Enviro nme ntal Manage me nt and He alth
8 / 5 [1997] 1 9 3 –1 9 6 © MCB Unive rs ity Pre s s [ISSN 0956-6163]
Occupational medicine, toxicology, biological
monitoring, safety and environmental health,
occupational hygiene
Wai-On Phoon
Pro fe s s o r o f Oc c upatio nal He alth, Unive rs ity o f Sydne y, Pymble , Aus tralia
It is n ot p ossible t o p r esen t a com p r eh en sive a ccou n t of t h e en or m ou s n u m b er of r esea r ch t op ics d on e in ou r r e gion . We ca n p ick ou t on ly a few exa m p les, select ed on t h e b a sis of r efl ect in g cu r r en t t r en d s a n d geogr a p h ica l r e p r esen t a t ion .
Occupational medicine
In J a p a n , t h e In d u st r ia l Sa fet y a n d H ea lt h Associa t ion p r ov id es in t er est in g in for m a t ion a b ou t it s r esea r ch a n d su r vey t h em es for 1995 (Ta ble I). Ma n y of t h ose t h em es a r e r eleva n t t o ot h er Asia -P a cifi c cou n t r ies a s w ell.
In Ch in a a la r ge n u m b er of st u d ies h ave b een con d u ct ed t o t est t h e effica cy of d iffer en t d r u gs on silicosis. Sever a l t h er a p eu t ic t r ia ls of d iffer en t p r e p a r a t ion s of P VN O (P 240 or Ke-Xi-P in ) w er e p r e p a r ed a n d a d m in ist er ed
t o la r ge n u m b er s of silicosis p a t ien t s. T h e r esu lt s sh ow ed t h a t t h er e w er e im p r ovem en t of sy m p t om s a n d d elayed p r ogr ession of d is-ea se in som e p a t ien t s. Am on g t h ou sa n d s of d r u gs b ein g t est ed for t h is p u r p ose, t et r a n d r in e, a lu m in iu m cit r a t e, q u in on y lp ip er -a zin e p h osp h -a t e -a n d q u in oly l-p ip er -a zin e h yd r oxy p h osp h a t e w er e fou n d t o b e effect ive in in h ib it in g t h e p r ogr ession of silicosis b ot h in exp er im en t a l a n im a ls a n d silicot ic p a t ien t s. An ot h er n ew d r u g ca lled “Xin in ” is n ow b ein g st u d ied (Li, 1994).
An in t er est in g a n im a l st u dy w a s a lso con -d u ct e-d in Ch in a on t h e effect of a h er b. S a lv ia m ilfi or r h iz a B ged em on st r a t ed a p ot en t ia l t o p r even t t h e p r ocess of sk in a gein g, w h ich occu r s b ot h in sen escen ce a n d ext r in sic d a m a ge by en v ir on m en t a l fa ct or s. H ow ever, fu r -t h er s-t u d ies a r e r eq u ir ed on h u m a n s -t o va li-d a t e t h ose fi n li-d in gs (Zh ou et a l., 1995).
