Document 854pdz7rjxMz09xpD655DQQJZ
FILE NAME: Welding (WELD) DATE: 1972
DOC#: WELD013 DOCUMENT DESCRIPTION: Journal Article - Radiological Survey of Men Exposed to Asbestos in Naval Dockyards
Radiological survey of men exposed to asbestos in naval dockyards
P. G. H A R R I E S , F. A. F. M A C K E N Z I E , G. S H E E R S , J. H. KEMP, T. P. O L I V E R , and D. S. W R I G H T
Rc'si;;iroh Unit, H.M Dockytmi, Devonport; Radiolo.jieal Department, Royal Nava* Hospital, Plymouth; Plymouth Chest Clinic, Beaumont House, Plymouth; and H.M Dockyards Chatham, Rosyth, and Portsmouth
Hurries. I ' . G ., Maeken/.ie, I'. A . I'.. Sheers, G .. Kemp, .). I I . , O th e r, I . I*., unci W rig h t. I). S. (1972). lirit. ./. iiu lu sir. M ed., 29, 274-279. RadiolwKieal survey o f men exposed to asbestos in naval dockyards. Asbestos related ahnornialilies were found in V , , o f a 1 0 ",, samivle popularion in radiological surveys o f the naval dockyards at Portsm outh, C hatham , and Rosy 111. The prevalence o f these ahnornialilies was related to the type o f occupation and duration ol exposure to asbestos. T he results confirm the findings o f an earlier survey at D evonport dockyard.
N o association between sm o k in g , o r the am ount smoked, and the ineideneeof parenchym al or pleural disease due to asbestos was delected.
Pleural abnorm alities were found 10 times more frequently than parenchym al disease, and concern is felt over the uncertainty o f the prognosis in men w ith pleural abnorm alities, especially as .77 men have developed pleural m esotheliom a at D evonport since 1965.
M o re w ork is required to establish the true significance o f pleural abnorm alities caused in asbestos and to explore possible methods o f treatment.
I he radiologic,i! survey of Devonport dockyard workers (Sheers and lem plcton, I96S) has now been extended to the other three naval dockyards at C h ath am , Portsm outh, and Rosyth. T he results of the D evonport survey emphasized the extent o f the problem s associated with the use o f asbestos in one naval dockyard and gave added impetus to the com plete reassessment o f the use o f asbestos materials, and o f w orking methods involving asbestos, in all naval dockyards which has been carried out by the M in is try o f Defence ( N a v y ) (H a rries, 1968, 1971).
Methods
'the methods used in this survey were the same as those used by Sheers and Templeton (1968).
T lie sam p le consisted of e very lentil man on the stall and weekly paid payrolls of Portsmouth, Chatham, and Rosyth dockyards. Only female employees and male finance department employees were excluded because
they were not exposed to asbestos. There were 2 5f>8 men
in
the The
sample and 2 442 (95",,) medical departments of
oelacthhedseocwkeyraerdexsaumpienrevdis.ed
the completion of a short qucstiotmaiie on occupational
history, smoking habits, and details of past illnesses Irout
each subject at the time of the chest radiograph. The
l(X> mm chest photolluorographs were produced b) 1,1
Odelca camera with stationary grid coupled to a 2(X) mA
.v-ray generator and phototimer. The l(X) mm films were read independently by three
readers (P .G .H ., T .A .T .M ., and CCS.) and subjects were
recalled for largo films if any reader suspected an ab
normality. Clinical examination of the chest was per
formed by dockyard medical officers for each recalled
subject and included the completion of the Medical
Research Council long respiratory symptoms question
naire and the measurement of lorccd vita) capacity (I-VC)
and one-second forced expiratory volume (I I V, ,,) using
u Vitalograph. When pulmonary fibrosis was suspected
more detailed lung function examinations were under
taken at respiratory physiology laboratories.
Classifieui m
The In Ii m , .
of recall,,,
film IC.iil;'!
tore qiic- !
vcntilahu
between u
and an am.
The is
osurspeexcctleudde
Harries. I
f o r the
Paictich\ in
fibrosis v.,
aphiiilKm.i.
