Effects of long-standing exposure to heavy-duty diesel vehicle traffic on respiratory symptoms and airway inflammation in older adults

In the present study, we evaluated the effects of chronic exposure to traffic from a heavy-duty diesel-fueled vehicle area on respiratory symptoms and airway inflammation in a nonsmoking adult and elderly population. Respiratory symptoms were evaluated by the ISAAC questionnaire (International Study of Asthma and Allergies questionnaire), and airway inflammation was assessed by fractional exhaled nitric oxide (FeNO). Forty volunteers were selected from the 112 volunteers who completed the ISAAC questionnaire for the measurement of FeNO. The FeNO population comprised seven men (six aged >= 64 years old, four aged >= 75 years old) and 32 women (27 aged >= 64 years old, nine aged >= 75 years old). FeNO levels were tracked for six months, from November 2014 to June 2015. Results: Twenty-four percent of the volunteers reported having had wheezing in the chest in the last 12 months. However, only 2.7% of the volunteers reported doctor-diagnosed asthma. There was a positive association between FeNO and pollutants in most of the study months. An increase of 1 mg m(-3) in NO2 was associated with a mean increase of 1.08 ppb in FeNO, and an increase of 1 mg m(-3) in O-3 was associated with a mean increase of 1.06 ppb in FeNO. The relative risk for NO2 ranged from 1.009 to 1.32 and that for O-3 ranged from 1.014 to 1.020. Conclusion: The frequency of respiratory symptoms was much higher than the previously described levels of 6% in the Brazilian adult population. In summary, a high frequency of respiratory symptoms and high levels of FeNO were described in an underdiagnosed adult population living very close to a heavy-duty diesel-traffic area. Older elderly adults presented greater susceptibility to airway inflammation than younger adults. (C) 2020 Elsevier Ltd. All rights reserved. (AU)