Acute effects of summer air pollution on pulmonary function and airway inflammation in healthy young women

J Epidemiol. 2014;24(4):312-20. doi: 10.2188/jea.je20130155. Epub 2014 May 24.

Abstract

Background: Exposure to air pollution has been reported to be associated with asthma exacerbation. However, little is known about the effects of air pollutant exposure in healthy people. A panel study was conducted to evaluate the acute effects of air pollutants on pulmonary function and airway inflammation in healthy subjects.

Methods: Exhaled breath condensate (EBC) pH, fractional concentration of exhaled nitric oxide (FeNO), and pulmonary function were measured in 21 healthy young women repeatedly for two weeks in the summer in Tokyo, Japan. The concentrations of air pollutants were obtained from the monitoring stations in the neighborhoods where the subjects lived. Statistical analyses were performed using generalized estimating equations.

Results: EBC pH decreased significantly with a 10-ppb increase in the 4-day average ozone (O3) concentration and a 10-µg/m3 increase in the 4-day average suspended particulate matter (SPM) concentration (-0.07 [95% confidence interval {CI} -0.11 to -0.03] and -0.08 [95% CI -0.12 to -0.03], respectively). Subjects with a history of rhinitis showed marked decreases in EBC pH associated with increases in O3 and SPM. The changes in forced expiratory volume in 1 second (FEV1) were also significantly associated with a 10-µg/m3 increase in the 3-day average concentration of SPM (-0.09 L [95% CI -0.17 to -0.01]). FeNO increased significantly in relation to the increase in O3 and SPM among only subjects with a history of asthma.

Conclusions: Over the course of the study, EBC became significantly acidic with increases in O3 and SPM concentrations. Furthermore, higher SPM concentrations were associated with decreased FEV1. Subjects with a history of rhinitis or asthma are considered to be more susceptible to air pollutants.

背景:: 大気汚染への曝露が喘息患者の症状悪化と関連していることは数多く報告されている。しかし、健常者に対する大気汚染の急性影響はほとんど知られていない。そこで、健常成人を対象にパネル研究を実施し、肺機能と気道炎症に対する大気汚染物質の急性影響を評価した。

方法:: 東京都内の健常な女子学生21名を対象として、呼気凝縮液(EBC)のpH、呼気一酸化窒素濃度(FeNO)及び肺機能の測定を夏季の2週間の間に繰り返し実施した。大気汚染物質の濃度は、対象者が居住する近隣の測定局における浮遊粒子状物質(SPM)及びオゾン(O3)濃度を用いて、各指標との関連を一般化推定方程式により解析した。

結果:: EBC pHは、検査前4日平均のO3濃度10ppb増加あたり-0.07 [95%信頼区間:-0.11,-0.03]、検査前4日平均のSPM濃度10 μg/m3増加あたり-0.08 [95%信頼区間:-0.12,-0.03]であり、いずれも有意な低下が観察された。鼻炎の既往があるものは、O3及びSPM濃度の増加によりEBC pHの顕著な低下がみられた。1秒量(FEV1)も検査前3日平均のSPM濃度と有意に関連しており、10 μg/m3増加あたり-0.09 [95%信頼区間:-0.17, -0.01] Lの低下であった。FeNOは、喘息の既往のあるものにおいてのみO3及びSPM濃度が増加すると有意に増加した。

結論:: 研究期間中に大気中のO3及びSPM濃度が上昇すると、EBC pHが有意に酸性になることが明らかとなった。また、SPMが高濃度ではFEV1の低下との関連があった。鼻炎または喘息の既往があるものは大気汚染物質の影響を受けやすいと考えられた。

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Air Pollutants / adverse effects*
  • Air Pollutants / analysis
  • Air Pollution / adverse effects*
  • Environmental Exposure / adverse effects*
  • Environmental Exposure / analysis
  • Female
  • Humans
  • Japan
  • Ozone / adverse effects
  • Ozone / analysis
  • Particulate Matter / adverse effects
  • Particulate Matter / analysis
  • Respiratory Function Tests / statistics & numerical data
  • Respiratory Tract Diseases / etiology*
  • Respiratory Tract Diseases / physiopathology
  • Seasons*
  • Young Adult

Substances

  • Air Pollutants
  • Particulate Matter
  • Ozone