There is a potentially high risk of dietary MeHg exposure for the population of the GBA. Existing studies on dietary MeHg exposure of inhabitants mainly focus on the national and provincial scales. Inventory of high spatial resolution of dietary MeHg exposure at an urban agglomeration (especially the GBA) scale is scarce. We constructed a gridded dataset for dietary MeHg exposure of the GBA with the 1km×1km spatial resolution from 2009 to 2019. 

This study first compiles a time-series inventory of dietary MeHg exposure for each county/district in the GBA during 2009-2019. Subsequently, it spatializes the dietary MeHg exposure in the GBA at the 1km×1km scale, using gridded data on food consumption expenditure in the GBA as the proxy. This dataset can describe the spatially explicit hotspots, distribution patterns, and variation trend of dietary MeHg exposure in the GBA. It lays the foundation for evaluating and controlling MeHg-related health risks of the GBA.

The uncertainties caused by the accuracy of data and the calculation methods of this dataset can be reduced through three aspects. (1) The improvement of the statistical system of countries/districts in the GBA could avoid parts of the assumptions and related uncertainty during the calculation of the EDI of MeHg at the county/district level. (2) Using more accurate proxy gridded data (i.e., to be more consistent with official statistics) can reduce the uncertainty of gridded dietary MeHg exposure in the GBA. (3) For the estimation of missing data in certain years, more advanced methods (e.g., machine learning and artificial intelligence) can be used to complement the interpolation method.