Document Detail


Non-monotonic concentration-response relationship of TiO2 nanoparticles in freshwater cladocerans under environmentally relevant UV-A light.
MedLine Citation:
PMID:  24507152     Owner:  NLM     Status:  In-Data-Review    
Abstract/OtherAbstract:
The effects of UV-A on the toxicity of TiO2 nano-particles (NPs) were evaluated using Moina macrocopa and Daphnia magna under environmentally relevant level of UV-A. The waterfleas were exposed to TiO2 NPs with different sizes of ~298nm, ~132nm, or ~72nm for up to 48h, with or without UV-A light. Whole body reactive oxygen species and transcription of antioxidant enzyme genes were measured, as well as the survival of the waterflea. In the presence of UV-A, the survival rates of M. macrocopa significantly decreased in concentration dependent way until ~1mg/L TiO2 NPs, but the survivals were reversed at greater concentrations. This peculiar non-monotonic trend of concentration-response relationship might be explained by changes of particle size under different light conditions. TiO2 NPs within a certain size range could be trapped in the filter apparatus and exert toxicity, and the NPs of greater size were subject to either precipitation or ingestion leading to no or little toxicity. Observed TiO2 toxicity was associated with oxidative stress in the filter apparatus. The results of this study showed that the size change due to UV-A irradiation should be considered in evaluation of ecological risks of TiO2 NP.
Authors:
Jungkon Kim; Sangwoo Lee; Chul-Min Kim; Jihyun Seo; Yena Park; Dongwook Kwon; Song-Hee Lee; Tae-Hyun Yoon; Kyungho Choi
Publication Detail:
Type:  Journal Article     Date:  2014-01-25
Journal Detail:
Title:  Ecotoxicology and environmental safety     Volume:  101     ISSN:  1090-2414     ISO Abbreviation:  Ecotoxicol. Environ. Saf.     Publication Date:  2014 Mar 
Date Detail:
Created Date:  2014-02-10     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7805381     Medline TA:  Ecotoxicol Environ Saf     Country:  United States    
Other Details:
Languages:  eng     Pagination:  240-7     Citation Subset:  IM    
Copyright Information:
Copyright © 2014 Elsevier Inc. All rights reserved.
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