Health care education, delivery, and quality
Health effects of indoor nitrogen dioxide and passive smoking on urban asthmatic children

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Background

Nitrogen dioxide (NO2) and environmental tobacco smoke (ETS) have been associated with adverse respiratory effects.

Objective

We sought to assess the effect of NO2 and ETS on asthma morbidity among children in inner-city environments.

Methods

Asthmatic children between the ages of 4 and 9 years had exposure to NO2 and ETS measured by using Palmes tubes in the home and urinary cotinine. A baseline interview and telephone assessments at 3, 6, and 9 months evaluated health service use, asthma symptoms, and peak flow rates.

Results

Gas stoves were present in 87.8% of 469 homes. The median level of indoor NO2 was 29.8 ppb compared with the US national outdoor median of 18 ppb. Of 1444 children, 48% had urinary cotinine/creatinine ratios of greater than 30 ng/mg. The median level of the cotinine/creatinine ratio was 42.4 ng/mg in smoking homes compared with 18.0 ng/mg in nonsmoking homes. The relative risk for asthma symptoms with increased NO2 exposure was 1.75 (95% CI, 1.10-2.78) in children who did not have positive skin test responses. Higher NO2 exposure resulted in lower peak flows during colder months (relative risk, 1.46; 95% CI, 1.07-1.97). Higher ETS exposure in colder months was weakly associated with lower peak flows (relative risk, 1.21; 95% CI, 0.99-1.47). There was no effect of ETS exposure on symptoms or use of health care services.

Conclusion

Higher levels of indoor NO2 are associated with increased asthma symptoms in nonatopic children and decreased peak flows.

Clinical implications

Interventions to reduce NO2 exposure, such as venting of gas stoves, might help reduce asthma morbidity.

Section snippets

Methods

The NCICAS (1992-1994) included 1528 children ages 4 through 9 years from 8 inner-city areas in the United States (Bronx, NY; East Harlem, NY; St Louis, Mo; Washington, DC; Baltimore, Md; Chicago, Ill; Cleveland, Ohio; and Detroit, Mich). The full design and methodology have been published and are summarized here.2, 24, 25 Children were recruited from emergency departments and clinics based on physician-diagnosed asthma and the presence of symptoms in the previous 12 months or cough, wheeze, or

Results

A total of 1528 caretaker and child pairs completed the baseline interview. The population was predominantly low-income African American and Latino. A large proportion of the participants had high-level social and psychological stress, allergen skin test reactivity, and exposure to NO2 and ETS in the home (Table I). Of the 525 Palmes tubes returned, 56 were missing duration of exposure, resulting in an analyzable sample of 469 (71%) of the 663 placed during the home visit. Valid cotinine

Discussion

High levels of NO2 and ETS were found in the indoor environments of inner-city children with asthma. Increased NO2 exposure was associated with increased asthma symptoms among nonatopic children. Higher NO2 exposure resulted in decreased peak flow during colder months. We found no association between the level of exposure to ETS and symptoms or unscheduled visits for asthma exacerbations. High levels of ETS were weakly associated with lower peak flow rates during colder months.

The median NO2

References (41)

  • L.M. Neas et al.

    Association of indoor nitrogen dioxide with respiratory symptoms and pulmonary function in children

    Am J Epidemiol

    (1991)
  • K.M. Mortimer et al.

    The effect of air pollution on inner-city children with asthma

    Eur Respir J

    (2002)
  • B.J. Smith et al.

    Health effects of daily indoor nitrogen dioxide exposure in people with asthma

    Eur Respir J

    (2000)
  • M.H. Garrett et al.

    Respiratory symptoms in children and indoor exposure to nitrogen dioxide and gas stoves

    Am J Respir Crit Care Med

    (1998)
  • J. Just et al.

    Short-term health effects of particulate and photochemical air pollution in asthmatic children

    Eur Respir J

    (2002)
  • K. Belanger et al.

    Association of indoor nitrogen dioxide exposure with respiratory symptoms in children with asthma

    Am J Respir Crit Care Med

    (2006)
  • J.R. DiFranza et al.

    Morbidity and mortality in children associated with the use of tobacco products by other people

    Pediatrics

    (1996)
  • F.D. Martinez et al.

    Asthma and wheezing in the first six years of life. The Group Health Medical Associates

    N Engl J Med

    (1995)
  • S. Lewis et al.

    Prospective study of risk factors for early and persistent wheezing in childhood

    Eur Respir J

    (1995)
  • R.I. Ehrlich et al.

    Risk factors for childhood asthma and wheezing. Importance of maternal and household smoking

    Am J Respir Crit Care Med

    (1996)
  • Cited by (0)

    Supported by grants UOI A1-30751, A1-30752, A1-30756, A1-30772, A1-30773-01, A1-30777, A1-30779, A1-30780, and N01-A1-15105 from the National Institutes of Allergy and Infectious Disease (National Institutes of Health, Bethesda, Md).

    Disclosure of potential conflict of interest: M. Kattan is on the speakers' bureau for AstraZeneca. P. Eggleston has consulting arrangements with the Chlorine Chemistry Council, Proctor and Gamble, SC Johnson, Nexcura, and Church and Dwight and is on the speakers' bureau for AstraZeneca, Merck, and GlaxoSmithKline. The rest of the authors have declared that they have no conflict of interest.

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