Influences of humic acid on the bioavailability of phenanthrene and alkyl phenanthrenes to early life stages of marine medaka (Oryzias melastigma). (March 2016)

• Record Type: Journal Article
• Authors: Liu, Yangzhi; Yang, Chenghu; Cheng, Pakkin; He, Xiaojing; Zhu, Yaxian; Zhang, Yong
• Is Part Of: Environmental pollution. Volume 210(2016)
• Page Start: 211
• Page End: 216
• Publication Date: 2016-03
• Subjects: Humic acid -- Alkyl polycyclic aromatic hydrocarbons -- Phenanthrene -- Bioavailability -- Marine medaka; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2015.12.011
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The influences of humic acid (HA) on the environmental behavior and bioavailability of parent polycyclic aromatic hydrocarbons (PAHs) and alkyl PAHs were investigated and compared using the early life stages of marine medaka ( Oryzias melastigma, O. melastigma ). It was demonstrated that the binding affinity of parent phenanthrene (PHE) with HA was smaller than that of 3-methyl phenanthrene (3-MP) and 9-ethyl phenanthrene (9-EP). Furthermore, the bioaccumulation of the three PAHs and the levels of lipid peroxidation (LPO) were calculated to study the changes in bioavailability of PAHs in presence of HA. The results indicated that the addition of HA significantly decreased the bioaccumulation and toxicity of PAHs by decreasing free PAHs concentrations. The bioavailable fractions of HA-bound PAHs in bioaccumulation (α) and toxicity (β) were evaluated, indicating that the HA-bound 3-MP and 9-EP show higher bioavailability in bioaccumulation and lower bioavailability in toxicity relative to those of PHE. The β/α values were less than 1 for all PAH treatment groups containing HA, suggesting that the fraction of HA-bound PAHs contributing to bioaccumulation was higher than that of HA-bound PAHs inducing toxic effect. In addition, we proposed that the free PAHs generated by desorption from HA in the cell were toxic by showing that the β/α ratio values are correlated with the log K OW values ( p = 0.007 and R 2 = 0.8355). Thus, oil spill risk assessments should consider both alkyl PAHs and the factors that influence the bioavailability and toxicity of PAHs in the natural aquatic environments. Graphical abstract: Highlights: Effects of HA on bioavailability of parent and alkyl PAHs were firstly compared. Changes in the bioavailability due to HA depended on the alkylation of PAHs. The bioavailable fractions of the HA-bound parent and alkyl PAHs were calculated. The toxicity of HA-bound PAHs was related to the physicochemical properties of PAHs. Abstract : This study is the first report regarding the influence of HA on bioavailability of both PHE and alkyl PHEs and will be of great benefit to the assessment of possible damage in an oil spillage accident.