Table I
Re s e arc h and s urve ys the me s o f the Indus trial Safe ty and He alth As s o c iatio n, Japan (1 9 9 5 )
Safety and health measures for small and Safety and health measures of mac hine using operations in
medium-sized enterprises food proc essing industry
Press mac hine related industrial ac c idents c ases Safety measures for gravel industries
Safety and health measures in tertiary industry Safety and health during the produc tion of movies, television programmes, and c ommerc ials
Safety and health measures to meet Safety and health measures taken in non-routine operations
technological innovations (steel produc tion fac ilities)
Safety and health measures taken in non-routine operations (automated produc tion systems)
Safety and health measures for senior workers Evaluation of ageing in terms of oc c upational health management
M easures to prevent occupational diseases Diagnosis of pneumoc oniosis using c omputer tomographic
(including occupational health management) images
Safety and health measures for nurses Measures to prevent lumbago
Measures against passive smoking at the worksite Effec ts on health of organic solvents in the lac quer ware industry
Effec t on health of organic solvents in the textile industry
M easures to handle chemical substances Future approac hes for managing c hemic al substanc es Biologic al monitoring of c hemic al substanc es
Others Statistic s of oc c upational fatal ac c idents Studies of OHS management systems Tec hno-stress in the advertising industry
Wai-On Pho o n Curre nt re se arc h – Oc c upatio nal me dic ine , to xic o lo gy, bio lo gic al mo nito ring, safe ty and e nviro nme ntal he alth, o c c upatio nal hygie ne
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In d ia is a lso t r y in g ou t h er b s gr ow n in t h a t cou n t r y for a lon g t im e a ga in st som e en v ir on -m en t a l a n d occu p a t ion a l con d it ion s. A h er b a l p r e p a r a t ion , t er m ed H er b a l 95, con sist in g of vola t ile a n d n a t u r a lly occu r r in g oils, in com -b in a t ion w it h som e p la n t p r od u ct s, w a s r ecen t ly d evelop ed by t h e E n v ir on m en t a l Resea r ch La b or a t or y in Lu ck n ow. T h is p r e p a -r a t ion w a s a p p lied t o t h e sk in s of 180 h u m a n su b ject s, a n d a p p ea r ed t o h ave som e d esen si-t iza si-t ion effecsi-t s (Sa xen a a n d Ch a n d r a , 1995).
Toxicology
T h e sem icon d u ct or in d u st r y is of v it a l im p or -t a n ce -t o -t h e econ om ies of m a n y Asia -P a cifi c cou n t r ies. A n ew m et h od h a s b een d ev ised for b iologica l m on it or in g of low level exp osu r es t o a r sen ic t h r ou gh t h e con cen t r a t ion of in or -ga n ic a r sen ic in u r in e. Ga lliu m a r sen id e a n d in d iu m a r sen id e a r e im p or t a n t su b st a n ces in t h e m a n u fa ct u r e of sem icon d u ct or m a t er ia ls. Mon it or in g of a r sen ic in h a ir is a lso u sed for exp osed wor k er s (Ya m a u ch i et a l., 1996).
Wh et h er liv in g or wor k in g in d eser t s ca r -r ies a n a p p -r ecia ble -r isk of silicosis h a s b een sh r ou d ed w it h con t r over sy for som e t im e. An in t er est in g st u dy fr om Ga n su , Ch in a , in d ca t ed t h a t su ch a r isk ca n occu r in in h a b i-t a n i-t s liv in g in d eser i-t a r ea s (Xu et a l., 1996).
Lea d st ill p oses a t h r ea t t o t h e h ea lt h of t h ou sa n d s of wor k er s in Asia n d evelop in g cou n t r ies. In a Ta iw a n st u dy of wom en wor k -er s in lea d b a t t -er y com p a n ies, t h -er e w -er e 363 (54.2 p er cen t ) w h o h a d blood lea d levels exceed in g 30 m icr ogr a m s/ d l. It w a s ca lcu -la t ed t h a t fr om t h ese wom en , t h er e wou ld b e 15 n ew b or n b a b ies w it h a blood lea d level b et w een 10 a n d 30 m icr ogr a m s/ d l a n d 19 b a b ies w it h a blood lea d level over 30 m icr o-gr a m s/ d l (Wa n g et a l., 1996). T h ese a r e r a t h er d ist u r b in g fi n d in gs, a s w e k n ow fr om ot h er st u d ies t h a t in t ellect u a l d efi cit cou ld occu r in b a b ies b or n w it h h igh lea d levels.
