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NIOSH HEALTH HAZARD EVALUATION REPORT 

HETA # 97-0137-3026 

New York City Police Department 

Police Communications Section 

New York, New York 

January 2007 

DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health
PREFACE

The Hazard Evaluation and Technical Assistance Branch (HETAB) of the National Institute for 

Occupational Safety and Health (NIOSH) conducts field investigations of possible health hazards in the 

workplace. These investigations are conducted under the authority of Section 20(a)(6) of the Occupational 

Safety and Health (OSHA) Act of 1970, 29 U.S.C. 669(a)(6) which authorizes the Secretary of Health and 

Human Services, following a written request from any employers or authorized representative of 

employees, to determine whether any substance normally found in the place of employment has 

potentially toxic effects in such concentrations as used or found. 

HETAB also provides, upon request, technical and consultative assistance to federal, state, and local 

agencies; labor; industry; and other groups or individuals to control occupational health hazards and to 

prevent related trauma and disease. Mention of company names or products does not constitute 

endorsement by NIOSH. 

ACKNOWLEDGMENTS AND AVAILABILITY OF REPORT

This report was prepared by Richard Driscoll, Randy Tubbs, and Daniel Habes of HETAB, Division of 

Surveillance, Hazard Evaluations and Field Studies (DSHEFS). Field assistance was provided by Jenise 

Brassell, Susan Burt, Pam Shumacher, Patricia McGraw, Carol Goetz, Patricia Lovell, Barbara Jenkins, 

Larry Mazzuckelli, Kathy Mitchell, Elaine Moore, Vera Drake, Betty Walpole, and Tamara Wise. 

Analytical support was provided by Charles Mueller. Desktop publishing was performed by Robin Smith. 

Editorial assistance was provided by Ellen Galloway. 

Copies of this report have been sent to employee and management representatives at the New York 

Police Department and the OSHA Regional Office. This report is not copyrighted and may be freely 

reproduced. The report may be viewed and printed from the following internet address: 

http://www.cdc.gov/niosh/hhe. Copies may be purchased from the National Technical Information 

Service (NTIS) at 5825 Port Royal Road, Springfield, Virginia 22161. 

ii 

For the purpose of informing affected employees, copies of this report 

shall be posted by the employer in a prominent place accessible to the 

employees for a period of 30 calendar days.
Highlights of Health Hazard Evaluation 

Highlights of the NIOSH Health Hazard Evaluation

NIOSH received a request from the New York Police Department (NYPD) and the union (AFSCME) to 

evaluate work stress among 911 emergency response operators and police dispatchers. Six hundred and seven 

of 970 employees participated in a comprehensive evaluation of work stressors and noise at the police 

communications office at 11 Metro Tech Center in Brooklyn. 

What NIOSH Did

 We collected symptom questionnaires to 

evaluate work stress among dispatchers and 

emergency phone operators. 

 We collected saliva samples to measure 

cortisol, an indicator of work stress. 

 We evaluated noise exposures. 

What NIOSH Found

 workers who participated in this 

 satisfied or somewhat satisfied 



 levels approached or exceeded 

guidelines for communication in an office 

setting. 



nd improving work place job 

 age workers to use their accumulated 



 eparate 

ing 

Of the 607 

evaluation: 

48% were very

with their job. 

42% considered the best part of their job was 

helping the public. 

 32% reported symptoms consistent with major 

depression. 

 22% reported symptoms consistent with 

anxiety. 

 87% reported muscle or joint pain that had 

lasted at least a week during the year.

 Salivary cortisol levels were not associated 

with self-reported stressors at work. 

Noise 

 Improve supervisory training and develop 

conflict management skills. 

 Seek ways to improve social support among 

departmental personnel. 

 Improve working relationships between police 

communication workers and police officers. 

Evaluate sources of low job satisfaction and 

involve employees in the process of 

identifying a

satisfaction. 

Encour

leave. 

Recognize the contributions made by the 911 

operators and police dispatchers. 

 Involve employees in decision making 

processes. 

Make changes to rooms to further s

operators and dispatchers thereby reduc

noise from background conversations. 

What New York Police Department 

Employees Can Do 

 Join with management in seeking innovative 



 rs to keep extra 

conversations to a minimum (reduce 

background noise). 

solutions to routine problems. 

Participate in safety committee meetings. 

Encourage worke

What New York Police Department 

Managers Can Do

What To Do For More Information:

We encourage you to read the full report. If you 

would like a copy, either ask your health and safety 

representative to make you a copy or call 

1-513-841-4252 and ask for 

HETA Report #HETA 97-0137-3026

iii 
Health Hazard Evaluation Report 97-0137-3026 

New York City Police Department 

Police Communications Section 

New York, New York 

January 2007 

Richard J. Driscoll, Ph.D., M.P.H. 

Randy L. Tubbs, Ph.D. 

Daniel J. Habes, M.S.E., C.P.E. 

SUMMARY

On March 14, 1997, the Senior Safety Coordinator, District 37, American Federation of State, County, & 

Municipal Employees (AFSCME), contacted the National Institute for Occupational Safety and Health 

(NIOSH) to request a health hazard evaluation (HHE) at the NYPD’s 911 emergency call center in 

Brooklyn, New York, and at 1 Police Plaza, New York City. On March 27, 1997, the Safety Director, 

New York City Police Department, submitted an HHE request on behalf of NYPD management, also 

requesting an HHE at this location. Both management and union representatives were concerned that 

work within the 911 Call Center was highly stressful, that workers experienced high demands, potentially 

hostile interactions with the public, difficulty overcoming distressing call-related memories, increased 

tension and irritability, and chronic musculoskeletal discomfort because of improperly designed work 

stations. 

In response to this labor and management request, NIOSH personnel conducted a series of interviews 

with managers and employees at the 911 emergency call center at the 11 Metro Tech Building in 

Brooklyn, New York. Following these meetings, NIOSH personnel developed a study protocol to 

evaluate each of the concerns expressed in the HHE request and subsequently returned to the 911 

emergency call center to carry out the evaluation. 

Participants completed a 200-item self-administered questionnaire designed to examine a range of work 

place stressors and health related outcomes (depression, anxiety, lost work days, musculoskeletal injury). 

Participants submitted saliva samples four times daily for 5 days to assess physiologic reactions to stress. 

In addition, a comprehensive area noise assessment consisting of octave band noise measurements was 

made at the active dispatch consoles and 911 operator telephone consoles. 

Of the estimated 970 on-duty 911 operators and police dispatchers, 607 participated in this study for a 

participation rate of 63%. Participants were predominately female (88%), had an average age of 38 years 

(range 21-73 years), and had worked for the city for an average of 10 years (range 1-34 years). 

One hundred ninety three workers (32%) reported experiencing symptoms that were consistent with 

major depression according to the Centers for Epidemiologic Studies Depression Scale (CES-D). 

Predictors of depressive symptoms in this work force included low supervisory social support, anxiety, 

iv 
low job satisfaction, greater than 6 months since last vacation, increasing age, lower levels of social 

contact, and increasing years working for the City. 

Symptoms consistent with anxiety were reported by 138 participants (22%), 68% of whom also had 

symptoms consistent with major depression. Predictors of anxiety were age, low job satisfaction, more 

than 6 months since last vacation, and increasing years worked for the City. 

The annual work absentee rate for participants in this study was approximately two times the rate reported 

by workers nationwide (New York workers 13.7 vs. 6.2 days nationally). 

Musculoskeletal symptoms were most commonly reported for the low back (53%), wrists (43%), upper 

back (40%), and shoulders (40%-43%). 

According to ANSI S12.2 Criteria for Evaluating Room Noise, ambient noise levels measured in the work 

area were found to be appropriate for moderately fair listening or just acceptable speech and telephone 

communication conditions. 

NIOSH investigators conclude that conditions at the New York City Police 911 

Emergency Response Communications Center contributed to the increased reporting of 

depressive symptoms and that a health hazard does exist at this location. 

