研究發現：室內盆栽並不能真正改善空氣質量

在室內放上綠色盆栽讓人感覺良好，似乎空氣也變得清新起來，然而研究發現，室內盆栽並不能有效地淨化空氣，效果遠不如開窗通風和空氣淨化器。

In 1989, NASA conducted its famous Clean Air study to see whether common houseplants might purify indoor air by removing toxins in addition to absorbing carbon dioxide and releasing oxygen. It worked, and while plants are still capable of absorbing harmful toxins in the air, new research suggests that potted plants’ ability to improve air quality in the home or office is largely overstated and buries a more effective solution to keeping the air clean.

1989年，美國國家航空航天局進行了著名的清潔空氣研究，以觀察普通室內植物除了吸收二氧化碳和釋放氧氣之外，是否還能通過排除毒素來淨化室內空氣。當時的研究證明這種方法起到了作用。但儘管植物能夠吸收空氣中的有害物質，新研究卻表明，盆栽植物改善家庭或辦公室空氣質量的能力在很大程度上被誇大了，使我們忽視了一個保持空氣清潔的更有效的辦法。

Writing in the Journal of Exposure Science and Environmental Epidemiology, researchers found that natural ventilation of indoor environments dilutes concentrations of potentially harmful air pollutants much faster than a plant is capable of extracting them.

研究人員在《暴露科學與環境流行病學》雜誌上發表文章稱，室內自然通風稀釋有害空氣污染物濃度的速度遠遠快於植物吸收這些污染物的速度。

"The best way to have a healthy home is to try to reduce indoor emissions, ventilate well (especially when doing high impact emissions like cooking), and using filtration for certain pollutants (e.g. particulate matter),” study author Michael Waring of Drexel University told IFLScience.

該研究的作者、德雷塞爾大學的邁克爾·沃林告訴IFLScience網站說：“擁有一個健康家庭的最佳方式是減少室內排放物、保持通風良好（尤其是在從事烹飪等排放量大的活動時），並且對某些污染物（比如顆粒物）使用過濾器。”

Where NASA and similar studies went wrong is that they conducted their experiments in sealed chambers in laboratories, which do not accurately mimic the many factors that influence our indoor environments.

美國國家航空航天局和類似的研究出錯的地方是，他們都是在實驗室的密封環境中進行實驗，這並沒有準確地模擬影響普通家庭室內環境的許多因素。

To come to their conclusions, Waring and his team systematically reviewed a dozen studies by taking the available VOC removal data from different studies and converting the findings into a common metric they nicknamed the clean air delivery rate (CADR). CADR was used to parameterize air cleaning indoors. Using that metric, the impact of plants’ ability to remove VOCs was compared to the removal ability of other kinds of ventilation, both natural and mechanical.

爲了得出他們的結論，沃林和他的團隊系統地回顧了十幾項研究，他們從不同研究中提取了去除揮發性有機化合物的數據，並將這些數據轉換成一個他們稱之爲清潔空氣排放率的通用指標。利用清潔空氣排放率對室內空氣淨化進行參數化，將植物去除揮發性有機化合物的能力與自然通風或機械通風的去除能力進行了比較。

VOC: abbr. 揮發性有機化合物（volatile organic compounds）

"In a small office, you would have to have somewhere between 100 to 1,000 plants to have the same air cleaning impact of ventilation at 1 air change per hour,” said Waring.

沃林表示：“在一個小型辦公室裏，你必須要有100甚至1000盆植物才能達到每小時換氣1次所達到的空氣淨化效果。”

To understand the effects of indoor pollution, Waring says to think of it in three categories. The first is volatile organic compounds, which are gas-phase molecules that are emitted from many sources such as consumer products, cleaners, and building materials. These tend to reside in the air itself.

爲了理解室內污染的影響，沃林說可以將污染物分爲三類。第一種是揮發性有機化合物，它是氣相分子，從消費品、清潔劑和建築材料等多種來源排放出來，往往存在於空氣本身。

The second is semi-volatile organic compounds (SVOCs), which are in things like pesticides, flame retardants, or plasticizers. These tend to be 'sticky' and stick to surfaces indoors and may persist for months or years.

第二種是半揮發性有機化合物，它們存在於殺蟲劑、阻燃劑或增塑劑等物質中。這些粘性物質會粘在室內的表面上，並且可能會留存數月或數年。

Lastly, particulate matter, which can be solid or liquid, may be found floating in the air. These indoor pollutants have been linked to asthma, allergic reactions, irritation, and other respiratory ailments.

最後，則是漂浮在空氣中的固體或液體的顆粒物質。這些室內污染物與哮喘、過敏反應、刺激和其它呼吸系統疾病有關。

That doesn’t mean you should chuck out your plants just yet. Waring says that although houseplants do not clean the air under typical settings, houseplants have many benefits, most of which are psychological.

不過，這一研究結果並不意味着你現在就應該扔掉你的植物。沃林表示，雖然室內植物不能在典型環境中高效地淨化空氣，但室內植物有許多好處，其中大部分是心理上的好處。