Titelbnlatt Für Sommer Newsletter

M E D I C H E M November 2001

Editorial of many chemical enterprises worldwide with a subsequent Honorary President: This November 2001 Prof. Dr.med. Dr.h.c. Alfred M. change in the professional Newsletter is the first to be Thiess issued by the new team of priorities of some people. Stephen Borron and Michael Others have just retired from Chairman: Nasterlack, who have been work. On the other hand, there Dr. Stephen W. Borron elected as Chairman and as seems to be too little International Toxicology Consultants, LLC Secretary respectively by awareness in our younger colleagues of the opportunities 2000 L Street NW, Suite 200 Medichem's members after the Washington, DC 20036-4924 (USA) stepping down of Noel and benefits which arise from a Phone: +1-202-588-0620 Humphry and Andreas Medichem membership, not Fax: +1-202-478-0444 Flückiger. During their periods least of all is a unique network in office our predecessors have of occupational health ------professionals and experts all delivered outstanding work Secretary: which was unanimously over the world who give each Dr. Michael Nasterlack acknowledged by the board other help and guidance in BASF AG members as well as by the many of the questions and DOA/WS, H 306 General Assembly during our problems associated with daily D-67056 Ludwigshafen (Germany) congress at Prague (see work. Thus, we see it as one of Phone:+49-621-604 2833 Fax: +49-621-609 3645 minutes of the General our primary tasks to enhance Medichem's visibility and Assembly in this issue). They ------left to us Medichem in attractiveness in the relevant excellent condition an they professional community and to Treasurer: have set standards of facilitate the future prosperity Dr. Andreas Flückiger (Switzerland) performance which will not be of our society by an increase in ------easy for us to achieve. active and interested members. Now, the two of us have taken To achieve this goal we do rely Board Members: over responsibility and we are on the support of every single grateful and proud that you, member and we do encourage Dr. L.J.N.G.M. Bloemen (Netherlands) the Medichem members, have everyone to actively participate Prof. M. Cikrt (Czech Republic) placed this confidence in us. in this by distributing and Dr. W.M. Coombs (South Africa) promoting Medichem's Dr. S.S. Guirguis (Canada) We will always strive to gain Dr. N.F. Humphry (Australia) this confidence anew and to objectives in your respective Prof. O. Jahn (Austria) serve Medichem and its countries, wherever you live. Prof. Y. Kudo (Japan) members as well as we can. Of Dr. T. Wai-Hoong Phoon (Singapore) course, we are well aware of Stephen Borron Prof. T. Popov (Bulgaria) the challenges that lie before Chairman Medichem Dr. T. Rajgopal (India) Prof. K. Rydzynski (Poland) us. Although Medichem is still Dr. A. R. Reid (U.K.) an active and healthy society Michael Nasterlack Dr. S.O. Salomon (Argentina) we have suffered a gradual loss Secretary Prof. F.W. Schmahl (Germany) of members in recent years. Dr. Leslie M. Yee (USA) This is obviously due to the fact that major reorganisations have taken place in the occupational health provision Medichem Newsletter Nov 2001 Pg 2

Prof. Alfred Thiess footsteps of great leaders (including those planned). It is is 80 years young before me was humbling, in this vein that I ask each of On October 3rd 2001 nothing could have prepared our members to look beyond Medichem's founder and me for the shock that followed the obvious risks in our Honorary President Alfred on September 11, 2001. While workplaces, most of which Thiess celebrated his 80th on the surface these two have been dramatically birthday. Born in events, the Medichem reduced through the efforts of Hermannstadt /Romania he Congress and the World Trade occupational health and safety came to Germany to study Center attack, may seem to be personnel working alongside medicine in Frankfurt. In 1954 unrelated, there are in fact ties. management. As was the case he joined BASF where 1963 he The Medichem Congress is a for the intelligence community became head of the meeting of professionals in the U.S., we in our world of Occupational Medical whose “job” it is to assure the thankfully diminishing Department until his retirement health and safety of workers occupational disease have in 1986. During this time he and the community in a setting perhaps become a little decisively influenced the where the potential for danger complacent. It is now development of occupational has always existed and will necessary that we seriously medicine in Germany by always exist: industries using consider the unthinkable risks: fostering occupational chemicals. Our society is what would happen if someone epidemiology, and dependent on potentially with a grudge decided to use strengthening health promotion hazardous chemicals for its my facility (as the hijackers and its evaluation. Besides, he very existence. From the used the huge fuel reservoirs in found the time to participate in petroleum that fuels our the airplanes) as a “chemical numerous national and machines and economies to the weapon”? Would a stick or