Evaluation of perfluoroalkyl substances in field-cultivated vegetables
By Heesoo Eun, Eriko Yamazaki, Sachi Taniyas, Agata Miecznikowsk, Jerzy Falandysz, and Nobuyoshi Yamashita
September 16, 2019
Perfluoroalkyl substances (PFASs) were investigated in three types of vegetables (fruit, leafy, and root vegetables) that were cultivated and harvested from 2014 to 2017. The cultivated soil was mainly affected by perfluoroalkyl carboxylic acid (PFCAs; 91.8% detection rate) rather than perfluoroalkyl sulfonic acids (PFSAs; 8.2%). The cultivated soil (i.e., a volcanic cohesive soil) had a high total organic carbon (TOC = 3.4%) and therefore showed strong adsorption of long-chain PFASs. Short-chain PFCAs (i.e., under C9) were mainly detected in vegetables; specifically, PFBA showed high concentration in tomato shoots. Principal component analysis (PCA) plots clearly showed that PFASs in vegetables were different from those of cultivated soil, air, and rainwater. Interestingly, the whole potato (i.e., including peel) was in the same group as soil, indicating that the whole potato can easily be affected by the cultivated soil. Energy Dispersive X-ray Spectrometry-Scanning Electron Microscope (EDS-SEM) results showed that presence of unremovable micron-sized cultivated soil particles on the potato surface. Comparing the regional differences between the cultivated area of Tsukuba city (East Japan) and Osaka city (West Japan), PFASs patterns were similar in cucumber but differed in green perilla and potato.
• This is the initial report of PFAS analysis in leafy, fruit and root vegetables cultivated in an open-field in Japan.
• Short-chain PFCAs under C9 were mainly detected in the vegetables.
• PCA indicates that PFASs residue in vegetables shows different composition profiles in soil, air, and rainwater.
• Although potatoes were washed with water, the unremovable soils on peel affected the concentrations of PFASs residues.