Agricultural Plastic Pollution in China: Generation of Plastic Debris and Emission of Phthalic Acid Esters from Agricultural Films
Qian-Qian Zhang, Zhao-Rong Ma, Ya-Ya Cai, Hui-Ru Li, and Guang-Guo Ying*
Environ. Sci. Technol. 2021, 55, 18, 12459–12470
マイクロプラスチックの論文かと思って読み始めたら、農業用フィルムや温室用ビニールからのフタル酸の環境排出量推定の論文だった。
2017年の中国における農業用フィルムの使用量2,528,600トン。
そのうちの環境流出量は465,016トン。（プラスチックデブリとして。リサイクル過程と水侵食過程の合計量）
water erosionを経て水環境に流出する量は4329トン。
典型的なフタル酸エステル2種類の環境排出量（合計値）91.5トン。
（・・・さすが中国。数が大きすぎて頭の中でスケールを調整することができない。）
マルチメディアモデルを用いて野菜のフタル酸汚染について評価したところ、直接的な健康被害はない。モンテカルロ法に基づく不確実性分析あり。
Agricultural plastic films have been proven highly advantageous, but they also cause pollution of plastic debris and associated chemicals. Phthalates (phthalic acid esters, PAEs), an important additive of agricultural films, can be released and contaminate the environment. Here, we analyzed the agricultural plastic usage and assessed plastic debris in China and developed a method to estimate PAE emissions from agricultural films. Additionally, the environmental fate of PAEs was evaluated using a fugacity-based multimedia model. The agricultural plastic film usage in China in 2017 was 2,528,600 tons. After agricultural film recycling and water erosion, the plastic debris amount was estimated as 465,016 tons. The water erosion process carried 4329 tons of plastic debris into the aquatic environment. During its lifetime, the agricultural film released a total of 91.5 tons of two typical types of PAEs. PAEs from the mulching film would mostly be removed through degradation, while those from the greenhouse film accumulate in vegetables. Populated regions exhibited more serious PAE pollution in vegetables but with no immediate health risks. The model was well evaluated using comparable measured concentrations and uncertainty analysis based on the Monte Carlo method. The findings from this study demonstrate the serious agricultural plastic pollution problem and associated PAE contamination in China.