Cogn it ive dy sfu n ct ion cou ld occu r in wor k -er s exp osed t o or ga n ic solven t s in in d u st r ies su ch a s p r in t in g, sp r ay p a in t in g a n d glu e m a n u fa ct u r in g. An Au st r a lia n st u dy h a s sh ow n t h a t t h e a u d it or y evok ed p ot en t ia l is a r elia ble a n d u sefu l in vest iga t ion in wor k er s exp osed t o su ch solven t s (Teo a n d P h oon , 1996).
An ot h er Au st r a lia n st u dy focu sed on t h e ver y im p or t a n t su b ject of p est icid e exp osu r es a m on g a gr icu lt u r a l wor k er s. It w a s fou n d t h a t a p p r oxim a t ely 25 p er cen t of a gr icu lt u r a l wor k er s in a st u dy r e p or t ed a dver se h ea lt h effect s, su ch a s h ea d a ch e, n a u sea , fa t igu e a n d eye, n ose a n d t h r oa t ir r it a t ion , a lt h ou gh n o wor k er exp osed t o or ga n op h osp h a t es h a d a r ed blood cell ch olin est er a se b elow t h e
r efer en ce r a n ge. Ch lor py r ifos w a s t h e m ost com m on ly cit ed or ga n op h osp h a t e p est icid e a ssocia t ed w it h sy m p t om s (Ken yon et a l., 1996).
Ca se r e p or t s of p est icid e in t oxica t ion a r e u sefu l in h elp in g t h e a ccu m u la t ion of k n ow l-ed ge for d ia gn ost ic cr it er ia a n d in t er ven t ive m ea su r es. In J a p a n , d elayed n eu r ot oxicit y w a s d escr ib ed in a 70 yea r -old wom a n w h o in gest ed 40 m l of fen it r ot h ion em u lsion . N o t oxic sy m p t om s w er e a p p a r en t in it ia lly bu t a p p ea r ed a ft er 48 h ou r s. Im p a ir ed con sciou s-n ess, fa scicu la t ios-n s a s-n d m u scle w ea k s-n ess w er e n ot ed . P la sm a a n d u r in a r y
4n it r o3m et h y lp h en ol (P MC) w er e con sid er -a b ly r -a ised . N eit h er -a t r op in e su lp h -a t e n or PAM w a s effect ive. For t h r ee w eek s t h e p a t ien t r eq u ir ed ven t ila t or y su p p or t . Mu scle st r en gt h a n d n eu r ologica l fu n ct ion s r ecov -er ed w it h fa llin g N MC levels (Sa k a m ot o et a l., 1984).
In Au st r a lia ser u m b ile a cid s w er e st u d ied for t h eir u sefu ln ess a s a n in d ica t or of liver dy sfu n ct ion in exp er im en t a l a n im a ls a n d wor k er s exp osed t o h e p a t ot oxic a gen t s. An im p r oved a ssay p r oced u r e u sin g h igh p er for -m a n ce liq u id ch r o-m a t ogr a p h y t r ich lor et h y l-en e a n d AN IT, a n exp er im l-en t a l ch olest a t ic a gen t , ca u sed sh ift s in ser u m b ile a cid levels. Ta u r och olic a cid w a s fou n d t o b e t h e m ost sen sit ive in d ica t or (Wa n g a n d St a cey, 1990).
In T h a ila n d a st u dy w a s con d u ct ed b et w een t h e d iet a r y lea d in t a k e a n d t h e blood lea d level of b a t t er y wor k er s w it h n or m a l n u t r i-t ion a n d i-t h ose w ii-t h ca lciu m , ir on or zin c d efi cien cies. T h e st u dy sh ow ed t h a t p oor n u t r it ion a l st a t u s, esp ecia lly in ir on d efi -cien cy, cou ld in cr ea se t h e blood lea d level of t h e wor k er s. Mor eover, t h e blood lea d levels w er e p osit ively r ela t ed t o d iet a r y lea d level, w h ich w a s st a t ist ica lly sign ifi ca n t (Pva lu e < 0.05), a n d ciga r et t e sm ok er s h a d h igh er level of blood lea d t h a n n on -sm ok er s (Pva lu e < 0.05). H ea lt h ed u ca t ion in n u t r it ion a n d p er -son a l h ygien e cou ld im p r ove wor k er s’ h ea lt h a n d r ed u ce lea d a b sor p t ion (Ru jir aw a t , 1995).
