Exposures to high levels of volatile organic compounds (VOCs) in indoor air are related with oxidative stress and decreased lung function. This study is conducted to evaluate whether exposures to VOCs could affect the airway inflammation.
Methods
40 people from a 60-bed rehabilitation hospital which had moved into new building were enrolled. Symptoms related with sick building syndrome, pulmonary function test, and FeNO were evaluated, and random urine samples were collected one week before move. Among them, 34 people were followed up with same parameters and atopy test and random urine samples were collected one week after move. Random urine samples were analyzed for metabolites of VOCs [tt-muconic acid (tt-MA), hippuric acid (HA), mandelic acid (MA), phenylglyoxylic acid (PGA), and methylhippuric acid (MHA)], oxidative stress biomarkers [malondialdehyde (MDA) and 8-oxo-29-deoxyguanosine (8-OHdG)], and urinary leukotriene E4 (uLTE4).
Results
In longitudinal analysis for 40 people before move, urinary tt-MA and MA were positively related with urinary MDA (r=0.440, p=0.005 and r=0.338, p=0.033, respectively). Urinary MDA, HA, and MA were related with decreased FEV1, FVC, and FEF25-75. Urinary PGA was related with decreased FEV1 (%) and FEF25-75. For 34 people after exposure to higher level of indoor VOCs in the new building, eye dryness, eye irritation and urinary o-MHA were increased (p=0.012, p=0.008, and p < 0.0001, respectively), and urinary level of tt-MA was decreased (p=0.012). FeNO were decreased after move (p=0.04), but uLTE4 and uLTE4/ FeNO were increased (p=0.005 and p=0.04, respectively).
Conclusion
Urinary VOCs metabolites were related with oxidative stress and decreased lung function. And exposures to higher but far below toxic level of VOCs might affect airway inflammation.