United States
Environmental Protection
Agency
Health Effects Research
Laboratory
Research Triangie Park NC 27711
EPA 600 1 79 01
February 1979
Research and Development
Chromosomal
Abnormalities
Among Welder
Trainees
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
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8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL HEALTH EFFECTS RE-
SEARCH series. This series describes projects and studies relating to the toler-
ances of man for unhealthful substances or conditions. This work is generally
assessed from a medical viewpoint, including physiological or psychological
studies. In addition to toxicology and other medical specialities, study areas in-
clude biomedical instrumentation and health research techniques utilizing ani-
mals but always with intended application to human health measures.
This document is available to the public through the National Technical Informa-
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EPA-600/1-79-011
February 1979
CHROMOSOMAL ABNORMALITIES AMONG WELDER TRAINEES
by
Arthur D. Bloom
Columbia University
New York, New York 10032
Contract No. 68-02-1738
Project Officer
Dorothy C. Calafiore
Population Studies Division
Health Effects Research Laboratory
Research Triangle Park, N.C. 27711
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
HEALTH EFFECTS RESEARCH LABORATORY
RESEARCH TRIANGLE PARK, N.C. 27711
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DISCLAIMER
This report has been reviewed by the Health Effects Research Labora-
tory, U.S. Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the views
and policies of the U.S. Environmental Protection Agency, nor does mention
of trade names or commercial products constitute endorsement or recommenda-
tion for use.
n
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FOREWORD
The many benefits of our modern, developing, industrial society are
accompanied by certain hazards. Careful assessment of the relative risk of
existing and new man-made environmental hazards is necessary for the estab-
lishment of sound regulatory policy. These regulations serve to enhance the
quality of our environment in order to promote the public health and welfare
and the productive capacity of our Nation's population.
The Health Effects Research Laboratory, Research Triangle Park, conducts
a coordinated environmental health research program in toxicology, epidemi-
ology, and clinical studies using volunteer subjects. These studies address
problems in air pollution, non-ionizing radiation, environmental carcino-
genesis and the toxicology of pesticides as well as other chemical pollutants.
The Laboratory participates in the development and revision of air quality
criteria documents on pollutants for which national ambient air quality
standards exist or are proposed, provides the data for registration of new
pesticides or proposed suspension of those already in use, conducts research
on hazardous and toxic materials, and is primarily responsible for pro-
viding the health basis for non-ionizing radiation standards. Direct support
to the regulatory function of the Agency is provided in the form of expert
testimony and preparation of affidavits as well as expert advice to the
Administrator to assure the adequacy of health care and surveillance of per-
sons having suffered imminent and substantial endangerment of their health.
This report presents the results of a study of welder students who,
during their welding training, it was thought would be exposed each day to
ozone generated by the welding process. Mutagenicity of this frequently
encountered air pollutant had been suggested by several previous studies.
Thus, as a biological indicator of ambient air pollution health effects,
chromosomal change offered a heretofore little-used, objective measurement.
Demonstration of its feasibility and efficacy as an indicator could provide
a new method of determining the effects of community air pollution.
F. G. Hueter, Ph.D.
Di rector
Health Effects Research Laboratory
m
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ABSTRACT
Serial cytogenetic observations were made on a group of
273 military recruits who were being trained as welders at
Aberdeen, Maryland. The trainees were being exposed to pre-
sumably increased levels of ozone in the course of their
welding school experience, and it was the purpose of this
study to determine whether or not ozone, at low to moderate
doses, is capable of inducing chromosomal aberrations in peri-
pheral blood lymphocytes.
Previous exposures and the past medical experiences of
the trainees were determined by questionnaire, enabling us to
obtain a profile on the medical-social characteristics of the
study sample. Each welder was to serve as his own control,
having a blood sample drawn at the beginning of his twelve
week training program, prior to ozone exposure, with two post-
exposure bloods being obtained at six and twelve weeks after
the start of the program.
Ozone levels and the levels of the oxides of nitrogen
were determined in the immediate area of the welding. The ozone
levels were repeatedly found to be negligible, with the nitro-
gen oxides appearing to be the primary toxic agents involved.
For those 165 subjects on whom two blood samples were obtained,
and for those 86 on whom all three blood samples were obtained,
no statistically significant increases in chromosomal aberra-
tions were found.
IV
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ACKNOWLEDGEMENTS
The cooperation of the U.S. Army welder trainees at
Aberdeen formed the basis of this study, and the leadership
at the Base and at the welding school in particular, helped
us throughout.
Numerous persons helped directly in the generation of
the data included in this Report. Among these were Dr. S.
Neriishi, Mr. K. Ohki, Ms. J. Beaird, Ms. D. Campos, and Ms.
Z. Pyatt. We are particularly indebted to Dr. Neriishi, who
aided in the laboratory supervision, and Ms. Pyatt, who was
invaluable in the laboratory and in the on-site work at the
Aberdeen Proving Grounds in Maryland. Dr. Granville Sewell
and his colleagues of the School of Public Health at Columbia
University were responsible for the measurements of ozone and
the oxides of nitrogen.
James Stebbings of EPA was the original Project Officer.
