|
|
|
|
||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||||||||||||
|
 |
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
Present:
ITEM 1: APOLOGIES FOR ABSENCE/ANNOUNCEMENTS 1. Apologies for absence were received from Dr R Roberts, Dr L Hetherington (DH), Mrs M Meldrum (HSE), Mr H Stemplewski (MRHA), Mr A Browning (VMD) and Mr R Alexander (WAG).
2. The Chairman noted that this was Dr Kennedy's last meeting as a member of the committee as she had now completed 3 terms of service. He thanked Dr Kennedy for the valuable advice that she had provided over the years. 3. The Chairman welcomed the officials attending from Government Departments and the DH Tox Unit, and Drs S Barlow and Iona Pratt, who were representing the EFSA AFC Panel. 4. The Chairman also welcomed the members of the public who were attending as observers. He reminded them that they may not participate during discussion of an item but would have the opportunity to make a statement and to ask questions at the end of the item. Any questions should be put to members through the Chairman. He also asked them to note that it is the practice of the committee not to attribute comments to a particular member and that no recording equipment should be used. 5. Members were reminded of the need to declare any relevant interests before discussion of items. ITEM 2: MINUTES OF THE MEETING OF 14 JULY 2005 (CC/MIN/2005/2) 6. The minutes were agreed subject to the following corrections and clarifications:
It was noted that the EU committee report referred to in para 19 had now been published and the secretariat was asked to include the reference. ITEM 3: MATTERS ARISING NOT COVERED BY LATER AGENDA ITEMS
7. Dr Carthew declared a specific, non-personal interest. The secretariat explained that, during the horizon scanning discussion at the last meeting, members had discussed whether to address issues appearing in the media in relation to chemical carcinogenic risks. An example was the hypothesis that the preservative parabens, stated to be used in underarm deodorants and antiperspirants, was absorbed through the armpit and was a possible cause of upper outer quadrant breast cancer. However, members had decided to review breast cancer in general. A member who did not attend the last meeting reported that the European Commission's Scientific Committee on Consumer Products had recently reviewed the parabens hypothesis and had concluded that, in the light of the present knowledge, there was no evidence of demonstrable risk for the development of breast cancer caused by the use of paraben-containing underarm cosmetics. It had been informed by the relevant Trade Association that 98% of underarm cosmetics do not contain parabens as preservatives (SSCP/0874/05, January 2005, http://europa.eu.int/comm/health/ph_risk/committees/04_sccp/docs/sccp_o_00d.pdf). A member noted that antiperspirants are self-sterilising and do not require preservatives.
8. The secretariat noted that the committee had addressed this subject on a number of occasions although no definitive conclusions on ranking have been reached. The current paper proposed a scheme for ranking the potency of single exposure genotoxic carcinogens. As a first step, the relative ranking of genotoxic carcinogens using chronic life-time bioassay data and single exposure studies would be compared and an acute T25 might be developed. It was proposed that the nine most commonly studied chemicals in the Calabrese database could be the subject of a pilot study. Unfortunately, Dr Calabrese had not replied to a request from the secretariat for the information used to compile his database. Members were asked whether they could suggest a way forward. 9. Members acknowledged that there was a real issue about what advice could be given to the public following a single exposure to a genotoxic carcinogen e.g. after an accidental release. A member reported that he had contacted Dr Calabrese who reported that he still had the database and was happy to pursue further work. However, the software would need upgrading before interrogation of the database could be progressed and this would require funding. Members noted that potency ranking of genotoxic carcinogens by using molar doses instead of mg/kg bw/day might alter the ranking order. The example of urethane was quoted from the current paper. 10. Members considered that a number of issues would need to be explored for the proposed ranking scheme to be helpful e.g. does linear extrapolation hold up for a range of single dose levels, do tumours occur in the absence of cytotoxicity. However, they agreed that the pilot project should go ahead. ITEM 4: ROYAL COMMISSION ON ENVIRONMENTAL POLLUTION (RCEP): CROP SPRAYING AND THE HEALTH OF RESIDENTS AND BYSTANDERS (CC/06/1 and addendum) 11. The COT and COC have been asked by the Advisory Committee on Pesticides (ACP) and Defra to provide toxicological advice on the report published by the Royal Commission on Environmental Pollution (RCEP) on crop spraying and the health of residents and bystanders. The report was commissioned by the Rt Hon Alun Michael (Defra Minister) in June 2004 in response to concerns raised by stakeholder groups about buffer zones to protect bystanders from crop sprays, and was published in September 2005. Members heard that the COT had discussed the RCEP report on the 14 February and had made a number of comments. It had noted that occupational exposures would be considerably higher than those experienced by bystanders and/or residents. The COT had also noted that there were a number of possible epidemiological approaches which could be used such as investigation of para-occupational exposures (such as those of spouses and children of farmers) and that further investigations of genotype/phenotype in self reported bystanders with self-reported illnesses could, if appropriate controls were available, help to identify hypotheses for further epidemiological investigation. However, the COT had considered that it would not be feasible to develop animal models for multi-system diseases at this time because members were aware that all pesticides undergoing approval would be tested for potential carcinogenicity in rodents. 