heta 94-0370-2511heta 94-0370-2511heta 94-0370 …

HETA 94-0370-2511HETA 94-0370-2511HETA 94-0370-2511HETA 94-0370-2511HILLSBOROUGH COUNTYHILLSBOROUGH COUNTYHILLSBOROUGH COUNTYHILLSBOROUGH COUNTY

SHERIFF’S OFFICESHERIFF’S OFFICESHERIFF’S OFFICESHERIFF’S OFFICECOMMUNICATION CENTERCOMMUNICATION CENTERCOMMUNICATION CENTERCOMMUNICATION CENTER

TAMPA, FLORIDATAMPA, FLORIDATAMPA, FLORIDATAMPA, FLORIDA

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved. Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports



This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.


applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved. Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

http://www.cdc.gov/niosh/hhe/reports



PREFACE

The Hazard Evaluations and Technical Assistance Branch of NIOSH conducts fieldinvestigations of possible health hazards in the workplace. These investigations are conductedunder the authority of Section 20(a)(6) of the Occupational Safety and Health Act of 1970, 29U.S.C. 669(a)(6) which authorizes the Secretary of Health and Human Services, following awritten request from any employer and authorized representative of employees, to determinewhether any substance normally found in the place of employment has potentially toxic effects insuch concentrations as used or found.

The Hazard Evaluations and Technical Assistance Branch also provides, upon request, medical,nursing, and industrial hygiene technical and consultative assistance (TA) to federal, State, andlocal agencies; labor; industry; and other groups or individuals to control occupational healthhazards and to prevent related trauma and disease.

Mention of company names or products does not constitute endorsement by the National Institutefor Occupational Safety and Health.

- ii -

HETA 94-0370-2511HETA 94-0370-2511HETA 94-0370-2511HETA 94-0370-2511 NIOSHNIOSHNIOSHNIOSHINVESTIGATORS:INVESTIGATORS:INVESTIGATORS:INVESTIGATORS:JUNE 1995JUNE 1995JUNE 1995JUNE 1995 Robert Malkin,Robert Malkin,Robert Malkin,Robert Malkin,

Dr.P.H.Dr.P.H.Dr.P.H.Dr.P.H.HILLSBOROUGH COUNTY SHERIFF’S OFFICEHILLSBOROUGH COUNTY SHERIFF’S OFFICEHILLSBOROUGH COUNTY SHERIFF’S OFFICEHILLSBOROUGH COUNTY SHERIFF’S OFFICE Beth Donovan Reh,Beth Donovan Reh,Beth Donovan Reh,Beth Donovan Reh,

M.H.S.M.H.S.M.H.S.M.H.S. COMMUNICATION CENTER COMMUNICATION CENTER COMMUNICATION CENTER COMMUNICATION CENTERTAMPA, FLORIDATAMPA, FLORIDATAMPA, FLORIDATAMPA, FLORIDA

I. I. I. I. SUMMARYSUMMARYSUMMARYSUMMARY

On August 12, 1994, the National Institute forOccupational Safety and Health (NIOSH) received aconfidential request for a Health Hazard Evaluation(HHE) at the Hillsborough County Sheriff's Office inTampa, Florida, from three employees working inthe Communication Center. The employees wereconcerned that poor ventilation and possibleexposure to mold and mildew were causingrespiratory symptoms, headaches, and fatigue. NIOSH investigators conducted a site visit onJanuary 4-6, 1995. During the site visitenvironmental measurements were taken, 26employees (selected either by the requestors orrandomly from employees at work on the day ofthe evaluation) were interviewed, and aquestionnaire was administered to 77 employeesof the Communication Center.

The most common symptoms reported on thequestionnaire that were experienced more thanonce a week for the last four weeks that improvedwhen the employees left the worksite (and thesymptom prevalence rate) included: irritated eyes(35%); headache (25%); fatigue (25%); and stuffynose/sinus congestion (25%). From thequestionnaire, 56% of the employees reportedhaving frequently experienced one or more such"building-related" symptoms during the four weekspreceding the administration of the questionnaire. These prevalence rates are not very different fromwhat NIOSH has found in similar studies of theindoor, non-industrial environment. During theinterviews, employees reported that there wasinsufficient fresh air at the Communication Center,

and 65% of the employees who completed thequestionnaire said that there was frequently toolittle air movement in the work area.

The measured temperature and relative humiditieswere within the comfort ranges currentlyrecommended by the American Society forHeating, Refrigerating, and Air-conditioningEngineers (ASHRAE). The measured carbondioxide (CO2) concentrations ranged from 400 to975 parts per million (ppm), below the ASHRAEguideline of 1,000 ppm, but could be furthercontrolled by manipulating the exhaust system. Since the employees are moving into a newbuilding by the end of the year, these changesshould suffice until that time. The bulk samplescollected from the heating, ventilating, and air-conditioning (HVAC) unit revealed microbialcontamination with Pseudomonas, Flavobacterium, andMoraxella.species, specifically in and around thestanding water found in the humidifier. Microbial contamination of standing water in theventilation system, poor housekeeping, andovercrowding were noted in the CommunicationCenter. Microbial contamination in the HVACsystem creates the potential for dissemination ofbioaerosols from the HVAC system into theoccupied spaces. Specific recommendations toimprove environmental quality included: (1)increasing the frequency of exhaust cycles for theroom, (2) removal of a humidifier from the HVACsystem, (3) cleaning or replacing the HVAC systemif the room is to be occupied in the future, and (4)improving HVAC maintenance and housekeeping.

SIC 9221 (police protection): indoor environmentalquality, carbon dioxide, fungi, bacteria.

Health Hazard Evaluation Report No. 94-0370-2511Page 3 - Health Hazard Evaluation Report No. 94-0370-2511Page 3 - Health Hazard Evaluation Report No. 94-0370-2511Page 3 - Health Hazard Evaluation Report No. 94-0370-2511

II.II.II.II. INTRODUCTIONINTRODUCTIONINTRODUCTIONINTRODUCTION

On August 12, 1994, the National Institute forOccupational Safety and Health (NIOSH) received aconfidential request for a health hazard evaluation(HHE) at the Hillsborough County Sheriff's Office inTampa, Florida, from three employees in theCommunication Center. The employees wereconcerned that poor ventilation and possibleexposure to mold and mildew were causingrespiratory symptoms, headaches, and fatigue. ANIOSH industrial hygienist and a medicalinvestigator conducted a site visit on January 4-6,1995.

III.III.III.III. BACKGROUND AND DESCRIPTIVE INFORMATIONBACKGROUND AND DESCRIPTIVE INFORMATIONBACKGROUND AND DESCRIPTIVE INFORMATIONBACKGROUND AND DESCRIPTIVE INFORMATION

The present Hillsborough County Sheriff's Officebuilding was constructed in 1979 in anurban/commercial area of Tampa, Florida. It is atwo-story, brick building that houses all thedepartments of the county sheriff's office. There isno smoking allowed in the building. TheCommunication Center (the 911 response andpolice dispatch operations) occupies one room inthe northwest corner of the second floor, which isits original location. It is essentially one 2,452square foot (ft2) room and contains one enclosedcorner office, one enclosed break room, threeenclosed storage and utility rooms, andapproximately 29 open workstations. The separaterooms are accessible only through the mainCommunication Center room. Previously, anotherenclosed office for secretaries was present alongthe north wall of the room, but the wall has beenremoved and the area now houses 4 of the 29workstations. The only windows are located in thebreak room, and the workers are free to openthem. The room has a raised floor that consists ofa metal grid filled with 1.5 ft2 tiles; about 50% ofthe tiles are linoleum and about 50% are carpet. The walls are painted wallboard and there aresuspended ceiling panels. Primary illumination is


from fluorescent lights in the ceiling andapproximately five incandescent lamps used fortask lighting. Most of the workstations are plasticveneer systems furniture, but a few are woodveneer conventional office furniture.

