Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Oct;119(10):1472-7.
doi: 10.1289/ehp.1103516. Epub 2011 Jun 27.

Residential traffic-related pollution exposures and exhaled nitric oxide in the children's health study

Sandrah P Eckel  1 , Kiros Berhane, Muhammad T Salam, Edward B Rappaport, William S Linn, Theresa M Bastain, Yue Zhang, Frederick Lurmann, Edward L Avol, Frank D Gilliland
Affiliations

Residential traffic-related pollution exposures and exhaled nitric oxide in the children's health study

Sandrah P Eckel et al. Environ Health Perspect. 2011 Oct.

Abstract

Background: The fractional concentration of nitric oxide in exhaled air (FeNO) potentially detects airway inflammation related to air pollution exposure. Existing studies have not yet provided conclusive evidence on the association of FeNO with traffic-related pollution (TRP).

Objectives: We evaluated the association of FeNO with residential TRP exposure in a large cohort of children.

Methods: We related FeNO measured on 2,143 children (ages 7-11 years) who participated in the Southern California Children's Health Study (CHS) to five classes of metrics of residential TRP: distances to freeways and major roads; length of all and local roads within circular buffers around the home; traffic densities within buffers; annual average line source dispersion modeled nitrogen oxides (NOx) from freeways and nonfreeway roads; and predicted annual average nitrogen oxide, nitrogen dioxide, and NOx from a model based on intracommunity sampling in the CHS.

Results: In children with asthma, length of roads was positively associated with FeNO, with stronger associations in smaller buffers [46.7%; 95% confidence interval (CI), 14.3-88.4], 12.4% (95% CI, -8.8 to 38.4), and 4.1% (95% CI, -14.6 to 26.8) higher FeNO for 100-, 300-, and 1,000-m increases in the length of all roads in 50-, 100-, and 200-m buffers, respectively. Other TRP metrics were not significantly associated with FeNO, even though the study design was powered to detect exposures explaining as little as 0.4% of the variation in natural log-transformed FeNO (R2 = 0.004).

Conclusion: Length of road was the only indicator of residential TRP exposure associated with airway inflammation in children with asthma, as measured by FeNO.

PubMed Disclaimer

Conflict of interest statement

F.L. is employed by Sonoma Technology, Inc. The other authors declare they have no actual or potential competing financial interests.

Figures

Figure 1
Figure 1
Estimated percent difference in FeNOa and 95% CI associated with an increaseb in each length of road metric: (A) adjusting for asthma status and (B) fitting separate models by asthma status. aAdjusted for race/ethnicity, sex, asthma status (A), asthma medication, rhinitis history, age at collection, BMI percentile, secondhand tobacco smoke, parental education, month and hour of FeNO collection, outdoor testing, and community of residence. bExposure contrasts: 100 m, 300 m, and 1,000 m for length of roads in a 50-m, 100-m, and 200-m buffer, respectively.
Figure 2
Figure 2
Smooth association of length of local roads in a 50-m buffer with FeNO for children with asthmaa (black solid line: smooth fitted value for a child with average values for the adjustment covariates; black dashed line is the 95% CI). The estimated degrees of freedom (EDF) and the p-value testing the association of the smooth with FeNO are displayed. On the y-axis, values are plotted on the natural log scale and labeled on the original scale. aAdjusted for race/ethnicity, sex, asthma medication, rhinitis history, age at collection, BMI percentile, secondhand tobacco smoke, parental education, month and hour of FeNO collection, outdoor testing, and community of residence.
See this image and copyright information in PMC

References

    1. ATS (American Thoracic Society) Recommendations for standardized procedures for the on-line and off-line measurement of exhaled lower respiratory nitric oxide and nasal nitric oxide in adults and children – 1999. This official statement of the American Thoracic Society was adopted by the ATS Board of Directors, July 1999. Am J Respir Crit Care Med. 1999;160(6):2104–2117. - PubMed
    1. ATS/ERS (American Thoracic Society and the European Respiratory Society) ATS/ERS recommendations for standardized procedures for the online and offline measurement of exhaled lower respiratory nitric oxide and nasal nitric oxide, 2005. Am J Respir Crit Care Med. 2005;171(8):912–930. - PubMed
    1. Baraldi E, de Jongste JC. Measurement of exhaled nitric oxide in children, 2001. Eur Respir J. 2002;20(1):223–237. - PubMed
    1. Bastain TM, Islam T, Berhane KT, McConnell RS, Rappaport EB, Salam MT, et al. Exhaled nitric oxide, susceptibility and new-onset asthma in the Children’s Health Study. Eur Respir J. 2010;37(3):523–531. - PMC - PubMed
    1. Beck-Ripp J, Griese M, Arenz S, Koring C, Pasqualoni B, Bufler P. Changes of exhaled nitric oxide during steroid treatment of childhood asthma. Eur Respir J. 2002;19(6):1015–1019. - PubMed

Publication types