Do Polystyrene Beads Contribute to Accumulation of Methylmercury in Oysters?
Do Polystyrene Beads Contribute to Accumulation of Methylmercury in Oysters?
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DOI：
10.1007/s00244-021-00848-w
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发表时间：
2021-04-24
影响因子：
4
通讯作者：
Yamamoto，Megumi
中科院分区：
文献类型：
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作者：
Kataoka，Chisato;Yoshino，Kenji;Yamamoto，Megumi
为了弄清微塑料是否会导致水生生物甲基汞（MeHg）的生物积累增加，我们研究了甲基汞在聚苯乙烯珠（PBs）上的吸附模式，并通过对甲基汞吸附的PB在牡蛎长牡蛎中的吸收来评估甲基汞的积累。将mehg -半胱氨酸偶联物以10、100和1000µg/L的汞浓度加入海水中，将φ= 0.02、0.2和2µm的聚苯乙烯珠浸泡在海水中24 h，然后用还原汽化法测定吸附在PBs上的总汞（T-Hg）的浓度。直径为0.02、0.2和2µm的PBs在加入了100µg/L汞的2ml海水中浸泡时，T-Hg浓度分别为10.6±0.4、1.8±0.1和1.3±0.1 ng/mg-PBs。因此，当直径较小的PBs存在时，MeHg在PBs上的吸附效率更高。然后，将1mg PBs浸泡在含100µg/L MeHg的2ml海水中24 h，加入到含1l海水的牡蛎池中。在暴露6小时后测量牡蛎的t -汞浓度。在PBs（干重0.30±0.01 ~ 0.37±0.05 ng/mg）存在和不存在PBs（干重0.36±0.03 ng/mg）的情况下，牡蛎T-Hg浓度与MeHg无显著差异。我们的研究结果表明，海水中PBs的存在对牡蛎对甲基汞的吸收影响不大。
To clarify whether microplastics contribute to elevated bioaccumulation of methylmercury (MeHg) in aquatic organisms, we studied the sorption pattern of MeHg on polystyrene beads (PBs) and evaluated MeHg accumulation, via uptake of MeHg-adsorbed PB, in the oysterCrassostrea gigas. MeHg-cysteine conjugates were added to seawater at 10, 100, and 1000 µg/L as Hg. Polystyrene beads (φ= 0.02, 0.2, and 2 µm) were immersed in the seawater for 24 h. The concentrations of total mercury (T-Hg) adsorbed onto the PBs were then measured using the reduction vaporization method. T-Hg concentrations for the PBs with diameters of 0.02, 0.2, and 2 µm were 10.6 ± 0.4, 1.8 ± 0.1, and 1.3 ± 0.1 ng/mg-PBs, respectively, when immersed in 2 mL of MeHg-added seawater (100 µg/L as Hg). Thus, the adsorption efficiency of MeHg onto PBs was higher in the presence of smaller diameter PBs. Next, 1 mg of PBs immersed in 2 mL of seawater containing 100 µg/L of MeHg for 24 h was added to an oyster tank containing 1 L of seawater. The T-Hg concentration of the oysters was measured after 6 h of exposure. No significant difference was found in the T-Hg concentration of oysters in the presence of PBs (0.30 ± 0.01 to 0.37 ± 0.05 ng/mg as dry weight) with MeHg and in the absence of PBs (0.36 ± 0.03 ng/mg as dry weight). Our results suggest that the presence of PBs in seawater has little effect on MeHg uptake by oysters.