There is a central heating, ventilating, and air-conditioning (HVAC) system for this area, locatedin the southeast corner of the room. It is notenclosed, but there is a partition against the westside of the unit and a smaller one that covers thenorthwest corner. A smaller partition covers thefront right half of the unit, and there is a set ofenclosed shelves in front. This HVAC systemsupplies conditioned air through ten square ceilingdiffusers. There are no return vents except on topof the unit itself. In 1991, an old ceiling exhaustfan that was originally intended for use during fireemergencies was converted into an outside air(OA) intake. The rooftop OA intake deliversunconditioned air into the workspace through aceiling diffuser that is located above the HVACunit. At about the same time in 1991, anotherceiling exhaust, with two ducts into the ceiling,was converted into a daily-use exhaust system. This system was cycled on for three hours and offfor five hours each shift. A few weeks before thissite visit, the cycle was changed to four hours onand four hours off. During the site visit, the cyclewas changed to two hours on and two hours off.

There are 118 employees in the CommunicationCenter including dispatchers, community serviceofficers (CSOs), secretaries, switchboard operators,and supervisors. There are a total of 93dispatchers, divided into 10 squads ofapproximately 9 to a squad. On any given shift(day – 7 a.m. - 3 p.m.; evening – 3 p.m. - 11 p.m.;night – 11 p.m. - 7 a.m.) there were 20dispatchers. On the first day of the NIOSHevaluation, there were 30 people working in theCommunication Center on the day shift, 27 on theevening shift, and 21 on the night shift, for a total


of 78 workers. Since the job involved shiftrotations that did not necessarily involveweekends, there were approximately 90 differentworkers who were present over the two days ofthe evaluation.

Dispatchers in the Communication Center receiveall 911 calls for Hillsborough County, judge theseverity of the emergency, and route the call forthe appropriate response. Incoming calls arehandled in three ways: 1) voice contact is madewith a dispatcher for emergencies, 2) computermessages are sent for less urgent calls, or 3) areferral is made to the sheriff's office or otherappropriate agency for non-emergencies.

IV.IV.IV.IV.EVALUATION METHODSEVALUATION METHODSEVALUATION METHODSEVALUATION METHODS

Medical EvaluationMedical EvaluationMedical EvaluationMedical Evaluation

During the site visit on January 4-6, 1995,interviews were held with 26 employees. Theseemployees were chosen because: 1) theyreportedly had experienced symptoms while in thebuilding and wished to talk to the NIOSHinvestigator or 2) they were randomly selectedfrom employees present at work on the days of thesurvey. In addition, questionnaires weredistributed to all employees present at work on theday of the evaluation. Questionnaires werehanded directly to day and evening shift employeesat their workstation. The night shift supervisorwas given the questionnaires for night shiftemployees and was instructed on how todistribute the questionnaire. For the day andevening shifts, questionnaires were returneddirectly to NIOSH investigators; night shiftemployees were instructed to leave thequestionnaire at the supervisor's desk.

The questionnaire asked if the employee hadexperienced, while at work on the day of the


survey, any of the symptoms (such as eyeirritation, nasal congestion, headaches, etc.)commonly reported by occupants of "problembuildings"1 and symptoms possibly indicative ofmore serious respiratory problems (such as chesttightness, wheezing, and shortness of breath). The questionnaire also asked about the frequencyof occurrence of these symptoms while at work inthe building during the four weeks preceding thesurvey, and whether these symptoms tended toget worse, stay the same, or get better when theywere away from work. The final section of thequestionnaire asked about environmental comfort(too hot, too cold, unusual odors, etc.) experiencedwhile the employees were working in the buildingduring the four weeks preceding the questionnaireadministration.

To assess how severely employees were affectedby symptoms, symptom groups were defined thatconsisted of possibly related symptoms. Thesegroups required a participant to have more thanone symptom, one day a week or more, thatimproved away from work. A category called“multiple atopic symptoms” was developed toassess the number of employees possibly havingallergic symptoms, and required two of thefollowing: sneezing, itchy eyes, and runny nose. A category called “multiple sick building syndromesymptoms” required at least three of the followingfive symptoms: headache, sore or dry throat, nasalcongestion, unusual fatigue, or irritated eyes. These symptoms have been shown to have highprevalence rates in studies of the non-industrialindoor environment by NIOSH and otherresearchers.1,2,3 Having multiple symptoms of thistype can serve as a marker for the severity ofhealth problems among occupants of a building. Afinal symptoms group, the “multiple respiratorygroup,” required having at least three of thefollowing symptoms: shortness of breath, cough,chest tightness, or wheezing. Because of thepotential severity of these symptoms and the fact


that they are less likely to improve when leavingthe worksite, employees were considered to meetthe group criteria if they had the symptomfrequently (one day a week or more), withoutnecessarily improving when they left the office. Respondents in this group were subsequentlyinterviewed by telephone.

Environmental EvaluationEnvironmental EvaluationEnvironmental EvaluationEnvironmental Evaluation

During the environmental evaluation, informationwas collected using standardized checklists andinspection forms. These forms were used toaddress the whole building, the evaluation area,and the HVAC system. Descriptive information forthe building (age, size, construction, location, etc.),the area to be evaluated (size, type of office space,cleaning policies, furnishings, pollutant sources,etc.), and the HVAC systems (type, specifications,maintenance schedules, etc.) were included. Inspections of the evaluated area and HVACsystems were conducted to determine currentconditions. The purpose of the environmentalinvestigation was to evaluate the work area'scurrent indoor environmental status.

In addition to collecting the standardizedinformation described above, indicators ofoccupant comfort were measured. Theseindicators were carbon dioxide (CO2) concentration,temperature (T), and relative humidity (RH).

Real-time CO2 concentrations were measured usinga Gastech Model RI-411A, portable CO2 indicator. This portable, battery-operated instrument uses anon-dispersive infrared absorption detector tomeasure CO2 in the range of 0-4975 parts permillion (ppm), with a sensitivity of ±25 ppm. Instrument zeroing and calibration were performedprior to use with zero air and a knownconcentration of CO2 span gas (800 ppm).

Real-time temperature and humidity


measurements were made using a Vaisala, ModelHM 34, battery-operated meter. This meter iscapable of providing direct readings for dry-bulbtemperature and RH, ranging from -4 to 140°F and0 to 100%, respectively. Instrument calibration isperformed monthly using primary standards.

Bulk samples from the HVAC unit were collectedfor microbial analysis. One sample was collectedfrom each of the five following areas: the generalresidue of the drain pan, the inside of thehumidifier just above the water level, thehumidifier water, the drain pan residue under thehumidifier, and the sound liner.

Electromagnetic fieldsElectromagnetic fieldsElectromagnetic fieldsElectromagnetic fields

Because of the large amount of electronicequipment present in the Communication Center,measurements were made for extremely lowfrequency (ELF) electromagnetic fields (EMF). These measurements were made with the EMDEXII exposure system, developed by EnertechConsultants, under project sponsorship of theElectric Power Research Institute, Incorporated. The EMDEX II is a programmable data-acquisitionmeter which measures the orthogonal vectorcomponents of the magnetic field through internalsensors. Measurements can be made in theinstantaneous read or storage mode. The systemwas designed to measure, record, and analyzepower frequency magnetic fields in units ofmilliGauss (mG) in the frequency region from 40 to800 Hertz (Hz). Measurements were made withthis meter in the walk-around dosimetry mode atthe location of the worker's hands on theequipment, at the worker's head, at floor level,along the wall,

on top of the 911 units, and adjacent to the votingcomparators (machines that select availablemicrowave channels for transmission).


V. V. V. V. EVALUATION CRITERIAEVALUATION CRITERIAEVALUATION CRITERIAEVALUATION CRITERIA

Indoor environmental quality (IEQ) is affected bythe interaction of a complex set of factors whichare constantly changing. Four elements involvedin the development of IEQ problems are:

! sources of odors or contaminants,

! problems with the design or operation of theHVAC system,

! pathways between contaminant sources andthe location of complaints,

! and the activities of building occupants.