Recommendations have been made in this report to help improve conditions at this 

worksite. 

v 

Keywords: NAICS 922120 (Police Departments), work stress, work organization, psychosocial, noise, 

ergonomic, depression 
Table of Contents 

Preface..........................................................................................................................................................ii

Acknowledgments and Availability of Report..........................................................................................ii

Highlights of Health Hazard Evaluation .................................................................................................iii

Summary.....................................................................................................................................................iv

Introduction.................................................................................................................................................1

Background .................................................................................................................................................1

Methods........................................................................................................................................................2

Study Design............................................................................................................................................2

Questionnaire ..........................................................................................................................................2

Questionnaire Components: Psychosocial Scales.................................................................................2

Salivary Cortisol: A Marker for Stress.................................................................................................3

Noise .........................................................................................................................................................3

Statistical Analysis ..................................................................................................................................3

Missing Variables....................................................................................................................................4

Evaluation Criteria .....................................................................................................................................4

Psychosocial Factors ...............................................................................................................................4

Noise .........................................................................................................................................................4

Results ..........................................................................................................................................................5

Organizational Climate ......................................................................................................................5

Call Monitoring...................................................................................................................................5

Job Performance Factors ...................................................................................................................5

Self-Reported Sick Leave ...................................................................................................................6

Job Satisfaction ...................................................................................................................................6

Depression............................................................................................................................................6

Anxiety .................................................................................................................................................7

Musculoskeletal...................................................................................................................................7

Salivary Cortisol..................................................................................................................................7

Noise .....................................................................................................................................................7

Discussion ....................................................................................................................................................8

Depression................................................................................................................................................8

Stressors associated with reports of depressive symptoms in this work force ..................................8

Anxiety .....................................................................................................................................................8

Stressors Common to Anxiety and Depression ....................................................................................9
Call Monitoring.......................................................................................................................................9

Conclusions................................................................................................................................................10

Recommendations.....................................................................................................................................11

Work Organization...............................................................................................................................11

Noise .......................................................................................................................................................11

References..................................................................................................................................................12

Tables .........................................................................................................................................................14

Figures........................................................................................................................................................22
Health Hazard Evaluation Report No. 97-0137-3026 Page 1 

INTRODUCTION

On March 14, 1997, the American Federation of 

State, County and Municipal Employees 

(AFSCME), District 37 Safety Coordinator 

submitted a health hazard evaluation (HHE) request 

on behalf of NYPD Police Communication 

Technicians at the 11 Metro Tech Center and 1 

Police Plaza in New York City. The HHE request 

detailed concerns that work within the 911 Call 

Center was highly stressful and that workers 

experienced distressing call related memories, 

increased tension and irritability, and chronic 

musculoskeletal discomfort. On March 27, the 

Safety Officer for NYPD filed a joint HHE request 

on behalf of NYPD management and asked that the 

National Institute for Occupational Safety and 

Health (NIOSH) conduct a health hazard 

evaluation of Police Communication Technicians 

to determine whether working conditions at the call 

centers were hazardous to worker health. 

On August 3, 1998, an opening conference was 

held at 11 Metro Tech Center in Brooklyn, New 

York with representatives from the NYPD 

Department of Citywide Administrative Services, 

AFSCME District 37, and NIOSH to discuss the 

HHE request, the types of health concerns 

expressed by employees, and the steps that NIOSH 

researchers would propose to evaluate these 

concerns. Following this opening conference, 

employees at the 911 Call Center at 11 Metro Tech 

Center and 1 Police Plaza were randomly selected 

for confidential interviews. Employees who 

participated in the confidential interviews were 

asked to describe working conditions within the 

Police Communications Section and how these 

working conditions may have been affecting their 

health. 

As a result of meetings with management, workers, 

and union representatives, NIOSH representatives 

proposed to the NYPD that a survey be conducted 

to evaluate potential work stressors, ergonomic 

hazards, and noise levels at the call center. NIOSH 

investigators developed an evaluation protocol for 

the call center that included a self-administered 

questionnaire to ascertain work history, work load, 

employee and supervisory interactions, and health 

outcomes related to work stress such as depression, 

anxiety, and lost work days. Furthermore, NIOSH 

investigators proposed that salivary cortisol 

samples be collected as an objective measure of 

stress. To address concerns about noise and 

musculoskeletal strain, specific noise and 

ergonomic assessments were also proposed. 

During the week of March 1-5, 1999, 

representatives from NIOSH distributed 

questionnaires, collected serial salivary cortisol 

samples, measured ambient noise at selected 

locations in the call center, and evaluated the 

ergonomic design of workstations at 11 Metro Tech 

Center. 

BACKGROUND

The New York Police Communication Section 

occupies space at the 11 Metro Tech Center in 

Brooklyn and, at the time of the survey, a limited 

number of personnel occupied space at 1 Police 

Plaza. NYPD management estimated that 970 

workers were employed as emergency response 

operators and police dispatchers. The emergency 

response telephone operator’s job title is Police 

Communication Technician (PCT); supervisory 

PCTs are designated SPCT. Collectively, the PCTs 

are referred to as call takers. Individual call takers 

average over 120 calls per day; the 911 telephone 

system receives approximately 25,000 calls each 

day. In addition to the high volume of calls 

handled, the ethnic diversity of New York requires 

that the emergency response program be able to 

accommodate callers in over 143 languages and 

dialects. 

Call takers work an 8-hour shift with an hour for 

meals and an additional hour of breaks. Thus, call 

takers are expected to have their headsets 

connected to the system for 6 hours each day. 

Breaks can be cancelled in the event that call 

volumes increase and stations need coverage. 

When in a ready state (last call completed and open 

for a new call) an incoming emergency call can be 

automatically routed to the call taker. Call takers 

answer the phone according to protocol by 

informing callers that they have reached the 911 

operator and then asking them to describe the 

nature of their emergency. Call takers note the 
Health Hazard Evaluation Report No. 97-0137-3026 Page 2 

important facts of the call on their computer screens 

and then transmit this information to the police 

dispatcher who finds an available police unit to 

respond. All incoming calls and conversations 

between call takers and the public are recorded. In 

addition, call center supervisors routinely monitor 

calls to insure that call takers are following 

established protocols and handling calls efficiently. 

Call takers complete 7 weeks of training and 

supervised experience before they are scheduled on 

a duty roster. The training program includes 2 

weeks of training dedicated to using radios, 2 

weeks of classroom sessions where prospective call 

takers learn 10-codes and the use of the computer 

system, and a minimum of 2 weeks where the 

trainee sits with an experienced PCT to observe and 

learn procedures. 

METHODS

The methods employed in this health hazard 

evaluation were approved by the NIOSH Human 

Subjects Review Board. 

Study Design 

This was a cross-sectional study of NYPD 

Emergency Communication workers. Internal 

comparisons were made, as were comparisons with 

another metropolitan police communication 

program also evaluated by NIOSH. 

Questionnaire 

Data were gathered by means of a 200-item selfadministered questionnaire which included 

questions on work history, demographics, 

musculoskeletal injury and pain, depression, and 

psychosocial/work organization factors. 

Questionnaire Components: 

Psychosocial Scales 

Cognitive Demands 

Cognitive demands were assessed by a five-item 

scale that was developed by Hurrell and McLaney1

to capture the mental demands of workers. 

Anxiety 

Anxiety was assessed by a 12-item scale that has 

been routinely used in the NIOSH generic job 

stress questionnaire by Hurrell and McLaney.

Participants indicate how often they experienced 

dry mouth, muscle tension, headache, feeling as if 

blood was rushing to their head, feeling a lump in 

their throat, trembling, shortness of breath, 

pounding heart, sweaty hands, upset stomach, loss 

of appetite, and difficulty sleeping. 

Depression 

Depressive symptomatology was assessed by a 

modified (short form) version of the Center for 

Epidemiologic Studies Depression Scale (CESD).2,3

 Participants were asked how often in the last 

week they experienced any of the scale symptoms. 

Scores were adjusted to correspond to the full CESD. Persons who had scores of 12 or greater were 

considered to have symptoms consistent with major 

depression (equivalent to a score of 22 or higher on 

the full CES-D 20-item scale). 

Social Network 

The social network scale was developed by Donald 

and Ware4

 and consists of three subscales, social 

well-being, social contacts, and group participation. 