international expert groups pharmaceuticals used to treat two of dynamite attached to a and, not least, to initiate anthrax, the world depends on reactor vessel or tank car in my Medichem. chemicals, and by extension facility lead to countless Dear Fred Thiess, we all depends on us, as health injuries or deaths? Even if congratulate you on your professionals, to protect them nobody died, would the panic achievements in the past and from their inherent dangers. that ensued from such an event wish you the very best for the What happened on that blood- result in significant suffering? future. May your untiring chilling day in New York and Are there chemicals or energy last for many more Washington demonstrated to biological agents readily years to the benefit of yourself, us in an indelible way that accessible in my laboratory your family, and of course for even the richest countries, with that could be easily adapted to us at Medichem. unlimited intelligence budgets, criminal use? Is the security in Dr. Michael Nasterlack, Ludwigshafen state of the art military my facility what it should be? (Germany) resources, and rigid safety If such an incident were to standards cannot always happen, how prepared would  prevent catastrophes from my facility, my local health happening. Likewise, we in department, my community be A letter from the Medichem will not prevent all to deal with such a Medichem Chairman chemically-related catastrophe? Do we have I never anticipated that in the occupational or environmental appropriate decontamination week after I became Chairman disease or even grave accidents facilities and plans? Are there of Medichem that my life, and due to chemicals. But as was enough antidotes to deal with perhaps all our lives, would be the case for the World Trade hundreds (thousands?) of so profoundly changed in such Center, the fact that we cannot injured? Do local physicians a short time. While the honor always control our destinies know how to treat exposures to of being bestowed with the should not cause us to waver in our products? Could we title of chairman of such a our resolve to reduce human communicate that information prestigious organization, with suffering and the risks of grave to them rapidly if they didn’t? hopes to somehow fill the accidents and incidents Medichem Newsletter Nov 2001 Pg 3

While this is not a time for Agenda Item 2: Approval of In 2001, for the fourth year, panic or paranoia, I believe it the minutes of the 2000 the membership cards in credit is a time to critically rethink General Assembly in card format were produced and the way we approach chemical Singapore sponsored by BASF. safety in industry. We have to The minutes as published in The current count of members consider that elements in our the November 2000 Medichem is 313 from 44 countries, down society who wish to exert Newsletter and sent out to all 25 members from 2000. That greater control over others may Members by Secretary number includes a total of 240 resort to chemical terrorism. Andreas Flückiger were members in good standing As such, we must be the accepted without amendment. (including 17 living honorary driving force, as the At this point, the Chairman members) and 21 exempted professionals whose “job” it is introduced the newly elected members, basically single to assure the health and safety Officers and Board Members members from countries of the of workers and the community, (cf. item 13) who were greeted developing world and officers to assure that the chemicals our with a warm applause. of the ICOH. 125 members industries use to produce good Agenda Item 3: Chairman’s have not yet paid their dues for things are not diverted for Report 2001, a fact that raises heinous purposes. It is up to us As all important activities of concerns about a probable to discuss these possibilities the Chairman are all covered further decrease of among ourselves and within by agenda items later in the membership. In August, a industry, to communicate with meeting, no formal report was reminder was sent out to these our physician colleagues in the presented at this time. colleagues. The deadline for community and to help them to Agenda Item 4: Secretary’s payment of the 2001 prepare for such eventualities, and Treasurer's Reports membership dues is Dec. 31, and above all to work to Since the 2000 ICOH 2001. Medichem has gained 18 prevent chemical incidents as Congress in Singapore, the new members but 43 have best we know how. Medichem Secretary has published 3 resigned, mainly because of and its members are leaders in Newsletters. The Secretary retirement and change of their protecting workers and the thanked all contributors to the professional activity. public from chemical risks of Newsletters and would be After 8 years in office, all kinds. That we will grateful for a steadier flow of Andreas Flückiger is now capitalize on this strength contributions from the general stepping down as Secretary during these trying times is my membership. As in the past 8 and is handing over this task to greatest hope. years, these Newsletters were Michael Nasterlack. Andreas Dr. Stephen Borron, Paris (France) produced by the Secretary and expressed his gratitude to all by Hoffmann-La Roche at no colleagues of Medichem who Minutes Medichem cost to Medichem. gave him support and who General Assembly, An update of the Medichem shared advice and friendship September 5th, 2001 Handbook was sent out last with him – especially all those Prague November. A new update will who served on the Board Present: 43 members in good be published along with the during these years, and those standing (quorum needed for next Newsletter. All Board with whom he worked most decisions: 30) Members are encouraged to closely: Chairmen David Chairman Noel Humphry advise the Secretary of any Williams and Noel Humphry opened the meeting at 4:15 necessary changes at any time. and Honorary President Fred pm. The cost of the past Handbook Thiess. Agenda Item 1: Approval of updates and their distribution Andreas Flückiger then agenda for 2001 Assembly was also borne by Roche. The presented the financial report The agenda as distributed by Secretary also organised and for the calendar year 2000. the Secretary was accepted hosted the 2001 Medichem Medichem is solvent and at the without further amendments. Officers' Meeting which was end of 2000 held a credit held on May 22, 2001 in Basel. balance of CHF 156,316.08, (USD 96,491.41). Medichem’s Medichem Newsletter Nov 2001 Pg 4 credit balance is up CHF Agenda Item 6: Funds for the Therefore, in the next year, 6,079.92 from December 31, Medichem Scholarships, the new efforts are needed to 1999. Expressed in USD, the Medichem Prize Scheme as increase the number of assets went up by USD well as for reduced sustaining members. A 3,753.04. The credit balance as subscriptions working party under Leslie of August 21, 2001 was CHF The funds that Medichem sets Yee was set up to develop a 163,941.08 (USD 97,580) and aside for the 2002 Scholarship proposal for making sustaining the assets at the end of 2001 and Medichem Prize Schemes or corporate memberships are expected to be at a level will remain unchanged, i.e. a more attractive. Any similar to those at the end of maximum of USD 2000 each contributions from the general 2000. The Treasurer’s for no more than 3 membership are most financial statement was found scholarships, and USD 250 for welcome. Contact to be in good order by auditor each of the 6 Prize contestants [email protected]. Walter Urbatus and was plus USD 500 for the Prize Medichem has gained few new unanimously approved by the winner. members in the past 12 Board. Of the total balance, Only about 10 members make months. The new Chairman, CHF 100,000 have been placed regular use of the scheme of Stephen Borron declared that it into a certificate of deposit and reduced membership fees was a top priority to stop this thus earn more interest than in which is comfortably within trends and reverse it. Various a regular savings account. the limit of 40 as it was means including the use of Whilst stepping down now originally established by the specialist marketing advice are from the position of Secretary, Board. Therefore no changes being considered. At the Board Andreas Flückiger will or decisions are necessary, but Meeting, Board members continue to act as Medichem's Stephen Borron's working made a personal commitment Treasurer. party (cf item 5) will also re- to recruit 3 new members each Chairman Noel Humphry evaluate this programme. during the next year. An expressed the Board’s appeal was made for each appreciation for the work done member of the general by the Secretary-Treasurer. Agenda Items 7: Membership membership to also attempt to The Assembly thanked drive recruit one new member within Andreas Flückiger and his wife In 2000, eight companies paid the next 12 months. It is hoped who assists him with the a total of USD 7,453 in that by holding the next Treasury with a big round of sustaining membership fees. In Congress in the US, a group of applause. 2001, the following companies new members from this Agenda Item 5: Individual have so far paid their country will join Medichem. Memberships for the year sustaining membership dues: Agenda Item 8: The role of the 2002 Solvay, Hoffmann-La Roche, National Representatives The Board Meeting, at its Dow, Novartis, Boots, DSM, (NRs) meeting on Sept. 3rd, decided the Employers’ Union of the Andreas Flückiger gave a brief to leave the individual German Chemical Industry (all historical summary of the role membership dues for 2002 USD 1000), BASF (USD 500), of the NRs. Much of this role unchanged at USD 50. A and very recently, also the has been lost over the past working party chaired by German BG Chemie (DEM decade and most of the NRs Stephen Borron was estab- 3000, i.e. about USD 1500) are now non-functional. At lished to review Medichem's and Prosar (USD 250). their meeting on Sept. 3rd, the individual membership dues Borealis is no longer a vast majority of the Board and in particular the structure sustaining member. On the Members expressed their of reduced membership fees. average, over that past years, opinion that the concept of Any members wishing to almost half of Medichem's having NRs was good and contribute