A basic understanding of these factors is critical topreventing, investigating, and resolving IEQproblems.

The symptoms and health complaints reported toNIOSH by non-industrial building occupants havebeen diverse and usually not suggestive of anyparticular medical diagnosis or readily associatedwith a causative agent. A typical spectrum ofsymptoms has included headaches, unusualfatigue, varying degrees of itching or burning eyes,irritations of the skin, nasal congestion, dry orirritated throats, and other respiratory irritations. Usually, the workplace environment has beenimplicated because workers report that theirsymptoms lessen or resolve when they leave thebuilding.

A number of published studies have reported highprevalences of symptoms among occupants ofoffice buildings. Scientists investigating indoorenvironmental problems believe that there aremultiple factors contributing to building-relatedoccupant complaints.4,5 Among these factors areimprecisely defined characteristics of heating,ventilating, and air-conditioning (HVAC) systems,


cumulative effects of exposure to lowconcentrations of multiple chemical pollutants,odors, elevated concentrations of particulatematter, microbiological contamination, andphysical factors such as thermal comfort, lighting,and noise.6,7,8,9,10,11

There are also reports describing results whichshow that occupant perceptions of the indoorenvironment are more closely related than anymeasured indoor contaminant or condition to theoccurrence of symptoms.12,13,14 Some studies haveshown relationships between psychological, social,and organizational factors in the workplace and theoccurrence of symptoms and comfortcomplaints.15,16,17

Less often, an illness may be found to bespecifically related to something in the buildingenvironment. Some examples of potentialbuilding-related illnesses are allergic rhinitis,allergic asthma, hypersensitivity pneumonitis,Legionnaires' disease, Pontiac fever, carbonmonoxide poisoning, and reaction to boilercorrosion inhibitors. The first three conditions canbe caused by various microorganisms or otherorganic material. Legionnaires' disease andPontiac fever are caused by Legionella bacteria. Sources of carbon monoxide include vehicleexhaust and inadequately ventilated keroseneheaters or other fuel-burning appliances. Exposureto boiler additives can occur if boiler steam is usedfor humidification or is released by accident.

Problems NIOSH investigators have found in thenon-industrial indoor environment have included: poor air quality due to ventilation systemdeficiencies, overcrowding, volatile organicchemicals from furnishings or machines, structuralcomponents of the building and contents, tobaccosmoke, microbiological contamination, and outsideair pollutants; comfort problems due to impropertemperature and RH conditions, poor lighting, and


unacceptable noise levels; adverse ergonomicconditions; and job-related psychosocial stressors. In most cases, however, these problems could notbe directly linked to the reported health effects.

Standards specifically for the non-industrial indoorenvironment do not exist. NIOSH, theOccupational Safety and Health Administration(OSHA), and the American Conference ofGovernmental Industrial Hygienists (ACGIH) havepublished regulatory standards or recommendedlimits for occupational exposures.18,19,20

With few exceptions, pollutant concentrationsobserved in non-industrial indoor environments fallwell below these published occupational standardsor recommended exposure limits. The AmericanSociety of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) has publishedrecommended building ventilation design criteriaand thermal comfort guidelines.21,22 The ACGIH hasalso developed a manual of guidelines forapproaching investigations of building-relatedcomplaints that might be caused by airborne livingorganisms or their effluents.23

Measurement of indoor environmentalcontaminants has rarely been helpful indetermining the cause of symptoms andcomplaints except where there are strong orunusual sources, or a proven relationship betweencontaminants and specific building-relatedillnesses. The low-level concentrations of particlesand mixtures of organic materials usually found aredifficult to interpret and usually impossible tocausally link to observed and reported healthsymptoms. However, measuring ventilation andcomfort indicators such as CO2, temperature, andRH has proven useful in the early stages of aninvestigation in providing information relative tothe proper functioning and control of HVACsystems. The basis for measurements madeduring this evaluation are listed below.


Carbon Dioxide Carbon Dioxide Carbon Dioxide Carbon Dioxide

Carbon dioxide is a normal constituent of exhaledbreath and, if monitored, may be useful as ascreening technique to evaluate whether adequatequantities of fresh air are being introduced into anoccupied space. The ASHRAE Standard 62-1989,Ventilation for Acceptable Indoor Air Quality,recommends outdoor air supply rates of 20 cubicfeet per minute per person (cfm/person) for officespaces and conference rooms, and 15 cfm/personfor reception areas, and provides estimatedmaximum occupancy figures for each area.21

Indoor CO2 concentrations are normally higher thanthe generally constant ambient CO2 concentration(range 300-350 ppm). When indoor CO2

concentrations exceed 1000 ppm in areas wherethe only known source is exhaled breath,inadequate ventilation is suspected. Elevated CO2

concentrations suggest that other indoorcontaminants may also be increased.

Temperature and Relative HumidityTemperature and Relative HumidityTemperature and Relative HumidityTemperature and Relative Humidity

The perception of comfort is related to one'smetabolic heat production, the transfer of heat tothe environment, physiological adjustments, andbody temperatures. Heat transfer from the body tothe environment is influenced by factors such astemperature, humidity, air movement, personalactivities, and clothing. ANSI/ASHRAE Standard55-1981 specifies conditions in which 80% or moreof the occupants would be expected to find theenvironment thermally comfortable.24

Microbial ContaminantsMicrobial ContaminantsMicrobial ContaminantsMicrobial Contaminants

Microorganisms (including fungi and bacteria) arenormal inhabitants of the environment. Thesaprophytic varieties (those utilizing non-livingorganic matter as a food source) inhabit soil,vegetation, water, or any reservoir that can provide


an ample supply of a nutrient substrate. Under theappropriate conditions (optimum temperature, pH,and with sufficient moisture and availablenutrients), saprophytic microorganism populationscan be amplified. Through various mechanisms,these organisms can then be disseminated asindividual cells or in association with soil/dust orwater particles. Also, some species of fungiproduce mycotoxins and volatile organiccompounds (VOCs) and all gram-negative bacteriacontain endotoxin. All three of these groups ofsubstances include some compounds which canbe harmful to humans. In the outdoorenvironment, the levels of microbial aerosols andvapors will vary according to the geographiclocation, climatic conditions, and surroundingactivity. In a "normal" indoor environment, the levelof microorganisms may vary somewhat as afunction of the cleanliness of the HVAC system andthe numbers and activity level of the occupants. Generally, the indoor levels are expected to bebelow the outdoor levels (depending on HVACsystem filter efficiency) with consistently similarranking among the microbial species.25,26

Some individuals manifest increased immunologicresponses to antigenic agents encountered in theenvironment. These responses and thesubsequent expression of allergic disease is based,partly, on a genetic predisposition.27 Allergicdiseases typically associated with exposures inindoor environments include allergic rhinitis (nasalallergy), allergic asthma, allergicbronchopulmonary aspergillosis (ABPA), andextrinsic allergic alveolitis (hypersensitivitypneumonitis).23,26 Allergic respiratory diseasesresulting from exposures to microbial agents havebeen documented in agricultural, biotechnology,office, and home environments.28,29,30,31,32,33,34,35

Individual symptomatology varies with the disease. Allergic rhinitis is characterized by paroxysms ofsneezing; itching of the nose, eyes, palate, or


pharynx; nasal stuffiness with partial or totalairflow obstruction; and rhinorrhea (runny nose)with postnasal drainage. Allergic asthma ischaracterized by episodic or prolonged wheezingand shortness of breath in response to bronchial(airways) narrowing. Allergic bronchopulmonaryaspergillosis is characterized by cough, lassitude,low-grade fever, and wheezing.36,37 Heavyexposures to airborne microorganisms can causean acute form of extrinsic allergic alveolitis whichis characterized by chills, fever, malaise, cough,and dyspnea (shortness of breath) appearing fourto eight hours after exposure. In the chronic form,thought to be induced by continuous low-levelexposure, onset occurs without chills, fever, ormalaise and is characterized by progressiveshortness of breath with weight loss.38

Acceptable levels of airborne microorganisms havenot been established, primarily because allergicreactions can occur even with relatively low airconcentrations of allergens, and individuals differwith respect to immunogenic susceptibilities. Thecurrent strategy for on-site evaluation ofenvironmental microbial contamination involves aninspection to identify sources (reservoirs) ofmicrobial growth and potential routes ofdissemination. In those locations wherecontamination is visibly evident or suspected, bulksamples may be collected to identify thepredominant species (fungi, bacteria, andthermoactinomycetes). In limited situations, airsamples may be collected to document thepresence of a suspected microbial contaminant. Air sample results can be evaluatedepidemiologically by comparing those from the"complaint areas" to those from non-complaintareas, or by relating exposure to immunologicfindings.