The 11-item scale covers a range of social and 

group activities including quantifying the number 

of friends and family, frequency of interaction with 

family and friends, group membership, and the 

extent of active involvement in groups and 

religious activity. 

Quantitative Workload 

Quantitative workload is assessed by a seven-item 

scale developed by Caplan, et al.5

 that captures the 

pace of work and the amount of time available to 

complete an assignment or task. 

Work Control 

Work control, a combination of decision control 

and task control, was derived from job stress 

research by Greenberger6

 and Ganster.7 Hurrell 

and McLaney used the work of these researchers to 

compile a 16-item scale for the NIOSH Generic 

Job Stress Questionnaire that assesses a worker’s 

control over the selection of tasks and the pace of 
completing these tasks, workplace decision 

making, and influence over policies and 

procedures. 

Social Support 

For the purposes of this study, we focused upon 

social support provided by supervisory personnel 

based upon the work of Caplan et al.

Job Satisfaction 

The job satisfaction scale was developed by Caplan 

et al.5 and determines job satisfaction based upon 

responses to whether the worker would recommend 

that a friend take a similar job, whether the worker 

would decide to take the same type of job again if 

given the choice, and whether the worker is 

generally satisfied with his/her job. 

Salivary Cortisol: A Marker for 

Stress 

Salivary cortisol has been used in numerous studies 

as an objective measure for psychological 

stress.8, , 9 10 During periods of stress, the adrenal 

gland in the body produces a sharp rise in the levels 

of the glucocortical hormone cortisol. Normally, 

cortisol levels fluctuate during the day and are 

highest early in the morning. These levels taper off 

during late morning, then rise to a high again at 

noontime, and gradually decline to daily lows at 8-

9 p.m. Cortisol levels that fluctuate against the 

normal daily pattern are considered markers of 

stressful periods.11,12

We collected salivary cortisol samples from 

participants four times daily for one week. This 

schedule allowed us to capture the natural daily 

variation in cortisol levels. Participants were given 

a 1-week supply of plastic sampling vials. Each vial 

contained a 3/8-inch diameter by 1.5-inch long dry 

cotton roll similar to those routinely used by 

dentists. At prescribed sampling intervals, workers 

were asked to remove the cotton swab from the vial 

and chew it for approximately 1 minute or until the 

swab was saturated with saliva. Workers then 

placed the saturated swab back into the plastic vial. 

Vials were coded to identify the individual 

providing the sample, the sample time, and the day 

the sample was collected. Salivary cortisol samples 

were then refrigerated and shipped to the NIOSH 

laboratory daily. 

Samples were analyzed by NIOSH laboratory 

personnel using an enzyme-linked immunosorbent 

assay (ELISA) produced by Oxford Biomedical. 

Saliva samples were run in duplicate according to 

the manufacturer’s instructions. Calibration 

standards were run in duplicate on each plate. 

Samples yielding results > 10 nanograms/milliliter 

(ml) were diluted 1:5 with buffer solution and 

reanalyzed. 

Noise 

Real-time area noise sampling was conducted with 

a Larson-Davis Laboratory Model 2800 Real-Time 

Analyzer and a Larson-Davis Laboratory Model 

2559 1⁄2-inch random incidence response 

microphone. The analyzer allowed for the analysis 

of noise into its spectral components in a real-time 

mode. The 1⁄2-inch diameter microphone had a 

frequency response range (± 2 decibels [dB]) from 

4 Hertz (Hz) to 21 kilohertz (kHz) that allowed for 

the analysis of sounds in the region of concern. Full 

octave bands consisting of center frequencies from 

31.5 Hz to 16 kHz were integrated and stored in the 

analyzer. The analyzer was mounted on a tripod 

and placed at various locations where the police 

and the 911 telephone operators sat at their 

consoles with the microphone placed at 

approximately the level of peoples’ ears. 

Statistical Analysis 

Data were analyzed using SAS® version 8.0. 

Exploratory data analyses were conducted using 

univariate data techniques. Associations between 

questionnaire items were assessed by means of 

correlation statistics and odds ratios (OR) were 

calculated. ORs were used to measure the strength 

of association between psychosocial variables and 

health outcomes. The OR is a ratio between the 

odds of an event among those exposed to a 

specified variable and the odds of an event among 

those not exposed to that variable. For example, the 

association between depression (the health 

outcome) and sex of the participant (exposure 

variable) would be expressed as an OR in the 

following manner: 

ofOdds depression menamong

ofOdds depression among women

= OR 

Health Hazard Evaluation Report No. 97-0137-3026 Page 3 
Health Hazard Evaluation Report No. 97-0137-3026 Page 4 

If the ratio is 1 (the same odds of depression is 

found in women as is found in men) then there is 

no greater prevalence of depression in women 

compared to men. If the OR exceeds 1, then the 

prevalence of depression would be higher in 

women than in men. An OR of 3 would mean that 

the prevalence of depression is three times greater 

among women than among men. Conversely, an 

OR less than 1 indicates that the prevalence of 

depression is less among women than among men. 

Each estimated OR also has an associated 

confidence interval (CI). The confidence intervals 

are an indication of the statistical significance of the 

OR. A 95% CI of 1.1 to 2.0 indicates 95% certainty 

that the true OR is somewhere between 1.1 and 2.0. 

Conversely, this same range would suggest that 

there is a 5% chance that the true OR is outside of 

the range indicated. 

Missing Variables 

We imputed missing variables (i.e., assigned a 

value when data were missing) within 

psychometric scales when possible. Scale item 

responses were imputed when the participant had 

answered at least 75% of the scale. Individual 

average response scores were calculated from the 

scale items present and items where an answer was 

missing were assigned an average response score 

that reflected each individual respondent’s 

tendencies within that specific scale. 

EVALUATION CRITERIA

Psychosocial Factors 

With regard to psychosocial factors within the 

workplace, there are currently no minimum or 

maximum levels for identified work stressors. The 

purpose of this study was to assess what work place 

stressors were most associated with health 

outcomes, not to determine whether workers 

exceeded a reference range. National prevalence 

rates and normative data are available for many of 

the scales used in this HHE and where practical, 

comparisons were made with national normative 

data or comparisons with results from other 911 

Call Centers. 

Noise 

The A-weighted decibel (dBA) is the preferred 

unit for measuring sound levels to assess worker 

noise exposures. The dB(A) scale is weighted to 

approximate the sensory response of the human 

ear to sound frequencies near the threshold of 

hearing. The decibel unit is dimensionless, and 

represents the logarithmic relationship of the 

measured sound pressure level to an arbitrary 

reference sound pressure (20 micropascals, the 

normal threshold of human hearing at a 

frequency of 1000 Hz). Decibel units are used 

because of the very large range of sound 

pressure levels audible to the human ear. 

Because the dB(A) scale is logarithmic, 

increases of 3 dB(A), 10 dB(A), and 20 dB(A) 

represent a doubling, tenfold increase, and 

hundred-fold increase of sound energy, 

respectively. It should be noted that noise 

exposures expressed in decibels cannot be 

averaged by taking the simple arithmetic mean. 

Neither the occupational noise regulation 

promulgated by the Occupational Safety and 

Health Administration (OSHA),13 nor the limits 

published by NIOSH 14 and the American 

Conference of Government Industrial Hygienists 

(ACGIH),15 are appropriate for the situation 

observed at this work location. The above 

referenced criteria are designed to prevent 

hearing losses from exposure to intense noise 

levels. However, noise of intensities lower than 

that which may cause a hearing loss can be 

disruptive in the workplace. Interference with 

speech and interruption of office activities are 

possible results of unwanted noise. The noise 

can interfere with the efficiency and productivity 

of the office staff and can be detrimental to the 

occupants’ comfort, health, and sense of wellbeing. One set of noise criteria for occupied 

interior spaces, the balanced noise criteria 

(NCB) curves, have been devised to limit noise 

to levels where satisfactory speech intelligibility 

is obtained.16, , 17 18 The noise criteria were 

devised through the use of extensive interviews 

with personnel in offices, factories, and public 

places along with simultaneously measured 

octave band sound levels. The interviews 

consistently showed that people rate noise as 

troublesome when its speech interference level 

is high enough to make voice communication 

difficult. The recommended space classification 

and suggested noise criteria range for steady 
Health Hazard Evaluation Report No. 97-0137-3026 Page 5 

background noise heard in various indoor 

occupied activity areas are shown in Table 1. 

