NIOSH HEALTH HAZARD EVALUATION REPORT 

HETA #2004-0046-2950 

Kirkwood Community College 

Cedar Rapids, Iowa 

December 2004 

DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health

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.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports
ii 

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 Chandran Achutan and Randy L. Tubbs of HETAB, Division of 

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

Humann of the Department of Occupational and Environmental Health, University of Iowa College of 

Public Health, Iowa City, Iowa, Desktop publishing was performed by Shawna Watts. Editorial review 

was performed by Ellen Galloway. 

Copies of this report have been sent to employee and management representatives at MSEC 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. Single copies of 

this report will be available for a period of three years from the date of this report. To expedite your 

request, include a self-addressed mailing label along with your written request to: 

NIOSH Publications Office 

4676 Columbia Parkway 

Cincinnati, Ohio 45226 

800-356-4674 

After this time, copies may be purchased from the National Technical Information Service (NTIS) at 5825 

Port Royal Road, Springfield, Virginia 22161, Information regarding the NTIS stock number may be 

obtained from the NIOSH Publications Office at the Cincinnati address. 

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.
iii 

Highlights of Health Hazard Evaluation 

Noise Exposure at a Swine Confinement Facility

NIOSH investigators were asked to evaluate noise exposures at the Mansfield Swine Education 

Center (MSEC). 

What NIOSH Did

# We measured personal noise exposures 

on employees. 

# We kept a log of activities performed by 

employees to see how the activities 

relate to exposures. 

What NIOSH Found

# Noise levels were below the daily OSHA 

permissible exposure limits. 

# Noises associated with certain activities 

such as power washing were found to be 

excessive by the NIOSH criterion. 

# Begin a hearing conservation program 

for employees. 

# Use non-metal parts for feeding chutes. 

# Instruct employees on properly 

maintaining ear muffs, and provide 

replacements when needed. 

What the MSEC Employees 

Can Do 

# Report to the director when ear muffs 

are damaged before routine replacement. 

Highlights of the NIOSH Health Hazard Evaluation

What MSEC 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 #2004-0046-2950
iv 

Health Hazard Evaluation Report 2004-0046-2950 

Kirkwood Community College 

Cedar Rapids, Iowa 

December 2004 

Chandran Achutan, Ph.D. 

Randy L. Tubbs, Ph.D. 

SUMMARY

On July 11, 2003, the National Institute for Occupational Safety and Health (NIOSH), received a request 

from the management of Kirkwood Community College in Cedar Rapids, Iowa, to conduct a Health 

Hazard Evaluation (HHE) at the Mansfield Swine Education Center (MSEC). The requestor was 

interested in knowing the noise levels at the facility. NIOSH undertook this study due to the paucity of 

noise data in agricultural settings. A noise survey was conducted on March 22 and 23, 2004. 

Full-shift noise dosimeter measurements were collected on employees over 2 days. NIOSH investigators 

followed the employees to log their daily activities. In addition, ambient noise levels were stored on a 

real-time analyzer to capture the noise spectra for different activities. 

Seven full-shift dosimeter samples were collected during the evaluation. The daily noise levels were all 

well below the Occupational Safety and Health Administration’s (OSHA) permissible exposure limit (90 

decibels on an A-weighted scale [dBA], but exceeded the NIOSH Recommended Exposure Limit (REL) 

on three occasions. The potential for high noise exposures is evidenced in the noise dose measured for 

specific activities such as power washing, ear clipping, and snout snaring. Area samples taken during the 

various activities are consistent with dosimetry for specific activities. 

Because of the high noise levels (as determined by the NIOSH REL), that employees 

encounter during the course of employment, NIOSH investigators offer recommendations 

to reduce the risk of occupational hearing loss. These recommendations include enrolling 

employees in a hearing conservation program, caring for and maintaining hearing 

protection devices, and padding some metal pieces on feeding chutes with a softer 

material to reduce the noise produced by metal-to-metal contact. 

