世衛組織報告:市區空氣污染謀害百萬性命 | 台灣環境資訊協會-環境資訊中心

世衛組織報告:市區空氣污染謀害百萬性命

2011年10月05日
摘譯自2011年9月30日ENS瑞士,日內瓦報導;段譽豪編譯;蔡麗伶、洪美惠審校

2008年4月,埃及開羅的空氣汙染將金字塔籠罩在煙霧之中。圖片來自:Nina Hale相本。世界衛生組織(WHO)科學家尼拉(Maria Neira)表示,「全球各地的城市空氣,往往被廢氣、工廠的煙霧或是燃煤電廠的煙塵厚厚遮蓋,許多國家沒有空氣汙染法規,而即使有法規的國家,國家標準與執法狀況也存在著顯著差異。」

世界衛生組織估計,全球每年有超過200萬人死於室內外空氣污染中的微小顆粒。

直徑10微米以下的懸浮微粒(PM10)是城市空氣汙染的重要指標,也是城市中常見與健康風險有關的複雜混合汙染物。

小型懸浮微粒可以進入肺部深處,也能夠進入血液中,造成許多器官系統受損。暴露在這些顆粒中可能引起心臟病、肺癌、哮喘以及急性下呼吸道感染。

世界衛生組織對PM10懸浮微粒的標準是平均每立方公尺20微克,但新的數據顯示,某些城市的懸浮微粒量高達300(µg/m3)。

2011年1月,印度新德里的空氣污染狀況。圖片來自:Jean-Etienne Minh-Duy Poirier相本。絕大多數的城市居民,每年PM10暴露總量已超過WHO訂定的空氣品質標準。數據顯示,目前只有少數城市空氣品質符合WHO的標準。

以2008年為例,估計城市中因為室外空氣污染造成的死亡人數達134萬人。如果能夠普遍達到WHO的標準,2008年有109萬人可以免於死亡。

因城市空氣污染所造成的死亡人數,已經從2004年推估的115萬人向上攀升。與城市空氣污染相關的死亡人數預估值增加,與幾項原因有關,如近年空氣污染濃度上升、城市人口增加、數據的可用性以及取得方法的改善。

WHO呼籲更加重視城市空氣污染造成的健康風險,實施有效的政策並嚴密監控市區的狀況。

每立方公尺的懸浮微粒量從70微克降到20微克,可以降低15%的死亡率,這對公共衛生提升有很大的助益。

在開發中以及已開發國家之中,城市的空氣污染最大的來源是汽車運輸、小型製造業等工業活動、使用煤炭等生物燃料烹飪或取暖,燃煤電廠。

WHO歐洲健康與環境中心(總部於德國波昂)主任Michal Krzyzanowski博士說,「必須要綜合國際協議、國家政策以及地方行動來降低污染問題,並且減少污染對健康造成的廣泛影響。」

WHO: Millions Dying of Urban Air Pollution
GENEVA, Switzerland, September 30, 2011 (ENS)

"Across the world, city air is often thick with exhaust fumes, factory smoke or soot from coal burning power plants," says Dr. Maria Neira of the World Health Organization. "In many countries there are no air quality regulations and, where they do exist, national standards and their enforcement vary markedly."

WHO estimates more than two million people die every year from breathing in tiny particles present in indoor and outdoor air pollution.

PM10 particles, measuring 10 micrometers or less, are an important indicator of urban air pollution and the health risks associated with the complex mixtures of pollutants typically found in cities.

The smaller PM10 particles are able to penetrate deep into the lungs, and also to cross into the blood, causing damage in many organ systems. Exposure to these particles can cause heart disease, lung cancer, asthma, and acute lower respiratory infections.

The WHO air quality guidelines for PM10 particles is 20 micrograms per cubic metre (µg/m3) as an annual average, but the new data shows that average PM10 in some cities has reached up to 300 µg/m3.

The great majority of urban populations have an average annual exposure to PM10 particles in excess of the WHO Air Quality guidelines. Only a few cities currently meet the guideline values, the data show.

For 2008, the estimated mortality attributable to outdoor air pollution in cities amounts to 1.34 million premature deaths. If the WHO guidelines had been universally met, an estimated 1.09 million deaths could have been prevented in 2008.

The number of deaths attributable to urban air pollution has increased from the previous estimation of 1.15 million deaths in 2004.

The increase in the mortality estimated to be attributable to urban air pollution is linked to recent increases in air pollution concentrations and in urban population size, as well as improved data availability and methods employed.

WHO is calling for greater awareness of health risks caused by urban air pollution, implementation of effective policies and close monitoring of the situation in cities.

A reduction from an average of 70 µg/m3 of PM10 to an annual average of 20 µg/m3 of PM10 is expected to yield a 15 percent reduction in mortality - considered a major public health gain.

In developed as well as developing countries, the largest contributors to urban outdoor air pollution include motor transport, small-scale manufacturers and other industries, burning of biomass and coal for cooking and heating, as well as coal-fired power plants.

"Local actions, national policies and international agreements are all needed to curb pollution and reduce its widespread health effects," said Dr. Michal Krzyzanowski, head of the WHO European Centre for Environment and Health in Bonn, Germany.