Biological monitoring
Biologica l m on it or in g is som et im es con sid -er ed p a r t of h ea lt h su r veilla n ce a n d som e-t im es p a r e-t of occu p a e-t ion a l h ygien e. N oe-t a ble a dva n ces in b iologica l m on it or in g h ave b een m a d e in r ecen t yea r s in t h e r e gion . On e su ch a dva n ce is a n ew m et h od of h a ir a n a ly sis for lea d a n d ot h er m et a ls.
Wai-On Pho o n Curre nt re se arc h – Oc c upatio nal me dic ine , to xic o lo gy, bio lo gic al mo nito ring, safe ty and e nviro nme ntal he alth, o c c upatio nal hygie ne
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im a gin g w it h x-r ay m icr op r ob e. T h e m et h od a p p ea r s t o b e a ble t o d iffer en t ia t e b et w een en d ogen ou s a n d exogen ou s exp osu r es. E xt en -sive st u d ies a r e n ow p r oceed in g t o va lid a t e t h e m et h od in lea d -exp osed a n d zin c-exp osed wor k er s a n d m et a l-t r ea t ed r a t s (Sh im ojo et a l., 1997).
Safety
T h er e is st ill in su fficien t r esea r ch on sa fet y in t h e r e gion a s a w h ole. Most of t h e scien t ifi c p a p er s on sa fet y p r esen t ed a t con fer en ces t en d t o focu s on ser v ices a n d d escr ip t ive d a t a on in cid en ces a n d p r eva len ce of a ccid en t s on ly. T h er e is st ill a t en d en cy for t h e m or e t ech n ica l p a p er s on sa fet y t o b e p r esen t ed m or e by exp er t s fr om ou t sid e t h e Asia -P a cifi c r e gion t h a n by t h ose fr om w it h in . N ever t h eless, p a p er s on m a n y ot h er a sp ect s of occu p a -t ion a l h ea l-t h , su ch a s occu p a -t ion a l m ed icin e, er gon om ics a n d t oxicology, oft en h ave con sid -er a ble b ea r in g on sa fet y.
Environmental health
H ow a lea k a ge of a p oison ou s su b st a n ce a ffect ed a n a d ja cen t com m u n it y is t r a gica lly illu st r a t ed by Bh op a l. A com p r eh en sive r ev iew of t h e d isa st er w a s p u blish ed r ecen t ly. Mor e t h a n 200,000 p er son s w er e exp osed t o m et h y l isocya n a t e over a p er iod of on e t o t wo h ou r s. In it ia l d ea t h t oll w a s over 2,500 p er -son s. Of 361,966 exp osed p er -son s t r a ced , 173,382 h a d t em p or a r y in ju r ies a n d 18,922 p er m a n en t d a m a ge t o t h eir h ea lt h . Recor d ed d ea t h s even t u a lly t ot a lled 3,828. Accor d in g t o t h e a u t h or s of t h is p a p er, t h e lesson s lea r n ed fr om Bh op a l a r e a s follow s:
1 Up g ra d in g of relev a n t legisla tion . An E n v i-r on m en t (P i-r ot ect ion ) Bill w a s p a ssed in 1986 t o p r even t a n d com b a t en v ir on m en t a l p ollu t ion .
2 Grea ter em p h a sis on h ea lth a ccess of tech -n olog y tra -n sfer. In 1991 t h e T r ibu n a l on In d u st r ia l a n d E n v ir on m en t a l H a za r d s a n d H u m a n Righ t s em p h a sized t h e n eed t o look b eyon d sh or t -t er m ga in s in m a k in g d ecision s a b ou t t ech n ology t r a n sfer. 3 T h e n eed for em ergen cy p la n n in g stra tegies.