Electromagnetic FieldsElectromagnetic FieldsElectromagnetic FieldsElectromagnetic Fields

At present, there are limited occupational exposure


criteria for EMF field exposures for workersexposed to physical agents. Criteria for EMF notcovered by OSHA come from either the ACGIH,NIOSH, or in some cases, from consensusstandards promulgated by the American NationalStandards Institute (ANSI).

The ACGIH has published threshold limit values(TLVs) for sub-radio frequency electric andmagnetic fields (30 kiloHertz and below).39 TheTLV for magnetic fields (B) states "routineoccupational exposure should not exceed:

BTLV in milliteslas = 60/f

where f is the frequency in Hertz." In thisevaluation, we were particularly interested in 60Hz fields because of the large amount of electricalequipment present in the Communication Center. The current ACGIH occupational standard for 60Hzmagnetic fields is 1 millitesla. One millitesla isequal to 10,000 milliGauss (10 Gauss).

Conversely, the electric field (E) TLV states"occupational exposures should not exceed a fieldstrength of 25 kiloVolts per meter (kV/m) from 0 to100 Hz. For frequencies in the range of 100 Hz to4 kHz, the TLV is given by:

ETLV in Volts per meter (V/m) = (2.5 x 106 )/f

where f is the frequency in Hz. A value of 625 V/mis the exposure limit for frequencies from 4 kHz to30 kHz." This means, for example, that at 60 Hz,which is classified as ELF, the electricfield intensity TLV is 25,000 V/m.


VI.VI.VI.VI. ENVIRONMENTAL RESULTS AND OBSERVATIONSENVIRONMENTAL RESULTS AND OBSERVATIONSENVIRONMENTAL RESULTS AND OBSERVATIONSENVIRONMENTAL RESULTS AND OBSERVATIONS

The whole Communication Center should bemoved into a new building by the end of 1995, andtherefore, one of the goals of the evaluation is to ensure that, should the Communication Center bereoccupied, future occupants of this room will haveimproved conditions.

The Communication Center was noticeably dirtierthan the other areas of the building. The workareas and floors were very dusty, and the areabelow the raised floor was extremely dusty. Because the room is occupied 24 hours a day,thorough cleaning is difficult to perform. Sincethere is carpet, vacuuming is necessary, but itinterferes with the workers who mustcommunicate on the telephone. The room housesapproximately 20 to 25 people per shift and theworkstations are crowded together, which isanother factor that prevents thorough cleaning. There is no visible water damage and no leakshave been reported in the past in this area. Thebreak room contains a full refrigerator, amicrowave oven, a coffee-maker, a kitchen sink,and a TV.

The HVAC system was installed in 1979 when theoffice building was completed, and an outsidecontractor is responsible for preventive andas-needed maintenance. Although the unit is notenclosed, access is restricted by the partition thatcovers the right, front half of the unit. There aretwo large panel doors that open to expose thecoils, drain pan, and electrical components; the leftdoor opens completely, but the right door isobstructed and can only open about ten inches. The overall condition of the HVAC unit was fair topoor and the sound liners had some slightdamage. The drain pan was mostly dry with a fewmoist areas, but its surface was covered withresidue of varying colors and consistencies. Thecoils had some debris on them, but no visible


evidence of microbial contamination. The mostdeficient part of the HVAC unit was thehumidification system. This system consisted ofan open pan (approximately 1 ft. x 1.5 ft.) of watersuspended an inch above the drain pan. This panhad visible microbial growth around its edges,below it, on the components submersed in thewater, and in the water itself. It was apparentduring the survey that the drain pan, coils, andhumidification system had not been cleaned in therecent past. A rectangular, frameless fiberglassfilter was tacked to the top of the unit over thereturn vent for the system. The filter had less than20% efficiency and, without a frame, air couldbypass it quite easily.

The OA intake is located on the roof. In 1991, afan was added to an old exhaust duct just abovethe suspended ceiling to draw outside air throughthe duct and into the room through a ceilingdiffuser. A large piece of fiberglass filter material,similar to the kind used on the HVAC unit, hadbeen shoved into the flexible duct under the raincap to serve as a filter. When the filter wasremoved, we saw that the duct was covered witha mat of very fine dust.

A few of the ten supply diffusers had beentampered with by employees. One was completelyobstructed by a piece of cardboard. In the areathat used to be an enclosed office along the northwall of the room there was one air supply, but thisarea appeared to have little air movement. Therewas a strong negative air pressure in the roomrelative to the outside hallway – it was strongenough to hold the spring-loaded door slightlyopen if it was not pulled shut.

The bulk sample analysis for microbialcontamination revealed varying amounts of fungiand bacteria. The bulk sample collected from thedrain pan, under the humidifier, did not have anydetectable amount of bacteria or fungi (less than225 colony forming units per gram (CFU/g)), and


the sound liner had low to moderate amounts ofBacillus species of bacteria (3,125-12,500 CFU/g)and Aspergillus and Penicillium species of fungi (225-450 CFU/g). A different sample, collected from themiddle of the drain pan, had 300,000 CFU/g of thebacteria species Moraxella bovis but less than 225CFU/g of any fungi.

The humidifier bulk sample contained by far thehighest amounts of bacteria and fungi. Levels ofPseudomonas vesicularis, Pseudomonas stutzeri, andFlavobacterium bacteria ranged from 450,000,000-500,000,000 CFU/g; there were also 20,000,000CFU/g CDC Group II-I bacteria species; and30,000 CFU/g Acremonium fungi species. Thehumidifier water also had Pseudomonas vesicularis(7,500,000 CFU/ml), Comamonas testosteroni (1,600CFU/ml), and Acremonium species (140 CFU/ml).

Environmental CO2 measurements were collectedin nine locations in the evaluated area. Carbondioxide concentrations ranged from 400 ppm to975 ppm during the days of the site visit. From3:30 to 4:00 p.m. on January 4, 1995, theconcentrations ranged from 500 to 550 ppm; from5:50 to 6:15 p.m. on January 4, 1995, theconcentrations ranged from 400 to 500 ppm; from9:30 to 10:00 a.m. on January 5, 1995, theconcentrations ranged from 525 to 625 ppm; from11:20 to 11:35 a.m. on January 5, 1995, theconcentrations ranged from 950 to 975 ppm; andfrom 3:25 to 3:40 p.m. on January 5, 1995, theconcentrations ranged from 550 to 650 ppm. Thelower concentrations on January 4, 1995, could bedue to the fact that the door to the room waspropped open for most of that work shift –something that is rarely done. The outdoor CO2

concentrations ranged from 350 ppm to 375 ppmon both days.

The sheriff's office had set up a real-time CO2

monitor in the room a few weeks prior to thesurvey. This monitor had readings that were


similar to those taken by NIOSH. The real-timemeasurements showed that CO2 concentrationswere cycling from low (400 to 600 ppm) to high(sometimes greater than 1,000 ppm) every three tofour hours. These cycles corresponded perfectly tothe cycles of the exhaust fan operation. The fancycles were then changed to two hours on andtwo hours off to try to reduce the build-up of CO2

and any other potential contaminants. If the CO2

concentrations were still cycling, the fan operationcycle could be modified again.

