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Subject: Re: Meng - Response to PM Data Request

From: "Meng, Ying-Ying" <yymeng@ucla.edu>

To: Beth Hassett-Sipple/RTP/USEPA/US@EPA

Cc: Lindsay Stanek/RTP/USEPA/US@EPA, Rebecca Yang/RTP/USEPA/US@EPA, Pradeep 

Rajan/RTP/USEPA/US@EPA

Date: 11/16/2009 03:48 PM

Subject: RE: Request for PM AQ data

Dear Dr. Hassett-Sipple:

I am writing to respond to your request for information on our published paper:

Meng, Y. Y., M. Wilhelm, et al. (2007). "Traffic and outdoor air pollution 

levels near residences and poorly controlled asthma in adults." (Ann Allergy 

Asthma Immunol 98(5): 455-63)

To provide some background information, our study subjects were individuals 

from whom health data were collected between November 2000 and September 2001 

as part of the 2001 California Health interview Survey (CHIS, a secondary data 

source), who: (1) resided in Los Angeles or San Diego County during this same 

time period and (2) reported ever having been diagnosed with asthma by a 

physician. To estimate annual exposures to criteria air pollutants during the 

12 months preceding the date of interview, we obtained air-monitoring data 

collected between 1999 and 2001 at fixed-site stations in Los Angeles and San 

Diego Counties. In Los Angeles County,10 stations measured PM2.5 and in San 

Diego County, 5 stations measured PM2.5. Subjects were assigned annual average 

concentrations of PM2.5 based on measurements from the nearest station that

measured each specific pollutant within 5 miles of the reported residential 

cross-street intersection. Subjects residing outside of a 5-mile range were 

excluded from the criteria pollutant analyses. Annual average concentrations 

were calculated for the one-year period prior to the interview date. These 

averages were based on 24-hour average measurements taken every 6 and 3 days 

for PM2.5. 

I understand that our study fits Category C, which is a study designed to

evaluate morbidity effects associated with long-term PM2.5 ambient 

concentrations. The requested information is as follows: 

o mean of the ambient PM2.5 mean concentrations across cities reported in 

the study for the time period evaluated in the study: 19.14 ug/m3

o range (high-to-low) of the city-specific means across all cities or 

locations: 24.68-10.52 ug/m3

o where applicable, the above air quality information differentiated by:

specific individual years (N/A), if multiple years were evaluated 

season, as defined in the study (N/A), region, as defined in the study (e.g., 
east-west) see the above

o if your study considered air quality data from multiple monitors in a city, 

include the above information for the highest reporting monitor within each 

city (This question may not be applicable to our study since we used the county 

data and actual annual average was different for each study subject, which was

calculated for the one year period prior to the interview date)

However, the highest annual PM2.5 concentration in Los Angeles County was from Pico

Rivera monitor, which had a reading of 23.7 ug/m3 for year 2000; while the highest 

annual PM2.5 concentration in San Diego County was from San Diego (12th ave)

monitor, which had a reading of 15.9 ug/m3 for year 2000.

Please feel free to contact me if you need further information or any 

clarifications. Thanks.

Ying-Ying

Ying-Ying Meng. Dr.PH

Director, Chronic Disease Program

Senior Research Scientist

UCLA Center for Health Policy Research

10960 Wilshire Blvd., Suite 1550, Los Angeles, CA 90024

Tel: 310-794-2931

Fax: 310-794-2686

www.healthpolicy.ucla.edu