Fractional exhaled nitric oxide (FeNO) in Chinese children and its association with respiratory symptoms and home environment

The association between home environments and fractional exhaled nitric oxide (FeNO) has been insufficiently investigated. We measured FeNO levels in children aged 4-8 years (<i>N</i> = 105) in Tianjin, China, and examined their association with respiratory symptoms and various indoor environmental parameters, namely house dust mite allergens and phthalates in dust, dampness, environmental tobacco smoke (ETS) and furry pets (dogs/cats) in the home. FeNO levels were significantly higher in children with diagnosed asthma (<i>p</i> < 0.001) and pneumonia (<i>p</i> = 0.03). Exposure to Diisononyl phthalate (DiNP) - a new phthalate replacing the commonly used Di(2-ethylhexyl) phthalate (DEHP) - was significantly associated with increased FeNO in children (<i>p</i> = 0.01). In conclusion, diagnosed asthma and pneumonia were associated with increased FeNO levels in children. Exposure to DiNP may contribute to airway inflammation, as indicated by its association with increased FeNO levels. These findings underscore the importance of closely monitoring emerging contaminants to better understand their potential impacts on respiratory health.