Chairman:
Professor J G Ayres
Members:
Mr B Armstrong
Mr Fintan Hurley
Professor D Laxen
Mrs A Lambert
Professor T Frew
Dr J Pritchard
Dr V Murray
Professor D Strachan
Professor D Walters
Professor S Holgate
Secretariat:
Dr R Maynard
Dr H Walton
Ms I Lindup
Ms J Cumberlidge
Mrs S Haider
Assessors:
Dr M Meadows (DEFRA)
Mr R Alexander (Welsh Assembly)
Mr N. McMahon (Northern Ireland)
Dr P Harrison (IEH)
In Attendance:
Professor A Seaton (CV Sub-group)
Professor R Anderson (CV Sub-group)
Dr J Townend (CV Sub-group)
ITEM 1. OPENING REMARKS, APOLOGIES FOR ABSENCE AND ANNOUNCEMENTS
1. Apologies for absence were received from Professor K Donaldson,
Professor P Poole-Wilson, Dr V Stone, Professor D Derwent, Professor
W MacNee, and Dr P Harrison.
2. The Chairman welcomed Mr Ronnie Alexander from the Welsh Assembly,
Dr Nigel McMahon from the Northern Ireland Assembly, Dr John Townend
and Professors Hugh Tunstall-Pedoe, Anthony Seaton and Ross Anderson,
members of the Cardiovascular Sub-group who had come to provide advice
on the Cardiovascular report (COMEAP/2004/1). The Chairman also welcomed
Mrs Shahneela Haider, a member of the Secretariat.
3. The Chairman informed Members that the terms of appointment for
both Professor Bill MacNee and Dr John Pritchard had ended. The Chairman
thanked Dr Pritchard and Professor MacNee (in absentia) for their contributions.
4. The Chairman reminded Members to declare any interests they may
have at the beginning of each agenda item.
5. The Chairman reminded Members to submit their expenses claims forms.
Blank forms had been tabled.
ITEM 2. MINUTES OF THE MEETING HELD ON 25th June 2004
6. The minutes were agreed as an accurate record of the meeting.
7. It was requested that the minutes published on the website be anonymised,
although the version of the minutes provided to Members would remain
with actions attributed to individuals. This was agreed.
ITEM 3. MATTERS ARISING
8. The Chairman informed Members that the meeting scheduled for the
22nd October would be postponed due to a clash with the AirNet meeting
in Prague. The Chairman requested that Members provide the Secretariat
with suitable dates in November for the next meeting.
ITEM 4. KAISER ET AL (2004) Air Pollution Postneonatal Infant Mortality
in US Metropolitan Areas: A Risk Assessment Study. Environmental Health:
A Global Access Science Source 3:4)
9. The Secretariat brought this study to the attention of Members for
examination and comment. It was noted that some Members had already
provided the Secretariat with informal comment.
10. It was reported that many paediatricians would be surprised by
the findings presented within this paper. Although initially sceptical,
the concept that air pollution was playing a part in infant deaths was
regarded as interesting and believable. A Member informed the Committee
that SIDS is only considered the cause of death in children who die
with no apparent cause.
11. It was agreed that this was not a new epidemiological study but
rather an extension of an earlier study by Woodruff et al 1997. Although
the Woodruff et al study was considered a good study with control for
many important possible confounders, Kaiser et al had applied the findings
to baseline mortality data in the US. In light of this, Members thought
that it was confusing that this work had appeared as 'new evidence'.
12. Members were hesitant to reach a conclusion about the findings
of the paper as the methods used for quantification in this study were
less sophisticated than those used in their own Quantification report
(Quantification of the Effects of Air Pollution on Health in the UK
1998) and that no new scientific information had been used. One Member
suggested that it would be sensible to wait until an assessment had
been carried out within the UK. It was also noted that there would be
difficulties in transferring US data to the UK. Another Member noted
that the confidence intervals in the study were wide, making it difficult
to assess how much weight to place on the results.
