Occurrence, distribution, sources, substitution trend, and risk evaluation of legacy and emerging polyfluoroalkyl substances (PFASs) in the Hongyingzi sorghum cultivation base in China

Qin Yin¹Xu HuaJie^2*

• ¹Guizhou Institute of Technology, Guiyang, China
• ²Moutai Institute, Renhuai, China

As an emerging pollutant, polyfluoroalkyl substances (PFASs) are of significant concern globally, yet the contamination characteristics and sources of PFASs in the cultivation base for the production of raw materials, specifically Hongyingzi sorghum, represented by Moutai Wine, remain largely unknown. In this study, PFASs was tested for the first time in tilled soil (0 - 20 cm) across eight sample sites in the Hongyingzi sorghum cultivation base using liquid chromatography-triple quadrupole mass spectrometry (LC-TQMS). Two legacy PFASs and five emerging PFASs were detected, with Σ7PFAS concentrations ranging from 87.8 to 446 ng/kg and an average concentration of 248 ± 106 ng/kg. The ΣPFAS concentrations, predicted using the ordinary kriging method, were relatively uniform across most of the study area, ranging from 232 to 234 ng/kg. The emerging PFASs contributed 41.8% to the Σ7PFASs, and short-chain fluorine-containing products were identified as the primary substitutes for perfluorooctanoic acid (PFOA) in the study area. The principal component analysis results suggested that PFAS pollution originated from PFOA, perfluorononanoic acid, perfluorobutanoic acid, perfluoropentanoic acid, and perfluoroheptanoic acid, which are linked to rural living and agricultural activities, as well as perfluorobutanesulfonic acid, which is associated with industrial activities. The ecological risk assessment indicated that PFOA in the soils in the study area poses a very low ecological risk. In addition, the health risk assessment revealed that the PFASs in the soil do not present a significant risk to human health. These findings provide a scientific basis for the prevention, control, and management of PFAS pollution in the Hongyingzi sorghum cultivation base. Scope statement This study provides the first targeted survey of both legacy and emerging PFASs in tilled soils (0–20 cm) from the Hongyingzi sorghum cultivation base that supplies raw materials for Moutai-flavor liquor. By combining LC–TQMS measurements with spatial interpolation, source apportionment, and screening-level risk assessment, we highlight the ongoing shift from legacy PFASs to short-chain alternatives in a typical agro-ecosystem influenced by rural living activities and rapid winery-related development. The findings support evidence-based pollution prevention and long-term monitoring strategies for high-value crop production areas in the Chishui River Basin.