>niii.d .,11
clime , d . U S
I'lem.d ,
Will) .is? ,
in lee!;?ni
types ol .
into Im i ,
or luui , u
I he ii we. Chm luii; because 1 used at I the result four do. i
Anah. were m age oi l that the ; were m i ?
Radioing I lie .a . the do. A'h.itli.ii'
a t R l 1S \ ;
l*u h i n
D fU if.j'i' 1*01 I .lll.i C'Iu i i Im i ; K tcu l,
All Inui
m
ill
tl
,.1 !.d
In
sc ?. SbX men examined, d supervised occupational illnesses from lograph. The ulneed by an I 10 a 200 m A zntly by tlirce subjects were peeled an abliest was pereach recalled l die Medical loms questioncapacity (F V C ) il liV ,.,,) using was suspected us were under lies.
Radiological survey o f men exposed to asbestos in naval dockyards 275
Classification of radiographs The full-size postero-anterior and 45 oblique radiographs of recalled subjects were read independently by the three film readers who also considered data from the respira tory questionnaire, clinical examination, and tests of ventilatory capacity before classifying the film. Differences between readers on the assessment of films were discussed and an agreed reading was produced for each film.
The 45 oblique radiograph was useful in confirming or excluding the minor degrees of pleural thickening suspected on postero-anterior films (Mackenzie and Harries, 1470).
I or the purpose of this survey minor degrees of parenchymal abnormality suggestive of early pulmonary fibrosis were noted but were not classified as being abnormal. Films were classified as showing evidence of pulmonary fibrosis only when there was supporting clinical and physiological evidence.
I'lcural abnormalities were classified as being associated with asbestos only when other causes such as past infection, surgery, or trauma had been excluded, 1lietypes of asbestos pleural abnormalities were subdivided into limited or extensive pleural thickening anil calcified or non-ealcilied pleural lesions.
Results
The new w ork reported in this paper relates to C hatham , Portsm outh, and R osyth dockyards, but because the techniques used are the same as those used at D evonport by Sheers and Tem pleton ( l l) M ), the results are com parable and, as far as possible, the lour dockyards arc considered together.
A nalysis o f the questionnaires showed that there were no big, differences between the dockyards in the age or occupational structure o f the population, and that the proportions o f men in each sm oking category were sim ilar for each y ard.
Radiological abnormalities The overall prevalence o f asbestos abnorm alities in the dockyards was .T IP ",, (T a b le I). T he rates at Chatham and Portsm outh were slightly lower, and at Rosy th considerably lower, than at Devonport.
Pulm onary lihrosis (asbestosis) was suspected on
the radiographs and confirm ed by clinical and physiological exam ination in two men at Chatham , in three at Portsm outh, and in three at Rosyth. The men at Chatham and Rosyth were `neighbourhood workers', their trades being engine liner and electrical fitter (Chatham ) and a skilled labourer, shipwright, and joiner (R o sy th ). T w o o f the Portsm outh men were luggers, and the third was a retired R o yal N a v v engine room artificer w orking as an engine litter.
F iv e o f the eight men hail been employed at their trades for more than 25 years, and none fur less than 15 years. O n ly one man had less than 25 years elapsed time from his first exposure to asbestos. One man in each dockyard had radiological pleural abnorm alities in addition to the parenchym al changes.
F o u r cases of pulm onary fibrosis were found in the sample population at D evonport in I9PX. Three of them were luggers, and they had been exposed to asbestos dust for more than 15 years. The fourth man bad been interm ittently exposed to asbestos dust for 29 years, during which time he was periodically em ployed in cleaning up asbestos debris m ships.
Sixty-one o f the (9 men with asbestos abnui nudi ties had pleural changes, lim ite d plaques occurred more frequently than extensive pleural abnormalities and more non-ealcilied than calcified lesions were seen ( fa b le 2). These findings are sim ilar to those in the D evonport study.
Other radiographic abnormalities weie recorded in I 19 (44-2 " ,, ) o f the 2<V) men recalled lor large films in C hatham , Portsm outh, and Rosy th. I licse ab normalities included extensile healed pulm onary tuberculosis, unilateral pleural lihrosis resulting from empyema, and abnormalities associated with extensive surgical treatment. I here were m am rad io graphs with increased basal lung markings and some o f these men had a history o f chronic bronchitis and em physem a Sim ple tests o f ventilatory capacity showed the predominance o f airways obstructive disease in this group.