Keywords: SIC: 0213 (Establishments primarily engaged in the production or feeding of hogs on their 

own account or on a contract or fee basis), noise, swine confinement, spectral analysis, task-based 

analysis, power wash, breeding and gestation, snout snaring, ear clipping 
Table of Contents 

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

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

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

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

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

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

Mansfield Swine Education Center.......................................................................................................1

Methods........................................................................................................................................................1

Evaluation Criteria .....................................................................................................................................2

Results ..........................................................................................................................................................3

Discussion ....................................................................................................................................................4

Conclusions..................................................................................................................................................5

Recommendations.......................................................................................................................................5

References....................................................................................................................................................5
Health Hazard Evaluation Report No. 2004-0046-2950 Page 1 

INTRODUCTION

On July 11, 2003, the National Institute for 

Occupational Safety and Health (NIOSH) 

received a request from the management of 

Kirkwood Community College in Cedar Rapids, 

Iowa, to conduct a Health Hazard Evaluation 

(HHE) at its Mansfield Swine Education Center 

(MSEC). The requestor was interested in 

knowing the noise levels at the facility. NIOSH 

undertook this study due to the paucity of noise 

data in agricultural settings. 

On March 22 and 23, 2004, NIOSH 

investigators conducted a noise evaluation at 

MSEC. On March 22, an opening conference 

was held with NIOSH representatives and the 

director of MSEC. Following the opening 

conference, NIOSH investigators toured the 

facility with the director and the farm technician. 

The proceedings from the opening conference 

were relayed to the farm technician during the 

tour. On March 22 and 23, 2004, NIOSH 

measured noise exposure for employees working 

throughout the facility. 

BACKGROUND

Mansfield Swine Education 

Center 

The Mansfield Swine Education Center is a 150-

head farrow-to-finish swine confinement center, 

located on the Kirkwood Community College 

Campus in Cedar Rapids, Iowa. Farrow-to-finish 

refers to the breeding and farrowing of sows and 

raising the piglets until they weigh 200 pounds, 

at which stage they are sold. The farrow-tofinish operation involves the following 

processes: breeding and gestation, farrowing, 

weaning the piglets in nurseries, and finishing. 

The whole cycle can take up to 11 months. 

MSEC is a small-scale swine confinement 

facility used for teaching students at the 

community college. The day-to-day operations 

are handled by a farm technician with the 

assistance of students who work part-time. The 

facility is run by a veterinarian, who also 

examines the animals and assists with chores as 

needed. 

In the breeding and gestation barn, it is 

determined if sows are ready for breeding. This 

is done by passing a boar in a cage in front of 

the sows’ pens. Sows that are ready for breeding 

are quiet, and those that are not, squeal in the 

presence of the boar. This process is called “heat 

checking.” Sows are inseminated artificially, and 

the pregnant sows remain in the barn during 

their gestation period. 

Upon giving birth, the sows and their litters are 

moved to the farrowing rooms, where the piglets 

are nursed. After a few months, the piglets are 

moved to the nursery where the males are 

castrated. In the farrowing and nursery barns, 

piglets and the mothers are routinely checked for 

health problems. The animals are also given 

appropriate vaccinations in these rooms. 

As the piglets get bigger, they are moved to the 

finishing area. The finishing area consists of 

different barns that house litters of similar 

age/weight groups. In the finishing area, the 

hogs have their snouts snared and ears tagged 

for identification. These activities are usually 

performed by two individuals, one to round up 

the animals, and the other who manually 

performs the snout snaring and ear clipping. 

Hogs are periodically weighed in the finishing 

area, and when they have attained the optimal 

weight (usually 200 pounds), they are sold. 

METHODS

Quest® Electronics Model Q-300 Noise 

Dosimeters were worn by a total of seven 

employees over a 2-day period while they 

performed their daily activities. Samples were 

collected throughout the work shifts that ranged 

from less than an hour to approximately 4 hours. 

The noise dosimeters were attached to the 

wearer’s belt and a small remote microphone 

was fastened to the wearer’s shirt at a point 

midway between the ear and the outside of the 

shoulder. A windscreen provided by the 

dosimeter manufacturer was placed over the 

microphone during recordings. At the end of the 
Page 2 Health Hazard Evaluation Report No. 2004-0046-2950 

sampling period, the dosimeter was removed and 

paused to stop data collection. The information 

stored in the dosimeters was downloaded to a 

personal computer for interpretation with 

QuestSuite® Professional computer software. 

The dosimeters were calibrated before and after 

the measurement periods according to the 

manufacturer’s instructions. 