Dorothy Calafiore was the EPA Project Officer in the later
stages of the study, and we here wish to express our gratitude
to her for her considerable assistance in the data analyses
and for her guidance on this Report. Ms. Rhoda Serra, Adminis-
trative Assistant to the author, is owed a particular note of
thanks for her high quality work in preparation of this Final
Report.
v
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TABLE OF CONTENTS
Page No.
Forward iii
Abstract iv
Acknowledgements v
Table of Contents vi
Introduction 1
Materials and Methods 2
Results 5
Discussion 10
Conclusion 13
References 14
Tables 15
Appendix A 24
Appendix B 25
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INTRODUCTION
A. SUMMARY BACKGROUND
Considerable evidence exists for the induction by ozone
of both point and chromosomal mutations. Zelac et al.[1] ex-
posed Chinese hamsters to 0.2 parts per million of ozone for
five hours, and demonstrated an increase in chromosomal aber-
rations in their peripheral blood lymphocytes.The major types
of aberrations reported were chromosomal exchanges and dele-
tions. Sachsenamier et al. [2] had earlier found ozone-induced
chromosomal aberrations in chick embryo fibroblasts, and
Fetner [3] had demonstrated chromosomal aberrations produced
by ozone in Vicia fava. Furthermore, ozone is known to induce
point mutations. Prat et al. [4] demonstrated that ozone al-
ters the pyrimidine bases thymine and uracil in E. coli DNA,
and Davis [5] demonstrated the induction of mutant colonies
of E. coli after mutagenesis with ozonated water.
Human cell studies of ozone effects have been few.
Merz et al. [6] showed that in six subjects exposed to 0.5 ppm
ozone for six and ten hours, as part of an assessment of the
effects of ozone on pulmonary function, neither chromatid nor
chromosome-type aberrations were produced in peripheral blood
lymphocytes; but achromatic lesions, interpreted as representing
unrepaired single strand breaks, and chromatid deletions were
seen. The peak frequencies of aberrations were seen at two
weeks post-exposure, with a return to lower aberration fre-
quencies by six weeks.
B. SCOPE OF WORK
In addition to exposure of humans to ozone in areas of
heavy air pollution, occupational exposure, particularly among
welders, is known to occur. The mounting evidence for genie and
cytogenetic effects of ozone warranted a more exhaustive iri
vivo study of human chromosome response to ozone and to the
oxides of nitrogen than has been available to the present time.
For this reason, we undertook a study, on behalf of the U.S.
Environmental Protection Agency, to determine whether the peri-
pheral blood lymphocytes of military welder trainees would have
increased numbers of chromosomal aberrations after six to twel\e
weeks of welding experience. The study consisted of two major
aspects: 1) the cytogenetic laboratory program; and 2) the en-
vironmental monitoring program.
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MATERIALS AND METHODS
A. SELECTION OF SUBJECTS
The target population for this study was a group of
military recruits (U.S. Army) who were training as welders at
Aberdeen, Maryland. Each welder trainee served as his own con-
trol, having a blood sample, for peripheral blood cell chromo-
some studies, drawn at the beginning of the twelve-week
training period, prior to ozone exposure. This blood sample was
to establish the baseline frequency of chromosomal aberrations
for that individual. Each recruit in the twelve-week, over-
lapping programs was asked to volunteer for this study and sign
a consent form (see Appendix A). Confidential questionnaires
(see Appendix B) were then administered to those who agreed to
participate. Information regarding x-ray exposure within the
preceding six to twelve months, viral infections and immuni-
zations, and drug histories were elicited at the time of the
initial blood drawing, with interval histories being obtained
at the time of the post-exposure blood drawings, at six and
twelve weeks after the start of the program. Thus, the ideal
situation was to have one blood sample prior to ozone exposure,
with two after exposure, at six week intervals.
B. BLOOD PROCESSING AND MICROSCOPY
Sterile heparinized vacutainers were used for trans-
portation of blood samples from Aberdeen to New York City. Each
blood sample was assigned a code number by the blood drawers in
Aberdeen, with the code not having been broken until after the
chromosomes were analyzed. Bloods were drawn once or twice per
week, as required, and the time interval between blood drawing
and culture initiation did not exceed six hours. The bloods
were chilled, but not frozen, in a portable container, and
sent by commercial bus.
Leukocytes were then separated by low-speed centrifu-
gation and duplicate cultures were initiated from each blood
sample, as back up. Short-term, leukocyte cultures were es-
tablished and cells were harvested after a fifty hour culture
time, according to the method of Bloom and lida [7]. Non-
banded Giemsa staining methods were used.
Slides were coded by subject number and read blindly,
without knowledge of the exposure status of the subject. An
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attempt was made to read 100 cells from each blood culture. The
following definitions [8] were applied for the major aberra-
tions: Single chromatid and isochromatid breaks were scored as
such if there was displacement of the distal portion of the
chromatid(s). When the chromosome of origin of an acentric
fragment could not be determined, it was called a free frag-
ment. Multicentric chromosomes were scored in accordance with
the number of centromeres, while ring chromosomes were classi-
fied as either centric or acentric. Fragments accompanying
multicentrics or rings were not scored separately. Transloca-
tions were generally detectable by the elongated long or short
arms of the affected chromosome. Inversions showed displacement
of the centromere. Other aberrations scored were quadriradials
(chromatid exchanges), breaks at the centromere, and deletions,
which were usually terminal. The presence of an aberration was
confirmed by at least two experienced microscopists.
