聯合國環境規劃署於17日發佈的年報中警告:「由於浪費資源的農耕方式以及未落實廢水回收,導致大量含磷肥料排放到海洋中。」
此外,年報中也提到近期關注的海洋塑膠垃圾污染問題,在於海洋中塑膠廢棄物裡具有持久性、可生物累積性且有毒性的物質。研究指出,細小的塑膠碎塊從海水和沉積物中吸收集中多氯雙酚、多氯聯苯以及殺蟲劑(DDT)。「許多污染物包含多氯聯苯等會造成許多慢性疾病,像是內分泌失調、基因突變和致癌等疾病問題。」
專家學者表示,磷排放和塑膠污染凸顯了全球廢水管理和生產消費模式均待改進。
聯合國環境規劃署執行長史坦納(Achim Steiner)表示:「磷污染和海洋塑膠廢棄物的事件,使人們關注到科學發展所產生的許多環境問題仍有待解決,這些事件也促使全球轉向綠色經濟發展,以達成更有效地利用資源,並落實永續發展和解決貧窮問題等目標。」史坦納說:「不管是在面對磷污染、塑膠垃圾或是其它任何難題,現今社會都可能會相應產生新的職業、以及更有效利用資源的產業,來解決這些問題。」
磷礦短缺 可催生新產業回收磷肥、降低磷污染
在20世紀時,磷的需求量大增,而在2011年的年報中也特別著重在磷的議題上,有部分原因是,有限的磷礦藏量是否即將耗盡的問題,已經引起激烈的討論。
目前估計有35個國家生產磷礦,蘊藏量前十大的國家依序為:阿爾及利亞、中國、以色列、約旦、俄羅斯、南非、敘利亞和美國。而在澳洲、秘魯和沙烏地阿拉伯等國家,則已經委任進行開發。有些國家和公司更不遠千里去找尋新的磷礦,甚至到那米比亞海岸的海床下尋找。
該年報建議,透過磷的全球性評估來準確地掌握磷礦在全球環境中的分佈,並預測經濟上可利用的儲備量。年報中寫到:「雖然在許多國家中有可供商業開採的磷礦,但對於沒有蘊藏磷礦的國家來說,在全球資源短缺時將會特別容易受影響。」年報建議,可以從回收廢水中重新取回磷。高達70%廢水中有含磷化合物和肥料,這些廢水都是未經處理就排放到河流或是海岸。
大量含磷、氮的化合物會增加藻華產生的機率,而藻華會加速減少漁場和可游泳區域。
其它可降低磷排放的措施,包含減少含有大量磷的表土流失和沖刷,這些磷是來自耕種後的土壤顆粒和過多的肥料化合物。
年報建議,需要有更進一步的研究來調查磷在環境中流動的方式,在農業和家畜養殖上更有效地利用磷,以及減少廢棄物對河流和海洋造成的污染。
Enormous amounts of the fertilizer phosphorus are discharged into oceans due to inefficiencies in farming and a failure to recycle wastewater, the United Nations Environment Programme warns in its 2011 Year Book released today.
An emerging concern over plastics pollution of the oceans is identified in the Year Book as "persistent, bio-accumulating and toxic substances" associated with plastic marine waste.
Research indicates that tiny pieces of plastic are adsorbing and concentrating from the seawater and sediments chemicals from polychlorinated biphenols, PCBs, to the pesticide DDT.
"Many of these pollutants, including PCBs, cause chronic effects such as endocrine disruption, mutagenicity and carcinogenicity," states the 2011 Year Book.
Experts cited in the book say that both phosphorus discharge and new concerns over plastics underline the need for better management of the world's wastes and improved patterns of consumption and production.
"The phosphorus and marine plastics stories bring into sharp focus the urgent need to bridge scientific gaps but also to catalyze a global transition to a resource-efficient Green Economy in order to realize sustainable development and address poverty," said UNEP Executive Director Achim Steiner.
"Whether it is phosphorus, plastics or any one of the myriad of challenges facing the modern world, there are clearly inordinate opportunities to generate new kinds of employment and new kinds of more efficient industries," Steiner said.
Demand for phosphorus has soared during the 20th century, and the Year Book 2011 highlighted the nutrient in part because of the heated debate over whether or not finite reserves of phosphate rock will soon run out.
An estimated 35 countries produce phosphate rock. The top 10 countries with the highest reserves are: Algeria, China, Israel, Jordan, Russia, South Africa, Syria and the United States.
New phosphate mines have been commissioned in countries such as Australia, Peru and Saudi Arabia and countries and companies are looking further afield, even to the seabed off the coast of Namibia.
The Year Book recommends a global phosphorus assessment to more precisely map phosphorus flows in the environment and predict levels of economically viable reserves.
"While there are commercially exploitable amounts of phosphate rock in several countries, those with no domestic reserves could be particularly vulnerable in the case of global shortfalls," the Year Book notes.
There is an enormous opportunity to recover phosphorus by recyling wastewater, the Year Book advises. Up to 70 percent of this water is laden with nutrients and fertilizers such as phosphorus, which currently is discharged untreated into rivers and coastal areas.
Heavy doses of nutrients such as phosphorus and nitrogen increase the risk of harmful algal blooms, which can prompt the closure of fisheries and swimming areas.
Other measures to reduce discharges include cutting erosion and the loss of topsoil where large quantities of phosphorus are associated with soil particles and excess fertilizers are stored after application.
The Year Book advises that further research is needed on the way phosphorus travels through the environment to maximize its use in agriculture and livestock production and cut waste, while reducing environmental impacts on rivers and oceans.
全文及圖片詳見:ENS報導