The NCB curves assume occupied spaces, with 

the heating, ventilation, and air-conditioning 

systems operating along with all other sources of 

normal interior and exterior noise. In general, 

the lower end of the range shown in Table 1 is 

selected if high reliability of speech 

communication is desired. The upper end of the 

range is used when economic conditions dictate 

that marginal conditions must be accepted and 

where it is expected that the users will not be 

overly critical of the space.

RESULTS

Of the 970 on-duty police dispatchers and 

operators, 607 (63%) participated in at least the 

questionnaire phase of this study. Participants had 

an average age of 38 (range 21-73 years); the 

majority were female (88%), married (40%), and 

either attended some college or were graduates of a 

community college (63%). Participants had worked 

for the city an average of 10 years (range <1 to 34 

years), and worked as a call taker for 8 years (range 

<1-27 years). 

Organizational Climate 

Participants were asked to select one of seven 

answers to describe what they liked best about their 

job. The seven choices represent those responses 

that were given most frequently during personal 

interviews with workers when asked the question, 

“What do you like best and what do you like worst 

about your job?” Forty seven percent responded 

“helping the public,” 25% selected “my paycheck”, 

and 20% selected “the people I work with” as the 

aspect of their job they liked best (Table 2). “How 

we are valued as employees” was selected by 354 

persons (71%) to represent the single worst part of 

working as a 911 operator (Table 3). 

Call Monitoring 

Department policy requires supervisory personnel 

to periodically monitor calls to ensure that 

operators are adhering to established procedures 

and determine whether a worker might require 

additional training. Call takers are aware that 

supervisors are able to monitor calls and that at 

least once per month their calls will be monitored. 

During a monitored call, the call takers are unaware 

that the supervisor is on the line. Immediately 

following the call, supervisors hand the call taker a 

score sheet that lists any deficiencies noted during 

the call. 

To evaluate how workers perceive call monitoring 

procedures, participants were asked to describe 

why calls were monitored, whether call monitoring 

helped them with their job, and what type of 

feedback was likely after calls were monitored. 

When presented the statement “Supervisors 

monitor our call to insure that we follow the correct 

procedures,” 58% of the respondents “strongly 

agreed,” and 33% “slightly agreed” with the 

statement (Table 4). Only 3% strongly disagreed. 

Additionally, when ask to respond to the statement 

“Supervisors monitor our calls to help us do our 

jobs better,” 29% “strongly agreed,” and 42% 

“slightly agreed.” Fourteen percent strongly 

disagreed with the statement. To evaluate what is 

likely to happen if the call taker adheres to policy, 

call takers were asked to respond to the following 

statement, “When calls have been monitored by a 

supervisor and we did a good job, our supervisor 

will tell us we did a good job.” Among participants, 

16% “strongly agreed,” 41% “slightly agreed” and 

42% slightly or strongly disagreed with the 

statement. 

Overall, when asked to respond to the statement “It 

bothers me that a supervisor may be listening to me 

on the phone,” 33% selected “strongly disagree,” 

32% selected “slightly disagree,” and 25% selected 

“slightly agree.” Forty eight persons (10%) strongly 

agreed that it bothers them when a supervisor 

monitors their phone conversations. 

Job Performance Factors 

Call takers were asked about their work 

environment and what aspects of it made it difficult 

for them to do their job effectively. Three hundred 

thirty three persons agreed (of these, 31% “strongly 

agreed,” 37% “slightly agreed”) that it is 

sometimes difficult to concentrate on a caller 

because of interfering noise from other operators or 

dispatchers talking. When responding to the 

statement, “I can tune out the noise in the room 
Health Hazard Evaluation Report No. 97-0137-3026 Page 6 

when I am doing my work,” 20% “strongly agreed” 

and 47% “slightly agreed.” When asked if they can 

clearly see the information on their computer 

screen PCTs responded somewhat evenly across 

the response categories. Twenty one percent 

“strongly agreed” that they could clearly see the 

information on the computer screen, 34% “slightly 

agreed”, 24% “slightly disagreed,” and 21% 

“strongly disagreed.” 

Self-Reported Sick Leave 

To evaluate sick leave use, participants were asked 

to estimate the number of days absent in the 

previous 12 months. Four hundred ninety two 

persons responded to this question. Of these 

respondents, 93% indicated that they had been 

absent from work one or more days during this 

period. The median number of days absent from 

work was 10 days (range 0-99 days). Some or all of 

the sick leave was used to care for a sick family 

member according to 55% of the respondents. Fifty 

six percent of the respondents indicated that they 

had not used leave in the last 30 days. Among those 

who had used leave in the last 30 days, they were 

absent an average of 3.5 days. Table 5 presents a 

comparison of New York Police Communications 

Center employee absences to those of a smaller 

urban 911 Call Center in Ohio. 

New York 911 operators used approximately 19.6 

days of sick leave annually compared to 13.7 days 

among 911 operators in Ohio. In both 911 centers, 

women used more sick days than men. 

Job Satisfaction 

Participants were asked three questions pertaining 

to job satisfaction. Answers to these questions were 

used to construct an overall job satisfaction score. 

These overall scores and individual item scores are 

presented in Table 6 along with comparison scores 

from the Ohio 911 Call Center. Overall, New York 

had worse job satisfaction, i.e., higher job 

dissatisfaction score than the comparison center 

(New York average job dissatisfaction score = 2.31 

vs. 2.04 in Ohio, p<0.0001). Among New York 

respondents, 62 (9%) would decide without 

hesitation to take the same job again, however, 438 

respondents (88%) would have second thoughts or 

would definitely not take the same job. When asked 

if they would recommend this job to a friend, 43 

(3%) would recommend it strongly, while 457 

(91%) would have doubts about recommending it 

or would advise their friends against taking a 

similar job. When asked directly how satisfied they 

were with their job, 19 (4%) were “very” satisfied, 

221 (44%) were “somewhat” satisfied, 16 (32%) 

were “not too” satisfied, and 99 (20%) were “not at 

all” satisfied. 

Table 7 shows the variables associated with job 

satisfaction in a multivariate statistical model. Call 

takers who reported perceived workload in the 

highest quartile (top 25%) were three times more 

likely than those who reported lower perceived 

workload to have low job satisfaction scores 

(OR=3.02, 95% CI 1.11, 8.62) and participants 

who reported they had not had a vacation in over 6 

months were more than twice as likely as those 

with a recent vacation to report low job satisfaction 

(OR 2.21, 95% CI 1.52, 8.62). 

Depression 

Two hundred sixty nine respondents (44%) 

reported symptoms consistent with depression 

(CES-D scale greater than or equal to 16). Of these 

workers, 193 (72% of those with depressive 

symptoms and 32% of the overall participants) had 

depressive symptoms consistent with major 

depression (CES-D greater than or equal to 22). 

Women had a slightly higher prevalence of 

reporting depressive symptoms than men (38% 

women vs. 35% men) but this difference was not 

statistically significant (p=0.364). 

The prevalence of symptoms consistent with 

depression among New York 911 Call Center 

employees was compared with those from the Ohio 

911 Call Center. Prevalence rates for New York 

workers were slightly higher than found at the 

comparison 911 Call Center (32% vs. 29% 

respectively); however, this difference was not 

statistically significant. (p=0.65). 

Univariate (unadjusted ) relationships between 

predictor variables and depression are presented in 

Table 8. Persons were more likely to report 

symptoms consistent with major depression if they 

reported anxiety (OR 8.36, 95% CI 5.51, 12.86), 

had high perceived workloads (OR 4.11, 95% CI 

1.54, 12.09), had low job satisfaction (OR 3.61, 
Health Hazard Evaluation Report No. 97-0137-3026 Page 7 

95% CI 2.51, 5.21), had musculoskeletal pain in the 

last 12 months lasting more than 1 week (OR 3.27, 

95% CI 1.72, 6.75), had low levels of social well 

being (OR 2.98, 95% CI 2.06, 4.31), and had more 

than 6 months elapse since last vacation (OR 2.74, 

95% CI 1.88, 5.21). The final multivariate model 

had four statistically significant predictor variables, 

anxiety (OR 6.78, 95% CI 4.33, 10.61), high 

perceived workload (OR 4.57, 95% CI 1.45, 

14.43), low social well being (OR 2.63, 95% CI 

1.73, 4.00), and low job satisfaction (OR 2.35, 95% 

CI 1.56, 3.56). 

