摘要

微塑料是越来越受关注的新兴污染物。尽管在农田土壤中发生了微塑料，但对稻 - 鱼共培养生态系统中微塑料的了解却很有限。在这项研究中，我们调查了上海三个稻鱼养殖站的微塑料分布。在非水稻和水稻种植期间，使用NaCl密度提取，H2O2消化和微傅里叶变换红外光谱法系统地测定水，土壤和水生动物（鳗鱼，泥鳅和小龙虾）中的微塑料。结果表明，水，土壤和水生动物样品的平均微塑性丰度分别为0.4±0.1itemsL-1,10.3±2.2itemskg-1,1.7±0.5items -1。我们发现从非水稻期到水稻种植期的水，土壤和动物样品中微塑性丰度的增加趋势。几乎所有的微塑料都存在于动物的消化道中。主要的微塑料是小的（<1mm）聚乙烯和聚丙烯纤维，颜色为白色和半透明。在环境和动物样品中类似地发现了微塑料的尺寸，形状，颜色和聚合物类型分布。此外，水生动物的微生物丰度与农田土壤的丰度相关。本研究首次揭示了稻 - 鱼养殖生态系统中微塑性污染的发生和特征，表明了微生物在农业生态系统中的潜在生态风险。

Microplastics are emerging contaminants of increasing concern. Despite the occurrence of microplastics in farmland soils, the knowledge on microplastics in rice-fish co-culture ecosystems is limited. In this study, we investigated the distribution of microplastics in three rice-fish culture stations in Shanghai. During non-rice and rice-planting periods, microplastics in water, soils and aquatic animals (eel, loach and crayfish) were systematically assayed using methods of NaCl density extraction, H2O2 digestion and micro-fourier transform infrared spectroscopy. Results showed that average microplastic abundances were 0.4 ± 0.1 items L-1, 10.3 ± 2.2 items kg-1, 1.7 ± 0.5 items individual-1 in water, soils and aquatic animal samples, respectively. We found an increasing trend in microplastic abundances in water, soil and animal samples from non-rice period to rice-planting period. Almost all of microplastics were found in digestive tracts of animals. Major microplastics were small (<1 mm) polyethylene and polypropylene fibers, with color of white and translucent. Size, shape, color and polymer type distributions of microplastics were similarly found in environmental and animal samples. Moreover, microplastic abundances in aquatic animals correlated to abundance in farmland soils. This study, for the first time, reveals the occurrence and characteristics of microplastic pollution in rice-fish culture ecosystem which suggests the potential ecological risks of microplastics in the agroecosystem.

https://www.ncbi.nlm.nih.gov/pubmed/30586807