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COMEAP/2001/16
Particles and cardiovascular admissions – methods of measurement of particles

1. A table of the cv admission studies with the methods used is attached. Several just refer to using the EPA AIRS database. This includes TEOM as well as high-volume (gravimetric) data but is probably dominated by gravimetric measurements.

2. The Secretariat, after discussion with some COMEAP members, suggest that the summary estimate is left as it is but a description of what it is based on is included. This description is based not just on how many studies were TEOM (3) and how many were gravimetric (2 definite, 9 probably predominantly gravimetric) but also how these studies weighted the overall estimate. The estimate was dominated by results from Hong Kong (TEOM) and Los Angeles (gravimetric). It would also be useful to comment on the direction of any errors. If the view is that the overall coefficient is mainly a gravimetric one, then the TEOM coefficients will be overestimates (e.g. for the Prescott study 4.8% per 10 ug/m3 TEOM will actually be per 13 ug/m3 gravimetric (using a conversion factor of 1.3) or 4.8/13x10 = 3.7% per 10 ug/m3 gravimetric). So conversion would bring the summary estimate down slightly but probably not by much.

3. A footnote has been added to the statement as follows. ‘The summary estimate is based mainly on studies using high volume samplers (gravimetric) to measure PM₁₀. The inclusion of a few TEOM studies may mean that the summary estimate is slightly overestimated’.

Is the Committee content with this?

Secretariat
November 2001

Author	City	Dates	Method	Comment
Schwartz	Tuscon	1988-1990	Hi-vol (grav)
Prescott	Edinburgh		TEOM
Atkinson	London		TEOM
Wong	Hong Kong		TEOM
Schwartz	Seattle	1988-1990	From EPA Aerometric Information Retrieval System (AIRS)	Mean of all monitors in county. May have included some TEOM data but probably mainly gravimetric
Schwartz	Minneapolis	1988-1990	"	"
Schwartz	Chicago	1988-1990	"	"
Schwartz	Tacoma	1988-1990	"	"
Schwartz	Colorado Springs	1988-1990	"	"
Schwartz	New Haven	1988-1990	"	"
Schwartz	Spokane	1988-1990	"	"
Schwartz	St Paul	1988-1990	"	"
Gwynn	Buffalo	1988-1990	AIRS	Population-weighted mean of monitors across Buffalo-Rochester area. May have included some TEOM data but probably mainly gravimetric
Linn	Los Angeles	1992-1995	Mixture of continuous and high volume data. Adjusted continuous data to high volume data.	Suggest treat as gravimetric.
NMMAPS	14 US cities	Various periods 1984 – 1995 (different for different cities)	AIRS	May have included some TEOM data but probably mainly gravimetric.

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