic, change is the norm.Therefore, routine health and safetyaudits and assessments are necessary todetermine if any changes have resulted inthe emergence of new potential hazards.For example, the placement of a newanalytical device in a local exhaustventilation fume hood could result inthe partial block of airflow, producingeddy currents which actually result inreintroduction of contaminants into thework environment (video clip 2). Ideally,such periodic inspections should be con-ducted by health and safety personnel,with the active involvement of thelaboratory staff, thus stimulating localinterest and control over the safetysystems in place.
One way of establishing a communityculture of safety in the organisationshosting laboratory work environmentsis through the creation of safety com-mittees that are inclusive of representa-tion of upper management and workers.Through the routine reporting of boththe successes and failures of an organi-sation’s health and safety efforts, theworkforce can be appraised of the sys-tems and procedures that work, andthose that warrant attention. The lessonslearned from these efforts can be appliedto the non-employee populations as well.Active worker involvement, combinedwith upper management commitment,can represent a powerful tool in main-taining a healthy, safe and productiveenvironment.
CONCLUSIONAlthough there are many workplaces inboth developed and developing nationsthat are associated with significant occu-pational hazards, laboratories representperhaps one of the microenvironmentswith the greatest diversity of risks, com-bined with a diverse at-risk population.The protection of workers in these envir-onments requires an in-depth knowledgeof the various exposures (which mayoccur simultaneously), management sup-port of health and safety, appropriatefacility design, worker training, protectiveequipment, a team approach to surveil-lance and inspections, and effective com-munication. When applied appropriately,these measures can assist laboratories infulfilling their essential functions so thatworkers remain productive withoutundue occupational risk.
Occup Environ Med 2005;62:200–204.doi: 10.1136/oem.2004.015305
Authors’ affiliations. . . . . . . . . . . . . . . . . . . . . .
R J Emery, G L Delclos, Southwest Center forOccupational and Environmental Health, TheUniversity of Texas School of Public Health atHouston, Houston, Texas, USA
Correspondence to: Dr R J Emery, AssociateProfessor of Occupational Health, TheUniversity of Texas School of Public Health, POBox 20186, Houston, TX 77225-0186, USA;[email protected]
N Video clip 1: Different types of protectiveequipment used in laboratories. Thisvideo segment shows some examplesof safety equipment and devices in alaboratory setting, including eyewash stations and safety showers,flammable storage cabinets, securedcompressed gas cylinders, groundfault circuit interrupters, sealed cen-trifuge cups, sharps containers,hazard signage, and material safetydata sheet binders.
N Video clip 2: Air flow through a laboratoryfume hood. This video segment illus-trates the consequences of improperplacement of a piece of laboratoryequipment within a local exhaustventilation fume hood, resulting inthe partial block of airflow, produ-cing eddy currents which actuallyresult in reintroduction of contami-nants into the work environment.
Figure 3 Workstation layout and task lighting are important considerations when designinglaboratory facilities.
Figure 4 Laboratory worker handlinginfectious agents under a biological safetycabinet.
Selected video clips related tothis article can be found byvisiting the OEM website atwww.occenvmed.com/supplemental.
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REFERENCES1 Code of Federal Regulations: Hazard
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4 National Institute of Environmental HealthSciences (NIEHS). NIEHS report on health effectsfrom exposure to power-line frequency electricand magnetic fields, NIH Publication No.99-4493. Research Triangle Park NC: NationalInstitute of Environmental Health Sciences, 1999.
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14 Code of Federal Regulations: BloodbornePathogens, 29 CFR Sect. 1910.1030(1992).
ECHO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specific criteria help patients to identify hip pain
Please visit theOccupationalandEnvironmentalMedicinewebsite [www.occenvmed.com] for a linkto the full textof this article.
Researchers have come up with a way of defining hip pain that is robust enough to usefor selecting patients for population studies. It should ensure more accurate studies andmore meaningful results.
They tested their method by asking patients in a primary care practice to respond to adirectly worded question whether they had ‘‘hip pain’’ and, again, with a validated diagramdefining the location of hip pain. They then compared the three groups of patients with pain(responding positively to the worded question only, the diagram only, and both questionand diagram) with patients without hip pain for a range of markers of hip disease. Theseincluded consulting a family doctor, taking prescribed painkillers or other remedies,difficulty in walking and use of a stick and—in a subset of each group—the range of hipmovement and x ray evidence of hip disease.
Patients with hip pain according to both question and diagram were positive for a greaterproportion of the markers of hip disease, including some restricted movement and x rayevidence, than the others with pain and those without pain in age and sex adjustedcomparisons. The overall response rate to the postal survey was 75%.
This cross sectional study surveyed 2935 patients aged 18–80 years in a GreaterManchester practice. A consecutive sample of patients with hip pain were age and sexmatched to the sample without hip pain.
Absence of a standard for defining hip pain has been a potential limitation in previousresearch.
m Birrell F, et al. Annals of the Rheumatic Diseases 2005;64:95–98.
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