During the days of the survey, the temperaturesranged from 73 to 77°F in the CommunicationCenter and they were in the high 60s outside. TheRH ranged from 48 to 62% on January 4, 1995,when it was raining outside, and from 34 to 41%on January 5, 1995, when it was not rainingoutside.

Electromagnetic Field MeasurementElectromagnetic Field MeasurementElectromagnetic Field MeasurementElectromagnetic Field Measurement

Extremely low frequency (ELF) fieldsmeasurements made at operators’ desks, near thelocation of their hands, ranged from 1.9 to 3.4 mG. Measurements made at operators’ heads werelower than those at their hands which were closerto the electrical equipment. Measurements madealong the floor and walls were similar to thosemade at the operators’ hands. Higher levels werefound on top of the 911 units (6.5-10.3 mG) andnext to the microwave voting comparators (17.8mG), which were located in an adjacent room. Itwas unlikely that workers would be present ineither location for extended periods of time. Thevalues at employee workstations are typical oflevels found in other office settings where acomputer is used.40

VII.VII.VII.VII. MEDICAL RESULTSMEDICAL RESULTSMEDICAL RESULTSMEDICAL RESULTS

Confidential medical Interviews were conductedwith 26 employees. Commonly reported


symptoms (and the number of interviewed workersaffected included): frequent headaches (4),burning or irritated eyes (7), runny nose orcongestion (5), sinus problems and infections (8),and severe fatigue at work (6). Five of theemployees reported frequently experiencing afeeling of insufficient ventilation while working inthe building.

Several employees commented on the symptomsthat had occurred during the renovation of anadjacent workspace, which had been completedseveral months prior to the visit, and occurredwhile the employees of the Communication Centerwere present. Workers reported that exposure todust, noise, and chemical odors (paint, flooringcements, etc.) had been common during therenovation. They also reported having experiencedexacerbations of sinus congestion and sinusitisduring this exposure and frequently felt ill,especially when exposed to the odors of flooringcements. Workers also reported a Freon® leak in1993 from the HVAC unit located in theCommunication Center. This leak resulted in illworkers being sent home.

During the visit, questionnaires were distributed tothe 90 Communication Center employees, workingon the day of the site visit. Of the 77 employeesthat responded (85% response rate), 30 were male(39%), and 47 were female (61%). Twenty-four(31%) currently smoked cigarettes, 23 (30%) wereformer smokers, and 30 (39%) had never smoked. Respondents ranged in age from 20-72 (mean 41years old), and had worked at the same location inthe building for an average of six years.

The questionnaire results are shown in Table I atthe end of this report. The first column of Table Ishows the percentage of the 77 respondents whoreported the occurrence of symptoms while atwork on the day of the survey. Stuffy nose orsinus congestion, eye irritation, unusual fatigue,


and cough were the most commonly reportedsymptoms.

The second column shows the percentage ofemployees who reported experiencing therespective symptom once a week or more oftenwhile at work during the four weeks preceding thesurvey. With a few exceptions, these symptomprevalences are slightly greater than those forsymptoms experienced on the day of the survey.

The third column shows the percentage ofemployees who reported experiencing therespective symptom once a week or more oftenwhile at work during the four weeks preceding thesurvey and also reported that the symptom tendedto get better when they were away from work. This latter criterion has, in some studies of indoorair quality, been used to define a "work-related"symptom, but it is possible that a symptom whichdoes not usually improve when away from thebuilding could also be due to conditions at work.

The reported "work-related" frequent symptomprevalences, shown in the third column, are lowerthan the corresponding symptom prevalences overthe last four weeks (shown in the second column),and are highest for eye irritation or strain,headache, fatigue, and stuffy nose or sinus nasalcongestion. Symptoms prevalences were similarto what NIOSH has found in other buildings, withthe exception of cough, which had a prevalencerate of 17% in this study, as compared withapproximately 9% in other NIOSHstudies.41,42 Overall, 43 (56%) respondents reportedhaving one or more symptoms that had occurredat work one or more days a week during thepreceding four weeks and tended to get betterwhen away from work and 29 (38%) reported threeor more symptoms once a week or more thatimproved when away from work.

Multiple respiratory symptoms (frequentlyexperiencing at least three of the following foursymptoms: wheezing, chest tightness, shortness


of breath, or cough) were reported by sevenworkers (9%) of the respondents. A previousNIOSH study of 80 office buildings found a meanprevalence rate of 5% for this symptom group.43 Although this represents an almost two–foldincreased mean prevalence rate, it fell within therange for all buildings (0-40%). Multiple atopicsymptoms (at least two of the followingsymptoms: sneezing, itchy eyes, or runny nose)were reported by 27% of the respondents with 14%reporting that the symptoms improved when theemployee left work. The latter may indicate anallergic reaction in some persons that is related toworking in the Communication Center.

Multiple sick building syndrome symptoms(frequently experiencing at least three of thefollowing: headache, sore or dry throat, nasalcongestion, unusual fatigue, or irritated eyes thatimproved when the employee left the worksite)were reported by 18% of the respondents.

Table II shows results of employee reportsregarding environmental conditions at theirworkstations on the day of the survey and duringthe four weeks preceding the survey. Column oneshows the results for the day of the survey; itshows that 48% of the respondents perceived thatthe ventilation system was not providing sufficientair movement, 36% thought it was too hot, and22% felt that it was too cold during at least part oftheir workday.

The second column shows the responses to thequestions about environmental comfort conditionsexperienced in the facility during the four weekspreceding the survey. Adverse environmentalconditions (too hot, too cold, odors, etc.) wereconsidered "frequent" if they were reported to occurat work once a week or more often. The resultsare generally somewhat higher than those shownin the first column for workstation environmentalconditions experienced during the day of the


survey. Sixty-five percent of respondentsperceived insufficient air movement, 16% reportedtoo much air movement, 57% frequently were toohot, 36% were frequently too cold, 21% perceivedfrequent chemical odors in the workplace, and 33%frequently sensed other unpleasant odors.

Seven employees who reported either multiplerespiratory symptoms or shortness of breath onthe questionnaire were contacted by the telephoneto determine, by interview, the severity of theirsymptoms. Five reported that they were aware ofshortness of breath after exercise that theypreviously had been able to do, such as climbingstairs. In all cases, this symptom began after theemployee started to work in the building. Of thosefive, one employee had been diagnosed with ausual interstitial pneumonitis and one other wasunder medical treatment for his shortness ofbreath. One other respondent who reportedshortness of breath had an underlying medicalcondition (unrelated to the building) that mayexplain the symptom.

VIII.VIII.VIII.VIII. DISCUSSIONDISCUSSIONDISCUSSIONDISCUSSION

Pseudomonas bacteria, other bacteria, and fungi wereidentified in the samples collected from thehumidifier. These organisms, endotoxin, ormycotoxin could potentially become entrained inthe air supplied by the Communication CenterHVAC system. Endotoxins are lipopolysaccharidecompounds from the outer cell wall ofgram-negative bacteria (such as Pseudomonas),which are ubiquitous in nature.23,44,45 Sinceendotoxins are part of the cell wall of the bacteria,endotoxins can usually be assumed to be presentwherever gram-negative bacteria are present.46 High concentrations have been reported in avariety of environments where gram-negativebacteria flourish, such as vegetable fiberprocessing operations, agriculture or wastewater


treatment operations, industrial washwater mists,and contaminated room humidifiers.44 Airborneendotoxin has also been reported in offices andlaboratories.23

Clinically, much is not known about the responseto inhaled aerosols of gram-negative bacteria andendotoxins.47 Workers exposed to endotoxin atsewage treatment plants have reported shortnessof breath, nausea, fever and wheezing.48 Onestudy of office workers found a six-fold increase inairborne endotoxin levels in "sick buildings" whencompared to "healthy buildings” and concludedthat contamination with gram-negative rods orendotoxin may be related to sick buildingsyndrome.49 The presence of gram-negativebacteria in the HVAC or humidification systemshas been linked, by some researchers, torespiratory infection and chronic bronchitis.50

Although no air measurements for either bacteriaor endotoxin were made in the workers' locationduring our site visit, the findings of bacteria withinthe humidifier may represent a possible hazard dueto the location of the humidifier in the air streamand the potential for dissemination to occur. Specifically, the presence of Pseudomonas couldrepresent a hazard to the occupants of the buildingdue to the presence of endotoxins if they were tobecome airborne.

