ptinelpul laorganie eoaal l laeat of feaaaa hones and teethe

Clangs to an iaomorphoos aerlaa of aabataaeea kaova as

•pat l ias* I t baa been tbe saHJeet of extensive iaveatigatioas

baaaaae of i t s b io logieal s ionif iaaaee aad ita raaarkabla

a b i l i t y to andargo a aariea of eat ioaie aad aaioaie axebaaga

raaetioaa, tbe er i t er ia for aaeb aa axafcaaga bslaa tlw

idaat i ty of ebarga sad the proximity of ionie radii of the

paira of ioas iavolvad. itaioag aaeb dlaarsa axebsage raaetlcns

a few bava attalaad aignifie«iaea dariag tba raeaat paat

eonsofiaaBt «pon tba tox i e i i y of tba aienaata involvedt aaab

sa axebaaga batag tba aaebaaiaai for ibair iaaorporatioa

tata tai«aa akatatat ayst«»* Baaed oa tba eoatftMporary

taportaaee glYsa to IHe toxie i ty eauaad by lead aad vaaadlaa

to tba baaiaa ayataa, atadiaa on tba replataaaat of ealalaai by

taad ( toa ie radii 0*99 aad 1*20 X ^apaet iva ly ) and of

pbaapbor«a by vanadina (Caraleat radii 1.10 aad 1.22 t

reepaclively) bava beaa eboaaa for tba preaeat tarest igat loaa.

I t la avideat tbat a eoieplata raplaeofseat of C|a IOM by 2*

Fb ioaa taada to lead pboapbate apat i te , ^^iQi^^^)^i^^)2*

vbi la tbat of <̂>?'* by yo^" teada to lead veaadata apat i te ,

Fb|Q(yo^)^ (^^}2« botb belag laMsorpba »t ealeims hydraxyl

iH»atite« A part ia l raplaaeaeat la aitber eaae laada to

fapaatloa of eel Id aalatloaa of tba eoaearaed ead'Haaabara*

• 2 «.

Xt liaa haaa aatabliahad that inhalation of laad

in the fora of daat or faaaa or I t a abaorptioa throngh tlM

•k ia laada to "lead poiaoalag** (Pluabian) vhleh i a , la

9aaaral« an oeeapatioaal dlaeaaa. I t la v a i l kaiHrn thai

load aalts are extaaaiireljr used in patrol to inprova i ta

ifaallty «id la pottery asd paiats raaaltiatp la eaataslaatioa

leadlRf thereby to a poasihi l i ty of iaeorporatlon of this

•leneat iato the haataa akeletal ayst^a. As ia the eaae of

lead the toxie effaet of Taaadias is ha»aa aysieai haa haaa

eoafiroted. Ia addlttoBt i t eoald be proved that a few

apeeies eoaiag under the siarine organiama are also valnerabla

to aaeh a t a x l e l t y . I t eoald be ahova that the priaeipal

pollttt iag aoarcea ot Tasadiaai are i t s preseneo In certaia

variet iea of ateel aa v a i l as the iadastr ia l establiaha«Bta

tavotviag the eleaent and i ta sotlts as eatalyata*

I t eoald be anwabigBoaaly established that iMia

laeerporatfid ta the ha»an skeletal system throanh exehttnga

raaetioaa oa ealettta hydroxylapatite of bones play a

• ign i f iesa t role ia tee priaeipal boae proecssos, aa»ely,

ea le i f i ea t ioa aad reaorptioa, the depositioa sad dissolutioa

respeetively of ealeias hydroxrlapaiite at the inte^rfaee of

bone aad body f l u i d s . €oRse(iaeatly» say attempt in the

tflreetioB of eliminatioa or aiaiesisattoa of aaeh a tex ie i ty

ta a8So<<'iatPd with a study of ih«> solubil i tT of ealeiaa

hydroxylapatite aa wall aa of the prodsata af the exehaage

- s -

reae i i«aa m n i t o a v d above aader siaialat«d b lo loo iea l

eoBditioos*

f*roaipled b j aaeb a eonslderat loa tbe present work

vhieb deals a t t b the preparattoR, ebaraeter isat l^B aad

• o l t t b l l i t y e ^ t t i l i b r i a of lead phoaphaie a p a t i t e , lead

