Air Pollution and Bronchitic Symptoms in Southern California Children with Asthma

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http://ehpnet1.niehs.nih.gov/docs/1999/107p757-760mcconnell/abstract.html

Children's Health Articles

Environmental Health Perspectives Volume 107, Number 9, September 1999

[ Citation in PubMed ] [ Related Articles ]

Air Pollution and Bronchitic Symptoms in Southern California Children with

Asthma

Rob McConnell,1 Kiros Berhane,1 Gilliland,1 J. London,2 Hita

Vora,1 Avol,1 W. Gauderman,1 Helene G. Margolis,3 Fred

Lurmann,4 Duncan C. ,1 and M. s1

1Department of Preventive Medicine, University of Southern California School

of Medicine, Los Angeles, California, USA

2National Institute of Environmental Health Sciences, Research Triangle

Park, North Carolina, USA

3California Air Resources Board, Sacramento, California, USA

4Sonoma Technology Inc., Petaluma, California, USA

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Abstract

The association of air pollution with the prevalence of chronic lower

respiratory tract symptoms among children with a history of asthma or

related symptoms was examined in a cross-sectional study. Parents of a total

of 3,676 fourth, seventh, and tenth graders from classrooms in 12

communities in Southern California completed questionnaires that

characterized the children's histories of respiratory illness and associated

risk factors. The prevalences of bronchitis, chronic phlegm, and chronic

cough were investigated among children with a history of asthma, wheeze

without diagnosed asthma, and neither wheeze nor asthma. Average ambient

annual exposure to ozone, particulate matter (PM10 and PM2.5; 10 µm and <

2.5 µm in aerodynamic diameter, respectively), acid vapor, and nitrogen

dioxide (NO2) was estimated from monitoring stations in each community.

Positive associations between air pollution and bronchitis and phlegm were

observed only among children with asthma. As PM10 increased across

communities, there was a corresponding increase in the risk per

interquartile range of bronchitis [odds ratio (OR) 1.4/19 µg/m3; 95%

confidence interval (CI), 1.1-1.8). Increased prevalence of phlegm was

significantly associated with increasing exposure to all ambient pollutants

except ozone. The strongest association was for NO2, based on relative risk

per interquartile range in the 12 communities (OR 2.7/24 ppb; CI, 1.4-5.3).

The results suggest that children with a prior diagnosis of asthma are more

likely to develop persistent lower respiratory tract symptoms when exposed

to air pollution in Southern California. Key words: air pollution, asthma,

bronchitis, children, respiratory tract. Environ Health Perspect 107:757-760

(1999). [Online 5 August 1999]

http://ehpnet1.niehs.nih.gov/docs/1999/107p757-760mcconnell/abstract.html

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Address correspondence to R. McConnell, Department of Preventive Medicine,

USC School of Medicine, 1540 Alcazar Street, CHP 236, Los Angeles, CA 90033

USA. Telephone: (323) 442-1593. Fax: (323) 442-3272. E-mail:

rmcconne@...

We are grateful for the important input from our External Advisory

Committee: D. Bates, M. Lippmann, J. Samet, J. Spengler, F. Speizer, J.

Whittenberger, A. Winer, and S. Zeger. In addition, W. Linn, H. Gong, G.

Cass, S. Colome, S. Hering, W. McDonnell, R. Reiss, and P. provided

excellent advice. We acknowledge the hard work of the study field team and

the cooperation of the 12 communities, the school principals, the many

teachers, the students, and their parents. Programming support was provided

by E. Rappaport and J. Manila. S.S. Stanley provided clerical support.

This study was supported by the California Air Resources Board (contract

A033-186), the National Institute of Environmental Health Science (grant

#5P30ES07048-02), the U.S. Environmental Protection Agency (contract

#CR824034-01-3), and the Hastings Foundation.

The statements and conclusions in this report are those of the contractor

and not necessarily those of the California Air Resources Board. The mention

of commercial products, their source, or their use in connection with

material reported herein is not to be construed as either an actual or

implied endorsement of such products.