13. Members agreed that confounding was a problem as was interpretation
of the study. Despite confounding having been addressed, there were
measures which might not have been adjusted for such as social status
and smoking. Environmental tobacco smoke is a strong risk factor for
SIDS and lack of full control for this risk factor could influence the
results.
14. It was noted that WHO was preparing a report on air pollution and
effects on children and it was agreed that COMEAP would consider this
issue again once that report was available.
Action
The Secretariat agreed to condense Members' views into a paragraph for
use if DH is asked about this study.
Secretariat to provide members with WHO website address for Executive
Summary of the WHO report on air pollution and its effects on children.
ITEM 5. AIR POLLUTION AND CARDIOVASCULAR DISEASE
General Comments
15. The Chairman requested that Members make general comments on the
report before considering each chapter in greater detail.
16. Members were in agreement that the executive summary and conclusions
of the report were very important and that these sections should be
drafted so as to provide firm conclusions and clear recommendations
for research. A detailed list of suggestions for actions by the CV sub-group
has been compiled and will be sent as an aide memoir to the sub-group.
[In the interests of brevity, not all the suggested actions, some minor,
others major are listed in these minutes].
Action:
Chairman and Secretariat to get together to write the executive summary
and conclusions chapter
17. Members of the Committee asked members of the sub-group what conclusions
were being considered. It was stated that the broad view was that air
pollution and, specifically, particles did affect the cardiovascular
system. Attention was drawn to the forest plots in Chapter 2, which
provided persuasive evidence of an effect: On discussion of Chapter
3, mechanisms of effect, sub-group members thought that the evidence
was not as convincing as the epidemiological data, although it was felt
that plausible explanations for effects were emerging.
18. Some Members of the Committee were concerned that the report did
not provide enough background on air pollution and air pollution science
and thought that such a section should be included. This will be considered
by the sub-group.
19. The Chairman reminded members that the Committee had produced a
number of reports which examined both individual and mixtures of air
pollutants. These reports already contained the information being suggested
by members for inclusion in the report and were available to the informed
public. The Chairman stated that it would be inappropriate for this
information to be repeated. However, the chairman did suggest that it
would be noted how the recent paper emanating from the United States
on cardiovascular disease and air pollution dealt with this issue. [Robert
D. Brook et al AHA Scientific Statement Air Pollution and Cardiovascular
Disease A Statement for Healthcare Professionals From the Expert Panel
on Population and Prevention Science of the American Heart Association
Circulation. 2004;109:2655-2671].
Action:
Chairman to consider adding as appropriate to report
20. Members were complimentary of sections which provided a lay summary,
as had been requested at the previous meeting of COMEAP. Members were
very complimentary of the lay summary which had been produced at the
beginning of Chapter 2 - Epidemiological evidence from Short-term exposure
studies. It was requested that other sections provide a lay summary
written in a similar style.
Action:
Secretariat
21. The Secretariat informed Members that a comprehensive glossary
was being compiled to assist readers. Some Members would receive a copy
of the glossary and it was requested that they fill in any 'blanks'
against words specific to their specialism. The explanation of difficult
terms in the text was considered helpful and further explanations in
this style were recommended.
Action:
Secretariat to circulate, Members to complete
22. Members were in agreement that the report was still somewhat disorganised
in structure. The Secretariat did note that unlike on previous occasions,
polished contributions from Members, had, on the whole, not been received.
23. Members thought that having the epidemiology chapters before the
toxicology chapter was sensible and useful.
24. In helping to steer the report, one Member suggested the question
being asked of the report needed now to be changed from 'Is there an
association between cardiovascular disease and air pollution' to ' What
is the nature of the association, what pollutants are involved and what
is the nature of the (heart) disease'. Members were reminded that the
1998 QUARK report accepted a relationship between cardiovascular disease
and air pollution, but the CV report was taking this a stage further.