Real time, instantaneous noise monitoring was 

done by a Quest Electronics Model 2400 Sound 

Level Meter (SLM). The instrument was set to 

measure noise levels between 70 and 140 dB, on 

an A-weighted slow-response scale, The SLM 

was calibrated before and after the measurement 

periods according to the manufacturer’s 

instructions. Real time spectral analysis was 

done 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 

allows for the analysis of noise into its spectral 

components in a real-time mode. The 1⁄2-inch 

diameter microphone has a frequency response 

range (± 2 decibels [dB]) from 4 Hertz (Hz) to 

21 kilohertz (kHz) that allows for the analysis of 

sounds in the region of concern. One-third 

octave bands consisting of center frequencies 

from 25 Hz to 20 kHz were integrated for 10-60 

seconds and stored in the analyzer. 

EVALUATION CRITERIA

As a guide to the evaluation of the hazards posed 

by workplace exposures, NIOSH field staff 

employ environmental evaluation criteria for the 

assessment of a number of chemical and 

physical agents. These criteria are intended to 

suggest levels of exposure to which most 

workers may be exposed up to 10 hours per day, 

40 hours per week for a working lifetime 

without experiencing adverse health effects. It 

is, however, important to note that not all 

workers will be protected from adverse health 

effects even though their exposures are 

maintained below these levels. A small 

percentage may experience adverse health 

effects because of individual susceptibility, a 

pre-existing medical condition, and/or a 

hypersensitivity (allergy). In addition, some 

hazardous substances may act in combination 

with other workplace exposures, the general 

environment, or with medications or personal 

habits of the worker to produce health effects 

even if the occupational exposures are controlled 

at the level set by the criterion. These combined 

effects are often not considered in the evaluation 

criteria. Finally, evaluation criteria may change 

over the years as new information on the toxic 

effects of an agent become available. 

The primary sources of environmental 

evaluation criteria for the workplace are: (1) 

NIOSH Recommended Exposure Limits 

(RELs),1

 (2) the American Conference of 

Governmental Industrial Hygienists’ (ACGIH®) 

Threshold Limit Values (TLVs®),2

 and (3) the 

U.S. Department of Labor, Occupational Safety 

and Health Administration (OSHA) Permissible 

Exposure Limits (PELs).3

 Employers are 

encouraged to follow the OSHA limits, the 

NIOSH RELs, the ACGIH TLVs, or whichever 

are the more protective criteria. 

OSHA requires an employer to furnish 

employees a place of employment that is free 

from recognized hazards that are causing or are 

likely to cause death or serious physical harm 

[Occupational Safety and Health Act of 1970, 

Public Law 91–596, sec. 5(a)(1)]. Thus, 

employers should understand that not all 

hazardous chemicals have specific OSHA 

exposure limits such as PELs and short-term 

exposure limits (STELs). An employer is still 

required by OSHA to protect their employees 

from hazards, even in the absence of a specific 

OSHA PEL. 

Noise-induced loss of hearing is an irreversible, 

sensorineural condition that progresses with 

exposure. Although hearing ability declines with 

age (presbycusis) in all populations, exposure to 

noise produces hearing loss greater than that 

resulting from the natural aging process. This 

noise-induced loss is caused by damage to nerve 

cells of the inner ear (cochlea) and, unlike some 

conductive hearing disorders, cannot be treated 

medically.4

 While loss of hearing may result 

from a single exposure to a very brief impulse 

noise or explosion, such traumatic losses are 
Health Hazard Evaluation Report No. 2004-0046-2950 Page 3 

rare. In most cases, noise-induced hearing loss is 

insidious. Typically, it begins to develop at 4000 

or 6000 Hz (the hearing range is 20 Hz to 20000 

Hz) and spreads to lower and higher frequencies. 

Often, material impairment has occurred before 

the condition is clearly recognized. Such 

impairment is usually severe enough to 

permanently affect a person's ability to hear and 

understand speech under everyday conditions. 

Although the primary frequencies of human 

speech range from 200 Hz to 2000 Hz, research 

has shown that the consonant sounds, which 

enable people to distinguish words such as "fish" 

from "fist," have still higher frequency 

components.5

The A-weighted decibel [dBA] is the preferred 

unit for measuring sound levels to assess worker 

noise exposures. The dBA 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 which are audible to the human 

ear. Because the dBA scale is logarithmic, 

increases of 3 dBA, 10 dBA, and 20 dBA 

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. 