C. OZONE DETERMINATIONS
Using an AeroChem Chemoluminescence Analyzer Model AA-5
for NO, NOX/ and 03, a mobile air sampling unit was assembled
during early September, 1974, in the welding school facility
at Aberdeen. About a week was spent in testing and refining the
operation of the equipment, and a program of testing air in-
tensively initially and then on a monthly basis over an 18-
month period, was subsequently conducted. For readings during
the welding operations, a teflon tube with dust filter was
used to collect air samples within the welding booths at six
positions (described below) around the welder's head, so
measurements represented the gas mixture that was probably in-
haled. The readings were later verified by field tests per-
formed, as confirmation, by the staff of the U.S. Environmental
Protection Agency.
Test
Sequence Code Position
1 F (Front) Front of welder over the welding or
cutting activity. This represented
the position of highest gas concen-
tration. Some of this gas was drawn
directly under the bottom edge of
the face shield for respiration.
Proportion appeared to vary according
to the physique of the individual
and his work habits.
2 R (Right) Next to welder's right ear where
respiratory air was being drawn into
the face shield. This represented
one of the four zones - top, bottom
(above), and two sides - that acted
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Test
Sequence Code Position
as sources of respiratory air.
3 B (Back) Behind head of welder. Since he was
usually bending over his work, this
test registered respiratory air
quality entering the top of his face
shield, usually the first or second
most important point of air entry.
4 L (Left) Next to welder's left ear.
5 T (Top) Top of booth at exhaust duct.
6 0 (Outside) Ambient air quality approximately
two feet from front of booth at nose
level.
Operation of the instrumentation was supervised by
Granville H. Sewell, Ph.D., Associate Professor of Public
Health (Environmental Health Sciences) and Acting Head, Division
of Environmental Health Sciences, and Dhun B. Patel, Ph.D.,
Assistant Professor of Public Health (Environmental Health
Sciences) .
D. STATISTICAL ANALYSIS OF CYTOGENETIC DATA
All statistical analyses were carried out by John P.
Creason, Ph.D., Chief, Statistics Staff, Environmental Pro-
tection Agency.
The aberration types analyzed were:
1. Single chromatid gaps
2. Single chromatid breaks
3. Isochromatid gaps
4. Isochromatid breaks
5. Multicentric-dicentric rings
6. Acentric fragments
7. Translocations
8. "Others"
Analysis of the counts was done using the Grizzle-
Starmer-Koch analysis procedure for categorical data. In this
analysis, functions of the proportions, F(ir), in the cells are
estimated for the model under consideration. The tests appro-
priate to this problem are formulated as F far) = 0. A test
statistic is generated which has asymptotically a central -^2
distribution if the hypothesized model is true.
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RESULTS
A. OF THE QUESTIONNAIRE ON POPULATION CHARACTERISTICS
The questionnaire, developed by us with J. Stebbings
of the EPA, was administered to all of the 273 trainees from
whom blood was originally drawn. However, we have analyzed
only those bloods yielding 75 cells or more, or a total of
253. Thus, for the sake of consistency, we wanted to include
only the data from the questionnaires of that group. However,
six of these people failed to answer the questions, so the
following data is based on a total of 247 questionnaires.
One hundred eighty-four (74.0%) of the trainees were
between the ages of 18-21, eight being only slightly younger,
and 55 ranging in age from 22 to 57.(Note that the 57 year old
was not a military recruit but a Civilian attending the school^.
One hundred seventy-five (70.9%) of the trainees were
White; 42 (17.0%), Black; 1 ( 0.4% ), Oriental,
and 3 (1.2%), "other American." Six made no reply.
The majority (210 trainees, or 85%) had had a high
school education, while 13 (5.3%) had completed grade 8, and
3 (1.2%) had completed four years of college. Fifty-eight
(23.5%) had attended a trade school.
All entered the welding school in 1975, and 91.9%
entered active duty either the year of the study or the year
immediately preceding it.
Of the total 247 trainees, 122 (49.4%) stated they
had had previous school or job welding experience. However,
70 trainees (28.4%) who had had previous experience, had it
more than one year before the first blood was taken.
Two hundred nineteen trainees (88.7%) reported that
they were in generally good health, with no significant
physical or mental condition. One hundred sixty-nine (68.4%)
were cigarette smokers at the time of the study.
Information regarding various illnesses the trainees
had had within six months prior to the drawing of the first
blood is summarized in the following table:
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Disease No. affected
Rash, non-specific 14
Infectious Mononucleosis 4
Hepatitis 1
Flu 19
Alcoholism 1
Anemia 1
Blood Poisoning 1
Nerves 1
Measles 3
Respiratory Infections 19
Seizures 1
Unknown Illness 2
In addition, the following information regarding health
problems six months or more prior to the initial blood sampling
was ascertained: 3 trainees reported tuberculosis; 4, a psycho-
genie illness such as a nervous condition or migraine; 1, re-
covered drug addiction and alcoholism; 1, ulcer; 1, liver and
kidney problem; 1, abdominal pain of unknown origin; 1, asthma;
and 2, orthopedic problems.