25. Members were asked whether they regarded the inclusion of the occupational
studies as useful. The chapter author stated that the results did not
appear to be particularly consistent and many of the studies which looked
at, for example diesel fumes, were looking for an effect on cancer.
The Chairman mentioned the Sjögren B (1997) paper, which contained
a useful table, which it was suggested should be included in this section.
Action:
Secretariat to add table from Sjögren paper and to consider dividing
Chapter 2 into two parts
26. Members of the sub-group thought that the primary objective of
the report should be to give cardiologists an appreciation of the fact
that air pollution has an impact on cardiovascular disease. However,
it was noted that the report should not address only cardiologists,
but also highlight and address other areas through the answering of
questions such as those listed below:
27. From policy makers' standpoint:
" Does an association matter?
" What should policy makers do with the results?
28. The Cardiologists would wish to know:
" What are the key results?
" What do the results mean to the cardiologist and to the patient?
" What can be done by the cardiologist / patient to help avoid
the effects
" What advice can be given by the cardiologist to the patient?
29. It was also suggested that societal risk and individual risk needed
to be explained in the report.
30. The Chairman stressed the need to be able to answer these questions
by the 5th October (date of the CV workshop).
Action:
Chairman/Sub-group/ Secretariat to address these areas
31. Members noted that the report would be likely to attract a good
deal of comment in the media and that cardiologists might well be asked
for comments. The need to inform the cardiological community as fully
as possible was accepted. It was agreed that the meeting with the BHF
would be useful in this regard.
Action:
Secretariat to confirm main messages.
EXECUTIVE SUMMARY
32. Discussion on the Executive Summary highlighted the importance of
this section of the report. In particular, it was decided that the Executive
Summary would have an impact on the style in which the lay summaries
at the beginning of chapters were written. It was questioned whether
the Executive Summary should be written for a non-scientific/press/public
audience and it was also noted that different levels of technical detail
were required by the different scientific audiences. The lay member
of the Committee commented that most of the summaries were digestible
and the style in which the introduction had been written, with explanations
of some words provided in brackets after them, worked well. It was suggested
that the Executive Summary be written in a similar style. The Secretariat
noted that the Chief Medical Officer was the key recipient of the advice
provided by the report.
33. The Secretariat reminded Members of the Executive Summary of the
Non-Biological Particles report, which the Secretariat considered exemplary.
It was agreed that the Executive Summary of this report would be circulated
by the Secretariat to Members. It was requested that the Lay Member,
in particular, provided comment on the style of the Executive Summary
of the Non-Biological Particles report.
Action:
Secretariat to circulate Executive Summary to Members. Members to provide
comment.
34. The Secretariat took the Members through the different types of
reports which had previously been written by COMEAP and MAAPE Committees.
The MAPPE reports contained a greater teaching element than some of
the later COMEAP reports, due to air pollution not having been well
understood in the late 1980s and early '90s. It was agreed that the
CV report needed to take a step back towards the style of the MAPPE
reports, as the target audience was one which did not necessarily expect
or accept the role that air pollution could play in cardiovascular disease.
It was agreed that this report had two functions, providing technical
detail on evidence and also a teaching element.
35. The need for this report to provide and educational focus was agreed
and a Member reminded the Committee of the importance of illustrations
in making it both appealing as well as educational.
Action:
Visual material to be added by Members, Secretariat
36. It was agreed that the Executive Summary needed to be tackled as
a matter of urgency and that it should be circulated to COMEAP for comment
prior to further changes to the report being made.
Action:
Chairman to write Executive Summary
INTRODUCTION
37. One Member requested that reference to 'Accident and Emergency'
be replaced by 'Emergency Department'. This was agreed.
Action:
Chairman to amend
CONCLUSION
38. It was noted that the conclusions chapter was still being worked
upon. It was suggested that the chapter authors should discuss the conclusions
and write this chapter prior to making changes in the main report, as
completion of this section would aid the re-writing and re-organising
process discussed earlier.
