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Li M, Luo Z, Yan Y, Wang Z, Chi Q, Yan C, Xing B. Arsenate Accumulation, Distribution, and Toxicity Associated with Titanium Dioxide Nanoparticles in Daphnia magna. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:9636-43. [PMID: 27485179 DOI: 10.1021/acs.est.6b01215] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Titanium dioxide nanoparticles (nano-TiO2) are widely used in consumer products. Nano-TiO2 dispersion could, however, interact with metals and modify their behavior and bioavailability in aquatic environments. In this study, we characterized and examined arsenate (As(V)) accumulation, distribution, and toxicity in Daphnia magna in the presence of nano-TiO2. Nano-TiO2 acts as a positive carrier, significantly facilitating D. magna's ability to uptake As(V). As nano-TiO2 concentrations increased from 2 to 20 mg-Ti/L, total As increased by a factor of 2.3 to 9.8 compared to the uptake from the dissolved phase. This is also supported by significant correlations between arsenic (As) and titanium (Ti) signal intensities at concentrations of 2.0 mg-Ti/L nano-TiO2 (R = 0.676, P < 0.01) and 20.0 mg-Ti/L nano-TiO2 (R = 0.776, P < 0.01), as determined by LA-ICP-MS. Even though As accumulation increased with increasing nano-TiO2 concentrations in D. magna, As(V) toxicity associated with nano-TiO2 exhibited a dual effect. Compared to the control, the increased As was mainly distributed in BDM (biologically detoxified metal), but Ti was mainly distributed in MSF (metal-sensitive fractions) with increasing nano-TiO2 levels. Differences in subcellular distribution demonstrated that adsorbed As(V) carried by nano-TiO2 could dissociate itself and be transported separately, which results in increased toxicity at higher nano-TiO2 concentrations. Decreased As(V) toxicity associated with lower nano-TiO2 concentrations results from unaffected As levels in MSFs (when compared to the control), where several As components continued to be adsorbed by nano-TiO2. Therefore, more attention should be paid to the potential influence of nano-TiO2 on bioavailability and toxicity of cocontaminants.
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Affiliation(s)
- Mengting Li
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Zhuanxi Luo
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, China
- Stockbridge School of Agriculture, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Yameng Yan
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, China
| | - Zhenhong Wang
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, China
- Stockbridge School of Agriculture, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Qiaoqiao Chi
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, China
| | - Changzhou Yan
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences , Xiamen 361021, China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts , Amherst, Massachusetts 01003, United States
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