Indoor Environment and Health Effects: Protocol of an Exploratory Panel Study among Young Adults in China (China IEHE Study)

Indoor environment and health have drawn public attention worldwide. However, the joint health effects and mechanisms of exposure to different types of indoor environmental factors remain unclear. We established an exploratory panel study on indoor environment and health effects among young adults in China (the China IEHE Study) to comprehensively investigate 3M issues, including multiple indoor environmental factors, multiple health effects, and multiple omics methods for mechanism exploration. This protocol aims to systematically introduce the entire China IEHE Study. Eighty-one young adults aged 18–28 years from a university adjacent to traffic arteries in Beijing were recruited and followed up four times. Sham/real air purification intervention was simultaneously applied in a randomized crossover order. A broad range of indoor physical, chemical, and biological factors were characterized through real-time monitoring and external and internal exposure analyses. Subclinical health indices reflecting cardiopulmonary, sleep, and cognitive health were repeatedly measured in a prospective order. Various biosamples including fasting venous blood, morning urine, nasal mucosal lining fluid, and exhaled breath condensate were collected to explore the underlying biological mechanisms. The China IEHE Study comes up with an enlightening framework for future prospective studies associated with the exploration of multisystem health effects and underlying biological mechanisms of indoor exposure.