Action: Secretariat and Chairman to draft conclusions chapter and sub-group
members to provide comment
CHAPTER 2 - EPIDEMIOLOGY
SHORT TERM EFFECTS
39. It was agreed that the whole of Chapter 2, which currently contained
sections on both short term and long-term effects, needed to be split
into two separate chapters.
Action: Secretariat to divide into two parts
40. One member noted that in many of the epidemiological studies cardiopulmonary
effects are amalgamated and it was questioned why this was and why the
results were not collected separately for cardiological and pulmonary
effects. Members were informed that this was the style in which the
studies considered had presented their results.
41. It was agreed that this area required revision and the Secretariat
and the Chairman agreed to do this.
Action: Secretariat and Chairman
42. One Member asked if the cohort studies picked up all the effects
recorded in time-series studies. It was agreed that they did not pick
up respiratory mortality.
43. Members thought that it would be useful if a diagram was added explaining
how to read a forest plot. It was also requested that some explanation
be provided on publication bias.
Action:
The Secretariat agreed to do this
44. The following questions were asked of this chapter:
" Why were we looking at cardiac and not cerebrovascular effects?
" Why is there an association between ozone and cardiovascular
mortality and not between ozone and cardiovascular admissions?
" Do mechanisms point to particles, sulphur dioxide or nitrogen
dioxide as being the most likely to be important?
45. The chapter author reported some preliminary work. The association
between particles and CV mortality was robust to the inclusion of O3
and SO2 but disappeared on inclusion of NO2 in two pollutant models.
The association of O3 with CV mortality was robust to the inclusion
of PM in a two-pollutant model as was the association with NO2. These
findings will be included in the report. It was noted that PM and NO2
are closely related as regards urban sources and differentiating epidemiologically
between their effects was difficult.
Action:
New data to be provided by chapter author
LONG TERM EFFECTS
46. It was acknowledged that this section had a different layout to
the short-term effects section and that the splitting of the two sections
was sensible. It was also noted, as a general comment, that the section
on smoking needed to be relocated and it was agreed that it should be
placed within the introduction.
Action: Secretariat to move section as agreed.
47. One member provided comment on the section on smoking, stating
that it helped with the bio-plausibility of fine particles and irritant
gasses both in the domestic (RR1.2 for heart disease) and workplace
(RR 1.3 for heart disease) environment. It was noted that some of the
conclusions taken from this section could help in the formulation of
the final chapter.
48. It was noted that there were a few studies missing from this section
and the author explained that, though he had searched, he had been unable
to find them. The latest update on Abbey's Seventh Day Adventist studies
had not been found and it was decided that the Secretariat would write
directly to the author. The Dublin and Hong Kong studies on the long-term
effect on cardiovascular mortality had also been omitted. One member
provided the reference for the Hong Kong study as being Hedley et al
2002, which was published around the same time as the Dublin paper by
Luke Clancy.
Action:
Secretariat to contact Abbey. Author to source other papers with assistance
from the Secretariat if necessary.
49. One Member thought that it would be good if the long-term section
could state whether air pollution worsened chronic cardiovascular disease
or whether it initiated heart disease. It was agreed that this was a
good idea and that it would open up a series of further research opportunities.
Members agreed that it would be interesting to see how the evidence
from air pollution compared with studies of passive smoking, especially
from a mechanistic angle.
MECHANISMS
50. This newly revised chapter was discussed at great length. It was
agreed that the re-write had significantly improved the chapter. However,
Members did express differences in opinion which, it was agreed, needed
reflecting within the report.
51. An important question was whether suggested mechanisms supported
triggering of acute CV events or the initiation of CV disease processes.
One plausible route was suggested which lead to the conclusion that
the mechanism was triggering an event. If the cohort information evidence
was accepted, then it suggested that longer-term exposure increased
susceptibility to cardiovascular disease, which had not been discussed
within the mechanisms chapter.
