Effect of different size suspended particles on the bioaccumulation of polycyclic aromatic hydrocarbons in zebrafish tissues.

Polycyclic aromatic hydrocarbons (PAHs) are easily bound with suspended particles (SPS) in rivers, and this will further affect their bioaccumulation. However, it is unclear whether SPS will affect the PAH bioaccumulation in different fish tissues. In the present 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 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 the muscle tissue increased respectively 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. Moreover, the small size SPS performed much stronger effect than the large size SPS on the PAH bioaccumulation in the digestive tract and gill tissues, and this might further affect the PAH bioaccumulation in other zebrafish tissues. The present study is favorable to understand the bioaccumulation of the PAHs bound with the SPS in turbid rivers.