Document zdgz8X0Rnqd9oyXVBYnmJjRMm
FILE NAME: Welding (WELD)
DATE: 1971 Sept
DOC#: WELD012
DOCUMENT DESCRIPTION: Journal Article - Prevalence of Chronic Respiratory Disease
"X 4 '' 220
Prevalence of Chronic Respiratory Disease
Asbestosis in Ship Repair Workers
Benjamin G. Ferris, Jr., MD; Manmohan V. Ranadive, MD; John M. Peters, MD, DSc Hyg; Raymond L. H. Murphy, MD, DSc Hyg; William A. Burgess, SM; and Henry P. Pendergrass, MD, Boston.
Study of pipe coverers, pipe fitters, and weld ers at a ship repair yard indicated that pipe coverers had more changes in their lungs, as evidenced by examination of x-ray films, and slightly lower pulmonary function than the other two groups. All groups showed slightly lowered pulmonary function as compared with workers who did new-ship construction and were not ex posed to asbestos. Aerometric measurement showed levels of asbestos that were, in general, lower than current threshold limit values. These findings reemphasize the need for control of asbestos in the work areas, as well as careful medical surveillance of workers exposed to as bestos.
IN AN earlier report on respiratory disease
in new-ship construction, we noted a 10.7% prevalence of asbestosis in pipe coverers.1 We also noted that workers exposed to 75 million particles per cubic foot year or more were considered to have asbestosis by our criteria. New-ship construction is regarded as less hazardous than repair work because it is less dusty. Specific data on disease prevalence in shipyard repair work is scant, and criteria used to assess disease preva-
Submitted for publication Feb 3, 1971; accepted March 5.
From the Kresge Center for Environmental Health, Harvard University School of Public Health, Boston.
Reprint requests to Kresge Center for Environ mental Health, Harvard University School of Public Health, 665 Huntington Ave, Boston 02115 (Dr. Ferns).
lence vary. Accordingly, the purpose of the present study was to assess the risk of ship repair work and to examine the dose-re. sponse relationship of asbestos exposure to asbestosis in a different working population
Methods
The 63 pipe coverers listed in the personnel files of the shipyard were selected for study Each was matched with a welder and a pipe fitter of approximately the same age and years of work at the shipyard. This matching was done by us from records supplied by the per sonnel department. These factors agreed to within two years. The men were contacted | through their foremen and asked to participate IT in the survey. In instances where the "control" r person had terminated, another matched con I trol was selected. Persons out ill or retired were not replaced.
All participants were asked a set of standard | questions concerning respiratory symptoms and smoking habits, similar to the British Medical 1 Research Council questionnaire. Occupational { histories were obtained. Pulmonary functira t, was measured by a variety of tests. Forced vital capacity (FVC) and forced expiratory volume t in one second (FEVt 0) were measured on a | Stead-Wells spirometer at fast paper speed (3.2 |, cm/sec) with the subject seated without a nose- | clip. Five trials were made, and the average oi the last three was used. Volumes were correct i ed to body temperature, pressure, and satuiatio n (B T P S ),
Peak expiratory flow rates (PEFR) were measured on a Wright peak flowmeter that had
, calibrated under con| % . e meter. Readings w e,| '',l . f ^ e trials were madifl ';ilj jiisf three was used. 'I
;1"-lod at ambient tempe
f,.i pirated.
.
.Maximum expiratory f|i
Miips were G a in ed on " ith the subject standing
greeted to BTPS. Total respiratory resista
3 Hz using a fixed oseillaf ^otal respiratory resistan a,,. functional residual caj
ujet breathing with the si more satisfactory breaths uhject then either inhale! lung capacity or exhaled ! ul,,,> and then relaxed h rccistance measurements
edge of five breaths was measured during inspirati
0f 0.25 and 0.5 liters/sec. 1'osteroanterior and la t
were obtained on most olj were read by three observ H.P.) separately and wittj occupational history of thj
films were classified by th of fibrosis and presence aj calcification according to the International Labor agreements in readings observers reading the film to a decision as to the res applying standard nomei niosis to asbestosis was re ommendations of ILO e lowed.