Anxiety 

Participants were asked to describe how often they 

experienced symptoms consistent with anxiety. 

Symptoms consistent with anxiety included dry 

mouth, muscle tension, headache, feeling as if 

blood was rushing to their head, feeling a lump in 

their throat, trembling, shortness of breath, heart 

pounding, sweaty hands, upset stomach, and loss of 

appetite or difficulty sleeping. Symptoms 

consistent with anxiety were reported by 138 

respondents (22%). Table 9 lists the unadjusted 

(crude) relationship between work organization 

variables and anxiety. Nine of the variables 

presented in Table 9 showed a statistically 

significant relationship with anxiety. However, 

multivariate modeling showed that two items were 

significantly associated with anxiety, reporting 

musculoskeletal pain that lasted more than a week 

in the last year and low job satisfaction. Workers 

who reported having musculoskeletal pain were 

more than five times as likely as those without 

musculoskeletal pain to report having anxietyrelated symptoms (OR 5.55, 95% CI 1.96, 15.70). 

PCTs who reported low job satisfaction (lowest 

quartile of job satisfaction) were twice as likely as 

those with better job satisfaction (highest three 

quartiles) to report anxiety related symptoms (OR 

2.03, 95% CI 1.53, 3.4). 

Musculoskeletal 

Participants were asked to recall whether they had 

any muscle, joint pain, or discomfort that lasted at 

least a week during the previous 12-month period. 

Those who had experienced pain were asked the 

location of the pain and to rate the pain from 0 

(none at all) to 5 (worst imaginable). 

Four hundred forty three persons (87%) indicated 

they had experienced muscular pain or discomfort 

that had lasted at least a week in the past year. 

Table 10 describes the location and severity of the 

pain reported by call center participants. 

Table 11 lists the results of univariate modeling of 

musculoskeletal pain. Increased prevalence of 

musculoskeletal pain is associated with anxiety 

(OR 4.53, 95% CI 2.89, 7.68), depressive 

symptomotology (OR 3.26, 95% CI 1.72, 6.75), 

low job satisfaction (OR 2.54, 95% CI 1.38, 5.00), 

low supervisory social support (OR 2.57, 95% CI 

1.48, 4.42), and being in the highest quartile of sick 

leave users (OR 2.25, 95% CI 1.15, 5.16). The 

multivariate model for musculoskeletal pain 

includes low supervisory social support, anxietyrelated symptoms and high use of sick leave. 

Participants with anxiety-related symptoms were 

five times more likely to report musculoskeletal 

pain (OR 5.62, 95% CI 2.37, 18.88), twice as likely 

to report low supervisory social support (OR 2.25, 

95% CI 2.28, 3.92) and twice as likely to be in the 

highest quartile of sick leave use (OR 2.16, 95% 

CI 1.07, 4.89). 

Salivary Cortisol 

Salivary cortisol samples were collected from 384 

participants who submitted three samples per day 

for 5 days. In general, individual cortisol responses 

followed patterns that have been reported in other 

studies, namely cortisol levels were highest in the 

morning and decreased as the day progressed.19 

Additionally, as others have found, measured 

salivary cortisol diminished as the week 

progressed.20 However, salivary cortisol levels 

were not associated with any of the health 

outcomes evaluated (no statistically significant 

difference in salivary cortisol levels was found 

between groups evaluated). Thus, salivary cortisol 

was not a predictor of depression, anxiety, or work 

stress in this study. 

Noise 

Area octave band noise measurements were 

made at seven of the fifteen 911 operator pods 

and at the 11 dispatch stations that were being 

used in the police dispatch area. Generally, the 

communication activity in the two locations was 

very heavy during the 60-second period when 
Health Hazard Evaluation Report No. 97-0137-3026 Page 8 

the measurements were made. Multiple noise 

readings were collected at each operator position 

at a 911 pod or dispatch station. Median noise 

levels were calculated for the octave bands and 

overall levels at each pod or dispatch station. 

The median overall sound levels measured in the 

911 Call Center ranged from 62 to 73 dBA. For 

the police dispatch area, the median overall 

levels ranged from 65 to 72 dBA. The median 

octave bands at each measurement site were 

graphed and are shown in Figures 1-20. The 

horizontal lines placed on each of the octave 

bands represent the high and low noise values 

captured at the measurement site. Each figure 

has a similar pattern, maximum sound energy in 

the 16 and 31.5 Hz bands and a second area of 

higher energy in the 500 and 1000 Hz bands. 

The lower frequencies are the result of the 

ventilation system in the office area. The higher 

frequencies are the result of conversations in the 

work areas. 

When the octave bands were compared to the 

NCB criteria for occupied spaces, the police 

dispatch and the 911 operator areas met the 

NCB-62 curve and NCB-59 curve, respectively 

(Figure 21 and 22). The determining octave 

band for the measured criteria was 500 Hz in the 

911 operator area and 2000 Hz in the police 

dispatch area. According to the NCB 

classification scheme, the ambient levels 

appropriate for fair listening conditions or 

general secretarial areas are between the range 

of NCB-40 and NCB-50. Levels above NCB-60 

are not recommended for any office or 

communication situation.7

DISCUSSION

The purpose of this health hazard evaluation was to 

identify work stressors associated with work as a 

911 operator and evaluate how these stressors 

affect worker health. Work stressors (factors that 

contribute to work stress) evaluated included 

supervisory social support, job satisfaction, 

workload, mental demands, and the degree to 

which workers had control over aspects of their job. 

Because workers have activities outside of the 

work environment, we also evaluated the extent of 

social networks, use of vacation time, amount and 

frequency of exercise, and ways employees chose 

to wind down after their shift. The work-related 

strains that were measured in this evaluation were 

symptoms of major depression, anxiety, lost work 

days (absenteeism) and musculoskeletal injury. 

Depression 

We found that 33% of the NYPD 911 Call Center 

employees and 29% of the employees at a 

comparison location in Ohio report symptoms 

consistent with major depression. Published 

estimates from the National Institute of Mental 

Health place the prevalence of major depression in 

the general public at approximately 9.5%.21 Rates 

of depressive symptoms among 911 operators and 

police dispatchers appear higher than what we 

would expect given the rates observed in the 

general population; however, the National Institute 

of Mental Health rates reflect actual diagnosed 

cases of depression and not responses to a 

screening questionnaire. 

Stressors associated with 

reports of depressive 

symptoms in this work force 

We compared those who reported the highest levels 

of depressive symptoms to others in this study. Our 

findings show that NYPD 911 Call Center 

operators were more likely to report depressive 

symptoms if they were highly anxious in their 

work, had low job satisfaction, reported having 

heavy workloads, and reported not taking a 

vacation within the last 6 months. 

Anxiety 

We found 22% of the participants reported 

symptoms consistent with anxiety. This is slightly 

higher than would be expected in the general 

population given that the National Institute of 

Mental Health estimates that 18% of the general 

adult population can report an anxiety disorder each 

year.22 Participants who were most likely to report 

symptoms consistent with anxiety were those who 

reported low job satisfaction and musculoskeletal 

pain that lasted longer than a week. 
Health Hazard Evaluation Report No. 97-0137-3026 Page 9 

Stressors Common to Anxiety 

and Depression 

Job satisfaction is a contributor to both depression 

and anxiety. Thus, factors that can improve job 

satisfaction may have far-reaching effects including 

reduced depressive symptomatology, reduced 

anxiety-related symptoms, and improved 

attendance at work. Those with poor job 

satisfaction are more than twice as likely to report 

depressive symptoms, anxiety-related symptoms, 

and musculoskeletal-related symptoms. The four 

statistically significant predictors of depression in 

this study were anxiety, high perceived workload, 

low social well being, and low job satisfaction. 

