世衛研究:PM2.5導致不良生育結果、早死 | 台灣環境資訊協會-環境資訊中心

世衛研究:PM2.5導致不良生育結果、早死

建立於 2013/02/07
編譯自2013年1月31日ENS比利時,布魯塞爾報導;藍巧軒編譯;蔡麗伶審校

車陣。(攝影:Paul Oliver)世界衛生組織(WHO)發佈報告指出,長時間暴露於空氣中的細懸浮微粒,會引發不良生育結果、兒童呼吸道疾病、動脈粥樣硬化等問題。

細懸浮微粒又稱PM2.5,也就是粒徑小於2.5微米的粒子。WHO這份報告指出,PM2.5也和神經系統發育、認知能力發展、糖尿病有關,並更加肯定細懸浮微粒與心血管和呼吸系統疾病致死的因果關係。

懸浮微粒的是由懸浮在空氣中的固態和液態粒子所組成,當中包含硫酸鹽、硝酸鹽、氨以及其他物質。人為的懸浮微粒主要來源是家用暖氣產生的廢氣、工業活動、和路上行駛的交通工具。

WHO指出,以WHO於2005年訂定的《空氣品質準則》(Air Quality Guidelines)為基準,超過80%的歐洲人暴露在超量的懸浮微粒中,而這樣的情況使每人減少8.6個月的壽命。

WHO建議於2015年以前修訂懸浮微粒《準則》,訂定更嚴格的二氧化氮(NO2)暴露值,並研擬出臭氧長期平均濃度標準。

這份報告名為《回顧空氣污染對健康方面的證據》,是WHO在歐盟執委會要求下,以2013年歐盟空氣相關政策為框架所作。

英國River Tees河口的工廠。(照片提供: FreeFoto.com/攝影:Ian Britton)歐盟環境執委波托奇尼克(Janez Potočnik)說,「歐盟的空氣政策必須要以最新的科學研究為依據,這也是我要求WHO做出這項研究的原因,研究中發現了空氣污染與人類健康之間的關聯,促使我們擴大相關政策的施行。

波托奇尼克宣告2013是歐盟「空氣政策年」,其主要計畫是向所有人凸顯乾淨空氣的重要性,並注重於增進歐盟整體空氣品質。

WHO歐洲區主任賈卡(Zsuzsanna Jakab)提到,「過去因為缺乏相關數據,所以無法針對人體健康建立空氣污染標準和法規。WHO多年來所進行的研究終於提供了首次大量的關於懸浮微粒引發之疾病的評估,也找出了空氣污染物與健康之間的關聯。」

賈卡表示,「我們相信,這個新認知最終將可以讓我們做出更嚴謹的空氣污染控制政策,進一步的保護歐洲人民的健康。」

WHO也建議更改歐盟法律,因為現行歐盟《環境空氣品質指令》規範的的PM2.5暴露限值,高達WHO《空氣品質準則》建議值的兩倍。

空氣中懸浮微粒所引發的健康問題包括空氣呼吸道疾病、心血管疾病和肺癌,這是人們長期以來就知道的;而WHO研究還發現,長期暴露在高濃度地面臭氧中,則會引發可能致死的呼吸道疾病,也會誘發有慢性疾病的人發病,嚴重者將導致死亡。

研究中也指出,暴露在臭氧中會影響認知系統發展和早產等生殖健康問題。

研究新方向:NO2 臭氧的長期暴露影響

之前的規範主要是以短期暴露影響為重點,之後將會把這些新的發現加入其中。

臭氧方面,新的研究建議對臭氧濃度做出長期空氣品質管理。

新的標準也針對NO2方面,這種有毒氣體通常是由暖氣系統、發電廠,特別是車輛引擎的燃料在燃燒過程所產生的。

報告指出,短期與長期暴露在NO2中,即便濃度是在歐盟規範的限值(規範值與WHO相同)之下,也可能導致死亡、住院、呼吸道症狀,而這個濃度與WHO的標準相同。

關於2005年WHO《空氣品質準則》

設立《準則》的目的在提供全球一個共同的標準,以減少空氣污染對人體健康的影響。由於原本的準則是以歐洲為中心,2005年新版的標準則是全球都適用,而且是由專家根據最新科學研究做出的評估,規範項目包括懸浮微粒、地表臭氧濃度、二氧化氮、二氧化硫等物質的暴露標準。

