Traffic-related air pollution exposure is associated with allergic sensitization, asthma, and poor lung function in middle age

J Allergy Clin Immunol. 2017 Jan;139(1):122-129.e1. doi: 10.1016/j.jaci.2016.05.008. Epub 2016 May 24.

Abstract

Background: Traffic-related air pollution (TRAP) exposure is associated with allergic airway diseases and reduced lung function in children, but evidence concerning adults, especially in low-pollution settings, is scarce and inconsistent.

Objectives: We sought to determine whether exposure to TRAP in middle age is associated with allergic sensitization, current asthma, and reduced lung function in adults, and whether these associations are modified by variants in Glutathione S-Transferase genes.

Methods: The study sample comprised the proband 2002 laboratory study of the Tasmanian Longitudinal Health Study. Mean annual residential nitrogen dioxide (NO2) exposure was estimated for current residential addresses using a validated land-use regression model. Associations between TRAP exposure and allergic sensitization, lung function, current wheeze, and asthma (n = 1405) were investigated using regression models.

Results: Increased mean annual NO2 exposure was associated with increased risk of atopy (adjusted odds ratio [aOR], 1.14; 95% CI, 1.02-1.28 per 1 interquartile range increase in NO2 [2.2 ppb]) and current wheeze (aOR, 1.14; 1.02-1.28). Similarly, living less than 200 m from a major road was associated with current wheeze (aOR, 1.38; 95% CI, 1.06-1.80) and atopy (aOR, 1.26; 95% CI, 0.99-1.62), and was also associated with having significantly lower prebronchodilator and postbronchodilator FEV1 and prebronchodilator forced expiratory flow at 25% to 75% of forced vital capacity. We found evidence of interactions between living less than 200 m from a major road and GSTT1 polymorphism for atopy, asthma, and atopic asthma. Overall, carriers of the GSTT1 null genotype had an increased risk of asthma and allergic outcomes if exposed to TRAP.

Conclusions: Even relatively low TRAP exposures confer an increased risk of adverse respiratory and allergic outcomes in genetically susceptible individuals.

Keywords: Air pollution; Glutathione S-Transferase genes; allergic sensitization; asthma; respiratory function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Air Pollutants / adverse effects*
  • Air Pollutants / analysis
  • Air Pollution / adverse effects*
  • Air Pollution / analysis
  • Australia / epidemiology
  • Environmental Exposure / adverse effects
  • Environmental Exposure / analysis
  • Female
  • Genetic Predisposition to Disease
  • Glutathione Transferase / genetics*
  • Humans
  • Hypersensitivity / diagnosis
  • Hypersensitivity / epidemiology*
  • Hypersensitivity / genetics
  • Hypersensitivity / physiopathology
  • Lung / physiopathology
  • Male
  • Nitrogen Dioxide / adverse effects*
  • Nitrogen Dioxide / analysis
  • Odds Ratio
  • Skin Tests
  • Spirometry
  • Vehicle Emissions / analysis
  • Vehicle Emissions / toxicity*

Substances

  • Air Pollutants
  • Vehicle Emissions
  • glutathione S-transferase T1
  • Glutathione Transferase
  • Nitrogen Dioxide