Effect of hourly concentration of particulate matter on peak expiratory flow in hospitalized children: A panel study

• Main Authors: Watanabe Hiroko (Author), Nitta Hiroshi (Author), Ando Michiko (Author), Shima Masayuki (Author), Yamazaki Shin (Author), Nishimuta Toshiyuki (Author)
• Format: Book
• Published: BMC, 2011-03-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

<p>Abstract</p> <p>Background</p> <p>Little information is available on the possible association between hourly short-term air pollution and peak expiratory flow (PEF) in asthmatic children.</p> <p>Methods</p> <p>PEF was measured twice daily, from October through December, 2000, in 17 children aged 8 to 15 years hospitalized with severe asthma. A total of 1198 PEF measurements were made at 7 a.m. and 1175 at 7 p.m. Measurements were conducted immediately prior to medication under the guidance of trained nurses. PEF changes were estimated in 10-μg/m³increments of particulate matter with a 50% cut-off aerodynamic diameter of ≤2.5 μm (PM_2.5), with adjustment for sex, age, height, and temperature. Lagged-hour exposures of up to 24 hours were examined.</p> <p>Results</p> <p>Increased 24-hour mean concentration of PM_2.5was associated with a decrease in both morning and evening PEF (-3.0 l/minute; 95%CI: -4.6, -1.4 and -4.4 l/minute; 95%CI: -7.1, -1.7, respectively). In addition, hourly concentrations of PM_2.5and PEF showed a significant association between some lags of PM_2.5and PEF. Effect size was almost -3 l/minute in both morning and evening PEF for an hourly PM_2.5concentration of 10 μg/m³in several lags. Even after adjustment for other air pollutants, some of the significant associations with PEF remained.</p> <p>Conclusion</p> <p>Among hospitalized children with severe asthma, increased hourly concentration of PM_2.5was associated with a decrease in PEF.</p>

Item Description

10.1186/1476-069X-10-15
1476-069X