51.0% of the trainees reported taking no medicines or
drugs within 6 months prior to blood #1. 23.1%, however, had
taken over-the-counter cold remedies; 6.1% had taken anti-
biotics; 2.8% - analgesics; 2^0% - allergy medication; 2.4% -
prescription drugs such as Mellaril, Emprazil, Parafon Forte,
Antabuse, and Amyl Nitrate; 5.3% reported taking unknown drugs.
4.5% had taken the drug before entering active duty;
19.8%, after entering active duty; 12.1%, both before and after;
while 12.6% made no reply.
63.5% of the trainees reported that they had been
x-rayed within the six months preceding blood #1; the largest
percentage (17.8%) having had dental x-rays, followed by 17.0%
who had had a chest or back x-ray. 45% of those x-rayed had
been done so either before, after, or both before and after
entering active duty. No-one reported receiving radiation
therapy, although one man stated he had been given a radio-
active substance for pain and dizziness, but couldn't re-
member when. X-ray exposures six months or more prior to the
initial blood sampling were varied, as expected, with most
(41 persons, or 15%) of these exposures having been for studies
of the upper or lower extremities.
B. OF THE CYTOGENETIC ANALYSES
As presented in Table 1, a total of 610 blood samples
were drawn from 273 welder trainees. The culture failure rate
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was 1.6%, with an additional 9.2% of cultures providing less
than 75 readable metaphases. In the following discussions of
these results, we will focus primarily on the data obtained
from the 89.2% of cultures which yielded at least 75 quality
cells.
It should be pointed out that while compliance was
reasonably high for the first and second blood drawings (75.5%),
it fell off markedly for the third blood sample, with only 131
of the original 273 subjects (48.0%) providing the final, third
blood sample. The major reason for this decline was that many
of the recruits did not complete the entire twelve weeks of
the training program, with approximately 25% leaving prior to
the final sampling date.
Examination of the data provided in Table 2, in which we
pooled all cases having 75 or more cells analyzed, revealed
that small increments, not statistically significant, were
seen in the frequencies of cells with isochromatid gaps, with
dicentrics and accompanying acentric fragments, and in trans-
locations and quadriradials. These minimal increases were
generally seen in the six week blood sample, much less im-
pressively or not at all, in the twelve week, or third, blood
sample.
However, analysis of the data from those 86 subjects
a) who contributed three blood samples, and b) each of whose
three blood samples provided more than 75 cells, suggests that
chromatid-type aberrations were more generally increased,
particularly, again, in the six week sample. The percentage of
cells with single chromatid gaps rose from 0.84 in the 86
control bloods, to 1.40 at six weeks, and declined to 1.10 by
twelve weeks. The proportion of cells with isochromatid gaps
rose from 0.04 in the controls, to 0.11 at six weeks, and to
0.18 at twelve weeks. The isochromatid break frequency showed
a rise from 0.01% of cells to 0.06% at six and twelve weeks.
Among the chromosome-type aberrations, no statistically sig-
nificant increases were seen in any category of aberration,
though a few more dicentrics with fragments, fragments alone,
and quadriradials were detected at six and twelve weeks than
in the control bloods (see Table 3).
C. OF THE O-^, NO, AND NOX MONITORING PROGRAM
The trainees were exposed to ozone levels ranging from
below the sensitivity of the instruments to a maximum of 0.015
ppm in both the ambient air of the welding sheds and the res-
piratory zone within individual welding booths. Normally,
however, the instrument registered "zero" ozone levels.
The NO levels varied from 6.0 ppm to 0.2 ppm, while the
NOX levels were found to register from 8.0 ppm to 0.5 ppm.
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Highest exposures occurred for each trainee only during periods
of active welding, which totaled considerably less than one
hour each day. Typical maximum ambient exposure levels were 1.0
ppm of NO and 1.5 of NOX. Exposure varied from booth to booth,
area to area, and time to time.
Averaging the readings did not appear feasible for three
reasons: 1) the readings were typically close to the sensitivi-
ty limits of the instrument, 2) general atmospheric pollution
conditions were so severe that the instrument deteriorated
rapidly and later readings did not have the reliability of the
initial ones, and 3) the readings at specific locations were
not sufficient in number and comparability to provide statis-
tical reliability. On any one day, the school may have had up
to fifty trainees welding in various parts of the facility.
However, the locations and type of work being performed by
these trainees varied from day to day. Furthermore, the in-
tensity of exposure for each trainee varied constantly during
welding.
During operation of the instruments, the teflon filters
in the sampling line had to be replaced frequently, usually
twice a day, due to accumulation of gritty particles. Towards
the end of the monitoring period, the instrument began to in-
creasingly lose sensitivity despite the filter changes. When
the instrument case was removed, severe corrosion was found
to have occurred on many surfaces, particularly at electrical
contacts and soldered points. This was interpreted as further
evidence of the corrosive nature of the emissions from the
welding.
Table 4 provides data from two days during the early
stage of the project when the standard testing procedure was
rigorously applied.
D. OF STATISTICAL ANALYSIS OF CYTOGENETIC DATA
The previously described statistical approach to the
data was used by Dr. John Creason of EPA and us to interpret
the findings. A number of data analyses were done, some of which
are not presented here but are available on request. These in-
clude summaries of aberration types by week; and analysis of
the final counts used for subjects with one and two bloods and
for subjects with all three bloods.