Pulmonary diffusing c; by the single-breath te< monoxide and helium in room air. The method a: Cotes and Saunders were!
suremont was ribboned oxygen. T he high-oxyge ways done first. From thlj blood in the pulmonary membrane component ( as well as the diffusa ng sureraents that did no I i! lished c rite ria were n, bill. The cviieria that ine iollowing; (!) poo. luildim (1efectiw, poor e volumes on room air ani by aioro than -toil cc; (3 big differing by more th (-1) op,i r tor error.
Arch Environ Health--Voi 23, Sept 1971
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ASBESTOSIS--F E R R IS E T AL
223
tahie r,.- Carbon Monoxide Diffusing Capacity With Single-Breath Method by Occupation
,a
and Cigarette Smoking in Repair Shipyard, 1968
CO Diffusing Capacity (m l/m in /m m Hg)
------------------------------------------------------ -
pm
No.
Room Air
High Oxygen
(m l/m in /m m Hg)
Vc (m l)
.:kers
10
17
22.2 21.5
13.8 12.3
27.4 31.9
114.5 101.8
kers
12
. . _rfcnt ^|i' 6
11
nkers
12
- .{fen ;
s
21
f'3*
rient :
kers
33
,,.rient
30
", :^ita f:
; pby.1
25.9 20.3
24.5 22.9
25.69 22.47
14.1 12.0
13.9 11.9
12.22 9 .0 3
33.0 27.3
34.3 39.7
39.48 43.20
103.2 91.5
99.1 86.5 \ 69.01 45.44
7.-- Asbestos Dust Sampling at Repair Shipyard During Period, 1952-1966*
Dust Concentrations (Million Particles/cu ft)t
No. of Samples
M in im um
Maximum
M ean + SD
..A samples /,,rieral shop
19
0.6
9.4
2.8 2.6
V i ^ t a ^ a (layout,
,,mooing, stapling, sewing)
15
0.8
13.3
4.8 3.7
ti m e (hand saw, band saw)
26
1.1
100.0
19.0 30.0
Opening & unrolling hulk material
22
0.8
33.6
7.2 7.3
Mixing cement
8
27.2
90.0
57.3 23.5
..rihnard samples
taring out
41
2.4
132.0
29.2 30.4
Most sampling was conducted prior to 1 9 6 5 . In 1 9 6 5 , fib er glass was substituted for am osite on m ajor portions
*Total dust was counted. No a tte m p t was m ade to define % of fibers. Concentrations represented instantaneous renditions.
Table 8.-- Summation o f Sampling Results in Repair Shipyard, 1969*
i-xat/on ViOp
Total No. of Air Samples
19 62
Concentrations (Fibers/m l)
.------------------------------------- -------------------------------------
M in im um
M axim u m
Mean
0.01
3.1
0.3
0.01
25.0
2.9
Data from J. Lynch and W. A. Burgess, SM (unpublished data).
No. of Samples With
---------------------------- ----------------> 5 Fibers/ml > 12 Fibers/m l
0
0
11
2
category, "questionable," refers to the Z or Z/p category of the ILO and a profusion of 2/1 or less; "marked change" refers to p classification or more, with a profusion of 2/2 or more.3 Questionable readings were more frequent in pipe coverers but occurred in all groups, while marked changes were noted only in pipe coverers. It should be emphasized that the occupation of the man *is not known at the time of the initial readings, and only the posteroanterior and
lateral films taken at the time of the survey were available to the readers.
The difference between pipe coverers and the other categories was significant at the probability level, P < 0.01, when those with a marked change are considered. Similarly, the pipe coverers had significantly higher prevalence of questionable readings (P <
0.05). Calcifications, either pleural or pleural
and diaphragmatic, were significantly more
Arch Environ Health--Vol 23, Sept 1971
m@mviw
224
ASBESTOSIS--FE R R IS E T AL
common among pipe coverers. This could not be accounted for by a previous history of pneumonia, bronchopneumonia, or trauma. Diaphragmatic calcification was more common among pipe coverers, but it was present in only five cases. This was not a statistically significant increase in prevalence. Pleural calcification, observed in 11 cases, was significantly higher (P < 0.05) in pipe coverers.