to the discussion are income has resulted from should be maintained if kindly asked to contact sustaining memberships. The possible. Several colleagues Stephen Borron loss of a single member makes from the General Membership ([email protected]). a big difference for our budget. spoke up, all of them also in Medichem Newsletter Nov 2001 Pg 5 favour of maintaining the NRs. Marriott Hotel in the Inner ICOH Scientific Committee on It was said that they could act Harbor area. Sunday will be OH in the Chemical Industry as national focal points for planned as an overlap day, i.e. and would therefore have to go initiatives to be carried out Medichem and ACOEM will through an ICOH approval locally or brought forward to hold joint meetings. Co- process. the Board, assist the Secretary operations are being set up Agenda Item 12: Medichem on and Treasurer in their with other reputable American the internet administrative tasks (address institutions and the programme Thanks to Noel Humphry and changes, chasing up those who should be excellent. Les Yee's his assistant Kerry Campbell, do not pay), but it was also efforts in this matter were Medichem now has an pointed out that this was only acknowledged by a round of attractive site on the internet. possible if the NRs were applause. The address is closely tied in with the national Agenda Item 10: 2003 and http://www.medichem.org.au. networks of professional 2004 Congresses All Medichem members are organisations active in The 2003 Conference will be encouraged to visit this site occupational health. organised by the ICOH in Foz and send any comments and Thirumalai Rajgopal agreed to do Iguaçú, Brazil. It will take suggestions directly to Kerry act as the Board member in place at an extraordinary time, ([email protected]). Noel charge of the NR issue and namely not in has agreed to continue acting take the following first steps: August/September as usual, as Medichem's webmaster. a) write to all those on the but from February 23rd to 28th. Since someone unaware of present list of NRs and ask A website has been set up at Medichem's internet address them whether they are willing www.icoh2003.com.br where would not necessarily look for to fulfil the specific tasks of a further information is Medichem in an Australian site NR. b) For key countries or available. Registration is ("au"), Noel, with the help of regions without a NR, contact already possible. Stephen will check out one key national professional Sergio Salomon will assist whether the owners of society active in the field of Medichem in organising a "medichem.org" would be occupational health and ask venue for the General willing to install a link to our them to nominate a liaison Assembly and in setting up a "medichem.org.au" address. person who would act as NR. Mini-Symposium if this is Noel will also investigate Contributions to this once again requested. whether "medichem.int" and discussion are most warmly Informal proposals for the "medichem.pro", two new welcomed from anyone. venue of the 2004 Medichem suffixes, are still available. Contact Conference have been received It was pointed out that e-mail [email protected] and are under evaluation. The addresses are known for about om. meeting is likely to be held in one third of the Medichem Agenda Item 9: 2002 Europe. membership only. Since e-mail Medichem Congress Agenda Item 11: Position communication will become Les Yee reported on the Papers more and more important and progress of the preparations of Because of more urgent can also save a lot of the cost this meeting. Medichem will matters, there has been no of printing documents, all hold its annual meeting in action in the past year on this members are asked to send Baltimore, MD, from Sunday, agenda item. It is however still their e-mail addresses to October 27th through Wed., the intention of Medichem to Medichem's new Secretary at Oct. 30th, 2002. That will be pursue this idea, be it by michael.nasterlack@basf- immediately following and at simply providing internet links ag.de. the same venue as the ACOEM to existing good position Agenda Item 13: 2001 and (American College of papers of other organisations, 2002 Board Elections Occupational and be it by developing position At this meeting, the following Environmental Medicine) papers of its own. Position Members are leaving the SOTAC (State Of The Art papers of Medichem would Board: Leo Miksche, Kalle Conference), held at the also be position papers of the Ahlberg, Abed Bin Onn and Medichem Newsletter Nov 2001 Pg 6