Two variables, workload and job satisfaction, are 

work-environment issues that, if properly 

addressed, could improve the mental health of the 

workforce. Factors that influenced perceived 

workload among participants included how much 

time workers had to think and contemplate their 

tasks. Unfortunately, work as a 911 operator 

allows little if any time to contemplate anything 

other than the emergency situation at hand; 

however, call takers could be included in decision 

making along with supervisors to consider broader 

organizational concerns, such as how to improve 

working conditions, supervisory/support 

relationships, or what changes could be 

implemented to accomplish their jobs more 

effectively. Factors that influenced job satisfaction 

were workload and time since last vacation. 

Persons who had perceived high workload were 

three times more likely to have low job satisfaction 

scores (OR 3.02, 95% CI 1.52, 3.24) after 

controlling for time since last vacation. Persons 

who reported more than 6 months since their last 

vacation were more than twice as likely to have 

low job satisfaction scores (OR 2.21, 95% CI 1.11, 

8.62). 

Work absenteeism, primarily in the form of sick 

leave, represents one of the major concerns of 

management. When the rates for the NYPD 911 

Call Center were adjusted to reflect a 12-month 

period, absentee rates for New York were higher 

than those found in the Ohio 911 center (19.6 vs. 

13.7). However, both call centers have absentee 

rates that exceed the national average for all 

workers. Factors contributing to absenteeism have 

been the subject of numerous studies and 

researchers have shown absenteeism is associated 

with not only acute illness but chronic disease, 

child care responsibilities, low job satisfaction, and 

work stress.23, , 24 25 In addition, some studies have 

shown sickness absence rates to be highest among 

employees who have jobs with high cognitive or 

physical demands and limited choices or options 

for coping. On both a national level and within this 

work group, women tend to use more sick leave 

than men.26 Among New York 911 participants, 

women had a median of 5 days sick leave vs. 1 day 

for men. The higher sick leave use by women may 

be attributed to the disproportionate responsibility 

for child care shouldered by the women (although 

55% of the men had children in the household, 0% 

of the men had reported using sick leave to care for 

others, while 50% of the women had children in the 

household and 15% of them had used sick leave to 

care for others). 

Call Monitoring 

Preliminary interviews with workers suggested that 

the policy of the department to monitor calls was a 

source of concern to workers. However, worker 

questionnaire responses seem to contradict the 

findings from oral interviews. Survey results 

indicated that call takers understood the reason for 

call monitoring and were aware that supervisors 

were monitoring calls to insure that they adhered to 

correct policies and procedures. This apparent 

disparity is most likely a factor of the questions 

asked and the context of the questions. Specifically, 

we may not have asked the questions in the same 

way we did in the interviews, and the questionnaire 

responses reflect an understanding of the reasons 

calls are monitored but they do not capture the 

feelings people have about being monitored. Thus, 

both situations may be correct, that 911 call takers 

understand why calls are monitored but are 

disturbed by the process. 

Similarly, interviews with workers suggested that 

room noise could at times be distracting and at 

times it was difficult to hear the callers. 

Questionnaire responses also seemed to contradict 

these findings. For instance, 61% strongly or 

slightly agreed that it is sometimes difficult to 

concentrate on a caller because of room noise, but 

95% reported that they are able to “tune out” the 
Health Hazard Evaluation Report No. 97-0137-3026 Page 10 

room noise in order to do their work. On the 

surface, these results, appear to conflict; however, 

the most likely explanation for this is that room 

noise is a problem, but each person possesses the 

ability (at times) to tune out this noise. Thus, it is 

likely that not all persons are able to tune out all the 

noise all the time. The ambient sound levels 

measured during this survey show that the 

listening conditions are not ideal. The majority 

of the sound in the room is being created by 

human speech, which is verified by the octave 

band sound measurements. The maximum 

octave band levels are between 500 and 2000 

Hz, which is the middle of human speech.27 

Thus, it will be very difficult to improve 

listening conditions with the floor plan currently 

in use. A reconfiguration of the consoles where 

the operators and dispatchers are isolated from 

one another would reduce the ambient speech 

noise at each location. Also, the use of headsets 

that have sound attenuation cups over the ear 

piece, much like a pair of ear muffs, or an eartip 

that is also a hearing protector would also reduce 

the ambient noise at each station. The literature 

on the Plantronics headset that was given to 

NIOSH investigators by the NYPD management 

does show that a hearing protector eartip is 

available for the StarSet system. 

Musculoskeletal symptoms described by 

participants were consistent with the type and 

severity of symptoms shown in other studies 

involving computer-based communication work. 

Wrist and extremity pain can be associated with the 

number of key strokes on the computer as well as 

static posture while listening to incoming 

calls.28, , 29 30 The most severe and most frequent 

symptoms included back, shoulder, and wrist pain. 

As was shown in the other health outcomes 

evaluated, two of the strongest predictors of 

musculoskeletal pain were low job satisfaction and 

low supervisory social support. However, because 

these studies were cross-sectional studies, it is not 

possible to determine causal direction (did low job 

satisfaction cause musculoskeletal pain or did the 

presence of musculoskeletal pain result in low job 

satisfaction). 

The City’s health and safety program conducted an 

ergonomic assessment of the chairs and 

workstations just prior to this study. Steps were in 

place to conduct periodic ergonomic training and 

review of furniture procurement to ensure that 

furniture purchased would be adjustable and well 

suited to the needs of the workers. 

CONCLUSIONS

Of the available workers, 63% participated in this 

study. Thus, nearly 40% of the population chose 

not to be included this survey and are, therefore, 

unaccounted for in the analyses. A low 

participation rate lessens the confidence one can 

have about both the associations reported and the 

conclusions reached. While the results reported 

may not be as robust as planned, because of the 

moderately low participation rate, the results do 

point to specific areas where careful attention could 

result in improved conditions for workers at the 

911 Emergency Response Center. 

The high prevalence of symptoms consistent with 

depression and anxiety and the fact that these 

symptoms increase with time on the job suggest 

that operators may not be adjusting to the stressors 

of this job over time and may be at increased risk 

for worsening symptoms of depression and anxiety. 

Two of the strongest predictors of depressive 

symptoms and anxiety in this study were time since 

last vacation (greater than 6 months) and social 

support from the immediate supervisor. Both of 

these variables were highly associated with health 

outcomes and can be points of focus for 

management at this center. Management should 

recognize that the intensity of work requires that 

employees take a break to mentally rest and 

regroup. The apparently high use of sick leave 

among employees may be interpreted as a sign that 

current work-rest schedules are not sufficient to 

allow workers to return to work fully rested and 

ready to resume their duties. 

The assessment of supervisory support in this study 

was not a measure of how well supervisors and 

workers like each other, or a measure of the 

personality of the supervisor. Rather, it measured 

the extent the manager and employee are able to 

communicate and work as a team and the extent to 

which a supervisor has the employee’s best interest 

in mind when decisions have to be made. Those 

who did not feel they had a manager they could talk 

to, or felt they did not have a manager they could 
Health Hazard Evaluation Report No. 97-0137-3026 Page 11 

rely on when things got tough at work, or felt they 

did not have a manager who was willing to listen to 

their problems, were more likely to report more 

symptoms consistent with anxiety and depression 

and were more likely to use sick leave. Thus, 

efforts on the part of management to improve the 

relationship between supervisor and employee may 

have some of the most influential results for 

improving the health and well being of this 

workforce. 

Lastly, we asked participants to list what they 

perceived to be the worst aspect of their job. By far 

the choice most often selected was “How we are 

valued as employees.” Virtually all of the call 

takers interviewed prior to the survey indicated that 

they became 911 operators because they wanted to 

help people. They described a sense of pride in 

having a job that provided a vital service to the 

community. Call takers also reported that over 

time they came to believe that the job is a thankless 

position. They perceive that they are the first to be 

blamed if something goes wrong and that their 

name and picture are likely to be aired on the 

nightly news. Seldom is the expedient handling of a 

911 call praised in the media or by Police 

Department management. However, this workforce 

also sees a tremendous good in the work they do. 