52. It was noted that the evidence and hypotheses included in the chapter
pointed to acute effects on the CV system. But it was agreed that the
clotting/ atherosclerosis hypothesis could be seen as applicable to
both acute and chronic effects and it was though that this needed further
discussion.
Action:
Secretariat to amend
53. One member commented on how useful the pathology section of this
chapter was. Some sections, e.g. that on innervation, were seen as perhaps
too lengthy. Members agreed that stroke should be added. It was noted
that stroke would also need to be added to the box in the flow-diagram
used.
Action:
Secretariat to add stroke (within text and diagram)
54. The discussion on stroke prompted one member to ask whether an
epidemiological review of the effects on stroke had been undertaken.
A member responded to the question, indicating that there were insufficient
studies in this area and that the major drawback was the fact that pneumonia
was a common cause of deaths in stroke victims and thus an element of
misclassification had to be considered.
55. The Chairman noted that there was some disagreement with the sub-group
regarding the likelihood of effects on clotting or on neural control
of the heat being the key explanation for the epidemiological findings.
Members discussed this and argued that the neural hypothesis fitted
well with acute effects whilst the clotting hypothesis fitted well with
both acute and sub-acute /chronic effects.
Action:
Chairman, Secretariat and Sub-group to discuss
56. The Chairman asked the Members how 'educational' they wished this
chapter to be. It was agreed that there should be diagrams depicting
the major steps, a cartoon on atherogenesis, all of which would decrease
the amount of text required.
Action:
Secretariat to re-do and add visuals as requested
57. The Secretariat suggested that there could be something at the
beginning of this chapter to help introduce the section. This was considered
a good idea by Members.
Action:
Secretariat to write an introductory section.
58. Discussion of HRV focussed on the possible differences in terms
of prognostic value between changes in HRV in patients with heart disease
and in apparently normal individuals. Some Members felt that the significance
of changes in apparently normal individuals was far from being established.
Action:
Chairman/Secretariat to move and modify HRV section as decided.
59. One Member recalled a request made at the last meeting of COMEAP
which suggested that a note on NOx and angina should be added to the
report. The Secretariat expanded on this, suggesting that a table should
be produced on all potential mechanisms and evidence of air pollution
involvement in cardiovascular disease. This was agreed by the Committee
and Professor Anderson agreed to send the appropriate additional information
for inclusion within the report.
Action:
Member
ITEM 6. INDOOR AIR GUIDANCE DOCUMENT
60. The Secretariat informed Members that this document had been returned
to the Committee for final comment and to consider avenues for publication.
61. Members were reminded that although the document predominantly
contained guidance, where applicable, guidelines had been incorporated.
Particles had not been considered, but it was envisaged that the Committee
would engage with this area on another occasion.
62. Members welcomed the report. One Member considered it useful for
people involved with chemical incidents within the home. It was suggested
that it be noted what areas had been excluded, for example, asbestos,
infections such as legionnaires, house dust mites, information on petrol
spills, specifics relating to DIY activities and housing on brownfield
sites. Another Member added VOCs to this list. It was agreed that the
inclusion of some of these areas at a later date might be useful.
63. There were a number of suggestions for minor wording changes which,
it was agreed, would be sent in via e-mail by Members.
64. Members questioned who would use the Guidance document and for
what purpose. A Member highlighted the possibility that this document
might be considered useful in, for example, tenant/landlord litigation
processes. Members were concerned by this proposal. It was agreed that
the Secretariat would amend the section outlining the purpose of the
report, the usefulness of the guidelines provided and how it was envisaged
individuals might use the report on a voluntary basis.
65. It was made evident that the guidance document did not deal with
the quality of the building stock, as this had been dealt with by BRE.
66. It was questioned whether a long-term, e.g. annual average guideline
level for NO2 should be included. It was decided that the WHO provisional
annual average for NO2 (40µg/m3) should be added to the table
which provided guideline values within the document.