N o cases (if pleural mesothelioma w ire recorded in the sample populations c ie n though they have
Ovt.K.Mi
Pm i l l i m i
i a iu .i: i
o r R adukuovi'iiic
A sm s i os A hno km ai tin s
ih <t Ai art!
Ho onpOFt ( I`>hh S111\ 0\ )
CPohrattshmamouth
Rosy, til
....................................
\ !! four >ai\!s
Xn. in
1
1
5to04o
S6(0<K0
4 072
Y<- a
!1 401147 0>-21-05 7(>s US (, DM) US S <KMi US 2
ii nil t\/ov/.?t i/./i
ah>unnKthiu \
Ut2\ 2 s i 2 1 'O
fVci a l n n c
-1H5 i' <'5 - it.
276 P. (j . Harm's, / k. / . Mackenzie, 0. Sheers, J, //. Kemp, /. /' Oliver, and /). .S liiieht
TABU-! 2 R a d io g k a i'iiic A s iiis t o s A u n o k m a i m i s
}}>i` of radiopraphic abnormal- v
1extensive calcified pleutal thickening
t xtenshe non-calcilied pleural thickening
. .
1 united ealcilied pleural plagues
l imited non-calcilied pleural plaques
Confirm ed pulm onary iibrosis
Devonport
l 10 () 42 4
No. of can's detected in sample
Portsmouth
C hatham
i
1
c
V
14
15
A
Total
hi
\2l
25'
'O n e man also li.nl pulm onary I t o m s , co n tin u a l Ivy clinical am! lung funelion exam ination.
Rosyth
1 41 1 4 }
been reported in men IVom D cvo n p o rl, C hatham , am! Portsm outh dockyards. 1lie reasons for not detecting sneli eases in the I in 10 sample are that the incidence o f this tum our is small and that persons sullering from the disease would probably not be at work.
A t D cvo n p o rl there have been 37 eases o f pleural m esothelioma in dockyard workers since 1905, and m 10 o f these cases bilateral non-caleilied pleural plaques were present on series o f chest radiographs taken before the developm ent o f the tum our. The rem aining 27 cases presented with large pleural tumours with or without pleural elfusions. Previous films were either normal (9) or there were no available previous films (IX ).
Smoking
There w-as no definite evidence in these surveys to suggest that asbestos abnorm alities occurred more frequently in men who smoked most heavily (T ab le 3). M en who adm itted sm oking at least 25 g o f tobacco daily and those who had given up smoking showed the highest rates o f radiological ab norm ali ties associated with other diseases.
I ting function
T he tests o f ventilatory capacity performed in these survey s on most men recalled for large films showed that men w ith pulm onary fibrosis tended to have restrictive ventilatory defects; those with pleural abnorm alities had norm al values. M en with other diseases showed an obstructive ventilatory pattern with the l b V ,.,, reduced proportionately to a gteater extent than the I V C .
Because this survey was essentially based on radiological appearances these tests were merely used as clinical screening aids, and more comprehen sive lung function assessment was confined to those men who were suspected o f having developed pulm onary fibrosis. Pu lm o n a ry fibrosis was con firmed when basal rales were present and when lung function tests showed a restriction o f static and dynam ic lung volum es w ith a low transfer factor.
bflccts of occupation
Sheers and Tem pleton (1968) grouped the various dockyard trades in an attem pt to subdivide the population into four grades o f intensity of asbestos exposure. In order to m ake com parisons between
TABLK 3
R a d io g r a p h ic A u n o k m a i i n (naontdreScmoordkeindgatHDa cuviiosn(pPoorrt)t s m o u t h , C h a t h a m , R o s y t h )
Nonsmok ers
No. o f men N o. o f asbestos abnorm alities Rate N o. o f other abnormalities . . K a t e ....................................................
