Dietary Exposure Assessment of Paralytic Shellfish Toxins through Shellfish Consumption in Shenzhen Population, China

Paralytic shellfish toxins (PSTs) produced by certain marine dinoflagellates accumulate in filter-feeding marine bivalves. We used LC-MS/MS to detect and quantify 13 PSTs in 188 shellfish samples of 14 species collected from Shenzhen city’s Buji seafood wholesale market from March 2019 to February 2020. Twenty-six of 188 shellfish samples (13.8%) were PST- positive, with highest values in samples of the Noble clam Chlamys nobilis (10/34, 29.4%). Samples originating from Nan’ao island among 11 source sites in China recorded the highest detected rate (7/17, 41.2%). Samples containing PSTs were concentrated in Spring and Winter, with the highest levels in March > December > January. Among PSTs detected, C1 was dominant. Acute dietary exposure assessments for Shenzhen residents were based on P99 consumption data (139.2g/day) and maximum PST concentration for each shellfish species. The outcome for Chlamys nobilis was 2.4 ~ 3.7-fold higher than recommended ARfDs (0.5 ~ 0.7 µg STX eq./kg bw/day). Mean PST concentration (10.9 ~ 134.1 µg STX Eq. /kg), mean shellfish consumption (4.8 g/day) and P99 consumption data were used to assess chronic dietary exposure. The results were lower than the recommended ARfDs. In conclusion, residents in Shenzhen are at risk for acute PST poisoning, while relatively safe from chronic PST exposure.