The OSHA standard for occupational exposure 

to noise (29 CFR 1910.95)6

 specifies a 

maximum PEL of 90 dBA for a duration of 

8 hours per day. The regulation, in calculating 

the PEL, uses a 5 dB time/intensity trading 

relationship, or exchange rate. This means that a 

person may be exposed to noise levels of 

95 dBA for no more than 4 hours, to 100 dBA 

for 2 hours, etc. Conversely, up to 16 hours 

exposure to 85 dBA is allowed by this exchange 

rate. The duration and sound level intensities can 

be combined in order to calculate a worker's 

daily noise dose according to the formula: 

Dose = 100 X (C1/T1 + C2/T2 + ... + Cn/Tn ), 

where Cn indicates the total time of exposure at a 

specific noise level and Tn indicates the 

reference duration for that level as given in 

Table G-16a of the OSHA noise regulation. 

During any 24-hour period, a worker is allowed 

up to 100% of his daily noise dose. Doses 

greater than 100% exceed the OSHA PEL. 

The OSHA regulation has an additional action 

level (AL) of 85 dBA; an employer shall 

administer a continuing, effective hearing 

conservation program when the 8-hour timeweighted average (TWA) value exceeds the AL, 

The program must include monitoring, 

employee notification, observation, audiometric 

testing, hearing protectors, training, and record 

keeping. All of these requirements are included 

in 29 CFR 1910.95, paragraphs (c) through (o). 

Finally, the OSHA noise standard states that 

when workers are exposed to noise levels in 

excess of the OSHA PEL of 90 dBA, feasible 

engineering or administrative controls shall be 

implemented to reduce the workers' exposure 

levels. 

NIOSH, in its Criteria for a Recommended 

Standard,7

 and the ACGIH,2 propose exposure 

criteria of 85 dBA as a TWA for 8 hours, 5 dB 

less than the OSHA standard. The criteria also 

use a more conservative 3 dB time/intensity 

trading relationship in calculating exposure 

limits. Thus, a worker can be exposed to 85 dBA 

for 8 hours, but to no more than 88 dBA for 

4 hours or 91 dBA for 2 hours. The NIOSH REL 

for 12-hour exposure is 83 dBA or less. 

RESULTS

The Quest dosimeters collect data so that one 

can directly compare the information with the 

three different noise criteria used in this survey, 

the OSHA PEL and AL, and the NIOSH REL. 

The OSHA criteria use a 90 dBA criterion and 

5-dB exchange rate. The difference between the 

two is the threshold level employed, with a 

90 dBA threshold for the PEL and an 80 dBA 

threshold for the AL. The threshold level is the 
Page 4 Health Hazard Evaluation Report No. 2004-0046-2950 

lower limit of noise values included in the 

calculation of the criteria; values less than the 

threshold are ignored by the dosimeter. The 

NIOSH criterion differs from OSHA in that the 

criterion is 85 dBA, the threshold is 80 dBA, 

and it uses a 3-dB exchange rate. Because of the 

different 8-hour criteria and exchange rates, the 

dose equations used to calculate the equivalent 

TWA values are different for the NIOSH and 

OSHA criteria. The OSHA dose equation is 

TWA = 16.61 x log10 [Dose/100] + 90, and the 

NIOSH equation is TWA = 10.00 x log10

[Dose/100] + 85. 

The results presented describe potential 

exposures to employees at MSEC during the2 

days of the survey. The workday at MSEC may 

vary depending on the number of hogs, number 

of student helpers, and the veterinarian’s 

schedule. On the assumption that the 2 days 

evaluated were typical workdays at MSEC, the 

data were analyzed to project an 8-hour dose for 

each individual. In addition, 8-hour doses for 

specific tasks were calculated to predict 

exposures in large-scale confinements. 

During the 2 days that NIOSH collected 

personal dosimetry data, noise exposures 

exceeded the NIOSH REL for three people for 

the actual time that they worked in the 

confinement facility. A summary of the personal 

dosimetry results is presented in Table 1. When 

the results were extrapolated to simulate an 8-

hour work shift, five of the seven personal 

dosimetry samples exceeded the NIOSH REL, 

and two exceeded the OSHA AL (more than 

50%). The extrapolation assumes that the 

percent dose collected during the actual work 

shift is representative of an 8-hour shift, and the 

dose has been increased accordingly. These 

results are presented in Table 2. 