vaaadate i^patile aad a aer lea of e igbt of thd t r ao l ld

• • l o t l e n s apread over the e n t i r e eottpoait loaal raa«a, «aa

sudertakOB. Adoptiag eopree ip i ta t ion of tbe ead-iaeaibera

in acfueoua aedia threo^h a Jadleioas aiodif ieat ioa of tbe

e x i a t i n ^ methods, the sa«plea were prepared at 37^C to

• isralate b i o l o g i e a l eosd i t ioaa ,

Cbaraeter iea t ioa of tbese sanples vas hroaght

•%o«t tbroagb aopbtat leated ina tnmoBta l techsiqaea aaeh

•a X<-ray d t f f r a e t i e a , e lee t roas i ie roscop7, i . r . spectra l

• t ad iea asd thermogravlaietry in addlt ioa to tiMi eonveatloaat

ei i«alcal aaalyaea* Vegard'a lav de»aada that tbe a a i t e e l l

vol««e of a ser ies of so l id s o l a t i o ^ i vftrtes l i n e a r l y v i t b

Ibe eo«positiOR and o f fe rs a eonvealeat method of s e r a i t a i a i a g

i b e i r boaegeneity. As la to be expected f ron tbe bigger s i s *

of vaaadate l e a , a repIaeeiMBt of pboapbate ion by i t brlags

aboat a d t l a i t e a of tbe a a i t c e l l , A systeaiatie l i a e a r

depeadeaee of tbe un i t e d t l volaaea v l t h tbe pre;>ortiea of

vraBBdate loa rap lae lag ptkoapbaie lea obaerved l a tbe preaeat

• 4 -

•ariaa of aol ld aotations eonflrmad thatr hoao^aaeity* ''

The alactroa«}ierographB of a fe« rapraaaataiira aanplas

ravealed fha haxagonal paiiarn of the erystala eoaf imlag

iha abaaaea of axiraaaaaa phaaaa aad aaabling ar>proxiaata

ealealat ioaa of the mpteitie anffaaa araaa aad avaraf*

diaaaaioaa of the individual er jata la . Tha i . r* abaorpiiaa

apaetra eoald eoaf lm the Ideatity of tha aaaplaa* Tha

pradoMlaaat abaorption peaka raoorded la tha tr^cee of tha

awaplaa vara foaatf to be daa to the orthopheaphata aad

erthovanadate laaa. la additioa, tha i^aorptiaa paaka daa

to earbonata aad pyrophoaohata iaaa* tha two l lkatf

i vpar i t las , vara feaad to be abseat. Th<» abaenea af

earbonata ion altaiaataa tha paaslbilitjp of ataoapharla

iRteraetioB leodlnq to tha fornatioa of carbonate apatite*

Theniegraviaetrie aaalysis iadleated that a tavparatura of

300*V: ahoaan far driving oat vo la t i l e lMp«rltl*a froa tlia

aaaplaa,dld not i a f l l a t a eheaical deeoapoaitioa on thea.

