The study is an observational research, which will recruit the community migratory old people and children at school using cluster sampling in Sanya by Sanya Maternal and Child Health Care Hospital (Sanya Women and Children's Hospital). Sanya Central Hospital(Hainan Third People's Hospital) and People's Hospital of Sanya will assist to diagnose old people disease. The data of climate and environment will be obtained from Sanya Meteorological Administration and Sanya Municipal Ecology and Environment Bureau.
1. The primary purpose is to investigate the influence of the unique tropical climate and environmental factors on the migratory old people with diseases such as asthma, allergic rhinitis, COPD or atopic dermatitis in Sanya from northern China, and to provide scientific evidence for publicity of the tourism and the health care industry.
2. The secondary purpose is to investigate prevalence and risk factors of asthma, allergic rhinitis and atopic dermatitis among children in Sanya, which will provide a base for prevention and control strategies.
3. The third purpose is to retrospectively analyze the influence of climate and environmental factors in Sanya on children with asthma, allergic rhinitis and atopic dermatitis in the past decade, and a comparative analysis of the incidence on children in Sanya and Shanghai.