A summary of the analyses for those subjects with blood
samples #1 and #2 is given in Table 5, while a summary of the
results for those subjects with all three blood samples is
given in Table 6. One should remember that all the subjects
with three blood samples also were included in the analysis of
those with the first two blood samples, so that these analyses
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are not independent of one another and should show similar re-
sults when examining the difference between blood samples #1 and
#2. It is clear that the magnitude of the differences in aber-
ration frequencies between bloods #1 and bloods #2 and/or #3
are small and, for the most part, not statistically significant.
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DISCUSSION
When this project was originally designed (1974), there
was legitimate concern over the possible cytogenetic effects
of ozone and of the oxides of nitrogen. (We have referred to
some of the most relevant papers on the subject of genetic
effects of ozone in the Background section above). This pro-
ject was one of several initiated by the EPA to study the
effects of these gases specifically on human chromosomes, with
our population being the occupationally exposed group.
As we discuss in the next several paragraphs, and as
presented under Results, the ozone levels were, in fact,
very low, and we were dealing here primarily with the nitrogen
oxides.
In interpreting the monitoring data, three circumstances
should be considered:
1.) The atmospheric conditions during welding were ex-
tremely adverse. In addition to the gases that were monitored,
the trainees were believed exposed to a wide variety of other
gases and particulates - many with corrosive or toxic proper-
ties - formed during the melting or combustion of welding rods
and flux coatings. Coatings can contain a deoxidizer, such as
ferromanganese or silicomanganese, and a slag former, such as
titanium dioxide, magnesium carbonate, feldspar asbestos, or
silica [9]. The steel of a welding rod can contain various
alloys including chromium, cobalt, molybdenum, tungsten, boron,
and other elements. Coatings on materials being welded can in-
clude cadmium, lead, beryllium, fluorides, and other materials
[10]. Each of these can form primary and secondary pollutants.
2.) Trainees were exposed to the welding atmosphere only
a small fraction of the time, generally on the order of 25%,
when they were assigned to the welding shops. Since they also
attended classes and other activities, they presumably re-
ceived the intense exposure for some time period of less than
10% of the total manhours of their tenure at the Aberdeen
Proving Grounds.
Even when welding, the intensity of exposure varied.
Trainees were required to master the welding procedures with
the work in three positions: a) horizontal on the table at
waist height, b) vertical on an extension rod that elevated
10
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the work from the table to approximately shoulder height, and
c) above the head. Because most of the gases rose while heavier
particulates fell, each position had its hazards, with position
(b) probably being the one with least exposure.
Identifying the passage of the inhaled air was com-
plicated by the welding face shield that extended from the
chest to above the head. When the head was tilted downwards,
the primary passages appeared to be from above the head and
over the shoulders since the bottom of the shield would fit
tightly against the chest. When the head tilted upwards, the
passage at the bottom of the shield would open.
3.) Trainees were required to gain experience with a
wide variety of welding materials, including brass, stainless
steel, and aluminum. Each had a special rod and set of hazards.
Some also involved gases such as acetylene.
When the trainees were not welding but were in the
welding shops, they were exposed to an ambient level of NO and
NOX. This was somewhat surprising because of the extensive
ventilation system. However, this system was primarily focused
on the welding booths, which were three-sided enclosures having
a canvas curtain that could be drawn over the open entrance
side. The NO and NOX levels could have had three sources:
a) gases that "escaped" the ventilation system, b) gases formed
in secondary reactions between the materials released in
welding and the air environment, and c) electrical equipment,
particularly the heavy transformers, that was on the shop floor.
Because heavy concentrations were not registered in the vicini-
ty of the equipment, this is not considered a probable source.
Because of the intense ionization of the air during
welding, ozone was presumably formed but it could not be regis-
tered in significant amounts. This phenomenon has also been
noted in the technical literature. The most likely explanation
was that the ozone rapidly oxidized the NO and other gases
formed during the welding, thus disappearing. This hypothesis
was supported by the relatively high ozone values registered
in readings immediately over the welding arc and the rapid
disappearance of ozone as readings at higher elevations were
taken.
Our cytogenetic findings indicated that for virtually
all types of scored aberrations, little difference in fre-
quency was seen between the control blood samples (bloods #1)
and the follow-up bloods (#'s 2 and 3), obtained when the sub-
jects were well into their welder training program. The most
impressive increases, such as they were, were seen in the
chromatid-types of lesions. The isochromatid breaks were found
to be minimally increased in follow-up bloods, as were the
single and isochromatid gaps which we well recognize to be far
11
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less a reliable indicator of chromosomal damage than any other
"aberration" type.
It is important to note here that, while many of the
welder trainees had had some previous welding experience, the
frequency of chromosomal aberrations in the control blood sam-
ples was compatible with that found in other putatively normal
human populations. Further, there were no subjects among those
studied in whom the follow-up aberration frequencies increased
consistently and strikingly.