Stadtaa on the a o l a b i l l i y of tha aaaplaa vara

aadartakaa at 97*C la order to laTaatlgata Ita dapaadanea

aa the raplaceaaat of f o . ion by ?0. Ion oa lead phoaphaie

apat i t e . Siaoe It vaa intended to deteralae tha aolubi l i ty

predaet of aaeh atapta froa data raaaltlag frme the ehaalaal

aaalyaea of the aatarated aolntion, a bnffered difisol\ing

aadtaa vaa aaad to aa lata ia eeaatasey of tha aat iT i t j of 0B'*1OM

« s •

tstrolved in saeh esleulstlons. la orddr to tnvostiaste tho

roprodQelbillty of tl» solubility prod«ets so detemiBod, tho u

stodios in oaeti esse ver« extended to s fow ehosen p trolnosy

tho rflUi0O bo lag rostrietod oaly from 2.0 to 2«7, sinee there

vas a aarkod f a l l ia the so lab l l i ty of a l l tbe 8«a;>les at p

l i l a o higher thaa 2 .7 , In addlt ioa, a l t aaeh haffared

tfiaolviag «odia wore aiaiataiaed at a aa tar l ty af 0.165 with

roapoet to aodiaa chloride to sisalate bielodieal eonditions,

Sy adopting aaeh a nedlaa of di«@olutioa the eoaplieated

proeesa of oralaating acearatoly the aet lT i ty eoeff ieieata

of polyvalent ions eonld ho avoided by aa«n«iBg a l l of thoa

to be uaiiy vlfchout foregoing aeearaey* I t is evident that

aaeh ealealatioaa aake tho aotah i l i ly prodaet. ff. » sad the

iealc prodaet, K. » aynonyaooa*

Eaeh one of the po«tfa»a4 oaaplaa «aa aipii l ihralad

« t t h tha ehoson baffer cMiblnatioa aa the aediaa of

diaaolatioB at a eontrotled rate of shaking uaiig a constant

taa^aratara ahaker'>hath« The eol loidal eoapoaoat of the solate

praaont ia i t s satarAted eolation dae io i ta lo« aolubi l i ty

wm» aeparated by f i l t r a t i o n at 37**C through a IGd aintered

f laaa eraeible before the solatitwa were aaalyaed for the

prodnets of diaaolutloa* A separate expdriment eonld prove

tha a a i i a b i l i t y of aaeh eraeibles for eol loidal separation*

Vhile phoar>horas and vanadlaa vera deterained

- 6 •

ee lor lne i r tea l l j y e«iipl«x<NM»lry ««• adopted for tko

determinalloa of lead, the attainable aeearsey la a l l %tm

oaaea being aerattalsod by aaaiyaia of oolvttoaa of koova

eorapoaltioaa*

A oorntiay of attatnMent of aataraticMn and tkO

aiataniM period of equll lbratioa r e h i r e d for the parpoae

wore dotemised tbroagh dlasolntloa Kiaotiea of a eeaple of

roproaoatativo amples, from aaoag tbe ooaeeatratloaa of tiM

prodaeta of di««ol«t loa, the aoaaarod tota l dlasolved

pfcoapboma vaa aabdl^lded Into tbe propertioaa of

orthopboopiiorle aeid aad i ta three diesoeiatioa prodaeta,

RJPO^ , WO. aad FO. aaing tbe tkree dtaaoeiatioa ooaataata n

of the aeld aad tbe oifailtbrlnn p of tbe airateM, tbe ta t ter

being repaired also for evalaating OH*" Ion eoaeeatratioa

aoeded for tbe ealoalatioa of aotabl l i ty predaot*

There exiate aa aMbigaity ta tbe ear l ie r IStArataro

rogardiag tbe aolute phaae l ike ly to eontrol the eolubi l t ty of

apatite ayateaa i lnoe tbe diaaolatlMi iavolTod ia bydrolytie*

That tbe apatitea exhibit atoiehiosetrle dtaaolatioa eonld not

aaaHblgaooaly bo oatablished by the ear l ie r workers, la order

to iareatigato thia aignlf ieaat aapoot of dteaotatioa of

apat i tee, the aolabi l i ty data of the preaeat Inveetigationa

wore aabjeeted to ealealatioaa to eatabltab vhieb waoag tiM

1 t

• f •

paaatbla pkaaaa axlitl»lt«d a eanatfwer far iha aet lTt ty

prodaet of i t a iona. i t la avidant i lwt far tfoa plieaphata

••tttalttiBg i^at i tea aseft phaaaa ara tHa pr i«arf «•<! aaeondary

phaapkataa af tke e^tal eoneanied ia addftioa to tha apat i ta .

By analogy with a deabla a a l t , Ca2(ttP0^)(6R)2t a piiaaa

r«portad to eenlrol tb«'> aolubi l i ty predaet af aaleiaa

bydraxylapatita hy faaetloaing aa a aerfaee eeatlag* tlM»

ianle predaat of i t a load eoaatarpartyPto2(*'*^4)^^*'')9* * * * alaa

•alaatatad for tha praaaai ayatma. Exwainatioa of the data im

ao lab i l i i y af a l l the phaaaa naatioaad abava ravaala that ike

ioale prodaet of i^^atita ahovad a eonaiaaey over the aat ira

p ranoa ia ' taai i faiad aad the ealealatad aat of valnaa ware

faaad to l i e v i th ia tha error l i is i ta* I t ia evident that iha

eorreapondiag vaaadate phaaaa are raiavant far lead rwiadata

i ^ a i i i a vhi le tha phaaaa af both pboaphate md vaaadata ara

io be eonaidered far the ayatena iavolving the ao!id aolntioaa.