12. The Chairman asked for any general comments and for comments on paragraphs 2.20-2.34 of chapter 2 of the report which dealt with epidemiology and referred to cancer epidemiology and the COC statement on prostate cancer. The Chairman noted that the ACP had recommended further research in respect of prostate cancer (meta-analysis of cancer incidence in manufacturers to identify potential pesticide active ingredients). 13. Members noted that the RCEP had not had time to undertake a rigorous evaluation of all the available epidemiological literature. Members commented that the RCEP report had not clearly distinguished between hypothesis generating studies (such as geographical studies of clusters e.g. as undertaken by the Small Area Health Statistics Unit (SAHSU)) and analytical studies which could be used to define dose-response relationships for pesticides associated with cancer and were of importance in the assessment of causality. After seeing an independent review of the Ontario College review of published papers, the RCEP had recommended that a definitive review should be carried out. Members recalled that the main problems identified with regard to the Ontario review were the selection of data used in it, which did not include available negative data as well as studies reporting positive associations for cancer, the selective interpretation of results, and the lack of good exposure data in most studies. This last problem could not be remedied in a future review. 14. Members agreed with the RCEP that better exposure measurement in cancer epidemiology studies was a high priority for further research. Members agreed that further evaluation of para-occupational studies would be valuable, but that using status such as married to farmer as a proxy for para-occupational exposure limited the value of such studies in identifying association with pesticide exposures. This was because exposures in these groups were difficult to assess and few appropriate data were available. Members agreed that biomonitoring data would be helpful in this regard. The secretariat noted that Pesticide Safety Directorate (PSD) was to undertake initial biomonitoring studies using cypermethrin and chlorpyrifos. Members agreed that this would be helpful in establishing exposure of bystanders and for method development but considered there was a need for a wider biomonitoring exercise, particularly if such data were to be linked to geographical studies of cancer incidence. However, members noted that such a study would be difficult to undertake, particularly the linking of biomonitoring data with cancer data, not least because exposure at the time of cancer diagnosis might have little relevance to that which could have been causal. Members commented on the potential value of bystanders and residents taking appropriate samples when an incident had occurred. 15. The Chairman asked members to consider the recommendations on the health aspects of chapter 2 of the RCEP report. Members doubted that a comprehensive systematic review (2.66 & 6.21) would be valuable in view of the deficiencies in exposure measures but agreed on the need for better population biomonitoring data. It was not considered that additional encouragement for the development of newer animal models for cancer was required at the present time (6.24), particularly in the area of cancer hazard identification. 16. The secretariat noted that draft minutes and a draft working paper would be circulated to members for comments so that a paper could be provided for the COT meeting on the 28 March 2006. 17. The Chairman asked observers if they wished to comment. Ms Downs commented that there were a number of factual inaccuracies in CC/06/01. The case she had consistently presented was that residents and bystanders are two different exposure scenarios. A bystander may only receive occasional short-term exposure, whereas a resident could receive repeated exposure to mixtures of pesticides over the longer term, sometimes decades. In relation to exposure of rural residents and communities, all exposure factors need to be included in the exposure calculations and not just exposure related solely to immediate spraydrift. Pesticides had been shown to travel considerable distances: a study from California had found pesticides located up to 3 miles away from pesticide treated areas and had calculated health risks for rural residents and communities living within those distances. Examples of reports of adverse health effects in individuals exposed to pesticides are available on a video made by Ms Downs, seen by Royal Commission members, copies of which could be made available to COC members. The Chairman agreed that the matter required attention and hence the Committee had considered the RCEP report. 