Our basically negative findings with respect to ozone and
the oxides of nitrogen are consistent with the findings of
McKenzie et al. [11], who examined the peripheral blood lym-
phocyte chromosomes of 30 men exposed to 0.4 ppm ozone for four
hours. If no increase in aberrations is to be expected after a
known, acute, relatively high dose exposure, it is possible, but
unlikely, that repeated exposure to minimal doses over a maximum
of twelve weeks will generate chromosomal aberrations. We say
this because the expectation is that repair of some damage will
doubtless take place in non-repair-deficient persons, interfering
with our ability to detect damaged cells which may be present in
very small numbers to begin with.
12
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CONCLUSION
While this study was set up primarily to evaluate the
cytogenetic effects of ozone in human somatic cells, there
appeared to be rapid conversion of ozone to the oxides of
nitrogen, providing measurable amounts of the latter with
little residual ozone. The frequency of chromosomal aberrations
in the six and twelve week bloods was not significantly dif-
ferent from that in the pre-exposure bloods, leading in-
evitably to the conclusion that at these exposure levels for
these gases, little, if any, chromosomal damage is induced.
13
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REFERENCES
1. Zelac, R.E., H.L. Cromroy, W.E. Bolch, Jr., E.G. Donavant,
and H.E. Bevis. Chromosomal Aberrations Induced in Chinese
Hamster Lymphocytes. Environ. Res. £:262, 1971.
2. Sachsenamier et al. Z. Krebsforsch ([7:113, 1965.
3. Fetner, R.H. Chromosome Breakage in Vicia fava by Ozone.
Nature (London) 194;793, 1962.
4. Prat. Ann. Inst. Pasteur 114;595, 1968.
5. Davis, I. Microbiologic Studies with Ozone. Quantitative
Lethality of Ozone for Eschericia coli. U.S.A.F. Sch.
Aerospace Med. 61-54:1-16. March, 1961.
6. Merz, T., M.A. Bender, H.D. Kerr, and T.J. Kulle. Ob-
servations of Aberrations in Chromosomes of Lymphocytes
from Human Subjects Exposed to Ozone at a Concentration of
0.5 ppm for 6 and 10 Hours. Mutat. Res. 3_1:299, 1975.
7. Bloom, A.D. and S. lida. Two-day Leukocyte Cultures for
Human Chromosome Studies. Jap. J. Hum. Genet. 12; 38-42,1967.
8. Bloom, A.D. Induced Chromosomal Aberrations in Man. In:
Advances in Human Genetics H. Harris and K. Hirschhorn (eds.)
Vol. 3, pp. 99-172. Plenum Press, New York, 1972.
9. Brady, G.S. Materials Handbook, 8th ed. (New York: McGraw-
Hill) pp. 340-341, pp.872-874, 1956.
10. Patty, F.A. (ed.), Industrial Hygiene and Toxicology, 2nd
ed. (New York: John Wiley and Sons) pp. 2304-2305, 1963.
11. McKenzie, W.H., J.H. Knelson, N.J. Rummo, and D.E. House.
Cytogenetic Effects of Inhaled Ozone in Man. Mutat. Res.
48:95-102, 1977.
14
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TABLE 4.
Arc Rm. 9/26
Body
Shop 9/26
30(MIG) 9/26
3 (TIG) 9/26
Sample Levels of 03, NOX and NO
in the
Welding School, Aberdeen Proving Ground
1975
Ozone levels in ppm
Booth
4 (MIG/
TIG)
12 "
62 "
57 (ARC)
9 (TIG)
Date
9/17
9/17
9/17
9/17
9/26
Front
0.006
8.0**
0.01
0.012
off scale
(over oil)
Right
0.006
0.006
0.015
0.012
0.042
Back
0.007
0.006
0.005
0.012
0.004
Left
0.007
0.006
0.004
0.012
0.008
Top
0.007
0.007
0
0.012
0.001
Ambient
0.006
0.006
0
0.012
0.001
ALL READINGS ZERO
WORK NOT OCCURRING
ALL READINGS ZERO
0.002
0.005*
NO levels in ppm
Booth
Date
9/17
0
0
3
5
Front
1.8
.1-1.0
2.3
1.0
1.0
.8-3.2
.5-5.4
.0-6.0
Right
1
0
2
0
0.
4
1.
.3
.1
.5
.5
1-0.8
.0
2-1.4
Back
1
1
1
0
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.2
.0
.4
0.2-0.6
3
2
.6
.0
Left
1.0
1.2
1.0
0.6
0.2-0.4
2.0
4.8-5.3
Top
6.0-8
1.
2.
0.
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5
0
8
1.5-3.4
2.
1.
0
3
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1
0
1
1
0
0
2
0
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.0
.4
.1-0.
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.5
0
3
5
4 (MIG/
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12 " 9/17
65 " 9/17
62 " 9/17
57 (Arc) 9/17
9 (TIG) 9/26
Arc Rm. 9/26
30 (MIG) 9/26
3 (TIG) 9/26
* Background. Work had not started for day.
** Believed to be caused by malfunction of equipment
0.004*
20
-------
TABLE 4 (CONTINUED)
NOV levels in ppm
Booth
Date
Front
Back
Left
Top
Ambient
4 (MIG/
TIG)
12 "
60 "
57 (Arc)
9 (TIG)
Arc Rm.
