Common cold among young adults in China without a history of asthma or allergic rhinitis - associations with warmer climate zone, dampness and mould at home, and outdoor PM10 and PM2.5.

This paper studied associations between reported common cold and home dampness and mould, cleaning habits and ventilation, climate and outdoor air pollution in China among young adults without asthma or allergic rhinitis. Parents of children attending day care in eight Chinese cities answered a questionnaire on their health and home environment (75% response rate). We restricted the population to subject without asthma or allergic rhinitis (N = 37,275). Temperature and air pollution data was obtained from monitoring stations. Associations were estimated by multilevel logistic regression. Totally 12.5% reported common cold (≥3 colds) and 1.6% frequent common cold (≥5 colds) in the past 12 months. Female gender (OR = 1.53; 95% CI 1.37-1.71), residents in southern China (OR = 1.89; 95% CI 1.16-3.07) and living in homes with water leakage (OR = 1.32; 95% CI 1.16-1.50), mould odour (OR = 1.48; 95% CI 1.28-1.72), indoor mould (OR = 1.47; 95% CI 1.28-1.70), condensation on window panes (OR = 1.42; 95% CI 1.32-1.52) and damp bed clothing (OR = 1.19; 95% CI 1.11-1.28) were associated with common cold. Having many signs of dampness increased ORs. Daily cleaning (OR = 0.91; 95% CI 0.85-0.97) and mechanical ventilation in kitchen or bathroom (OR = 0.75; 95% CI 0.64-0.89) were protective. Higher mean ambient temperature (OR = 1.11 per °C; 95% CI 1.02-1.21), PM10 (OR = 1.17 per 10 μg/m3; 95% CI 1.14-1.21) and PM2.5 (OR = 1.28 per 10 μg/m3; 95% CI 1.20-1.37) were associated with common cold. The association with particulate air pollution was stronger in southern China. Similar associations were found for frequent common cold. In conclusion, indoor dampness and mould, a warmer climate and PM10 and PM2.5 can be associated with reported common cold. Further intervention and prospective studies are needed to verify causality of observed association in this cross-sectional study.