Shaggy heart occurred more often in the pipe coverers (P < 0.01) than in the pipe fitters or welders. Among the 13 pipe cover ers with shaggy hearts, six occurred in the persons with marked x-ray film changes and seven in those with questionable changes. Two pipe fitters were considered to have shaggy hearts but no welders were.
Diffusing Capacity.--Table 6 presents the results of the measurement of the diffusing capacities of men in whom the criteria for acceptance were met. Of the 186 subjects, only 83 were suitable for calculation of Dm and Vc. There were 27 subjects who offered poor cooperation; and in 74 subjects the alveolar volumes, as calculated from the sin gle-breath helium, were too different. There was one refusal and one operator's error.
The diffusing capacity is lower in the pipe coverers than in the other categories. It is also lower in smokers than in nonsmokers. As was noted in an earlier study by W. F. van Ganse, MD, B. G. Ferris, Jr., MD, and J. E. Cotes, MD (unpublished d a ta ), the Vc is decreased in cigarette smokers, where as the Dm generally shows a slight rise or no change. The Dm does tend to decrease with age, however. A group of unexposed workers from another study1 gave values for the diffusing capacity similar to those seen in the pipe fitters and welders but higher than those in the pipe coverers.
Rales in two or more sites were signif icantly more common in pipe coverers than in either welders or pipe fitters. Six of the ten pipe coverers whose x-ray films were consistent with moderately advanced asbestosis had rales, whereas the rate in pipe fitters and welders together was 12.1%. This occurred even though the observer did not know either work category or roentgenologic classification at the time of auscultation. Rales were less well correlated with "border line" asbestosis, being present in 15.8% of
the subjects in this category. Of pipe cover ers whose x-ray films were negative, 28.2 had rales, suggesting that rales can prece^ x-ray film changes as a manifestation 0; asbestosis, as has been observed by others' The converse can likewise occur.
There was no significant difference,
tween the prevalence of rales in the v. elders as compared to the pipe fitters. The preva. lence of rales (12.1%) in these two groups of subjects, who probably have some expo, sure to asbestos in the course of their work was more than the 8.2% that was found in a group of shipyard workers with little to no asbestos exposure.1
Measurements of the total respirat uy -fe. sistance by the oscillation method generally were not rewarding. We were not able to demonstrate any differences between occupational group, age, or smoking categories. Similar negative results were found with the volume-flow plots. Some of this may be due to the relatively small numbers. / A total of 131 dust samples were collected | from 1952 to 1966 at this yard (Table 7). In (addition, 81 extended-time personal lapel samples using membrane filters were collect ed during a special three-month study peri od (Table 8). Sampling times for these extended-time samples ranged from one-half to four hours. Two thirds of these samples were collected during shipboard operations, while the remainder were collected in the shop (J. Lynch and W. A. Burgess, SM, unpublished data). Mean shipboard and shop concentrations for the membrane-filter samples are summarized in Table 8. There may be occasions when the time-weighied average concentration may exceed the pro posed threshold limit value (TLV) or five fibers per milliliter in shipyard locations (J, Lynch and W. A. Burgess, SM, unpublished d a ta ). Because of the intermittent character of work of this yard, and with the recent substitution of fiber glass, it was not possible to develop good estimates of lifetime expo sure for comparison with the previous study. As expected, dust levels during tearing out were high. Unfortunately the number of samples taken during tearing out was low.
Definite changes consistent with asbestosis were seen in this yard despite the relatively low levels of exposure. Over the years these levels were probably comparable to or
higher than those seen in j,jp construction. Since w '[hoSe men who were still a l,ave missed diseased indi retired or left the job. It wi (to a retrospective study to farlier experiences had bei to the methods of record k f ^l records after a three-y gent to a central depositoi identified only by the man nel records also were not long periods.
Because this yard did groups may be slightly ex different types of work tei the same time and this siiru nmy result in less difference! {Jnexposed workers from aij loetter pulmonary function jng in the repair yard arit. once of rales, both of which this possibility. A number! measured indicate that th
1. Murphy RLH: Asbestosis struction, thesis. Harvard Univei lie Health, Boston, 1967.
% Peters JM, Mead J, Van G* flow-volume device for measurin' tion in the field: Results on wor levels of toluene diisocyanaie. / 99:617-622,1969.