The vast majority of workers indicated that the best 

part of their job was helping the public and working 

with the people in the department. The NYPD 

should be commended for the caliber of people 

they are able to recruit and retain. 

The results of this study have shown that health 

outcomes of 911 operators and dispatchers are 

associated with the social interaction of the 

employees and the support they receive from their 

supervisors. Steps that can be taken to improve 

managerial social support and job satisfaction will 

likely reduce absenteeism and reduce the impact of 

adverse health outcomes. 

RECOMMENDATIONS

Work Organization 

1. Improve social support by identifying areas 

where supervisors and their employees can 

increase a sense of teamwork and group 

cohesion. Include continuing education for 

supervisors and employees and establish routine 

meeting times to solicit staff input on steps that 

can improve working conditions. 

2. Encourage workers to use accumulated 

leave. Persons who had reported more than 6 

months since their last vacation were at 

increased risk for adverse health outcomes. 

Insufficient staffing may account for the 

inability of some of the workers to use vacation 

time. To that end, workers who have sufficient 

leave time accrued should be encouraged to 

periodically use their leave. Conversely, 

management should not discourage the use of 

accrued leave. Also, management should 

evaluate staff levels to see if additional 

personnel are needed. 

3. A greater effort should be made to recognize 

the accomplishments of this workforce, for 

example through regular awards, performance 

step increases, or positive media attention. 

Noise 

4. Add additional separation between the 

individual work areas. The pods in the 911 

operator area were developed with separation 

between the stations in mind. However, when 

the pods are placed adjacent to each other, the 

conversation at one pod directly travels to the 

work location of another pod. Partial barriers 

between pods will help to block some of this 

direct sound but not all of it. 

5. The “6 wire” located at pod 15 was one of 

the louder positions. The equipment used in the 

subway system’s emergency communications is 

different than the land line telephones at the 

other work stations. This particular operator 

location could be moved out of the general 911 

call area and into its own room. 

6. Hold discussions with Plantronics engineers 

to develop additional ways to eliminate 

background noise from interfering with 

communications. Other equipment that is 

similar to the hearing protector eartips can 

possibly be devised for the New York City 

Police Department along with other dispatch and 

911 Call Center sites that have similar problems 

with ambient noise interference. 
Health Hazard Evaluation Report No. 97-0137-3026 Page 12 

7. Extraneous conversations need to be kept at 

a minimum with the floor plan currently in use. 

Additional speech sounds only add to the 

interference levels in the room. 

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Health Hazard Evaluation Report No. 97-0137-3026 Page 14 

TABLES

Table 1 

Recommended Space Usage for Balanced Noise Criteria Range in 

Occupied Indoor Areas 

Type of Space and Acoustical 

Requirements NCB Curve

Concert halls, opera houses, and recital halls 10 - 15 

Large auditoriums, large drama theaters, and 

 large churches 

Not to exceed 20 

Small auditoriums, small theaters, small churches, 

 music rehearsal rooms, large meeting and conference 

rooms, and executive offices 

Not to exceed 30 

Bedrooms, hospitals, residences, apartments, 

 hotels 

25 - 40 

Private or semi-private offices, small conference 

 rooms, classrooms, libraries 

30 - 40 

Large offices, reception areas, retail shops and 

 stores, cafeterias, restaurants 

35 - 45 

Lobbies, laboratory work spaces, drafting and 

 engineering rooms, general secretarial areas 

40 - 50 

Light maintenance shops, industrial plant control 

 rooms, office and computer equipment rooms, 

 kitchens, and laundries 

45 - 55 

Shops, garages 50 - 60 *

Work spaces where speech or telephone 

 communication is not required 

55 - 70 

* Levels above NCB-60 are not recommended for any office or communication situation. 
Health Hazard Evaluation Report No. 97-0137-3026 Page 15 

Table 2 

Responses to the question 

“The best part of my job is....” 

Response Percent (number 

responding) 

Helping the public 47 (236) 

My paycheck 25 (127) 

The people I work with 20 (101) 

Other 4 (21) 

Working with the police 2 (11) 

How we are valued as 

employees 0.6 (3) 

Table 3 

Responses to the question 

“The worst part of my job is....” 

Response Percent (number 

responding) 

How we are valued as 

employees 71 (354) 

My supervisor 9 (45) 

My paycheck 7 (34) 

Working with the police 4 (21) 

The people I work with 4 (20) 

Helping the public 0.6 (3) 
Table 4

NYPD Call Center 

Call Monitoring Responses 

Statements Strongly 

Agree

Slightly 

Agree

Slightly 

Disagree

Strongly 

Disagree

Supervisors monitor our calls to insure that we follow 

the correct procedures 

 69 (50) 26 (19) 0 4 (3) 

Supervisors monitor our calls to help us do our jobs 

better. 

 35 (25) 46 (33) 13 (9) 7 (5) 

When calls have been monitored by a supervisor and 

we did a good job, our supervisors will tell us we did a 

good job. 

 27 (19) 37 (26) 18 (3) 17 (12) 

 

Table 5 

Comparison of Sick Leave Use 

New York vs. Ohio 911 Center 

New York Police 

Communication Center

(N=72) 

Ohio 911 

Comparison Location

(N=607) 

Average number of sick days 19.6 days*/year 13.7 days/year 

Multiple of average sick days in 

U.S. workforce (6.2/year)† 

3.3 2.2 

10.0 Days (all) * 10.0 Days (all) 

2.0 Days Men* 

12.0 Days Women* 

Median sick leave 8.0 Days Men 

10.0 Days Women 

Range of days 0-84 days 0-99 days 

† Harris Poll 

* Numbers adjusted to reflect 12 months 

Health Hazard Evaluation Report No. 97-0137-3026 Page 16 
Health Hazard Evaluation Report No. 97-0137-3026 Page 17 

Table 6 

Responses to Job Satisfaction Questions 

Question Response New York Police 

Communication 

Center

(n=72) 

Ohio 911 

Comparison 

Location 

(n=607) 

Knowing what you do now, 

if you had to decide all over 

again whether to take the 

type of job you now have, 

what would you decide?

Decide without hesitation to 

take same job 

Have some second thoughts 

Decide definitely NOT to take 

this type of job 

 29.6 (21) 

50.7 (36) 

19.7 (14) 

12.4 (62) 

59.6 (298) 

28 (140) 

If a friend of yours told you 

he/she was interested in 

working in a job like yours, 

what would you tell 

him/her? 

I would strongly recommend 

it. 

Have doubts about 

recommending it. 

Advise against it. 

21.1 (15) 

56.3 (40) 

33.2 (16) 

 8.6 (43) 

 58.2 (291) 

33.2 (166) 

All in all, how satisfied 

would you say you are with 

your job?

Very Satisfied 

Somewhat satisfied 

Not too satisfied 

Not at all satisfied 

11.4 (8) 

58.6 (41) 

25.7 (18) 

4.3 (3) 

3.81 (19) 

44.3 (221) 

 32.1 (160) 

19.8 (99) 

Table 7

New York Police Communication Center 

Multivariate model: Job Satisfaction 

Variable Odds 

Ratio 95% CI*

Workload 3.02 1.52, 3.24 

More than 6 months 

since vacation 2.21 1.11, 8.62 

 CI = Confidence Interval 
Health Hazard Evaluation Report No. 97-0137-3026 Page 18 

Table 8

New York Police Communication 

Center 

Univariate Model: Symptoms of 

Major Depression 

Variable Odds Ratio 95% CI 

Anxiety 8.36 5.51, 12.87 

Workload 4.11 1.54, 12.09 

Low job 

satisfaction 3.61 2.51, 5.21 

Musculoskeletal 

pain 3.26 1.72, 6.75 

Low social well 

being 2.97 2.06, 4.31 

Greater than 6 

mo. since 

vacation 

2.74 1.88, 4.04 

Low social 

contact 2.23 1.56, 3.18 

Low group 

participation 2.15 1.52, 3.04 

Age 2.00 1.41, 2.84 

Years worked 

for the city 1.90 1.28, 2.80 

Low supervisory 

social support 1.83 1.16, 2.94 

Work status 1.62 1.08, 2.41 

CI = Confidence Interval 
Health Hazard Evaluation Report No. 97-0137-3026 Page 19 