The output from the dosimeters also captures the 

minute-by-minute noise exposures monitored 

over the sampling period. Each data point 

represents the integrated average noise for a 1-

minute period. Figure 1 is a graph that include 

on the graph is the employee daily tasks and 

time at which tasks took place. The dosimeter 

software calculates the noise exposure and the 

corresponding dose for each activity, and allows 

extrapolating exposures to simulate an 8-hour 

work day. An analysis of noise exposures by 

tasks (Table 3) shows that the highest exposures 

occurred during the power washing job, and 

during the snout snaring and ear tagging 

operation. The power washing operation was 

observed for 29 minutes and snout snaring for 

17 minutes. During both operations, the percent 

dose exceeded the NIOSH criterion for the short 

time period for at least one of the employees 

performing the task. When all tasks were 

extrapolated to an 8-hour work day, the NIOSH 

criterion was exceeded eight times (128% to 

3111%), and the OSHA AL was exceeded four 

times (178% to 265%) during the snout snaring 

and the power washing operations, and once 

during activities at the breeding and gestation 

barn. 

Spectral noise data were collected for the 

evaluation during various job activities. On the 

first day of the survey, 10 measurements, each 

10 seconds long, were taken at the breeding and 

gestation barn. Seven of these samples were 

collected during the heat checking process, with 

the boar in a cage in front of the sows. The 

remaining three samples were collected with the 

feed line turned on. Typical spectral data are 

shown in Figure 2. On the second day of the 

survey, numerous 10-second measurements were 

collected of the snout snaring and ear tagging 

process in the finishing area, 60-second 

measurements were collected in the feed mill 

with the blower on and off and a 60-second 

measurement was collected during power 

washing. Figures 3-5 show typical spectral data. 

DISCUSSION

Though none of the workers’ noise levels in this 

survey exceeded any regulatory standards, noise 

levels of two employees exceeded the daily 

percent dose over the course of the survey, as 

calculated by the NIOSH criterion. The noise 

level exceeded one worker’s dose on both days 

that personal samples were collected. An 

analysis of associated tasks revealed that the 

power-washing job presents the highest noise 

hazard at this facility, contributing as much as 
Health Hazard Evaluation Report No. 2004-0046-2950 Page 5 

104% of the daily dose for approximately 30 

minutes of exposure. All employees were 

wearing ear muffs during the work day, but a 

close inspection of the ear muffs showed that the 

cushions were cracked and needed repair. 

Over the past several years, there has been a 

shift from small-scale swine confinements to 

large-scale production facilities.8

 At some of 

these large production facilities, employees 

perform dedicated chores throughout the work 

day. For example, employees may be required to 

power wash pens for a full work shift. The 8-

hour task-based results from this survey are 

useful to characterize potential noise exposures 

for these employees. Data from this evaluation 

suggest that some tasks related to swine 

production may result in excessive noise 

exposure, and employees should be enrolled in a 

hearing conservation program. 

CONCLUSIONS

There is potential excessive noise exposure to 

employees at MSEC (as determined by the 

NIOSH REL) though none of the values 

measured in this limited survey exceeded the 

OSHA PEL. However, if employees were to 

carry out their tasks over an 8-hour work day, 

the NIOSH REL would have been exceeded five 

times, and the OSHA AL would have been 

exceeded twice. The OSHA PEL would not have 

been exceeded. 

An analysis of specific tasks revealed that the 

power washing, snaring and ear tagging 

operations were the most hazardous. These jobs 

exceeded the 100% daily dose for the time 

period worked, per the NIOSH criteria. When 

the results from this survey were projected to 

reflect an 8-hour exposure, the OSHA AL for 

noise exposure during breeding, power washing, 

and snaring exceeded 50% of the employees’ 

daily dose. 

RECOMMENDATIONS

Based on the observations and findings of this 

evaluation, the following recommendations are 

offered to better protect the hearing of the 

employees at the MSEC: 

1. Establish a hearing conservation 

program for MSEC employees. Even 

though the exposures captured by the 

dosimeters never exceeded the OSHA 

limits for noise during this evaluation, 

they exceeded the NIOSH REL on three 

occasions. The basic elements of the 

program should, at a minimum, meet the 

requirements of the OSHA hearing 

conservation amendment (29 CFR 

1910.95). Other sources for defining 

effective hearing conservation programs 

are also available.9,10,11

2. Ensure that workers wear hearing 

protection devices during snaring, power 

washing, and in the breeding barns. We 

recommend that the cushions on ear 

muffs be checked periodically, and 

replaced at least every 6 months, or 

sooner if worn out. 

