The Danger of Indoor Air Pollution  
     Considering we breathe 23,000 times a day and move around 435 cubic feet of air, this is a major concern. Indoor air pollution is now considered a major environmental health problem. Among the fifteen criteria for “the healthy residence” set up by World Health Organization, eight of them which are important symbols of a high life quality are relevant to the indoor air quality.  
     为了节约能源,现代建筑物密闭化程度增加,无法无限制的加大中央空调换气频率,致使室内污染物不能及时排出室外,造成室内空气质量的恶化,出现 “亚健康” 、“空调病” 等现象,世界卫生组织将此定义为“致病建筑物综合症”。但是大楼若被完全密闭,污染物如霉菌容易滋生。当空气流通时,这些霉菌以及其他建筑材料、油漆、家具等所释放出的有害化学气体例如甲醛,苯等就会在整个大楼内流动,但却不会被净化。
     In order to save energy, we are sealing buildings with better windows, insulation, and moldings, which results in poor indoor air quality, odor and related air conditioning disease, which is named ‘sick building syndrome”. When buildings are sealed, contaminants such as mold can build up,  As air passes through it, the mold along with harmful chemicals gases such as formaldehyde and benzene given off by construction materials, paints, and furniture is picked up and circulated. 
      美国环保署研究表明室内空气污染物的浓度是户外的2—5倍。当我们把大楼严严实实地“密封”起来时,这个倍数可上升至100倍。 高度的室内空气污染是人们所关心的一个重要问题,因为大部分人90%的时间是在室内度过的。
      U.S. EPA studies indicate that indoor levels of air pollutants may be 2-5 times higher than outdoor levels Indoor pollutant levels can reach 100 times that of outdoor levels when we effectively “seal” our building. High levels of indoor air pollutants may be of particular concern because most people spend up to 90% of their time indoors. 
     Research shows that people who work or live in a condition with harmful gases such as formaldehyde are more suseptable to some diseases. Benzene is recognized as carcinogenic by the World Health Organization, which can lead to cancers such as leucocythemia and lung cancer. Harmful gases can have an harmful effect on women, particularly those who are pregnant, inducing miscarriages. 
      新世纪流感病毒几乎每年都发生,其中重要的传播途径为空气的飞沫传播。2003年SARS, 近年禽流感,手足口病及北美爆发影响世界的猪流感H1N1敲响警钟。如何积极预防以空气为媒介传播的流行性疾病,保护我们的健康是一项艰巨的任务。
      The influenza virus occurs nearly every year, primarily diseminated through the air. The SARS in 2003 and the Bird Flu and Swine Flu H1N1 that North America erupted and affect the world sounded the alarm. How to prevent the epidemic disease through air as medium to disseminate actively is a challenging task.