研究目的
全球對塑料汙染的關注日益增加，這引起了對該汙染主要貢獻物質的關注。吸管被認為是主要的汙染源，導致全球對塑料吸管使用的強烈抗議。這也導致了塑料吸管替代材料日益普及。本文比較了南非五種吸管替代材料的選擇造成的環境影響。
研究方法
本文研究了五種吸管材料，包括一次性使用的吸管材料（聚丙烯，紙和聚丙交酯）和重複使用的吸管材料（玻璃和鋼）。塑料吸管是唯一用當地材料生產的，玻璃和鋼製吸管則是用進口材料製造的，紙和聚丙交酯吸管是進口的。本研究功能單位為每人每年消耗的塑料吸管量，相當於36個一次性吸管和1個可重複使用的吸管。本研究採用Recipe Midpoint (H)方法進行環境影響評估，共考慮了18種環境影響類別。基於所選材料的洩漏傾向及其可降解性，探討其潛在的海洋環境影響。
結果與討論
研究結果顯示紙質吸管比塑料吸管具有較低的溫室氣體排放量，這主要是由材料的性能引起的。在南非，煤炭是生產聚丙烯的主要原料，這與歐洲和美國主要由原油或天然氣為原料生產的聚丙烯相比，煤炭的碳強度更高。玻璃吸管和鋼製吸管需要分別使用大約23-39次和37-63次，所排放的溫室氣體才能與一次性使用的吸管材料相平衡。總的來說，吸管材料的生產過程是主要汙染源。與距離相比，運輸（包括進口）的相對貢獻更依賴於運輸方式，而不是距離。對於可重複使用的吸管來說，洗滌水溫度也顯著影響著排放。人們普遍認為可重複使用的吸管不太可能進入海洋環境。研究還發現一次性吸管的洩漏率為38％，其中紙張是唯一的海洋可降解材料。
研究結論
總體而言，與其他一次性吸管相比，紙質吸管在大多數環境類別中的影響最小，玻璃吸管相比於鋼鐵吸管對環境更有益。在海洋汙染方面，可重複使用的吸管被認為構成的風險最小。由於紙的可降解性，紙在各種處置方案中的潛在影響最小。
Abstract
Purpose
The increasing global concern surrounding plastic pollution has resulted in a spotlight being placed on major contributors. Straws have been identified as a top contributor in this regard leading to a global outcry against plastic straws. This has resulted in the increasing popularity of plastic straw material alternatives. This study compares the environmental impacts associated with five straw material options available in South Africa.
Methods
The straw materials compared include disposable options (polypropylene, paper and polylactide) and reusable straws (glass and steel). Plastic straws were the only option which are locally produced from local materials, whereas glass and steel straws are manufactured from imported materials and paper and polylactide straws are imported. The functional unit was based on an annual straw consumption per capita, which equates to 36 disposable straws and 1 reusable straw. The impact assessment was conducted using the Recipe Midpoint (H) method, which took into consideration 18 impact categories. The potential marine pollution impacts were explored based on the leakage propensity of the material option coupled with its degradability.
Results and discussion
The paper straw was found to have lower climate change emissions than the plastic one, which was mainly caused by the performance of the material. In South Africa, coal is used as a primary feedstock for polypropylene production making it more carbon-intensive in comparison with polypropylene produced in Europe and the USA which is primarily from crude oil and/or natural gas feedstocks. Glass and steel straws would require 23–39 and 37–63 uses respectively to break even with climate change emissions associated with disposable options. Overall, material production was the major contributor to straw emissions. The relative contribution of transportation, including import, was more dependent on the transportation mode compared with distance. For reusable straws, the washing water temperature was found to notably influence emissions. At end-of-life, reusable straws were considered unlikely to enter the marine environments. Disposable straws were found to have a leakage rate of 38%, with paper being the only marine degradable material.
Conclusions
Overall, paper straws had the least impacts in the majority of impact categories in comparison with other disposable options and glass was more favourable to steel. In terms of marine pollution, reusable straws were deemed to pose the least risk due to their unlikelihood to be polluted. Paper was associated with the least potential impacts of the disposal options, due to its degradability.