3. Replace or pad the metal flap at the end 

of the metal feed chute with a plastic or 

rubber material to reduce noise. By 

continuously lifting the metal flap, the 

animals created noise exposure from 

metal to metal contact between the flap 

and the chute. 

REFERENCES

 1. NIOSH [1992]. Recommendations for 

occupational safety and health: compendium of 

policy documents and statements, Cincinnati, 

OH: U.S. Department of Health and Human 

Services, Public Health Service, Centers for 

Disease Control and Prevention, National 

Institute for Occupational Safety and Health, 

DHHS (NIOSH) Publication No. 92-100. 

 2. ACGIH [2004]. 2004 TLVs® and BEIs®: 

threshold limit values for chemical substances 

and physical agents, Cincinnati, OH: American 

Conference of Governmental Industrial 

Hygienists. 
Page 6 Health Hazard Evaluation Report No. 2004-0046-2950 

 3. CFR [2003]. 29 CFR 1910.1000, Code of 

Federal Regulations, Washington, DC: U.S. 

Government Printing Office, Office of the 

Federal Register. 

 4. Ward WD, Royster LH, Royster JD 

[2000]. Anatomy & physiology of the ear: 

normal and damaged hearing, Chapter 4, In: 

Berger EH, Royster LH, Royster JD, Driscoll 

DP, & Layne M, eds, The noise manual, 5th ed, 

Fairfax, VA: American Industrial Hygiene 

Association, pp 101–122. 

 5. Suter AH [1978]. The ability of mildly 

hearing–impaired individuals to discriminate 

speech in noise, Washington, DC: U.S. 

Environmental Protection Agency, Joint 

EPA/USAF study, EPA 550/9–78–100, AMRL–

TR–78–4. 

 6. CFR[1992]. 29 CFR 1910.95. Code of 

Federal Regulations Washington, DC: U.S. 

Government Printing Office, Office of the 

Federal Register. 

 7. NIOSH [1998]. Criteria for a 

recommended standard: occupational noise 

exposure (revised criteria 1998), Cincinnati, OH: 

U.S. Department of Health and Human Services, 

Centers for Disease Control and Prevention, 

National Institute for Occupational Safety and 

Health, DHHS (NIOSH) Publication No. 98-

126. 

 8. Mallin, MlA.; Cahoon, LB [2003]. 

Industrialized Animal Production-A Major 

Source of Nutrient and Microbial Pollution to 

Aquatic Ecosystems. Population & 

Environment. 24(5):369-385

 9. NIOSH [1996]. Preventing occupational 

hearing loss.-A practical guide, Cincinnati, OH: 

U.S. Department of Health and Human Services, 

Centers for Disease Control and Prevention, 

National Institute for Occupational Safety and 

Health, DHHS (NIOSH) Publication No. 96-

110. 

 10. Suter AH [2002]. Hearing conservation 

manual. 4th ed. Milwaukee, WI: Council for 

accreditation in Occupational Hearing 

Conservation. 

 11. Royster, JD, Royster, LH [1990]. Hearing 

conservation programs: practical guidelines for 

success, Chelsea, MI: Lewis Publishers. 
Health Hazard Evaluation Report No. 2004-0046-2950 Page 7 

Table 1 

Personal Noise Dosimeter Results 

Kirkwood Community College 

Cedar Rapids, Iowa 

March 22 and 23, 2004 

HETA 2004-0046-2950 

Date Job Title Duration (hh:mm:ss) Dose (Percent) 

OSHA 

AL 

OSHA 

PEL 

NIOSH/

ACGIH 

March 22, 2004 Director 

Farm Technician 

Student I 

Student II 

03:37:29 

03:41:53 

01:42:14 

00:48:34 

11.7 

10.3 

21.4 

1.7 

5.5 

3.0 

20.6 

1.3 

42.4 

34.0 

140.4 

13.3 

March 23, 2004 Director 

Farm Technician 

Student I 

03:49:42 

03:41:38 

03:38:14 

13.8 

11.8 

27.7 

10.9 

7.8 

25.2 

116.2 

69.1 

219.7 

The various dose percentages are the amounts of noise accumulated during a work day, with 100% 

representing the maximum allowable daily dose. 

