Earthworm Sublethal Responses to Titanium Dioxide Nanomaterial in Soil Detected by 1H NMR Metabolomics

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• 作者：Melissa L. Whitfield 脜slund ; Heather McShane ; Myrna J. Simpson ; Andr茅 J. Simpson ; Joann K. Whalen ; William H. Hendershot ; Geoffrey I. Sunahara
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：January 17, 2012
• 年：2012
• 卷：46
• 期：2
• 页码：1111-1118
• 全文大小：281K
• 年卷期：v.46,no.2(January 17, 2012)
• ISSN：1520-5851

文摘

¹H NMR-based metabolomics was used to examine the response of Eisenia fetida earthworms raised from juveniles for 20鈥?3 weeks in soil spiked with either 20 or 200 mg/kg of a commercially available uncoated titanium dioxide (TiO₂) nanomaterial (nominal diameter of 5 nm). To distinguish responses specific to particle size, soil treatments spiked with a micrometer-sized TiO₂ material (nominal diameter, <45 渭m) at the same concentrations (20 and 200 mg/kg) were also included in addition to an unspiked control soil. Multivariate statistical analysis of the ¹H NMR spectra for aqueous extracts of E. fetida tissue suggested that earthworms exhibited significant changes in their metabolic profile following TiO₂ exposure for both particle sizes. The observed earthworm metabolic changes appeared to be consistent with oxidative stress, a proposed mechanism of toxicity for nanosized TiO₂. In contrast, a prior study had observed no impairment of E. fetida survival, reproduction, or growth following exposure to the same TiO₂ spiked soils. This suggests that ¹H NMR-based metabolomics provides a more sensitive measure of earthworm response to TiO₂ materials in soil and that further targeted assays to detect specific cellular or molecular level damage to earthworms caused by chronic exposure to TiO₂ are warranted.