Exposure to mycotoxins is another consideration,based on the finding of fungal growth in the HVACsystem. Mycotoxins are one group of secondarymetabolites formed by hyphae of common moldswhen growing under a variety of conditions;44 theyare produced as side effects of the fungal digestionprocess.23 No toxigenic fungus produces only asingle toxin, and the type and amount of toxinproduced will vary based on the surroundingconditions. However, most studies of thetoxicology of mycotoxins concern them ascontaminants in feed for farm animals, and almost


all cases of human mycotoxicosis have appeared inrural or agricultural settings, most resulting fromthe ingestion of contaminated food and/or skincontact. There is one isolated case of a severeStachybotrys atra colonization in a house that resultedin symptoms of headaches, sore throats, hair loss,flu symptoms, diarrhea, fatigue, dermatitis, andgeneralized malaise. S. atra, however, is notcommonly found in office buildings,23 and was notfound in this one. The effects of mycotoxins in theoffice environment are usually minimal but may bea factor in some cases.51

Allergic disorders associated with microorganismsare discussed in the Evaluation Criteria section ofthis report.

IX.IX.IX.IX. CONCLUSIONS AND RECOMMENDATIONSCONCLUSIONS AND RECOMMENDATIONSCONCLUSIONS AND RECOMMENDATIONSCONCLUSIONS AND RECOMMENDATIONS

The potential exists for dissemination ofbioaerosols from the HVAC system into theoccupied spaces. Whether this airbornedissemination is presently occurring or occurred inthe past could not be determined from ouranalyses. Since components of the HVAC systemare functioning as amplification sites formicroorganisms and future dissemination is apossibility, the microbial contaminatedcomponents of the HVAC system should beremoved. Although no air sampling was doneduring this visit, our recommendations wouldremain the same if it had been done, regardless ofthe outcome. Additional recommendations areoffered to correct environmental deficiencies thatwere found in the Communication Center duringthis evaluation such as overcrowding, poorhousekeeping, and poor design of the air filtersystem.

1. The present HVAC humidification systemshould be eliminated because it serves as areservoir for microbial amplification. In aclimate such as Florida’s, humidification


systems may well be unnecessary.

2. The room used for the Communication Centerwas too small to house 20 to 25 workers pershift, and the HVAC system was not designedto properly ventilate the room with that manypeople in it. The addition of an OA intake andexhaust system and increasing the frequency ofthe exhaust cycles has allowed for an adequatetemporary solution pending the move to thenew building. If necessary, the number ofexhaust cycles could be increased, if needed, tokeep CO2 levels from rising within the room. Also, the HVAC maintenance has been poor. Ifthis room is to be used as workspace in thefuture, NIOSH investigators recommend thefollowing:

a) This room should not again be used tohouse a large number of people. ASHRAEhas recommended occupancy levels foroffice workers of seven employees per 1,000square feet (ft2) of usable space. The federalgovernment (General ServicesAdministration) sets guidelines forworkspace area based on the pay grade(GS-level) of employees using the space. These workstation space allowances are 60ft2 for clerical personnel (GS 1-6), 75 ft2 fortechnical personnel (GS 7-11), and 100 ft2

and up for professional staff (GS-13 andhigher). The federal Internal RevenueService has a guideline of 125 ft2 of primaryoffice space per employee as an averageoccupancy level. This guideline does notinclude storage, lavatory, or cafeteria spaceas part of that 125 ft2 total.

b) To improve employee comfort, NIOSHinvestigators suggest that the room bethoroughly cleaned before re-occupation. This cleaning should occur when the area isnot occupied and the exhaust system should


be kept operating during the cleaningprocedures. Also, the routine housekeepingin this area should be improved to avoidfuture problems.

c) The present HVAC system should either beredesigned and replaced or at leastthoroughly cleaned. Since it was 15 yearsold, and may be approaching the end of itsintended lifespan, redesign and replacementmay be the more economically sound choice. If not replaced, it should be thoroughlycleaned while the room is not occupied.

d) The HVAC filter system was inadequate fortwo reasons. The first was that there is noframe to place the filter in, which allows forair to easily by-pass the filter. The secondwas that the filter was a very low efficiencyfilter. Efficiency is the measure used todetermine whether fine particles areremoved from the air stream. Considerationshould be given to using filters with 30 to40% efficiency. Pleated filters haveefficiencies around 40% and would help toreduce the dust in the work area. The OAshould also be filtered through a higherefficiency filter. Since the OA, in this case,was not introduced into the HVAC unitdirectly, the OA intake should have its ownhigher efficiency filter. A lower efficiencyfilter could be used upstream so that thehigh efficiency filter only has to filter

out the smaller particles and the larger oneswill be stopped by the first pre-filter.

e) If a raised floor is necessary for the newoccupants, the present one should either bereplaced with one consisting of vinyl tiles asopposed to carpeting (for easier cleaning), orat least thoroughly cleaned. There should beroutine cleaning both above and below the


raised floor.

f) Employees in either the old or new buildingmust not be allowed to adjust anycomponents of the HVAC system,specifically the supply diffusers. Workersshould be instructed that any alterations willaffect the entire system.

3. The workspace in the new building is clearlylarger and appeared to be better designed for atelecommunication center. To avoid any airquality problems in the future, preventivemaintenance is necessary. The HVAC system,including the drain pan, filters, OA intake,supplies, and returns, must be maintained on aroutine basis, preferably monthly or bimonthly. NIOSH investigators recommend a thoroughcleaning of the HVAC unit semi-annually orannually, and as–needed, in between. Also,filters with a 30 to 40% efficiency arerecommended.

4. Since this new work area will also be occupied24 hours a day, 7 days a week, housekeepingmay still be a problem. Supervisors andemployees should devise a way to allowadequate housekeeping practices with the leastamount of distraction to the workers.


1.Skov P, Valbjorn O [1987]. and The Danish Indoor Climate StudyGroup. The "sick" building syndrome in the officeenvironment: the Danish town hall study. Environ Int13:339-349.

2.Zimmer T, Malkin R. Health hazard evaluation andtechnical assistance report: Celebreeze FederalBuilding, Cleveland, Ohio. Cincinnati, OH: U.S.Department of Health and Human Services, Centersfor Disease Control and Prevention, National Institutefor Occupational Safety and Health, NIOSH Report No.HETA 92-269-2330.

3.Burr GA, Malkin R [1992]. Health hazard evaluation andtechnical assistance report: New York State Department ofTaxation and Finance, Albany, NY. Cincinnati, OH: U.S. Departmentof Health and Human Services, Centers for Disease Control andPrevention, National Institute for Occupational Safety andHealth, NIOSH Report No. HETA 91-378-2242.

4.Kreiss K [1989]. The epidemiology of building-related complaints and illness. OccupationalMedicine: State of the Art Reviews. 4(4):575-592.

5.Norbäck D, Michel I, Widstrom J [1990]. Indoor airquality and personal factors related to the sickbuilding syndrome. Scan J Work Environ Health. 16:121-128.

6.Morey PR, Shattuck DE [1989]. Role of ventilation inthe causation of building-associated illnesses. Occupational Medicine: State of the Art Reviews. 4(4):625-642.

