On May 31, is "world no tobacco day" is the theme of the 2007 no tobacco day "to create a smoke-free environment", aims to remind the public to know the harm of passive smokers, and environmental tobacco smoke.

　　Since the 1950 s, global has a large number of epidemiological studies confirm that smoking is the leading risk factors of lung cancer. In order to cause the attention of the international community for tobacco harm to people's health, suggested in November 1987, the world health organization will every year on April 7, as the "world no tobacco day", and in 1988 began to perform. Since 1989, the world no tobacco day to May 31 of each year.

　　Contains more than 1400 kinds of ingredients in cigarettes. Smoke smoke has more than 40 carcinogens, there are a dozen will material to promote the development of cancer, one of the biggest harm to human body is nicotine, carbon monoxide and various other metal compounds. A smoke contains nicotine is enough to kill a mouse. Cigarette smoke in the combination of a large amount of carbon monoxide with hemoglobin ability in 240-300 times larger than oxygen, seriously weakened the ability of red blood cells carry oxygen, therefore, smoking increased blood clotting, which easily cause myocardial infarction, stroke, cardiovascular diseases such as myocardial ischemia. More seriously, smokers also seriously hamper others health. The research results show that smokers smoke harm to others is greater than his own.

　　5月31日是 “世界無煙日”2007年無煙日的主題是“創(chuàng)建無煙環(huán)境”，旨在提醒公眾認(rèn)識(shí)煙草煙霧對(duì)被動(dòng)吸煙者和環(huán)境的危害。

　　自20世紀(jì)50年代以來，全球范圍內(nèi)已有大量流行病學(xué)研究證實(shí)，吸煙是導(dǎo)致肺癌的首要危險(xiǎn)因素。為了引起國(guó)際社會(huì)對(duì)煙草危害人類健康的重視，世界衛(wèi)生組織1987年11月建議將每年的4月7日定為“世界無煙日”，并于1988年開始執(zhí)行。自1989年起，世界無煙日改為每年的5月31日。

　　香煙中含有1400多種成分。吸煙時(shí)產(chǎn)生煙霧里有40多種致癌物質(zhì)，還有十多種會(huì)促進(jìn)癌發(fā)展的物質(zhì)，其中對(duì)人體危害最大的是尼古丁、一氧化碳和多種其它金屬化合物。一支煙所含的尼古丁就足以殺死一只小白鼠。香煙煙霧中大量的一氧化碳同血紅蛋白的結(jié)合能力比氧大240—300倍，嚴(yán)重地削弱了紅細(xì)胞的攜氧能力，因此，吸煙使血液凝結(jié)加快，容易引起心肌梗塞、中風(fēng)、心肌缺氧等心血管疾病。更為嚴(yán)重的是，吸煙者還嚴(yán)重妨礙他人健康。研究結(jié)果表明，吸煙者吸煙時(shí)對(duì)旁人的危害比對(duì)他自己還大。