808 20 ` 2-5 " .. 85 10 5 " .,
IS smok ers
54 0 0 11
20-4
Sm ok ittg categories: average daily /
-- -- ........
consumption
1-4
5-14 g
15-24 g
123 3
2-4 13 10-6
400 14 3-5 44 1 1 0 " ,,
1 011 32 4-20o
120 11-9,,
25 g :
47 0
1o87 0 "
iltcsc 1'W e d Have U l.il >'thcr ittern icaicr d on H. rely Ik titluise loped
coni lung , and
tii'ious ie the ncstos tween
' o " tr,
Radiological survey o f men exposed to asbestos in naval doekyards 111
the yards we used the same classification (T ab le 4). [n each yard those groups thought to have been exposed to higher concentrations o f dust showed more asbestos related abnorm alities than the groups with lesser dust exposure.
The prevalence o f asbestos abnorm alities js highest in men heavily and continuousiTeTposed' to asbestos^ Tgroup I asbestos sprayers an d ''la g g e rsjrT w fT iie results sh o w "th at there are otlier bceTipatioiis in Wtifch the'Tate?rarc; higher than in the g e i^ ja [d o e k - . 'ya?3~ p ipifcn,iu icr'T h tr mrrnbefs o f alTecied men in ^7ufivIdiKn^rTrdFs" are small so that it is unwise to draw firm conclusions from this survey, but the results suggest that joiners, painters, riveters, caulkers, drillers, shipwrights, engine fitters, and men who had been em ployed for most o f their working life as R o y a l N a v y engine room artificers have higher than average prevalence rates. Joiners have been exposed to dust by w orking with asbestos m h iir I insulation, and painters because o f their association with asbestos spraying, but most o f the remaining "high risk' groups are `neighhouihood workers' in engine room s and boiler rooms where insulating w ork has been undertaken by others.
It was thought that pulm onary fibrosis (asbestosis) might be limited It' those men continuously w orking with asbestos (group I occupations), but m ore than half o f the men with pulm onary fibrosis discovered in the present survey were "neighbourhood workers'. | xperience from till dockyard employees til Devon-
port confirm s the sample findings; only 41 o f the 128 men w ho have disability pensions for asbestosis are recognized asbestos workers.
Pleural abnormalities were found more frequently thail the parenchym al disease and they give rise to concern not only because o f the larger numbers of men allccted, but also because o f the uncertainly of the prognosis. There is some evidence to suggest that pleural abnorm alities tire associated with changes in lung function (Beck lak e et a!., 1970; H arries, 1970c) but the simple tests o f ventilatory function carried out in these surveys showed only that pulm onary fibrosis was associated with a restrictive lung defect, and that other chronic lung conditions were accompanied by an obstructive pattern o f lung function.
In te n siv e pleural fibrosis is associated with a reduced lung volum e and ventilatory capacity and can cause physical disability. Measurement of static and dynam ic lung volum es and transfer factor in 11 men with extensive pleural thickening identified in the D cvo n p o r! sample (Sheers and Tem pleton, |9(>H) shows that for till 1I men the bVC and T K V , . (1were less than the predicted norm al values and the transfer factor w;ts less than the predicted value in It) of them (T ab le 5). Piedictcd values for I V C , 1-1iV , . total lung capacity, and transfer factor were calculated from the regression equations from Cole-. (1908). These data form part of a more detailed study of men with asbestos pleural abnormalities presently being undertaken at D evonport.
T A H IT I 4 l ' KtA'Ai.iiNci: o r A m iis io n A h n o k m a i t i n s in Ot c o i'a i io n a i
( roups
D ochvari1
Truth'
(/><)///>
Portsm outh
Chatham
A\n vth
Dcvonoot f
J.x a m iiu i/ A b n o rm a l l.xam irn-tl A /m a n u al l.M im ifU 'd A b n o rm a l i, u in u n v il 4bn o rm a l
l aj'.i'.er, spi\i\cr,
itiiiM'n, s.iiim.iki'i -
la^i'.ei. pointer.
asbtMO'. storeman
1
40
a 112
24
1 (4
10
i f Ut",,)
42 15 ( >" ,t
l-lectricai finer,
burner, u d d e r,
riveter, caulker,
driller, shiplitter.
