Document mbdYyqnK82rm9w8epqp4MmrM4

s*ens 5tehendes Aktenzeichen angeben) Par Staatfichej Gewerbearzt, 463 Bochum, Marienpiatz 2 Mr.Robert A.Kehoe, M. D Professor of Occupat.Med. College of Medicine Eden and Bethesda Ave. Cincinnati, Ohio 45219 o j Fernruf 60575 - 79 Postscheckkonto Dortmund 32799 Pear Professor Kehoe! Many Thanks for your kind letter of 15 dec. 1970. A copy of the final communique'of the Amsterdam~conference is added. In this paper you may see the recommended limit values being for ALA 10 rng/1 and for 6PTJ 300^/ug/l. The limits should not be * exceeded but for short periods. As they are only slightly higher, than upper normal limits (M+3s = 8 . mg ALA and 250 yag CPU/l) the matter will lead to extreme difficulties in factory inspection. A report on the Amsterdam- conference including the "final Paper" published in Arbeitsmed.Sozialmed. Arbeitshygiene 4, 56,1969 With best wishes for the new year Sincerely yours / u efcejsys-sry, v ^t bXo pb^mmr /; great wealth of possible bioch0 parameters- provide Insight tho effects of lead on biological systems* ' Relatively fey of tlios have been, used up- to now frequently enough, to provide data for their use as- biology permissible limits* .Spiasinf logical study should bo promoted* if. possible oa sa international basis * in those parameters that- have a ~ relatively high .specificity" - relatively Mgh sonaltivity .. in regard to * beginning exposure ~ current exposure .raid long-term exposures - post exposurec She cybernetic approach should be promoted in the study of industrial to.xicol.og5r; it say increase the understanding of functional behaviour of biological systems* the combined increase of Ana and C? in urin and P0P* in srythroeytee is highly specific for the action of lead* fconoept of poisoning * Poisoning 5.a present if physical9 mental and/or social well being has been impaired? it supposes the presence of clini cal symptom and signs* bo Hie diagnosis of lead poisoning should be based upon well informed clinical judgement? the use of the term poisoning should be restricted to the above definition* 3o One should distinguish, between parameters indicating absorpv tidn. and parameters indicating response* She-response can be classified into three phases? acceptable; exposure below permissible limits excessive? exposure beyond permissible limits* 'where * poisoning may occur dangerous; Exposure beyond permissible limitsv where poisoning is likely to. occur * HE 0018372 N19535.01 .i-lz tioSexperta should study the_ establishment of the re lationship fcetweaft exposure -> absorption - responses they should lay down acceptable medical criteria.; 3?he practical blilty of this in different societies' and cultures may depend cn socic-ecoaoiaic factors' -and. other non-medical criteria, but. should always be considered in the light of expert isedleaX advice,, . There is sufficient correlation between, certain parameters, to permit calculation of interrelationships and hence permissible limits* . Chronic effects, 1; Present svidena suggest that industrial standards which prevent cases of lead poisonings oven after many years of exposure* also prevent long term sequelae* further, under-' standing of this problem may follow froio. epidemiological studies in groups cf vxorhers under less gatisfno to ry oondi-- tiono8 pari'ioulary by following up hnowu eases of poisoning* fro * grij.vn ---a Att tuxrcation in establishing permissible limits for lead in air most .reliance' 'should- be given to data bases upon personal sampling* Results should be qualified by particle else end composition cf the dust* . '* 2,- If absorption is to be acceptable the blood lead concen tration should fca below.?0 ^ug/IGO ml* which v/111 prevent I any untoward effect of lead* This corresponds to values fors I All ,\t 10 iag/1 CPU ,~J 300 /Cg/l I PbU /v' 130 yng/1 Pb in air 150 yisg/m^o I* fhses values .are solely guides* Because of the wide canfid once limits of the calculations no undue emphasis should be placed upon a single parameter* -;-o nnere there is adequate medical supervision above mentioned hhlilhl-ll'-y.b-a s&ightly exceeded for short periods * .-o -iuovc Lua^caea values only apply for a population at worh not being-treated with chelates* K% 001S373