19. Ms Craig asked whether the committee supported widespread biomonitoring of the UK population. The secretariat noted that the current PSD proposal was for focused work on two specific active ingredients. The Chairman considered that there was a case for wider population biomonitoring for pesticide exposure. The Chairman noted that the COC's role was to provide scientific advice. Decisions on funding of research were for Government Departments and Ministers. Members noted that geographical cancer incidence studies would be helpful in hypothesis generation but would not demonstrate causal effects. The COC had recommended additional exposure collection to the Biobank project whilst the study was being been devised and the comments had been incorporated into the development of the Biobank project. However, even studies of the size of the Biobank project would have limited power to detect associations between some rare forms of cancer and pesticide exposure in populations such as the U.K. The Chairman asked Ms Craig to forward any further comments to the secretariat. ITEM 5: RAMAZZINI STUDY ON THE CARCINOGENICITY OF ASPARTAME (CC/06/6) 20. The secretariat explained that aspartame is a widely used artificial sweetener which was initially approved in 1982 and which has been reviewed on several occasions subsequently. It was most recently reviewed in 2002 by the Scientific Committee for Food which had considered the data which had become available from 1989 onwards and had concluded that there was no need to revise the previous risk assessment or Acceptable Daily Intake. 21. In July 2005, a group from the Ramazzini Institute had published a carcinogenicity study which suggested that aspartame was associated with an increase in lymphomas and leukaemias in rats. The study protocol was unusual, allowing the animals to reach a natural death rather than sacrificing them after 2 years treatment; and utilizing a very wide dose range. The COC considered the publication at the July meeting and expressed a number of concerns about the study. A second, more detailed, paper was published by the group in November 2005. This paper expands on the initial publication and reports tumours in the kidney, nervous system and peripheral nerves and hyperplasia of the olfactory epithelium. The European Food Safety Authority (EFSA) had requested and received the full study report and will be undertaking a full evaluation of the study in the context of previous safety data. As part of this process the Food Standards Agency was seeking the views of the COC, in particular on:
The views of the Committee will be passed on to EFSA to assist in their detailed consideration. 22. Dr Carthew declared a personal, non-specific interest. Drs Kennedy and Wallis commented that aspartame might be used in other parts of the organisations for which they worked and, therefore, declared indirect non-personal, specific interests. 23. Members made the following general comments about the Ramazzini study:
24. In respect of the main findings, the committee concluded:
Overall, Members concluded that, in view of the problems in the design of the study and some concerns about the microbiological status of the colony, it was not possible to draw conclusions about the potential carcinogenicity of aspartame from the results. 25. The committee asked for the following information to be provided to clarify several points:
It was noted that it was also possible to request the NIEHS pathologists' report on the histopathology from the NTP. 26. The Chairman asked observers if they wished to comment. Professor
Millstone commented that the committee had only addressed whether the
study was giving false positive results, not that it might be underestimating
risks. He considered that this demonstrated a systematic bias in the discussion.
He produced a series of studies which he claimed demonstrated that the
original safety studies carried out on aspartame were deficient. He submitted
copies of these and asked whether the committee would consider them. The
Chairman explained that the committee was usually tasked by the secretariat,
although, in answer to a question from Ms Craig, he confirmed that members
could also raise issues for consideration. The secretariat reported that
a copy of Dr Millstone's papers had already been passed on to EFSA, which
was evaluating aspartame at present. 27. Mr Williams explained that some of his constituents had expressed
concerns about the safety of artificial sweeteners, including aspartame.
He thanked the committee for allowing him the opportunity of hearing the
discussion. He had visited the Ramazzini Institute and could report that
pelleted diet had been used in this study, and replaced daily. He expressed
surprise that the health status of the animals was not raised in previous
studies from the Institute (although it was noted that the previous studies
had not been subjected to the same degree of scrutiny). Mr Williams emphasised
that it was important for the public to have confidence in the approval
and review process and the work of EFSA. 28. Mr Levidow asked whether the same degree of scrutiny had been given
to previous studies on aspartame and the secretariat agreed to write to
him on this point. Ms Downs asked the COC Chairman why the COC did not
meet more often than three times a year, considering the seriousness of
cancer, its increasing prevalence and the need to determine the causes.
