Spatial analysis of diarrhetic shellfish poison contamination and dietary exposure of commercially available shellfish in coastal areas of China

ObjectiveThis study aimed to provide evidence for early warning， prevention， and monitoring strategies relating to the spatial distribution and clustering characteristics of diarrhetic shellfish poison （DSP） contamination and dietary exposure of commercially available shellfish in coastal areas in China.MethodsClassical substitution and the inverse normal imputation method were used to indicate undetected DSP values and calculate dietary exposure. Based on the provincial spatial scale， the global and local spatial autocorrelation analyses of food contamination and exposure in the DSP in coastal China were explored.ResultsFrom 2016 to 2021， a total of 6 355 shellfish samples were collected from 10 coastal provinces in China. The detection rate of DSP was 6.34%. Yessotoxins （YTX） reported the highest detection rate at 5.41%. The main contaminated areas include Fujian， Guangxi， Hebei， and Guangdong. The global Moran’s I value of contamination of pectenotoxins was 0.55 （P = 0.02） and of YTX was 0.27 （P = 0.01）， this demonstrated a spatial clustering effect on the contamination and dietary exposure of DSP. Local spatial autocorrelation analysis showed that two high-high clustering were detected in Liaoning and Shandong for DSP contamination. For dietary exposure to DSP， there was a high-low clustering phenomenon in Hebei， Guangxi， and Liaoning.ConclusionThere are regional differences in DSP contamination and dietary exposure in coastal China， demonstrating localized regionalization. To improve shellfish food safety， government agencies should formulate regionalized precision monitoring and dietary interventions based on the spatial distribution of DSP contamination and dietary exposure.