【相關文章】

Polluted Air Linked to Poor Birth Outcomes, Early Deaths
BRUSSELS, Belgium, January 31, 2013 (ENS)

Long-term exposure to fine particles of pollutants in the air can trigger adverse birth outcomes, childhood respiratory diseases and atherosclerosis, the World Health Organization warned today.

The report on particles smaller than 2.5 micrometers, or PM2.5, also suggests a link with neurodevelopment, cognitive function and diabetes, and strengthens the causal link between PM2.5 and cardiovascular and respiratory deaths.

Particulate matter consists of a mixture of solid and liquid particles suspended in the air a mix of sulphates, nitrates, ammonium, and other substances. The main sources of man-made PM include heating in households, industrial activities and road traffic.

More than 80 percent of Europeans are exposed to particulate matter levels above the 2005 WHO Air Quality Guidelines, depriving each person of 8.6 months of life, says the health agency.

The WHO review recommends a revision of the Air Quality Guidelines for particulate matter by 2015, establishing a stricter guideline for nitrogen dioxide (NO2), and the development of a guideline for long-term average ozone concentrations.

The study, "Review of evidence on health aspects of air pollution" was conducted at the request of the European Commission in the framework of the 2013 review of the European Union's air policy.

EU Commissioner for Environment Janez Potočnik said, "EU air policy must be based on the latest science. That is why I asked the WHO to undertake this research. The links it has found between air pollution and human health reinforce the case for scaling up our policy. It will be a key input to the 2013 air quality policy review."

Commissioner Potočnik has declared 2013 as the Year of Air for EU policies. The plan is to highlight the importance of clean air for all and to focus on actions to improve air quality across the EU.

"Only a few years ago in the absence of clear evidence, air pollution standards and regulations were not sufficiently targeting human health," said Zsuzsanna Jakab, WHO Regional Director for Europe. "Years of WHO-coordinated research have provided the first quantitative estimates of the burden of disease from particulate matter and have now established links between air pollutants and health outcomes."

"We are confident that this new knowledge will ultimately lead to more stringent air pollution control policies to protect the health of European citizens," she said.

WHO also recommends modifications to EU law, because the current limit value for PM2.5 in the EU's Ambient Air Quality Directive is twice as high as WHO's Air Quality Guidelines recommend.

Health effects of particulate matter in the air have long been known to include respiratory and cardiovascular diseases and lung cancer.

The WHO review found new evidence for effects of long-term exposures to ground-level ozone on respiratory mortality and on deaths among persons with predisposing chronic conditions.

Ozone exposure also impacts cognitive development and reproductive health, including preterm birth, the WHO study found.

This adds to previous findings on short-term effects which are the focus of current regulation.

The review recommends the development of an Air Quality Directive for long-term average ozone concentrations.

A new guideline is recommended for NO2, a toxic gas produced by the combustion process in heating, power generation and especially vehicle engines.

New studies have associated short-term and long-term exposure to NO2 with mortality, hospital admissions, and respiratory symptoms at concentrations at or below the current EU limit values, which are set at the same level as the WHO guidelines.

The 2005 WHO Air quality guidelines are designed to offer global guidance on reducing the health impacts of air pollution.

While the original guidelines had a European scope, the latest 2005 guidelines apply worldwide and are based on expert evaluation of current scientific evidence. They recommend limits for the concentration of particulate matter, ground-level ozone, nitrogen dioxide and sulfur dioxide.

※ 全文及圖片詳見:ENS