TY - JOUR
T1 - Time-dependent uptake and toxicity of nickel to Enchytraeus crypticus in the presence of humic acid and fulvic acid
AU - He, Erkai
AU - Qiu, Hao
AU - Qiu, Rongliang
AU - Rentenaar, Charlotte
AU - Devresse, Quentin
AU - Van Gestel, Cornelis A.M.
PY - 2017/11
Y1 - 2017/11
N2 - The present study aimed to investigate the influence of different fractions of dissolved organic carbon (DOC) on the uptake and toxicity of nickel (Ni) in the soil invertebrate Enchytraeus crypticus after different exposure times. The addition of DOC as humic acid or fulvic acid significantly reduced Ni uptake by E. crypticus in the soil-solution test system. Median lethal effect concentrations were calculated based on total dissolved Ni concentrations (LC50[Ni]), free Ni ion activity (LC50{Ni2+}), and Ni body concentrations (LC50Body-Ni). The LC50[Ni] values increased with increasing DOC levels and decreased with exposure time (4, 7, and 10 d). Humic acid exerted a greater protective effect on Ni toxicity than fulvic acid, but the protective effects decreased with prolonged exposure time. The LC50{Ni2+} values also decreased with exposure time but were almost constant with variation in DOC levels, indicating that the protective effect of DOC is mainly through complexation with free Ni ions to reduce Ni bioavailability. The LC50Body-Ni value was independent of DOC concentration and exposure time, with an estimated overall value of 22.1 µg/g dry weight. The present study shows that body concentration could serve as an effective indicator for predicting Ni toxicity with variations in the exposure environment (e.g., DOC) and exposure time. Environ Toxicol Chem 2017;36:3019–3027.
AB - The present study aimed to investigate the influence of different fractions of dissolved organic carbon (DOC) on the uptake and toxicity of nickel (Ni) in the soil invertebrate Enchytraeus crypticus after different exposure times. The addition of DOC as humic acid or fulvic acid significantly reduced Ni uptake by E. crypticus in the soil-solution test system. Median lethal effect concentrations were calculated based on total dissolved Ni concentrations (LC50[Ni]), free Ni ion activity (LC50{Ni2+}), and Ni body concentrations (LC50Body-Ni). The LC50[Ni] values increased with increasing DOC levels and decreased with exposure time (4, 7, and 10 d). Humic acid exerted a greater protective effect on Ni toxicity than fulvic acid, but the protective effects decreased with prolonged exposure time. The LC50{Ni2+} values also decreased with exposure time but were almost constant with variation in DOC levels, indicating that the protective effect of DOC is mainly through complexation with free Ni ions to reduce Ni bioavailability. The LC50Body-Ni value was independent of DOC concentration and exposure time, with an estimated overall value of 22.1 µg/g dry weight. The present study shows that body concentration could serve as an effective indicator for predicting Ni toxicity with variations in the exposure environment (e.g., DOC) and exposure time. Environ Toxicol Chem 2017;36:3019–3027.
KW - Accumulation
KW - Bioavailability
KW - Dissolved organic matter
KW - Ecotoxicity
KW - Soil organism
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U2 - 10.1002/etc.3870
DO - 10.1002/etc.3870
M3 - Article
AN - SCOPUS:85023187962
SN - 0730-7268
VL - 36
SP - 3019
EP - 3027
JO - Environmental Toxicology and Chemistry
JF - Environmental Toxicology and Chemistry
IS - 11
ER -