It w a s p oin t ed ou t t h a t t h ese cou ld h ave gr ea t ly r ed u ced t h e m or t a lit y a n d m or b id -it y of Bh op a l.
4 T h e n eed for m ore resp on sible tra n sfer of tech n olog y. T h er e sh ou ld b e a gr ea t er r ole by cou n t r ies a n d in t er n a t ion a l a gen cies t o h elp en su r e a sa fe a n d r esp on sible t r a n sfer of t ech n ology a n d a r a isin g of t h e level of en v ir on m en t a l aw a r en ess a n d ed u ca t ion (Dh a r a a n d Dh a r a , 1995).
Ru bb ish d u m p sit es ca n b e a p ot en t ia l sou r ce of h ea lt h r isk s t o b ot h wor k er s in scaven gin g a n d t h e com m u n it y a r ou n d . Oft en scaven ger s a n d t h eir fa m ilies live in t h e im m ed ia t e v icin -it y of r u bb ish d u m p s. A st u dy in T h a ila n d of su ch a solid w a st e scaven ger com m u n it y sh ow ed a h igh p r eva len ce of r esp ir a t or y d is-ea se, h e p a t it is B a n t igen a em ia , in t est in a l p r ot ozoa a n d h elm in t h s, esp ecia lly a m on g t h e ch ild r en . Sever a l k in d s of vola t ile or ga n ic com p ou n d s w er e a lso fou n d bu t a t r a t h er low con cen t r a t ion s (Ku n gsk u ln it i et a l., 1991). E sp ecia lly in d evelop in g cou n t r ies,
scaven ger s a r e on e of t h e m ost d isa dva n t a ged sect ion s of t h e com m u n it y, a n d a r e oft en exp osed t o m a n y b iologica l a n d ch em ica l h a za r d s.
Occupational hygiene
In d oor a ir q u a lit y is b ecom in g a su b ject of in cr ea sin g r esea r ch in t h e Asia -P a cifi c a r ea .
A la r ge Sin ga p or e st u dy of 57 a ir -con d i-t ion ed offices fou n d a r isk of ch r on ic h ea li-t h effect s fr om lon g-t er m exp osu r e t o for m a ld e-h yd e, a s 45 p er cen t of m ea su r em en t s exceed ed t h e t h r esh old lim it va lu es (TLVs) r ecom m en d ed for in d u st r ia l exp osu r e. Mor e-over, in 60 p er cen t of t h e offices st u d ied , t h er e w er e ca r b on d ioxid e levels of m or e t h a n 800p p m . Of t h e 669 wor k er s in t h ose offices 42 p er cen t felt t h a t t h eir office w a s t oo cold (Foo et a l., 1995). T h is a n d sever a l ot h er p a p er s on t h e sa m e su b ject d r aw s t im ely a t t en t ion t o t h e h a za r d s of t h e office en v ir on m en t a n d t o t h e fa ct t h a t a ir con d it ion in g oft en a ggr a -va t es t h e h ea lt h p r oblem s of in d oor a ir q u a l-it y.
In Au st r a lia , sever a l IAQ st u d ies h ave b een con d u ct ed , t oget h er w it h a r efi n em en t of st u dy m et h od ology for u se by a m u lt i-d iscip lin a r y t ea m , ilin volv ilin g m ed ica l, elin v ir olin m elin -t a l, m icr ob iologica l a n d p sych osocia l a sp ec-t s (P h oon et a l., 1995). T h is p a p er a t t em p t s t o est a blish som e d e gr ee of u n ifor m it y in a su b ject of in cr ea sin g im p or t a n ce bu t ch a r a c-t er ized by a la ck of cr ic-t er ia for d ia gn osis a n d a p a u cit y of m u lt i-d iscip lin a r y st u d ies.
