Asthma symptoms among Chinese children: the role of ventilation and PM10 exposure at school and home

SETTING: Respiratory symptoms in relation to environment in Taiyuan, China. OBJECTIVE: To study associations between school/home exposure and prevalence of respiratory symptoms and self-reported respiratory infections (RIs) among students. DESIGN: A total of 2134 pupils from 10 schools answered a questionnaire; air pollution at school was measured. RESULTS: The prevalence of current wheeze, daytime attacks of breathlessness, nocturnal cough, nocturnal respiratory symptoms and RI was respectively 4.4%, 18.7%, 11.6%, 3.6% and 32.3%. Environmental tobacco smoke (ETS) at home was associated with daytime attacks of breathlessness (OR 1.41), nocturnal cough (OR 1.41) and RI (OR 1.26). Redecoration or indoor painting at home was associated with wheeze (OR 2.02), daytime attacks of breathlessness (OR 1.57) and nocturnal symptoms (OR 1.83). Dampness or mould at home was associated with daytime attacks of breathlessness (OR 1.68), nocturnal cough (OR 1.68) and RI (OR 1.69). Particulate matter of diameter <= 10 microns (PM10) in the classroom was associated with nocturnal cough (OR 1.20/10 mu g/m(3)). PM10 outside school was associated with daytime attacks of breathlessness (OR 1.07/10 mu g/m(3)) and nocturnal cough (OR 1.13/10 mu g/m(3)). Indoor carbon dioxide, a marker of poor ventilation (OR 1.52/1000 parts per million), and relative humidity (RH) (OR 1.33/10%) were associated with nocturnal cough. CONCLUSION: Dampness, redecoration and ETS at home, as well as poor ventilation flow, and high RH and PM10 concentration at school may influence respiratory health.