Autor: |
Wang Y; Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, IL 61801, United States., Puthussery JV; Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, IL 61801, United States., Yu H; Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, IL 61801, United States., Verma V; Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, IL 61801, United States. Electronic address: vverma@illinois.edu. |
Jazyk: |
angličtina |
Zdroj: |
The Science of the total environment [Sci Total Environ] 2020 Sep 20; Vol. 736, pp. 139511. Date of Electronic Publication: 2020 May 25. |
DOI: |
10.1016/j.scitotenv.2020.139511 |
Abstrakt: |
Although PM 2.5 toxicity is known to be related to its chemical composition, the effect of interactions among various particles' components on the toxicity is not well explored. To understand these interactions, especially metals and organic compounds on PM 2.5 cytotoxicity, we chose several redox-active substances known to be present in the ambient particles such as metals (Cu, Fe, and Mn) and quinones [9,10-phenanthraquinone (PQ), 1,2-naphthoquinone (1,2-NQ), 1,4-naphthoquinone (1,4-NQ), and 5-hydroxy-1,4-naphthoquinone (5,H-1,4-NQ)]. Cytotoxicity was assessed through a Chinese hamster ovary (CHO) cells assay and expressed by a median lethal concentration (LC 50 ). Two methods were employed to assess the interactions. In the first method, we tested the impact of nontoxic level of a component on the LC 50 of other components. In the second method, we mixed two components in different concentration ratios to expose the cells and calculated a mixture toxicity index (MTI). MTI is a composite value to quantify the nature of interactions such that the interactions are considered synergistic when MTI > 1, additive when 0 < MTI ≤ 1 and antagonistic when MTI < 0. The interactions between quinones and metals were largely synergistic by both methods. To further assess the environmental relevance of these mixtures, we extracted organic compounds termed as water-soluble Humic-like substances (HULIS) from real ambient PM samples and mixed them with individual metals. A similar pattern, as observed from the interaction of quinones and metals, was found. Moreover, the interactions became more synergistic as the relative concentration of metals with respect to water-soluble HULIS was decreased in these mixtures. With environmentally relevant mass concentration ratios of organics to metals (75-7500), the interactions were strongly synergistic (MTI = 1-115). These results indicate the importance of incorporating the interaction among various PM components for estimating the net toxicity of ambient PM 2.5 . Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. (Copyright © 2020 Elsevier B.V. All rights reserved.) |
Databáze: |
MEDLINE |
Externí odkaz: |
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