7.Mendell MJ, Smith AH [1990]. Consistent patternof elevated symptoms in air-conditioned officebuildings: A reanalysis of epidemiologic studies. Am J Public Health. 80(10):1193-1199.

8.Molhave L, Bach B, Pedersen OF [1986]. Humanreactions during controlled exposures to lowconcentrations of organic gases and vapors known asnormal indoor air pollutants. Environ Int. 12:167-175.

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9.Fanger PO [1989]. The new comfort equation for indoor airquality. ASHRAE J 31(10):33-38.


10.Burge HA [1989]. Indoor air and infectious disease.Occupational Medicine: State of the Art Reviews. 4(4):713-722.

11.Robertson AS, McInnes M, Glass D, Dalton G,Burge PS [1989]. Building sickness, are symptomsrelated to the office lighting? Ann Occup Hyg33(1):47-59. Indoor environmental pollutants canarise from either outdoor sources or indoor sources.

12.Wallace LA, Nelson CJ, Dunteman G [1991]. Workplace characteristics associated with health andcomfort concerns in three office buildings inWashington, D.C. In: Geshwiler M, Montgomery L,and Moran M, eds. Healthy buildings. Proceedings ofthe ASHRAE/ICBRSD conference IAQ'91. Atlanta, GA. The American Society of Heating, Refrigerating, andAir-conditioning Engineers, Inc.

13.Haghighat F, Donnini G, D'Addario R [1992]. Relationship between occupant discomfort asperceived and as measured objectively. Indoor Environ 1:112-118.

14.NIOSH [1991]. Hazard evaluation and technicalassistance report: Library of Congress MadisonBuilding, Washington, D.C. Cincinnati, OH: U.S.Department of Health and Human Services, PublicHealth Service, Centers for Disease Control, NationalInstitute for Occupational Safety and Health, NIOSHReport No. HETA 88-364-2104 - Vol. III.

15.Skov P, Valbjørn O, Pedersen BV [1989]. Influenceof personal characteristics, job-related factors, andpsychosocial factors on the sick building syndrome. Scand J Work Environ Health 15:286-295.

16.Boxer PA [1990]. Indoor air quality: Apsychosocial perspective. J Occup Med 32(5):425-428.

17.Baker DB [1989]. Social and organizational factorsin office building-associated illness. OccupationalMedicine: State of the Art Reviews. 4(4):607-624.


18.CDC [1992]. NIOSH recommendations for occupational safety andhealth: Compendium of policy documents and statements.Cincinnati, OH: U.S. Department of Health and Human Services,Public Health Service, Centers for Disease Control, NationalInstitute for Occupational Safety and Health. DHHS (NIOSH)Publication No. 92-100.


19.ACGIH [1991]. 1991-1992 Threshold limit values for chemicalsubstances and physical agents and biological exposure indices.Cincinnati, OH: American Conference of Governmental IndustrialHygienists.

20.Code of Federal Regulations [1989]. OSHA Table Z-1-A. 29 CFR1910.1000. Washington, DC: U.S. Government Printing Office,Federal Register.

21.ASHRAE [1990]. Ventilation for acceptable indoorair quality. Atlanta, GA: American Society of Heating,Refrigerating, and Air-conditioning Engineers. ANSI/ASHRAE Standard 62-1989.

22.ASHRAE [1981]. Thermal environmental conditionsfor human occupancy. Atlanta, GA: American Societyfor Heating, Refrigerating, and Air-conditioningEngineers. ANSI/ASHRAE Standard 55-1981.

23.ACGIH [1989]. Guidelines for the assessment ofbioaerosols in the indoor environment. Cincinnati,OH: American Conference of Governmental IndustrialHygienists.

24.ASHRAE [1981]. Thermal environmental conditionsfor human occupancy. Atlanta, GA: American Societyfor Heating, Refrigerating, and Air-conditioningEngineers. ANSI/ASHRAE Standard 55-1981.

25.Burge HA [1988]. Environmental allergy: definition, causes, control. Engineering Solutions toIndoor Air Problems. Atlanta, GA: American Societyof Heating, Refrigeration and Air-ConditioningEngineers, 3-9.

26.Morey MR, Feeley JC [1990]. The landlord, tenant,and investigator: their needs, concerns andviewpoints. Biological Contaminants in IndoorEnvironments. Baltimore, MD: American Society forTesting and Materials, pp 1-20.

27.Pickering CA [1992]. Immune respiratory diseaseassociated with the inadequate control of indoor airquality. Indoor Environment 1:157-161.


28.Vinken W, Roels P [1984]. Hypersensitivity pneumonitis toAspergillus fumigatus in compost. Thorax 39:74-74.

29.Malmberg P, Rask-Andersen A, Palmgren U, Höglund S,Kolmodin-Hedman B, Stålenheim G [1985]. Exposure tomicroorganisms, febrile and airway-obstructive symptoms, immunestatus, and lung function of Swedish farmers. ScandinavianJournal of Work and Environmental Health 11:287-293.

30.Topping MD, Scarsbrick DA, Luczynska CM, ClarkeEC, Seaton A [1985]. Clinical and immunologicalreactions to Aspergillus niger among workers at abiotechnology plant. British Journal of IndustrialMedicine 42:312-318.

31.Edwards JH [1980]. Microbial and immunologicalinvestigations and remedial action after an outbreak ofhumidifier fever. British Journal of Industrial Medicine37:55-62.

32.Weiss NS, Soleymani Y [1971]. Hypersensitivitylung disease caused by contamination of an air-conditioning system. Annals of Allergy 29:154-156.

33.Hodgson MJ, Morey PR, Attfield M, Sorenson W,Fink JN, Rhodes WW, Visvesvara GS [1985]. Pulmonary disease associated with cafeteria flooding. Archives of Environmental Health 40(2):96-101.

34.Fink JN, Banaszak EF, Thiede WH, Barboriak JJ[1971]. Interstitial pneumonitis due tohypersensitivity to an organism contaminating aheating system. Annals of Internal Medicine 74:80-83.

35.Banaszak EF, Barboriak J, Fink J, Scanlon G,Schlueter EP, Sosman A, Thiede W, Unger G [1974]. Epidemiologic studies relating thermophilic fungi andhypersensitivity lung syndrome. American Review ofRespiratory Disease 110:585-591.

36.Molhave L, Bach B, Pedersen OF [1986]. Humanreactions to low concentrations of volatile organiccompounds. Environ Int 12:167-176.

37.Kaliner M, Eggleston PA, Mathews KP [1987]. Rhinitis andasthma. Journal of the American Medical Association258(20):2851-2873.


38.Jordan FN, deShazo R [1987]. Immunologicaspects of granulomatous and interstitial lungdiseases. Journal of the American MedicalAssociation 258(20):2938-2944.

39.American Conference of Governmental Industrial Hygienists(1993-1994). Threshold limit values and biological exposureindices of 1993-1994. Cincinnati, OH.

40.Bracken TB [1993]. Exposure assessment for power frequencyelectric and magnetic fields. An Ind Hyg Assoc J 54(4):165-177.

41.NIOSH [1993]. Health hazard evaluation and technicalassistance report: Pennsylvania Department of Revenue,Harrisburg, PA. Cincinnati, OH: U.S. Department of Health andHuman Services, Centers for Disease Control and Prevention,National Institute for Occupational Safety and Health, NIOSHReport No. HETA 92-166-2318.

42.NIOSH [1993]. Health hazard evaluation andtechnical assistance report: GTE Customer ServiceOperations Center (CSOC), Huntington Beach, California .Cincinnati, OH: U.S. Department of Health and HumanServices, Centers for Disease Control and Prevention,National Institute for Occupational Safety and Health,NIOSH Report No. HETA 93-0198.

