Heavy Metal Uptake and Toxicity in the Presence of Titanium Dioxide Nanoparticles: A Factorial Approach Using Daphnia magna.

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• 作者：Ricki R. Rosenfeldt ; Frank Seitz ; Ralf Schulz ; Mirco Bundschuh
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：June 17, 2014
• 年：2014
• 卷：48
• 期：12
• 页码：6965-6972
• 全文大小：267K
• 年卷期：v.48,no.12(June 17, 2014)
• ISSN：1520-5851

文摘

Unintentionally released titanium dioxide nanoparticles (nTiO₂) may co-occur in aquatic environments together with other stressors, such as, metal ions. The effects of P25-nTiO₂ on the toxicity and uptake of the elements silver (Ag), arsenic (As) and copper (Cu) were assessed by applying a factorial test design. The test design consisted of two developmental stages of Daphnia magna, two levels of nTiO₂ (0 versus 2 mg/L) as well as seven nominal test concentrations of the respective element. The presence of nTiO₂ increased Ag toxicity for juveniles as indicated by a 40% lower 72-h EC₅₀, while the toxicities of As and Cu were reduced by up to 80%. This reduction was even more pronounced for Cu in the presence of dissolved organic carbon (i.e., seaweed extract) and nTiO₂. This outcome coincides with the body burden of the elements, which was elevated 2-fold for Ag and decreased 14-fold for Cu in the presence of nTiO₂. Although the underlying mechanisms could not be uncovered, the data suggest that the carrier function of nTiO₂ plays a central role. However, to understand the processes and mechanisms occurring in the field due to the presence of nTiO₂ further systematic investigations considering environmental variables and nanoparticle characteristics are required.