Wai-On Pho o n Curre nt re se arc h – Oc c upatio nal me dic ine , to xic o lo gy, bio lo gic al mo nito ring, safe ty and e nviro nme ntal he alth, o c c upatio nal hygie ne
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clot h in g, wh ich w a s loca lly d esign ed , w a s a ssessed for it s effect . In on e gr ou p of sp r ayer s p la st ic vest s wer e wor n over t h eir T-sh ir t s, p la st ic b a gs cover ed t h eir h a n d s a n d p la st ic w r a p p in gs wer e w r a p p ed a r ou n d t h eir le gs. T h e con t r ol gr ou p wor e t h e sa m e clot h in g w it h ou t t h e p la st ic p r ot ect ive clot h es. In t h e a p p lica t ion of m et h y l p a r a t h ion , p est icid e-r esid u e levels wee-r e lowee-r in sp e-r ayee-r s wh o u sed p r ot ect ive clot h in g t h a n t h ose wh o d id n ot . In t h e a p p lica t ion of m on ocr y p t os st u dy, n o con clu sion cou ld b e d r aw n . P r oblem s en cou n t er ed w it h t h e loca lly d esign ed clot h es in clu d ed a sen sa t ion of w a r m t h a n d t h e ea se w it h wh ich t h e b a gs cover in g t h e h a n d s wer e t or n (Ca st a n ed a , 1993). Th is st u dy d r aw s a t t en t ion t o t h e p r oblem s of u sin g p er son a l p r ot ect ive eq u ip m en t , su ch a s p r ot ect ive clot h in g, in t h e h ot , h u m id cou n t r ies wh ich con st it u t e m ost of t h e d evelop in g wor ld .
Conclusion
It h a s b een ver y d ifficu lt a n d r a t h er in v id iou s for u s t o h ave t o select on ly som e scien t ifi c p a p er s for sp ecifi c m en t ion in t h is a r t icle. Ow in g t o la ck of sp a ce, m a n y p a p er s of gr ea t m er it h ave n ot b een in clu d ed . H er e w e h ave b een a ble t o in clu d e on ly som e a r t icles, la r gely select ed on t h eir focu s on cr it ica l or em er gin g issu es a n d p a r t ly on t h eir geogr a p h ica l r e p r esen t a t ion .
Refer ences
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Dh a r a , R. a n d Dh a r a , V.R. (1995), “Bh op a l – a ca se st u dy of in t er n a t ion a l d isa st er ”, In ter n a tion a l J ou r n a l of Occu p a tion a l a n d E n v ir on m en ta l H ea lth , Vol. 1 N o. 1, p p. 58-69.
Foo, S.C., Ya k , H .M., Ch a r, K.L.K., Gu ek , G.H ., Ch on g, K.W., Ta n , T.C., Ch a n , Y.C., Ta n , T.K., Ooi, P.L. a n d Goh , K.T. (1995), “IAQ Su r vey in Sin ga p or e com m er cia l offices”, in Pr oceed in gs of th e A sia Pa cifi c Con feren ce on Occu p a -tion a l H ea lth a n d S a fety, Br isb a n e, p p. 23-6. Ken yon , R.S., Mir ek , A. a n d O’Gr a dy, H . (1996), “An t ich olin est er a se exp osu r e a n d r e p or t ed h ea lt h effect s in a gr icu lt u r a l wor k er s in N ew Sou t h Wa les”, in A b stra cts of X X V In ter n a -tion a l Con g ress on Occu p a -tion a l H ea lth ,
St ock h olm , p. 218.
Ku n gsk u ln it i, N., P u lk et , C., Miller, F.D. a n d Sm it h , K.R. (1991), “Solid w a st e scaven ger com m u n it y : a n in vest iga t ion in Ba n gk ok , T h a ila n d ”, A sia -Pa cifi c J ou r n a l of Pu blic H ea lth , Vol. 5 N o. 1, p p. 54-65.
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