ITEM. 7 QUARK II
67. The Chairman provided some background to the planned report, highlighting
that a larger body of evidence now provided the opportunity to produce
an update to the 1998 QUARK report, which although at the time was a
novel production, was limited by problems of transferability.
68. The Chairman informed Members that a group of external reviewers
had been identified and although they had yet to be approached, it was
thought that the request would be positively received.
69. The first meeting of the new sub-group would be held in early 2005.
70. The sub-group would start by quantifying their confidence in causality
and combine this with a quantification of impact.
71. The importance of this report to policy was agreed by the Defra
representative who stated that QUARK I had provided input to cost benefit
based advice for ministers. The attendee from Northern Ireland looked
forward to the new report as QUARK I did not cover NI. It was requested
that any problems with regional data should be flagged up as early as
possible.
72. Another Member noted that the AQEG report on Particles also quoted
numbers from QUARK I and that it was encouraging to have a second report
coming out.
73. It was noted that the timescale for QUARK II did not match Defra's
timetable for revision of the Air Quality Strategy. It was accepted
that DH might need to provide Defra with preliminary or provisional
advice as work on QUARK II developed.
Action:
Defra to send relevant sections of the AQS and AQEG report to QUARK
II sub-group for review.
ITEM 8. HANDBOOK ON AIR POLLUTION AND HEALTH
74. This item was introduced by the Secretariat who informed the Committee
that this report was being updated. The Committee were provided with
an updated text and comments on this were requested. In particular,
Members were requested to submit to the Secretariat visual material
which they thought would be appropriate and would enhance the report.
It was emphasised that this was to be a very user-friendly report and
that it could be very influential.
75. It was agreed that it would be useful to list areas of continuing
discussion, but where associations between ill health and air pollution
remained uncertain or unknown. Dioxins were used as an example. It was
agreed that this Member and the Secretariat would work together on this
issue. Another Member suggested more material being presented on point
sources and fires. It was agreed that this Member would send in some
material so that this area could be covered.
76. It was made clear that the health advice given within the report
would include all the advice which had been given by COMEAP over the
years.
77. The Secretariat confirmed that a colour draft of the report would
be presented at the February 2005 meeting.
AOB
Ozone update
78. The Secretariat provided Members with a verbal update on the work
being carried out on the Ozone report. Members were informed that a
sub-group meeting had taken place in May which had considered chapters
1-5 of the report and that at this same meeting the decision had been
taken to publish the report in 2 sections. The first of these sections
would be presented as an advanced draft (Chapters 1-9) at the next meeting
of COMEAP.
NO2 Pilotto LS, Nitschke M, Smith BJ, Pisaniello D, Ruffin RE, McElroy
HJ, Martin J, Hiller JE. Randomized controlled trial of unflued gas
heater replacement on respiratory health of asthmatic schoolchildren.
Int J Epidemiol. 2004 Feb;33(1):208-14.
79. The Chairman informed Members that this paper had been brought
to COMEAP, taking into account the statement they had prepared on the
health effects of NO2 and carbon monoxide. This paper was based on the
data on releases of these pollutants from unflued gas appliances and
the Chairman thought it sensible, in light of this paper, for COMEAP
to decide whether they wished to alter the statement in any way.
80. The Secretariat outlined the various options for the Committee:
" Leave the statement as it stands
" Include reference to this study in the question and answer briefing
" Write a different statement which included reference to this
study
" Draft a note to include this study
81. Members praised the study. However, it was thought that the authors
had over interpreted the findings and the evaluation of symptoms was
only carried out after the interventions. Members were cautious of the
findings being truly the result of the interventions.
82. Another Member mentioned that the paper was statistically strong.
83. The Committee confirmed that they were happy to leave their statement
as it stood and that further discussion on NO2 would be held on another
day.
84. The Chairman reminded Members to send in receipts with their expenses
forms.
Date of Next Meeting
Date in November - To be confirmed
Secretariat
December 2004
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