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Subject: Fw: Coorespondence from Dr. Brooks - Re: Clarifications in 2008 J Occup Environ Med 

article

From: "Brooks, Edward G" <brookse@uthscsa.edu>

To: Molini Patel/RTP/USEPA/US@EPA

Cc: "Petronella, Sharon A." <spetrone@utmb.edu>

Date: 02/23/2010 02:52 PM

Subject: FW: clarifications in 2008 J Occup Environ Med article

Dr. Patel

Thank you for your careful review of our manuscript. I've reviewed our raw 

data files carefully and have corroborated the errors you noted below. Please 

let me know if you notice any more inconsistencies. I will submit corrections 

to the journal.

Sincerely

Ed Brooks

Edward G. Brooks, MD

UTHSCSA, Dept. of Pediatrics

Division of Immunology and Infectious Disease, Rm. 528L

7703 Floyd Curl Drive

San Antonio, Texas 78229-3900

brookse@uthscsa.edu

tel: 210-567-5250

fax: 210-567-6305

________________________________

From: Patel.Molini@epamail.epa.gov [Patel.Molini@epamail.epa.gov]

Sent: Thursday, February 04, 2010 12:17 PM

To: Brooks, Edward G.

Subject: clarifications in 2008 J Occup Environ Med article

Dear Dr. Brooks,

There appear to be a few discrepancies between tables and description of 

results in your 2008 J Occup Environ Med article, "Moderate Increases in 

Ambient PM2.5 and Ozone Are Associated with Lung Function Decreases in Beach 

Lifeguards." I did not find a published erratum, so I'm hoping you can 

provide clarification.

Thaller, E. I., Petronella, S. A., Hochman, D., Howard, S., Chhikara, R. S. 

and Brooks, E. G. (2008). "Moderate increases in ambient PM2.5 and ozone are 

associated with lung function decreases in beach lifeguards." J Occup Environ

Med 50(2): 202-11.

1. In Table 2, the point estimate and 95% CI for daily maximum O3 and FVC 

among asthmatics are -0.07 (-0.5 to -0.4). The point estimate is outside the 

range of 95% CI, and in the results (pg 206, Effects of PM2.5 and O3), you 

state "...there was a significant drop in the FEV1/FVC ratio with increases in 

average and maximum O3..., but no change in FVC (P = 0.69 and P = 0.36)..." 

Should the upper limit of the 95% CI be +0.4?

[Edward G. Brooks] Yes, you are correct; the table should read -0.07 (-0.5 to 

0.4).
2. In the results section on Effects of Gender, Asthma, and Smoking on pg 

206, you state, "The FEV1/FVC ratio was decreased in both asthmatics (P = 

0.05) and non-asthmatics (P=0.02) with increasing average O3 exposures, but 

increases in maximum O3 was associated with a decrease in FEV1/FVC only in 

non-asthmatics (P =0.01)" In Table 3, the 95% CI for daily average O3 is -1.1 

to -0.08 for asthmatics is -0.4 to -0.02 for nonasthmatics. Have the p-values 

been switched or could you have switched asthmatic and non-asthmatic data in 

the table? Additionally, for daily maximum O3, the point estimate and 95% CI 

for asthmatics are -0.4 (-0.7 to -0.08) which indicate that daily maximum O3 

was associated with a significant decrease in FEV1/FVC in asthmatics. The 

point estimate and 95% CI for non-asthmatics are -0.1 (-0.2 to 0). This 

association is only borderline significant, and the p-value cannot be 0.01.

[Edward G. Brooks] You are correct in that the FEV1/FVC change for asthmatics 

for average ozone P value is .022, and for non-asthmatics P=.03, the data is 

otherwise correct. Also the FEV1/FVC in asthmatics with max ozone was 

significant (p=.01) and for non-asthmatics was non-significant (p=.06). This 

was correct in the table but not in the text.

In addition to the above changes, I also found an error in the Rsquared value 

Table 3, average ozone, all data, should be .005, not .071.

[Edward G. Brooks] I appreciate your feedback on these inconsistencies.

Sincerely,

Molini M. Patel, PhD, MPH

Epidemiologist

U.S. Environmental Protection Agency

National Center for Environmental Assessment

Mail drop: B243-01

Research Triangle Park, NC 27711

Telephone: (919) 541-1492

Email: patel.molini@epa.gov