The Committee on the Medical Effects of Air Pollutants (COMEAP) has finally released its report into the effect on mortality of long-term exposure to air pollution – nearly two years after their July 2007 draft.
The following was submitted by UKWIN Steering group member Max Wallis:
COMEAP Report, long-delayed, published at last, 18 June 2009
The report on ‘Long-Term Exposure to Air Pollution: Effect on Mortality’ was released in draft in July 2007. Nearly two years later, this one comes with a rather weak response (Appendix 2) to public comments and peer reviews.
In the peer review, you can see:
Two important findings on the percentage change in mortality risk per 10-µg/m3 increase in PM2.5 exposure
First, that the final estimates are robust to the technique used and,
second, that the central estimate is always greater than that developed for COMEAP.
These are the findings from US studies using similar techniques and the same data, but conducted more thoroughly by a broad range of independent experts (unlike COMEAP’s in-group of appointees).
Evidently, COMEAP’s report failed its peer review.
So why was it ever published?
COMEAP’s defences (see Appendix 2 ) are
1. They adopted a cut-off in early 2006 for published work… this, unfortunately, excludes an important and influential US review by Pope and Dockery (2006)
2. the estimates from an “elicitation exercise adequately represents our opinions” whether on not US expert opinions differ.
3. COMEAP struck a balance between various counterbalancing factors, whatever the balance struck by others like Pope and Dockery.
Thus they admit being out of date, otherwise claim their opinions stand.
At issue is how strong is the link between particle pollution (best measured by PM2.5) and all-cause mortality, not only from smog episodes but over the long term. COMEAP has a record of undercounting – in 1998 COMEAP discounted long term (chronic) effects as too uncertain, in 2001 they accepted that PM probably caused chronic mortality, but decided the coefficient value of 1% was “most likely”. In January 1996, in an interim report they upped it to 6% after reviews in the EU fixed on the range 2 to 11 %.
The latest Report quibbles about the endpoints, but essentially accepts the range 2-11% of 2005 as well as sticking to the 6%. Yet already in mid-2006, the range 6% to 17% was established by the US work.
So an out-of-date figure and failing its peer review – what price COMEAP?
Long-Term Exposure to Air Pollution: Effect on Mortality (Final Report)
The Committee on the Medical Effects of Air Pollutants (COMEAP) announces the publication of its report ‘Long-term Exposure to Air Pollution: Effect on Mortality’.
* Download Long-Term Exposure to Air Pollution: Effect on Mortality in Portable Document Format (1.7MB)
A draft version of this report was released for comment and peer review on 17 July 2007. All reviews and comments received may be viewed using the hyperlinks below. These have been considered in the appendix of the final report.
* Download peer reviews on the draft report in Portable Document Format
* Download comments on the draft report in Portable Document Format (3. MB)
* Download draft report (released in July 2007 for comment)
COMEAP admit their report is out of date and make no case for departing from the findings from more thorough and up-to-date analysis in the USA, produced by an expert panel chosen specifically for its breadth of expertise and independence. How can government use this report that’s failed its peer review as a basis for policy ?
Defra use the 6% figure for cost-benefit analyses of measures to curb traffic or justify technology for abating vehicle pollution. A two or three times higher figure requires stronger action in both respect.
So essentially what Max states there is a large scientific deficit and lag by COMEAP panel behind the peer review and legally tested US (Pope/Dochery et al) studies/reviews. So Defra’s/ HPE policy makers really should be working with the US figures for emissions analyses rather than trudging on with the outdated figure and policy acceptance of incinerators spun for EfW/CHP.