Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Science, Shantou University, Shantou, Guangdong, 515063, China.
Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, 999077, Hong Kong, China.
Ecotoxicol Environ Saf. 2020 Apr 15;193:110356. doi: 10.1016/j.ecoenv.2020.110356. Epub 2020 Feb 25.
Microplastics have a strong affinity for potentially toxic organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). Since 2005, the International Pellet Watch used plastic pellets to monitor hydrophobic organic contaminants in marine environments. We examined the spatial distribution and sources of 16 PAHs and eight OCPs on microplastics (pellets, fragments, and foam) collected from eastern Guangdong beaches with the goal of evaluating the feasibility of exclusively using pellets in global monitoring of hydrophobic organic contaminants. The ∑PAH and ∑OCP concentrations ranged from 11.2 to 7710 ng g and 2.2-1970 ng g, respectively. Although inter-site and regional differences were insignificant in fragments and foam, regional differences were observed in ∑OCP concentrations on pellets samples collected at the estuary mouth and the distributary (p < 0.05). No regional difference in ∑PAH concentration on microplastics was observed, except between fragments from the remote beach and those from the distributary (p = 0.015) and the estuary mouth (p = 0.015). The compositional profiles of PAHs revealed that PAHs with 2-4 rings were more dominant than those with >4 rings. Considering low molecular weight PAHs are less hydrophobic and more toxic; the results suggest low molecular weight PAHs may pose a significant risk to marine organisms. This study shows that the International Pellet Watch could offer critical data on source and transport of microplastic-associated OCPs but may overlook critical vehicles of PAHs in coastal environments such as foam.
微塑料对多环芳烃（PAHs）和有机氯农药（OCPs）等潜在有毒有机污染物具有很强的亲和力。自 2005 年以来，国际颗粒观察组织一直使用塑料颗粒来监测海洋环境中的疏水性有机污染物。我们研究了从广东东部海滩采集的微塑料（颗粒、碎片和泡沫）中 16 种 PAHs 和 8 种 OCP 的空间分布和来源，目的是评估仅使用颗粒在全球监测疏水性有机污染物方面的可行性。∑PAH 和∑OCP 的浓度范围分别为 11.2-7710ng/g 和 2.2-1970ng/g。尽管碎片和泡沫中的各站位和区域之间没有显著差异，但在河口和分流口采集的颗粒样本中∑OCP 浓度存在区域差异（p<0.05）。除了来自偏远海滩的碎片与来自分流口（p=0.015）和河口（p=0.015）的碎片之间存在差异外，微塑料上∑PAH 浓度没有观察到区域差异。多环芳烃的组成特征表明，具有 2-4 个环的多环芳烃比具有>4 个环的多环芳烃更为优势。考虑到低分子量的 PAHs 疏水性较低且毒性更大；结果表明，低分子量的 PAHs 可能对海洋生物构成重大风险。本研究表明，国际颗粒观察组织可以提供有关微塑料相关 OCP 来源和传输的关键数据，但可能会忽略沿海环境中泡沫等 PAHs 的重要载体。