43.Malkin R, Wilcox T, Sieber K [in preparation]. The NIOSHIndoor Environmental Evaluation Experience, 1994: Part Two:Symptoms Prevalence. Cincinnati, OH: U.S. Department of Healthand Human Services, Centers for Disease Control and Prevention,National Institute for Occupational Safety and Health. Divisionof Surveillance, Hazard Evaluations, and Field Studies, HazardEvaluations and Technical Assistance Branch.

44.Burge HA [1995]. Bioaerosols. Ann Arbor: LewisPublishers, pp 77-90.

45.Hagmar L, Schütz A, Hallberg T, Sjöholm A [1990]. Health effects of exposure to endotoxins and organicdust in poultry slaughter-house workers. Int ArchOccup Environ Health 62:159-164.

46.Burge HA [1995]. Aerobiology of the indoor environment. In:Seltzer JM ed. [1995]. Occupational medicine: state of the artreviews, effects of the indoor environment. Philadelphia, PA;Hanley & Belfus. 10(1):30.


47.Seltzer JM [1995]. Biologic Contaminants. In: Seltzer JM ed.[1995]. Occupational medicine: state of the art reviews, effectsof the indoor environment. Philadelphia, PA; Hanley & Belfus.10(1):30.

48.Lundholm M, Rylander R [1983]. Work related symptoms amongsewage workers. British Journal of Industrial Medicine, 40: 325-329.

49.Teeuw KB, Vandenbroucke-Grauls CMJE, Verhoef J [1994].Airborne gram-negative bacteria and endotoxin in sick buildingsyndrome. Arch Intern Med 154:2339-2345.

50.Hood MA [1990]. Gram-negative bacteria as bioaerosols. In:Biological Contaminants in Indoor Environments, ASTM STP 1071.Morey PR, Feeley JC, and Otten JA, Eds. American Society forTesting and Materials, Philadelphia, PA.

51.Jarvis BB [1990]. mycotoxins and indoor air quality. In:Biological Contaminants in Indoor Environments, ASTM STP 1071.Morey PR, Feeley JC, and Otten JA, Eds. American Society forTesting and Materials, Philadelphia, PA.

XI.XI.XI.XI. AUTHORSHIP AND ACKNOWLEDGMENTSAUTHORSHIP AND ACKNOWLEDGMENTSAUTHORSHIP AND ACKNOWLEDGMENTSAUTHORSHIP AND ACKNOWLEDGMENTS

Report Prepared by: Robert Malkin, D.D.S.,Dr.P.H.

SupervisoryEpidemiologist

Medical Section

Beth Donovan Reh,M.H.S.

Industrial HygienistIndustrial Hygiene

Section

Originating Office:Hazard Evaluations

and Technical Assistance Branch

Division ofSurveillance, Hazard

Evaluations & Field Studies

Report Typed by: Kathy MitchellSecretary


XII.XII.XII.XII. DISTRIBUTION AND AVAILABILITY OF REPORTDISTRIBUTION AND AVAILABILITY OF REPORTDISTRIBUTION AND AVAILABILITY OF REPORTDISTRIBUTION AND AVAILABILITY OF REPORT

Copies of this report may be freely reproduced andare not copyrighted. Single copies of this report willbe available for a period of 90 days from the date ofthis report from the NIOSH Publications Office, 4676Columbia Parkway, Cincinnati, Ohio 45226. Toexpedite your request, include a self-addressedmailing label or envelope along with your writtenrequest. After this time, copies may be purchasedfrom the National Technical Information Service(NTIS), 5285 Port Royal Road, Springfield, Virginia22161. Information regarding the NTIS stocknumber may be obtained from the NIOSHPublications Office in Cincinnati.

Copies of this report have been sent to:

1. Hillsborough County Sheriff’s Department2. Confidential employee requestors3. OSHA Region IV

For the purpose of informing affected employees, copies of thisFor the purpose of informing affected employees, copies of thisFor the purpose of informing affected employees, copies of thisFor the purpose of informing affected employees, copies of thisreport shall be posted by the employer in a prominent placereport shall be posted by the employer in a prominent placereport shall be posted by the employer in a prominent placereport shall be posted by the employer in a prominent placeaccessible to the employees for a period of 30 calendar days.accessible to the employees for a period of 30 calendar days.accessible to the employees for a period of 30 calendar days.accessible to the employees for a period of 30 calendar days.

- 38 -

TABLE 1TABLE 1TABLE 1TABLE 1 Symptoms Experienced At Work Symptoms Experienced At Work Symptoms Experienced At Work Symptoms Experienced At Work

Hillsborough County Sheriff's DepartmentHillsborough County Sheriff's DepartmentHillsborough County Sheriff's DepartmentHillsborough County Sheriff's DepartmentTampa, FloridaTampa, FloridaTampa, FloridaTampa, Florida

HETA 94-0370-2511HETA 94-0370-2511HETA 94-0370-2511HETA 94-0370-2511

SymptomsSymptomsSymptomsSymptomsOfOfOfOf77777777

Workers Workers Workers Workers

ExperiencedExperiencedExperiencedExperiencedOn Days ofOn Days ofOn Days ofOn Days of

Survey WhileSurvey WhileSurvey WhileSurvey WhileAt Work At Work At Work At Work

FrequentlyFrequentlyFrequentlyFrequentlyExperiencedExperiencedExperiencedExperienced

Last FourLast FourLast FourLast FourWeeksWeeksWeeksWeeks

While atWhile atWhile atWhile atWorkWorkWorkWork

Have FrequentHave FrequentHave FrequentHave FrequentSymptomsSymptomsSymptomsSymptoms

that Improvethat Improvethat Improvethat ImproveWhenWhenWhenWhen

Away fromAway fromAway fromAway fromWorkWorkWorkWork

Dry, or irritatedeyes

39% 51% 35%

Wheezing 5% 13% 7%

Stuffy nose,or sinus congestion

43% 46% 25%

Sneezing 23% 25% 16%

Sore or drythroat

29% 30% 21%

Dry or itchyskin

23% 22% 8%

Unusualfatigue ordrowsiness

31% 39% 25%

Headache 22% 36% 25%

Muscle orjoint pains

22% 16% 4%

Difficultywithmemory orconcentration

10% 14% 5%

Itchy eyes 29% 36% 22%

Runny nose 29% 33% 16%

Cough 30% 30% 17%

- 39 -

Chesttightness

4% 10% 8%

Shortnessof breath

13% 14% 7%

- 40 -

TABLE 2TABLE 2TABLE 2TABLE 2Description Of Workplace ConditionsDescription Of Workplace ConditionsDescription Of Workplace ConditionsDescription Of Workplace Conditions

Hillsborough County Sheriff's DepartmentHillsborough County Sheriff's DepartmentHillsborough County Sheriff's DepartmentHillsborough County Sheriff's DepartmentTampa, FloridaTampa, FloridaTampa, FloridaTampa, Florida

HETA 94-0370-2511HETA 94-0370-2511HETA 94-0370-2511HETA 94-0370-2511

ConditionsConditionsConditionsConditions ExperiencedExperiencedExperiencedExperiencedAt Work DuringAt Work DuringAt Work DuringAt Work During

Days of theDays of theDays of theDays of theSurveySurveySurveySurvey

77 Workers77 Workers77 Workers77 Workers

FrequentlyFrequentlyFrequentlyFrequentlyExperienced Experienced Experienced Experienced

While at WorkWhile at WorkWhile at WorkWhile at Work During Previous During Previous During Previous During Previous

Four WeeksFour WeeksFour WeeksFour Weeks77 workers77 workers77 workers77 workers

Too much airmovement

10% 16%

Too little airmovement

48% 65%

Temperature toohot

36% 57%

Temperature toocold

22% 36%

Air too humid 6% 13%

Air too dry 37% 46%

Tobacco smokeodors

5% 8%

Chemical odors(e.g., paint,cleaning fluids,etc.

8% 21%

Otherunpleasantodors(e.g., body odor,food odor,perfume)

27% 33%

heta 94-0370-2511heta 94-0370-2511heta 94-0370 …

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