Hugo Rüdiger. Thanks were Efthymiou was unable to in Baltimore at the end of expressed for their valuable attend the ceremony conducted October 2002. The exact date contributions. by Medichem's Honorary and venue remain to be In a written ballot held in President, Fred Thiess. In his determined. June/July, Stephen Borron address, Fred acknowledged Dr. Andreas Flückiger, Basel (Switzerland) (USA) was elected the new the outstanding contributions Chairman of Medichem and of Marie-Louise and Kalle to  Michael Nasterlack (Germany) Medichem. Marie-Louise is a became Secretary. Newly founding member of Duodenal cancer in a elected Board Members are Medichem and was on its worker exposed to Oswald Jahn (Austria), Board for 25 years. She also acrylonitrile Thirumalai Rajgopal (India), organised Medichem's 10th A worker who is now 65 years Konrad Rydzynski (Poland), Congress in Paris in 1982. old and who has a history of 3 Sergio Salomon (Argentina) Kalle worked on the Board for decades of acrylonitrile and Friedrich Schmahl a similarly long time, was exposure was diagnosed with (Germany). Board members Medichem's Secretary for duodenal carcinoma when he re-elected are Teo Popov many years and also acted as was 54 years old. The case was (Bulgaria) and Andreas organiser of the 16th Medichem referred to the Department of Flückiger (Switzerland, as Congress in Helsinki in 1988. Occupational and Social Treasurer). According to the Marie-Louise and Kalle Medicine, Tübingen, to Constitution, Noel will serve received a certificate of establish whether there is a another year on the Board as Honorary Membership. possible relationship between Past-Chairman before he has to Agenda Item 15: the history of acrylonitrile leave the Board in 2002. Miscellaneous exposure and the cancer in In 2002, the terms of office of This was the last General question. the following Board Members Assembly for Noel Humphry will end: Louis Bloemen, as Chairman and from Andreas In 1990, Mr. FW was Murray Coombs, Sam Flückiger as Secretary. The diagnosed as having an Guirguis, Yoshiro Kudo, General Assembly thanked obstructing parapapillary Timothy Phoon, Alan Reid and both with repeated warm duodenal cancer. Leslie Yee. A call for applause. Noel thanked the Histologically, the tumour was candidates will be sent out by Medichem members, Board a moderately well the Secretary, as requested by members, David Williams, differentiated adenocarcinoma. the Constitution. Fred Thiess, Andreas No metastases were found. A Agenda Item 14: Honorary Flückiger, Marta Flückiger and duodenopancreatectomy Memberships 2001 Tala Humphry for all the according to the technique of The Secretary has received two support given to him during his Whipple was performed and, proposals for the nomination terms of office as Chairman. in addition to the tumour, a of two new Honorary Fred Thiess gave an address mild chronic gastritis was Members. These proposals honouring the efforts and found which was negative for were signed by the required achievements of both and also Helicobacter pylori. The number of 20 members in good pointed out the support Noel patient also had a history of standing. The individuals to be and Andreas had received from possible gastric ulcer and honoured by Honorary Life their wives. Fred handed a coronary heart disease. From Memberships of Medichem are beautiful bouquet of flowers to 1961 until he fell ill in 1990, Prof. Marie-Louise Efthymiou them and a framed antique FW was employed in a small of France and Dr. Rolf (Kalle) map of the world to Noel and enterprise producing Plexiglas. Ahlberg of Finland. one of Europe to Andreas as a He worked shifts mainly at The announcement of the two token of recognition. polymerisation water basins. names was accompanied by He was exposed to long applause. The Chairman adjourned the acrylonitrile and methyl Because of urgent other meeting at 5:30 p.m. The next methacrylate. When commitments, Marie-Louise General Assembly will be held occupational exposures were Medichem Newsletter Nov 2001 Pg 7 measured, methyl methacrylate throughout the whole body adenocarcinomas of the exposures did not exceed one without accumulation in any duodenum. As no significant tenth of the OEL. For this specific organ. increase in tumour incidence reason, it is assumed that there was detected in were not overexposures to this FW's cumulative exposure epidemiological studies on compound. On the other hand, over 29 years of working life is workers occupationally some of the acrylonitrile air between 49.3 and 104.4 ppm- exposed to acrylonitrile, it is of monitoring data taken near the years, depending on whether particular interest to discuss to polymerisation basins in the the lowest or highest exposure what extent animal studies are 1980s showed exposures in data are assumed to be relevant for human exposure excess of the OEL (technical representative. Dermal and situations. It is assumed that guidance limit, TRK). oral exposure must be added to humans have an additional Furthermore, hygienic this inhalative exposure. detoxification pathway for conditions at the workplace Furthermore, it must be acrylonitrile that rodents do were not good and a massive assumed that FW's exposure not possess, but it seems that dermal and possibly also oral was higher in the 1960s and only very limited quantities of exposure to acrylonitrile must 1970s than it was in the 1980s acrylonitrile are metabolised be assumed. Compared to when it was first measured. through this additional those of his colleagues, FW The present state of knowledge pathway. It appears that all in had high biomonitoring results does not allow an assessment all, the results of rat studies do for urinary acrylonitrile and as to potential adjuvant not allow to draw conclusions