First Report on the Tissue Distributions and Habitat Differences of PFMOAA and Other PFAS in Veined Rapa Whelk ( <i>Rapana venosa</i> )

Veined rapa whelks (<i>Rapana venosa</i>) are predatory marine snails that are widely distributed in the coastal water worldwide. In our previous studies, perfluoro-2-methoxy acetic acid (PFMOAA) has been found at extremely high levels in this species than in other benthos and fishes in estuaries and coastal waters. However, there is a knowledge gap regarding geographical bioaccumulative characteristics and tissue distribution patterns of PFMOAA in veined rapa whelk. This is the first study to investigate the tissue distributions of 17 legacy per- and polyfluoroalkyl substance (PFAS), 6 emerging polyfluoroether sulfonic acids (PFESAs), and 14 emerging perfluoroalkyl ether carboxylic acids (PFECAs) including PFMOAA in the kidney, liver, gill, foot, adductor muscle, Lebrin's gland, gonad, digestive tract, and mixed tissues of the veined rapa whelk (<i>R. venosa</i>) from five regions around the Bohai Sea. Overall, PFMOAA was consistently the predominant PFAS (20.7-93.7%) in all tissues. The kidney presented the highest PFAS concentration, followed by the gill, Lebrin's gland, digestive tract, and liver. Whelks from the Xiaoqing River Estuary showed the highest kidney ∑PFAS level (mean 629.2 ng/g dw) compared to those from other regions (119.9 ng/g dw). For PFMOAA, the contributions of the foot and mixed tissues to the whole-body levels were relatively high despite their low concentrations in these tissues. PFOA and PFOS showed the highest concentrations and the largest contributions in terms of whole-body concentrations in Lebrin's glands and the livers, respectively. Further research on the toxicity of PFMOAA and its associated risks to the ecosystem and human beings are urgently needed.