Occurrence, distribution, bioaccumulation, and ecological risk of bisphenol analogues, parabens and their metabolites in the Pearl River Estuary, South China

Bisphenol analogues and alkyl esters of p-hydroxybenzoic (parabens) can be defined as emerging endocrine disrupting compounds (EDCs) due to their similar characteristics. This study analyzed eight bisphenol analogues, six parabens, and five paraben metabolites in seawater (including aqueous and suspended particle matter (SPM)), as well as organism samples from the Pearl River Estuary, in order to determine their occurrence, distribution, bioaccumulation, and ecological and human health risk in South China's marine environment. The aggregation concentrations of bisphenol analogues, parabens, and paraben metabolites were 106 ng/L, 4.53 ng/L, and 231 ng/L in aqueous samples, 868 ng/g, 173 ng/g, and 9320 ng/g in SPM samples, 41.6 ng/g, 6.46 ng/g, and 460 ng/g in marine organisms, respectively. This study identified significantly higher concentrations of paraben metabolites than their parent parabens in the marine environment, which has not yet been reported in previous studies. These findings call for greater attention on the contamination of paraben metabolites in marine environments. Moreover, the median values of the logarithm of bioaccumulation factors (BAF) for the detected 20 target compounds ranged from 0.11 to 5.07. Bisphenol analogues including bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), bisphenol P (BPP), and Fluornen-9-bisphenol (BPFL) (3.3 < 1g BAF < 3.7), and three paraben metabolites including 4-hydroxybenzoic acid (4-HB) (3.3 < 1g BAF < 3.7), methyl protocatechuate (OH-MeP), and ethyl protocatechuate (OH-EtP) (Log BAF > 3.7), exhibited varying degrees of potential bioaccumulation effect in the majority of organism samples. Furthermore, all tested chemicals in this study were at low risk quotient (RQ) levels for acute and chronic toxicity in seawater. However, the target hazard quotient (THQ) values of two paraben metabolites, 4-HB and benzoic acid (BA), were higher than 1, which indicates that paraben metabolites have the potential to adsorb into organisms, and their associated human health risks should be of great concern. Overall, the study results suggest that the occurrence and risks of emerging EDCs in coastal waters are deserving of further studies, especially in densely populated regions of the world.