3. International Classification Pneumoconiosis (Revised JiMiS) tional Safety and Health tional JLabor Office, 1970.
4. Cotes J12: Measurement of (diffusing' capacity) foi the Lur sions, in Cotes Ji>2 Lung b'unclit Application in Medicine, ed 2. Davis Co, I960, pp 269-269.
5. K dw ards J K , L ynch J R : T
Arch Environ Health--Vol 23, Sept 1971
if
flit f: '<ltv
!'.(!' ll; -i't COI^ 1
who were still at work, we could
had more disease than the other two groups. In this particular study, changes in the chest x-ray films seemed to be most useful. Tests
of rs
L u a* T
lei H J !V!l- a
Ups i
ppork, in a
no
re. "ally e to xx u>ri -s. a the
due
ectofl ). In
. ,\V n- i diseased individuals who had . -jri'd < eft the job. It was not possible to ,, a ri' ' : :restive study to determine what iJf)ier >-i riences had been. This was due v the nu ods of record keeping, in which jil recon1 after a three-year period were
to c ntral depository and could be ientifiei'i sly by the man's name. Person,t \ reco! ' also were not maintained for
songPen ' 1 flecau- his yard did repair work, all
(roups a-. be slightly exposed, since the different t .es of work tend to be done at h*`same time and this simultaneous activity jviy result in less difference between groups, t'nexposed workers from another study had v<ter pulmonary function than those work
ing in the repair yard and a lower preva lenceof rales, both of which tend to support .jyj. possibility. A number of the factors nveasured indicate that the pipe coverers
of pulmonary function, such as FVC and
FEVi o, were not as dramatic as has been reported,0 although their lack of sensitivity may well reflect the more general exposures of the control groups in a yard doing repair work. It is of interest that, despite the rela tively low levels of asbestos in the yard, changes consistent with asbestosis were ob served. These may reflect higher exposures in the past. Even so, this study reemphasizes the need for continued control of exposure to asbestos and for careful medical surveillance
of workers exposed to asbestos.
This study was supported by Public Health Service research grants ES-0002, EC-00205, and ES-00044.
CAPT Roger W. O'Neil, MC, USN, made space and personnel available to us.
Ernani D. Stodazzi and Barkev Siroonian, MSPH, did the routine aerometric surveys.
The US Navy gave us permission to do this study on their premises and during working hours, with the cooperation of selected men.
Stefana Puleo, MS, did the computations.
lai>e| illect-
References
peri- i 1 Murphy RLH: Asbestosis in New Ship Con- the U.S. Public Health Service for enumeration of
these ,'ruction, thesis. Harvard University School of Pub- asbestos dust oh membrane filter. Amer Occup Hyg
]e-hali
lmplett
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in the
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ughted
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or
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fi(vJe.
blished
aracter '
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Sods of toluene diisocyanate. Amer Rev Resp Dis 17-622, 1969.
;i. International Classification of Radiographs of t'ueumoconiosis (Revised 1968), No. 22. Occupa r la ! Safety and Health series, Geneva, Interna rla! Labor Office, 1970.
4. Cotes JE: Measurement of the transfer factor diffusing capacity) for the lung and its subdivit*ns, in Cotes JE: Lung Function: Assessment and Ipplication in Medicine, ed 2. Philadelphia, F. A. Utvis Co, 1966, pp 239-259.
5 Edwards JH, Lynch JR: The method used by
11:1-6, 1968.
6. Fleischer WE, Vlles FJ, Gade RL, et al: A health survey of pipe covering operations in con structing navel vessels. J Industr Hyg Toxic 28:916, 1946.
7. Ferris BG Jr, Anderson DO, Zickmantel R: Prediction values for screening tests of pulmonary function. Amer Rev Resp Dis 91:252-261, 1965.
8. Leathart GL: Pulmonary function tests in as bestos workers. Trans Soc Occup M ed 18:48-55, 1968.
9. Becklake MR, Founier-Massey G, McDonald JC, et al: Lung function in relation to chest radiographic changes in Quebec asbestos workers. Bull Physiol Path Resp 6:637-659, 1970.
recent
rossible j
e expo- ;
t study,
ing out
iiber ol
low.
bestosis
datively
,rs these
Arch Environ Health--Voi 23, Sept 1971