The Chairman explained that the work required for the meeting, such as
writing of papers, was resource-intensive and, therefore, limited the
number of meetings which could be held. ITEM 6: HSE DISEASE REDUCTION PROGRAMME: PROJECT ON CHEMICAL CARCINOGENS
(CC/06/7) 29. HSE provided the committee with a brief update on the progress being
made as part of a high priority initiative to identify the scale and reduce
the incidence of occupational cancer. Members were provided with a presentation
which illustrated the different aspects of this work. One important aspect
of the work is to improve HSE's estimate of the burden of occupational
cancer, and to update figures derived by Doll and Peto. HSE indicated
that this work was ongoing and that more details could be available for
the committee in the autumn. HSE would discuss with the Secretariat how
the committee might best be consulted. A second strand of the initiative
was, for definite and probable carcinogens, to analyse toxicological evidence
and details of use and control with a view to identifying priorities for
risk reduction activity. This included an element of carcinogen potency
ranking. A stakeholder workshop is being planned for Spring 2007 to facilitate
this. HSE invited members of the COC to work with them to influence the
process over the next 6-7 months. As examples of the type of toxicological
data being gathered, carcinogen summary sheets were presented on 3 carcinogens:
acrylonitrile, rubber process fume and dust, and beryllium and beryllium
conmpounds, 30. Members were pleased that risk, not just hazard, was being taken into account by HSE. Members asked whether the carcinogen toxicology profiles would be made public. HSE was also asked about arrangements to peer review these profiles. HSE explained that those profiles already drafted were available to anyone on request but had not yet been published (e.g. on the internet). Options for peer review were still being considered. In answer to a question from a member of the committee, HSE said that there was no register of workers in the UK who had been exposed to occupational carcinogens. One useful source of data was the CAREX database. HSE was also gathering new information about the supply of carcinogens. ITEM 7: TESTICULAR CANCER (CC/06/3) 31. The secretariat reminded the committee that, at the 2005 horizon scanning discussion, it had decided to review the possible chemical aetiology of testicular cancer. This paper was intended to be an overview of background information and risk factors in testicular cancer to help the COC identify areas for further discussion. 32. The key conclusions from the paper were:
Members are asked whether there are any areas relating to chemical aetiology which it would be useful to review in more detail. 33. Members congratulated the secretariat on the quality of the review. It was noted that those men in white-collar jobs were likely to be of higher socio-economic class that those in blue-collar jobs and, therefore, these two sections should be linked. In relation to survival, Members commented that older men tend to get spermatocytic seminoma, which are harder to treat than the common tumour types seen in younger men and that this may impact on prognosis . It was noted that the amount of oestrogen in cows' milk had increased over the last 25 years. If intake of milk was also increasing, this could be a possible risk factor. The secretariat was asked to find out whether there was any further information on this. 34. It was reported that, at the recent COT seminar on adverse male reproductive effects, the predominant view was that the problem arose in utero and that, if the increase in testicular cancer was part of the testicular dysgenesis syndrome, a wider approach would be needed to understanding the cause(s). There was evidence of genetic predisposition to testicular cancer, with the gene responsible being carried on the X chromosome, but this did not explain why the incidence had increased. 35. It was suggested that Dr R Sharpe at the MRC Human Reproductive Sciences Unit should be approached for a view. No clear chemical aetiology was identified. ITEM 8: DRAFT REPORT OF THE COT WORKING GROUP ON VARIABILITY AND UNCERTAINTY IN TOXICOLOGY 36. The secretariat explained that, in 2003, the COT decided to review
the current approaches, or those that might be used in the future, for
dealing with variability and uncertainty in the biological data used in
the risk assessment of chemicals in food. It set up a new working group,
the Working Group on Variability and Uncertainty in Toxicology (VUT) to
consider the issue. This paper is the second draft of this report which
will be finalised and circulated for consultation shortly. It was noted
that there was little in the report which was specific to carcinogenicity
but the COC was being asked for comments as part of the consultation process.
In particular, members' views were invited on the recommendations for
further work and those in relation to policy. 38. Other comments were:
ITEM 9: COC ANNUAL REPORT 2005 (CC/06/5) 39. Members were asked for comments on this draft of the COC's annual report for 2005. 40. Members asked that the view reported in 3.5, that the increase in neuroblastomas in children was thought to be largely in benign tumours, in children under 1 year of age and due to better diagnosis, be checked. 41. The section on the paper by Knox (paras 3.8 - 3.9) should be shortened. ITEM 10: ANY OTHER BUSINESS 42. It was noted that this was the Chairman's last meeting after 10 years of service. The Members and secretariat thanked the Chairman for his work for the committee and his guidance over the years, and offered him their best wishes for the future. ITEM 11: DATE OF NEXT MEETING 43. 13 July 2006.
ACTIONS
|
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
You
are here: 