Phthalate esters distribution in coastal mariculture of Hong Kong, China

The aim of the study is to evaluate the impact of mariculture on phthalate esters speciation and distribution in sediments and cultured fish in the Hong Kong regions and near mainland China. Concentrations of ∑phthalate esters in mariculture surface sediments (0 to 5 cm) ranged from 0.20 to 54.3 mg/kg dw (mean 10.3 mg/kg dw), with the highest recorded at M2 (20.4 mg/kg dw). Concentrations of phthalate esters were not significantly (p > 0.05) enriched in surface and sediment cores at mariculture sites relative to the reference sediments, 1 to 2 km away in areas without mariculture activities. Among different congeners, only butyl benzyl phthalate (BBP) concentrations demonstrated a significant correlation (R² = 0.40, p < 0.05) with TOC values of sediments. The median concentrations of di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DBP) in the sediments were 1.57 and 6.96 times higher than the environmental risk levels (ERL), which may pose environmental risks. Results of health risk assessments revealed that the cultured fish (snubnose pompano, orange-spotted grouper, and red snapper) were safe for consumption, in terms of phthalate esters. This is the first study to assess the differences of phthalate esters contamination between mariculture and natural coastal sediments.