30 (MIG)
3 (TIG)
9/17
9/17
9/17
9/17
9/26
9/26
9/26
9/26
1.5
6.0-8.0
1.5
6.5-7.0
1.0-6.3
2.0-2.7
4.4-7.1
1.4
1.1
1.0
0.8
2.7
2.2r-5.2,
1.6-3.7
1.2
1.6
1.0
0.7
0.7-1.1
1.5
1.0-1.8
2.8
1.7
0.8
1.4
0.5
1.5-1.7
1.6-3.0
4.7
2.2-3.0
1.3
1.1
1.5
1.2-1.6
1.5-2.2
1.2
1.5
0.5
0.7
0.6
1.5-1.7
0.5
0.0125*
* Background. Work hr«d not started for day.
21
-------
TABLE 5.
Incidence of Chromosomal Aberrations:
Analysis of Subjects with Blood Samples I and 2
Percent Yes Percent Yes p-value
Aberration Type Blood 1 Blood 2 Difference for Difference
Single chromatid gaps 51.5 62.4 10.9 0.05
Single chromatid breaks 11.5 9.1 2.4 0.48
Isochromatid gaps 5.4 9.7 4.3 0.12
Isochromatid breaks 1.8 3.6 1.8 0.32
Multicentric-dicentric
rings 2.4 6.7 4.3 0.07
Acentric fragments 4.2 5.5 1.3 0.62
Others 1.2 4.8 3.6 0.06
22
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23
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APPENDIX A
ID Number
STATEMENT OF PERMISSION
I agree to participate voluntarily in this chromosome
study of welder trainees. The purpose of the study has been
explained to me. I have been informed that this study is being
conducted by doctors at Columbia University, in New York, for
the U.S. Environmental Protection Agency. I understand that the
study has been approved by the Department of the Army and by
the Army personnel in charge of this welder training program
at Aberdeen, Maryland.
I understand that a 10 cubic centimeter venous blood
sample (a small tube) will be requested of me on three oc-
casions: at the beginning of my participation in the study,
and twice thereafter, but that I have the right of refusal each
time.
I understand that I may refuse to answer any question
in this interview, or the brief interview to be given when I
leave the Welding School. I give permission for my Army medi-
cal and dental records to be reviewed for illnesses, x-rays,
or medicines which might affect my blood.
I understand that no information collected from me will
become part of my military record, nor will my items of in-
formation collected be released to any individual not working
in this study.
Signature
Name (Printed)
24
-------
APPENDIX B
D D
ID Number
CHROMOSOME STUDY IN WELDER TRAINEES
QUESTIONNAIRE (INITIAL)
1. Name
(last) (first) (middle)
2a. Date of Birth 2b. Serial Number
(day) (month) (year)
3a. Date entered Date of
Welding School 3b. Interview
(day) (month) (year) (day) (month) (year)
4. On what date did you enter active duty?
Day Month Year
IF GREATER THAN _ MONTHS BEFORE ENTRY INTO WELDING Rejected
SCHOOL, EXCUSE TRAINEE FROM STUDY for length
of service
5. Have you had past experience in a welding shop or in a
welding course in school?
No YES, High School
_ Rejected
[j YES, Trade School Previous I 1
_ . Welding
I _ I YES, Job Experience
IF YES, EXCUSE FROM STUDY
Duration
Participation..
6. Date of first blood sample OR Refused | |
(day) (month) (year)
YOUR ANSWERS TO THIS QUESTIONNAIRE WILL BE HELD IN STRICT CONFIDENCE.
THEY WILL NOT BECOME PART OF YOUR MILITARY RECORD. RESULTS WILL BE
SUMMARIZED FOR GROUPS OF PERSONS. NO INFORMATION ON INDIVIDUAL RESPONSES
WILL BE RELEASED.
THANK YOU FOR YOUR COOPERATION.
25
-------
APPENDIX B (CONT'D)
D
ID Number
7. ILLNESS HISTORY
Have you had one of the following illnesses within the last six months:
a. Rash YES
IF YES:
Cause
NO
Approximate Dates
Was that Before
b. Infectious Mononucleosis
IF YES:
Approximate Dates
After entering active duty?
YES Q NO [""]
Was that Before
c. Hepatitis
IF YES:
Approximate Dates
Was that Before
d. Flu
IF YES:
Approximate Dates
Was that Before
After entering active duty?
YES Q NO [~|
After entering active duty?
N°D
After
entering active duty?
e.
Any other illnesses in the last six months? YES[ | NO [ [
IF YES:
i. Nature of illness
Approximate Dates
Was that Before
ii. Nature of illness
After
entering active duty?
Approximate Dates
Was that Before After entering active duty?
(Continue on rear of page as necessary)
26
-------
APPENDIX B (CONT'D) , . . ..
ID Number
8. MEDICATION HISTORY
We need to know about any medicines or drugs that you have
taken in the last 6 months, such as aspirin, penicillin, hay
fever medicine, or any other drugs. Start with the most
recent. NONE [~~|
IF YES: Time in relation to
Name or type of medication Approximate Dates enetering active duty
(Circle)
Before After Both
Before After Both
Before After Both
(Continue on rear if necessary)
9a. RECENT X-RAY HISTORY
We also need to know about any x-rays you have had within the
last six months, again starting with the most recent. NONE jj
IF YES:
Part of body x-rayed Approximate Dates Time in relation to
entering active duty
(Circle)
Before After Both
Before After Both
Before After Both
9b-d. PAST RADIATION EXPOSURE
b. Have you ever had radiation therapy? YES [ [ NO [ |
IF YES: Describe suspected medical conditions and
test substances if known, and dates of therapy.