plumber, cop per
smith
It
21 1
') (4",,)
UiK
(< <4" J
1 70
1 (2",,l
22 ((>',,)
t
Slu|n w U'-bt. enpinc
litter
111
.\11 other oceupa-
|
lions
IV
j
Tout
220
7
515 1 01 7
10 (2".,) 22 1M " J
170
o (-1 ",,1
401
12 ( l" ,, l
7f>5 25(1 <",,)
1 b;
5 l-l ',,)
i ;
17 ( r.,i
J It ",,I 12(1 K".,i
Mi 4 i in
14 |2",,! ; n 5 <4 <
278 P. (,. Harries, l . .4. / . Mackenzie, (>. Sheers, J. II. Kemp, I'. P. Oliver, ami /). .S', lir/ph;
TABLT5
l.l.Nti V()l l!Ml S AM) (AS TXANSI I K IN 11 Ml-.N WITH 1:X I! NSIVI: I>1 I URAl. TllICKI.NING
lndc.\
H V-, , ! 1. 111P S ) . t \ r (i. n t i'si 1 1 ( i: n i l 's, I T (single breath) fiu K 'O m m mm ll).'.)
Adm it
Mean
SD
2 09
y 11
5-7|
. .
1904
0 61 0 60 0-51 4 71
/Vi <//r,;l
Mean
S I)
2 91 3 93 6 31 24-32
0-37 0 44 0-66 3-06
p
0 1)01 0 601 (HM 0-0025
Duration of exposure
1lie D evonport study showed th.it Il ia c was a long interval between lirst exposure to asbestos and the detection of radiographic asbestos abnormalities, and sim ilar results were seen in the other three yards. In 54 (7 X ",,) o f the 69 affected men more than 25 years had elapsed since their lirst exposure to asbestos, and 46 (6 7 '1,,) o f the 67 men had worked with or near asbestos for 25 years or more. The overall prevalence of asbestos abnormalities for men w ith more than 25 years since first exposure to asbestos was 81 (T ab le 6). The rote was higher in D evonport but sim ilar in the other three yards.
Discussion
T he results o f these surveys confirm that asbestos related abnorm alities o f the lungs anil pleura tire occurring in the employees at naval dockyards in Portsm outh, C hatham , and R o sylh as well as at Devonport. The prevalence rates are based on rela tively small numbers o f affected men, but on good representative samples with a very low lapse rate. T hus different rales in the four yards probably reflect the true situation in the total population o f each. Sheers and Tem pleton (1968) suggested that 600 men at D evonport dockyard might be expected to show evidence o f asbestos disease, and. since 1965, there have been 128 cases o f asbestosis at D evonport accepted for disability pensions by the Pneum o coniosis M edical Panel; 37 men have developed pleural m esotheliom a, and over 5(H) other dockyard
employees show evidence o f pleural fibrosis or
calcification.
The high rales at D evonport may be the result ol
the type o f refitting w ork involving the largest air
craft carriers at that yard, while the low rates at
R osyth are probably related to the small number ol
extensive refits o f surface ships undertaken there in
the last 25 years.
.
It is disturbing that more than half the cases of pulm onary fibrosis (asbestosis) and pleural ab norm alities related to asbestos exposure were found in so-called `neighbourhood vvorkets" who have not I themselves worked regularly w ith asbestos products. \ T he explanation lies in the widespread contamination \ o f ships during lagging and spraying involving i. asbestos insulating m aterials ; Harries. 1971). At i D evonport all o f the dockyard eases o f pleural i m esotheliom a are in neighbourhood workers; none ' in recognized asbestos workers. A sim .lar observa tion has been made by Stum piiiux (1971) in his i report on shipyard w orkers in the Netherlands.
Selikoff, H am m ond , and C hurg (1968) suggested that men exposed to asbestos as insulation workers w ho also smoke are at greater risk o f developing bronchial carcinom a than non-smokers. Radio logical abnorm alities associated with asbestos in the population o f the present survey do not appear to be associated w ith sm oking habits. The samples showed that the sm oking habits o f dockyard em ployees tire sim ilar to those o f the genera! population, and a m ortality study o f Plym outh men has indicated that at present there is no ev idence to suggest an
Pto v a u n < i oi
t a b l j: 6
Asm si os A h n o km a i tin s in M in
I IK SI I X fO SI Kl
with
25 Y i a r s oit M om
st\< t
N o. examined No. abnormal Prevalence
Occupational yroup four dockyards
i
II
hi
IV
63
250
249
606
15
26
23
50
24
I0 \
9%
5
Do< k y a rd a ll m. cupatUai.
