Effect of different-sized suspended particles on the bioaccumulation of polycyclic aromatic hydrocarbons in zebrafish...

Polycyclic aromatic hydrocarbons (PAHs) are easily bound with suspended particles (SPS) in rivers, and this will affect their bioaccumulation. However, it is unclear whether SPS will affect PAH bioaccumulation in different fish tissues. In this work, we studied the effect of different size SPS on the PAH bioaccumulation in different zebrafish tissues. The results showed that PAH concentrations in the different zebrafish tissues increased with time, and the bioaccumulation steady-state was reached in less than 16 days. In addition, the PAH steady-state concentrations were not affected significantly by the SPS (p > 0.05), but the PAH concentrations in different tissues of the zebrafish cultured with SPS were higher than that without SPS at the initial bioaccumulation stage. Meanwhile, it was found that the effect of SPS on the PAH bioaccumulation was relevant with the particle size; for example, the uptake rates of pyrene in muscle tissue increased by 45% ± 5%, 38% ± 8%, and 20% ± 4% for the zebrafish cultured with <20 μm SPS, 20-63 μm SPS, and 63-106 μm SPS, respectively. Moreover, the small size SPS had a much stronger effect than the large size SPS on PAH bioaccumulation in the digestive tract and gill tissues, and this might further affect the PAH bioaccumulation in other zebrafish tissues. This study is favorable to understand the bioaccumulation of PAHs bound with SPS in turbid rivers.