Table 9

New York Police Communication Center 

Univariate Model: Anxiety 

Variable Odds Ratio 95% CI

Muscle pain lasting 

more than a week in 

the last year 

6.33 2.27, 17.88 

Job satisfaction 3.52 2.37, 5.22 

More than 6 mo. 

since last vacation 2.50 1.63, 3.84 

Teens in household 2.45 1.60, 3.74 

Low social well 

being 2.03 1.36, 3.02 

Age (older) 1.98 1.35, 2.90 

Low levels of social 

contact 1.95 1.32, 2.88 

High workload 1.89 0.68, 5.21 

Years worked for the 

city 1.86 1.22, 2.82 

Low levels of group 

participation 1.72 1.18, 2.52 

Low supervisory 

social support 1.61 0.98, 2.74 

 CI = Confidence Interval 
Health Hazard Evaluation Report No. 97-0137-3026 Page 20 

Table 10 

New York Communications Center 

Prevalence and severity of musculoskeletal pain among participants 

Muscular Pain Location % Reporting (Number) Average Severity *

Low Back 53 (38) 2.94 

Left Shoulder 43 (31) 2.70 

Right Wrist 43 (30) 1.96 

Left Wrist 43 (30) 1.80 

Right Shoulder 40 (29) 2.62 

Upper Back 40 (29) 2.31 

Left Hip/Thigh 33 (24) 1.60 

Right Elbow 31 (22) 1.59 

Right Hip/Thigh 31 (22) 1.22 

Left Lower Leg 29 (21) 1.47 

Right Lower Leg 29 (21) 1.38 

Neck 29 (21) 1.47 

*Range 0-5 with 0=no pain and 5=worst imaginable 
Health Hazard Evaluation Report No. 97-0137-3026 Page 21 

Table 11

New York Police Communication Center 

Univariate Model: Musculoskeletal Pain 

Variable Odds 

Ratio

95% CI

Anxiety 4.54 2.89, 1.15 

Depression 3.26 1.72, 6.75 

Low job satisfaction 2.53 1.38, 5.00 

Low supervisory 

social support 2.57 1.48, 4.42 

Highest quartile of 

sick leave use 

2.29 1.15, 5.16 

 CI = Confidence Interval 
FIGURES

14 13 11 10 8 6 5 3 2

15 12 9 7 4 1

Figure 1

Pod Locations

911 Call Center

New York City Police Department

HETA 97-0137

Supervisor 

Position

Supervisor 

Position

Supervisor 

Position

All pods have six positions OBSERVATION DECK

except #8 with three positions

Health Hazard Evaluation Report No. 97-0137-3026 Page 22 
Figure 2

Dispatch Locations

911 Call Center

New York City Police Department

HETA 97-0137

1 Manhattan 20

Supvr. Brooklyn 14

Brooklyn/

Queens

Supvr. Queens 17

Transit Brooklyn 12

Not Used

Not Used

Queens

Manhattan

Not Used

9 Bronx 21

City Wide

B City Wide

3 Manhattan

Door

6

5

8

Transit

COMB

TRAFFIC

SOD

Transit

4

Staten Island/

Bronx

2 Supervisor

7

A

Supvr. Supvr. Transit Supvr.

23

15

Transit (Q)

25

26

10

13

22

15

24

11

Health Hazard Evaluation Report No. 97-0137-3026 Page 23 
Figure 3 

Median Octave Band Levels and Ranges 

911 Call Center - Pod 1 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

50

0

10

0

0

20

0

0

40

0

0

80

0

0

160

0

0

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Figure 4 

Median Octave Band Levels and Ranges 

911 Call Center - Pod 4 

New York City Police Department 

HETA 97-0137-3026

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

50

0

10

0

0

20

0

0

40

0

0

80

0

0

160

0

0

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Health Hazard Evaluation Report No. 97-0137-3026 Page 24 
Figure 5 

Median Octave Band Levels and Ranges 

911 Call Center - Pod 5 

New York City Police Department 

HETA 97-0137-3026

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Figure 6 

Median Octave Band Levels and Ranges 

911 Call Center - Pod 11 

New York City Police Department 

HETA 97-0137-3026

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

50

0

10

0

0

20

0

0

40

0

0

80

0

0

160

0

0

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Health Hazard Evaluation Report No. 97-0137-3026 Page 25 
Figure 7 

Median Octave Band Levels and Ranges 

911 Call Center - Pod 12 

New York City Police Department 

HETA 97-0137-3026

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

50

0

10

0

0

20

0

0

40

0

0

80

0

0

160

0

0

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Figure 8 

Median Octave Band Levels and Ranges 

911 Call Center - Pod 13 

New York City Police Department 

HETA 97-0137-3026

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Health Hazard Evaluation Report No. 97-0137-3026 Page 26 
Figure 9 

Median Octave Band Levels and Ranges 

911 Call Center - Pod 15 (“6 Wire”) 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

 

Figure 10 

Median Octave Band Levels and Ranges 

Police Dispatch Center - Brooklyn (Row 1) 

Div. 11, 12, 24 & Transit 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Health Hazard Evaluation Report No. 97-0137-3026 Page 27 
Figure 11 

Median Octave Band Levels and Ranges 

Police Dispatch Center - Queens (Row 1) 

Div. 15 & 22 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Figure 12 

Median Octave Band Levels and Ranges 

Police Dispatch Center - Brooklyn (Row 2) 

Div. 10, 13 & 14 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Health Hazard Evaluation Report No. 97-0137-3026 Page 28 
Figure 13 

Octave Band Levels and Ranges 

Police Dispatch Center - Brooklyn-Queens (Row 2) 

Transit Division 

New York City Police Department 

 HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Figure 14 

Median Octave Band Levels and Ranges 

Police Dispatch Center - Queens (Row 2) 

Div. 16, 17 & 23 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Health Hazard Evaluation Report No. 97-0137-3026 Page 29 
Figure 15 

Octave Band Levels and Ranges 

Police Dispatch Center - City Wide (Row 3) 

Division “A” 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Figure 16 

Median Octave Band Levels and Ranges 

Police Dispatch Center - Bronx/ Staten Island (Row 3) 

Div. 2 & 7 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Health Hazard Evaluation Report No. 97-0137-3026 Page 30 
Figure 17 

Median Octave Band Levels and Ranges 

Police Dispatch Center - Manhattan (Row 3) 

Div. 3, 4 & Transit 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Figure 18 

Median Octave Band Levels and Ranges 

Police Dispatch Center - City Wide (Row 4) 

COMB, SOD & Traffic 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Health Hazard Evaluation Report No. 97-0137-3026 Page 31 
Figure 19 

Median Octave Band Levels and Ranges 

Police Dispatch Center - Bronx (Row 4) 

Div. 8, 9, 21 & Transit 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

500

1000

2000

4000

8000

16000

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Figure 20 

Median Octave Band Levels and Ranges 

Police Dispatch Center - Manhattan (Row 4) 

Div. 1, 5, 6 & 20 

New York City Police Department 

HETA 97-0137-3026 

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

8

16

31.5

63

125

250

50

0

10

0

0

20

0

0

40

0

0

80

0

0

160

0

0

Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Health Hazard Evaluation Report No. 97-0137-3026 Page 32 
Health Hazard Evaluation Report No. 97-0137-3026 Page 33 











  

 











    







      

8

163263

125250500

1000

Octave Band Center Fre

200040008000

16000

quency [Hz]

0

20

40

60

80

100

Sound Pressure Level [dB]

Median NCB-62 NCB-40 NCB-50   

Figure 21

Police Dispatch Center 

New York City Police Department

HETA 97-0137









  



 









  



 





    



 

8

163263

125250500

1000

Octave Band Center Fre

200040008000

16000

0

20

40

60

80

100

Sound Pressure Level [dB]

Figure 22

911 Call Center

New York City Police Department

HETA 97-0137

Median NCB-59  NCB-40 NCB-50

quency [Hz]

 
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