Saeh ealealatioaa aare done ea the data of aolubi l i ty of a l l

tkaaa aaaiptaa. That the apatite phaaa ew»tralled the aa lab i l i t y

vaa farther aapplaoeated by the faet that tha g aioa ratta»

Pb/(F^V)» of the? aataraled aolatioaa of a l l tha aaaplaa vaa

ta the proxitaity of the theoretiaal valaa (1*67) eonflrsiag

•aaabigaoaaly ataiahioaiatrie diaaoluti^B of apati tea. Aat r

addltioaal attbataatiatloa of thia fact vaa that the p ip valaaa

• f tlM aaaplaa arare foand ta be anaffeated by the addition of

tea iosa*

8 - • -

I t <o«ld b« OBtabllshod fsrtlier that tho

• o l a h i l i t y product of oaeh aaaiple of th* aarioa whila

roaaislaff eoBstsnt at a l l the p valaaa iaveatigated^

iaareasad ayatettatteally vttti aa inera««a ia the e<taat

of raplaeoaeat of FO. by ro]: • Aa iatorpretatioa of thoaa

raaalta eoald be presided by the eoaeept of sltoratioaa

ia l a t t i e o and hydratioa oaargiaa of loaie eryatal«

eonaoqaoat apoa iao8tor^he«a aabatitatloa*

^..

/r-

- 9 - 9

%^ A«S« PMiaar, e l t « d la <*PkoaphorBa and i t s Cini{»o«atfa*', ? • ! • XI» t d i t « d hf J . f t . r«a l a s e r , l a i e r a e l m e a Pttbl laftera, Xne. , ffaa Yorfcf pp* 1439-39 <196|}»

S* » • M a l l « r , » • ! « • ClitM* A9ia» 30 , 2069 ( 1 9 4 7 ) .

$* t »A . Roblaaaa, 4 . 84Hi« aat Jotat S a r g . , 34 , 389(1952) .

• # A .S , Foaaer, "Cbanleal sad Pkyaieal Naiare of Hoaa t l iaara l * * , (A tav i t f * Praa«at«d at a Canfaraaea held at Vftalilagtoa, i } . r . l a 1968) ( C . A . , 7 6 , 31276 t , 1972 ) .

8 . A. Kaapp«aat» NataralaaeaaeHaftaa, 43 , 477 ( 1 9 5 6 ) . ( C . A . , S3, 16217, 1959) .

4* e . Rayak* H . Maaaaely, s, Raaaaaiaafal aad B, Kr ianar , Maaa tMh. Cheia., ^ , 249 ( I 9 6 0 ) ( C . A . , 54 , 20599, I 9 6 0 ) .

7 . V . Boifd., "A Taxt-Boofe of Pa iho lagy* , Laa rabtgar* P h i l a d e l p l i l a . pn, 428«29 (1962 ) *

• • Madhn P h a l l timti ? ,^, Nigaa* Ttia Tox ic i t y of 8 io lo0 lea l l3r Eaaani la l and ^««-E«sant la l E laaaata , ladlKa J . Clias. 22 -28 , B ( 1 9 8 1 ) .

f . T . S . B . fTarMaraJa, R.P. Siagb aad V.L. I f . t a a , J.laorg. Nael* ClMa., 3<|, 2072 (1972).

'I

19. H.L. Waahbara aad M.J. Shaar, 4. Sial. Cbaai.,ff li, 99 (1932)

II. Arthar f. ?og«l, A. Tazt noak of Qasatltattva Taargaalt Aaalfaia laeladlag Eleataatary Inatraaaatal Analyaia, Third Fdlllos, P443, Rngllah taagaaga Sook Soeleif* Laa Prleed Taxt Hoak <196|).

13. €.J. tavlaakaa aad «.r« Maaaan* J« Pbya* Cbaa., 99, 164 (19S5).

13. J . S . C l a r k , Caa .J .Cbea . ,33 , 1696(1985) . .^^m\

n^ii 14* a . l i . t e a t a r a , f . t . D ia ls and F . 6 . Carpaatar / u i \.--^ J . C a l l a t d . S a . , JX • *''^ ( 1 9 6 2 ) . r^^ -v ^t?

1 9 . f . I . La l f a r , J . Pbya. Chaa, , 66 , 973 ( 1 9 6 2 ) . 4*w. cv