cyanoethyl cystein. (additive or potentiating) as to the probability that effects of methyl methacrylate similar effects will appear in Assessment exposure to the carcinogenic man. Only 1 to 3 per cent of potential of acrylonitrile. malignant tumours of the Coggon and Cole conclude gastro-intestinal tract are All in all, epidemiological that it is very difficult to use located in the small intestines. studies published to date do epidemiological studies as a Among the malignant tumours not show a carcinogenic effect means of demonstrating that a of the small intestines, of acrylonitrile in man. Some compound is not a human adenocarcinomas are most partial results are of interest as carcinogen. On one hand, they frequent and represent 45% of they show that certain types of interpret the presently the cases. FW had no genetic tumours appear – however, not available data to conclude that risk factors and he had stopped always significantly – with a either acrylonitrile is not a smoking 13 years before the higher incidence than human carcinogen or that it diagnosis of his illness. As expected, although only in only leads to a small increase there is only mention of a those individuals with in cancer risk in man. On the possible peptic ulcer but no particularly long exposure other hand, they call for further data are available, it histories. Such tumour excess additional epidemiological remains uncertain whether this data also exist for tumours of studies to further substantiate might have played a role in the the small and large intestines their interpretations. These development of the cancer. as a whole. Acrylonitrile is an new studies should mainly animal carcinogen. The focus on workers with The German list of MAK experiments do not show a true cumulative exposures of more values has acrylonitrile listed organotropism, both as a result than 10 ppm-years. This is the with a TRK of 3 ml/m³ (ppm) of exposure in general or as a order of magnitude of or 7 mg/m³. Acrylonitrile is result of specific routes of exposure that Mr. FW was classified as a category 2 absorption. After oral and subjected to. The presently carcinogen. Acrylonitrile is inhalative exposure, rats available epidemiological readily absorbed by inhalation, developed amongst others, studies show shortcomings: through the intact skin and via tumours of the brain, the generally smoking status and the gastro-intestinal tract. In Zymbal gland and the fore- other workplace influences rats, acrylonitrile is distributed stomach as well as were not taken into Medichem Newsletter Nov 2001 Pg 8 consideration, exposure data ppm-years. They should also Oct. 27-30, 2002, Baltimore, are incomplete, the collectives include workers from small Maryland (USA) contain workers with greatly and medium size enterprises. XXX Medichem varying degree of exposure, Furthermore, it would be Further information will be the study populations also helpful to have data on the available shortly. contained workers who had effects of acrylonitrile in been exposed for no more than animals other than rats.  6 months. More recent publications are often nothing but reviews of earlier studies. Many studies cover workers Literature: from larger enterprises where 1: Esmen NA: Exposure worker health protection might estimation in four major have been better than in epidemiologic studies in the workplace settings of smaller acrylonitrile industry. Scand J companies. For the assessment Work Environ Health 24 of the duodenal cancer (1998), Suppl 2, 63-70 diagnosed in Mr. FW, it is 2: Coggon D, Cole P: important to know how Acrylonitrile and human tumours have been classified cancer – an overview. Scand J in epidemiological studies. Work Environ Health 24 These studies do not (1998) Suppl 2, 81-82 differentiate figures for small Dr. Doris Braun Prof. Friedrich W. Schmahl bowel tumours. Therefore, (Tübingen, Germany) they do not provide an answer to the incidence of such  tumours, and are thus not helpful in interpreting Welcome to New mortality from duodenal Members cancers in acrylonitrile Dr. Bernhard Schumacher, exposed workers. Dow Chemical, Stade (Germany) In conclusion, a causal Prof. Marco Maroni, relationship between the high International Centre for acrylonitrile exposures of Mr. Pesticide Safety, Milano, Italy FW and the duodenal tumour Dr. Mark Roberts, BP Amoco, cannot be ruled out, even Lisle, IL (U.S.A.) though human epidemiological Dr. Donald C. Cook, studies published to date do Shoreland Inc., Milwaukee, not demonstrate a significantly WI (U.S.A.) increased risk for this type of Dr. Martina Piasek, Inst. for cancer in acrylonitrile exposed Medical Research and Occ. individuals. However, it is also Health, Zagreb (Croatia) not possible to show a causal Drs. Jaroslav Mráz, Marián relationship with the necessary Rucki, Pavel Soucek and Pavel degree of probability. Further Vodicka: SZU, National epidemiological studies would Institute of Public Health, be needed to better assess the Prague (Czech Republic) probability of a causal relationship. These studies  would have to focus on workers with cumulative Forthcoming Events exposures of more than 10