Portsmouth
364 2! 6 " (,
(h a t ham
254 IS 7 ""
Ros \ih
144 10
7
Devonport
406 45
1 1 11 o
Radiological survey o f men e xposed to asbestos in naval dockyards 279
excess m ortality from lung or gastrointestinal cancers in dockyard employees (H a rrie s, I970d).
In an attempt to answer m any current uncertainties about asbestos related diseases a research programme is being prepared by the Institute o f N a v a l M edicine (for M in istry o f Defence (N a v y )) and the M edical Research Council Pneumoconiosis U nit. The work will include a radiographic survey o f the total population in each naval dockyard, together with more detailed studies o f selected groups o f men w ith asbestos abnorm alities, or in specified occupational groups. The detailed studies w ill include physio logical and im m unological investigations and w ill be linked with other research into possible methods of treatment of diseases caused by asbestos.
Conclusions
New cases o f asbestos disease m ay be expected to occur in nasal dockyard employees for m any years despite the preventive measures introduced to prevent extensive contam ination o f ships by harm ful concentrations o f asbestos dust. There are men in each dockyard w ith undetected asbestos disease, ami there are apparent dill'erences in the prevalence o f these diseases between the dockyards. T he prognosis of men with asbestos pleural disease is uncertain, and increasing numbers o f pleural m esothelioma are occurring in dockyard workers.
This work has been supported jointly by the Ministry of Defence (N avy) and the Medical Research Council. The clinical examinations were carried out by Surgeon Lieutenant Commander 1). S. Wright (Portsmouth) ami Surgeon Lieutenants R. D. Cole (Rosyth) and J. G. Munro (Chatham). W e are indebted to Dr L. H. Cupel
of the London Chest Hospital and D r G . J. R. Mel lardy of the City Hospital at liilinburgh for detailed lung function examination of some of the subjects. We are grateful for the skilled work of the stall'of the Plymouth Mass Radiography Unit for the 100 mm Minis, and of the Royal Navy radiographers at each port for the large films. W e thank the Admiral Superintendents and stall' of each dockyard for their co-operation ; and the Medical Director General (N aval) for his permission to publish this report.
References
Itecklake, M . R ., bom nter Masse , , (.. M c D o n a ld , .1.
Siem iatyeki, J. , and Kossitcr, ( ' . ! . ( 1070). I iing tunc lion
in relation to chest radiographic changes in Qucbee
ashestos workers. Hull, /tin dopm/t. rn /i , 6, 677-659.
Cotes, J. L . (1968). l imy 1 unction, 2nd ed.. pp 274.175
lilaekwell, Oxford.
Harries, P. Ci. (1968), Asbestos hazards in N aval D >ck varils.
Ann. occur. t h y . , I I , LL5-I45.
(1970a). fh e e lic its and control ol'diseases ; ssoeialed
with exposure to asbestos in a N aval D o c k la n d 1 omlon
M . l) . thesis, pp. 54-84.
( I970ht. Ibid., pp. 98-111.
( 1070c). Ihld.. pp. 140-240.
(197(81). Hud., pp. 285-295.
(1971), Asbestos dust concentrations in slap repainng:
A practical approach to im proving asbestos I", giene in
N a va l D ockyards, Ann. <;,</>. t h y . . 14, 241-254.
M ackenzie, I . A ., and Harries, P. G . (1970) < hanging
attitudes to the diagnosis o! asbestos disease. .1. r o ,. Xav.
m cJ. S e t : . 56, i 16 ; 7 t .
Sehkolf. I. J.. Ham m ond, I . ( . . anil ('liurg. J (I9n8).
Asbestos exposure, sm oking and ne o p la sia ../. A tier m at
204, Idti 112.
Sheers. ( i , and lem pleton, A. R. {I9 h 5 ). I ilcels of asbestos
in dockvard workers, lin t, m a l
d, 574 579
Slm nplm is. J . (1971). I pidcutiologi ol mesothelioma on
W alch crcn Island, licit. J . industr. M a l.. 28, 59-66.
Received for publication .August It), 1971.