27
-------
APPENDIX B (CONTINUED)
ODD
ID Number
c. Have you ever been given radioactive substances YES [ [ NO [ |
for diagnosis or treatment?
IF YES: Describe suspected medical conditions and test substances
if known, and dates of diagnosis or treatment.
d. Have you ever had x-rays other than routine chest and ^_^
dental x-rays? YES P""] NO | |
IF YES: Describe medical reason, if known, part of body
x-rayed, and dates of x-rays.
10. Are there any comments on your general health that you would like to
make? Anything you think we should know? ii
Describe:
28
-------
APPENDIX B (CONTINUED)
nan
ID Number
11. How would you describe your ethnic background?
Black/Afro-American | Mexican/Puerto Rican/ II
Other Latin American
White/Caucasian American Ij Oriental American j j
Other American j
12. EDUCATION
a. What is the highest grade in school that you have completed?
(Exclude any college)
b. Have you attended college? YES ( | NO
IF YES: For how many years?
Did you receive your Batchelor's degree? YES | [ NO | j
13. Have you attended any trade school after your regular schooling?
YES Q NO
IF YES: Describe course, and length of enrollment.
14. What is your age (last birthday)
15. a. Do you now regularly smoke cigarettes? YES | j NO
IF YES:
b. About how many cigarettes do you smoke per day?
(A pack = 20; record frequency if respondent does not
smoke every day)
29
-------
APPENDIX B (CONTINUED) ___. . . .
ID Number
c. At what age did you begin smoking cigarettes regularly?
(Record age; if respondent has smoked less than a year, also
record number of months of smoking to date)
SKIP TO QUESTION 18
16. a. Have you ever regularly smoked cigarettes? YES [ ) NO [ j
IF YES:
b. How long ago did you give up smoking cigarettes?
(Record months if less than 1 year ago, years if longer)
c. How many months or years did you smoke cigarettes?
d. When you were smoking what was the average number of cigarettes
you smoked per day?
17. APPLYING THE QUESTIONS ABOVE TO PIPE AND CIGAR SMOKING, CODE:
a. Cigars 1 Nonsmoker
[ I Smoker
No. per day How long smoked
[ | Exsmoker
No. per day How long smoked
How long since stopped
b. Pipe
Nonsmoker
[ [ Smoker
No. per day How long smoked
I I Exsmoker
No. per day How long smoked stopped
30
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing}
EPORT NO.
3A-600/l-79-011
2.
3. RECIPIENT'S ACCESSION NO.
ITLE AND SUBTITLE
:hromosomal Abnormalities Among Welder Trainees
5. REPORT DATE
February 1979
6. PERFORMING ORGANIZATION CODE
,UTHOR(S)
Arthur D. Bloom
8. PERFORMING ORGANIZATION REPORT NO.
EPFORMING ORGAN.ZATION NAME AND ADDRESS
] 10. PROGRAM ELEMENT NO.
Columbia University
New York, New York
1AA81 7
11. CONTRACT/GRANT NO.
Contract No. 68-C2-1738
SPONSORING AGENCY NAME AND ADDRESS
Health Effects Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC 277T1
13. TYPE OF REPORT AND PERIOD COVERED
RTP.NC
14, SPONSORING AGENCY CODE
EPA 600/11
SUPPLEMENTARY NOTES
ABSTRACT
Serial cytogenetic observations were made on a group of 273 military recruits who
>re being trained as welders at Aberdeen, Maryland. The trainees were being exposed to
-esumably increased levels of ozone in the course of their welding school experience,
id it was the purpose of this study to determine whether or not ozone, at low to mod-
-ate doses, is capable of inducing chromosomal aberrations in peripheral blood lympho-
ytes.
Previous exposures and the past medical experiences of the trainees were determined
y questionnaire, enabling us to obtain a profile on the medical-social characteristics
f the study sample. Each welder was to serve as his own control, having a blood sample
rawn at the beginning of his twelve week training program, prior to ozone exposure, with
wo post-exposure bloods being obtained at six and twelve weeks after the start of the
rogram.
Ozone levels and the levels of the oxides of nitrogen were determined in the
mmediate area of the welding. The ozone levels were repeatedly found to be negligible,
ith the nitrogen oxides appearing to be the primary toxic agents involved. For those
65 subjects on whom two blood samples were obtained, and for those 86 on whom all three
ilood samples were obtained, no statistically significant increases in chromosomal
.berrations were found.
'. KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Chromosomal
Cytogentic
Ozone
8. DISTRIBUTION STATEMENT
Release to Public
b. IDENTIFIERS/OPEN ENDED TERMS
Welders
Blood samples
19. SECURITY CLASS (This Report )
Unclassified
20. SECURITY CLASS I This page)
Unclassified
c. COSATI Field/Group
06, F T
21. NO. OF PAGES
36
22. PRICE
iPA Form 2220-1 (Rev. 4-77)
PREVIOUS EDITION IS OBSOLETE
31
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