OSHA: Occupational Safety and Health Administration 

NIOSH: National Institute for Occupational Safety and Health 

ACGIH: American Conference of Governmental Industrial Hygienists 

AL: Action Level 

PEL: Permissible Exposure Limit 
Page 8 Health Hazard Evaluation Report No. 2004-0046-2950 

Table 2 

Personal Noise Dosimeter Results extrapolated to an 8-hour TWA 

Kirkwood Community College 

Cedar Rapids, Iowa 

March 22 and 23, 2004 

HETA 2004-0046-2950 

Date Job Title Duration (hh:mm:ss) Dose (Percent) 

OSHA 

AL 

OSHA 

PEL 

NIOSH/

ACGIH 

March 22, 2004 Director 

Farm Technician 

Student I 

Student II 

08:00:00 

08:00:00 

08:00:00 

08:00:00 

25.9 

22.2 

100.3 

17.3 

12.0 

6.5 

96.8 

12.8 

93.6 

43.6 

659.3 

131.6 

March 23, 2004 Director 

Farm Technician 

Student I 

08:00:00 

08:00:00 

08:00:00 

28.8 

24.7 

60.8 

22.2 

16.3 

55.4 

242.8 

144.4 

482.7 
Health Hazard Evaluation Report No. 2004-0046-2950 Page 9 

Table 3 

Noise exposures, expressed as percent dose, as a function of tasks 

Kirkwood Community College 

Cedar Rapids, Iowa 

March 22 and 23, 2004 HETA 2004-0046-2950 

Task Criterion Director Farm 

Technician 

Student I 

Castration OSHA AL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

12 0.7 28.4 

 NIOSH REL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

12 3.2 128.4 

Breeding OSHA AL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

30 4.2 67.2 

 NIOSH REL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

30 14.2 227.8 

Gate Repairs OSHA AL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

41 1.2 13.8 

46 0.9 9.3 

46 0.7 7.7 

 NIOSH REL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

41 5.7 66.3 

46 5.4 56.6 

46 3.0 31.4 

Power Washing OSHA AL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

29 15.2 252.3 

 NIOSH REL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

29 103.8 1718.6 

Feed Mill OSHA AL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

13 13.8 28.8 

19 1.9 48.8 

8 0.1 5.3 

 NIOSH REL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

13 1.7 63.8 

19 5.5 139.5 

8 0.3 16.7 

Snaring OSHA AL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

17 8.5 238.9 

16 5.9 177.9 

17 9.4 264.9 

 NIOSH REL Exposure time (min) 

% dose for exposure time Projected % dose for 8 hours 

17 93.5 1496.4 

16 54.3 745.1 

17 110.2 3111.4 
Page 10 

 Health Hazard Evaluation Report No. 2004-0046-2950

Figure 1 

Profile of employee noise exposure at a swine confinement 

Kirkwood Community College 

March 22 and 23, 2004 

HETA 2004-0046-2950 

Label Time range Activity 

1 8:57 to 9:14 Snaring 

2 9:21 to 9:29 Feed mill operation 

3 9:33 to 10:02 Power washing 

80

85

90

95

100

105

110

bels [dB(A)]
Health Hazard Evaluation Report No. 2004-0046-2950 Page 11 

Figure 2 

Spectral Noise Data in the Breeding and Gestation Barn 

Kirkwood Community College 

March 22 and 23, 2004 

HETA 2004-0046-2950 

0

10

20

30

40

50

60

70

80

90

100

31.5

63

125250500

1000200040008000

16000

One-third Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Heat checking

Feed line on

Figure 3 

Spectral Noise Data in the Feed Mill 

Kirkwood Community College 

March 22 and 23, 2004 

HETA 2004-0046-2950 

0

10

20

30

40

50

60

70

80

90

100

31.5

63

125250500

1000200040008000

16000

One-third Octave Band Center Frequency 

[Hz]

Sound Pressure Level [dB]

mixer and corn feed

mixer and blower
Page 12 

 Health Hazard Evaluation Report No. 2004-0046-2950

Figure 4 

Spectral Noise Data in the Finishing Area 

Kirkwood Community College 

March 22 and 23, 2004 

HETA 2004-0046-2950 

0

20

40

60

80

100

120

31.5

63

125250500

1000200040008000

16000

One-third Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Snout snaring

Figure 5 

Spectral Noise Data during Power Wash 

Kirkwood Community College 

March 22 and 23, 2004 

HETA 2004-0046-2950 

0

10

20

30

40

50

60

70

80

90

100

31.5

63

125250500

1000200040008000

16000

One-third Octave Band Center Frequency [Hz]

Sound Pressure Level [dB]

Power wash
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