Assessment of Heavy Metal Uptake in Potatoes Cultivated in a Typical Karst Landform, Weining County, China

Abstract

The average content of heavy metals in Weining soil of karst landforms is generally higher than that of other agricultural regions. The aim of this study was to evaluate the heavy metal content in potatoes from Weining county and to analyze the correlation between the content of heavy metals in potatoes planted in the soil of karst landform and the soil’s environmental factors (soil heavy metals, soil pH, soil organic matter, altitude). Weining county (Guizhou province, China) is a typical karst landform, and has a potato production yield of 2.7 million tons. In this study, 56 soil and potato samples were collected from Weining county and the heavy metal content in the soils and potatoes was detected by inductively coupled plasma atomic mass spectrometry (ICP-MS). The content of Cr, Ni, and As in the soil was found to be higher, with almost half of the samples exceeding the maximum allowable levels. A total of 9 of the 56 samples tested had pollution load index values greater than 1.0, which indicates serious soil pollution. It was found that the ability of the potato to absorb heavy metals from the soil was very low, with the average bio-concentration factors of the metals Zn, Cu, Pb, Cr, Ni, and As being 0.087, 0.088, 0.0028, 0.0034, 0.0066, and less than 0.001, respectively. The content of the six heavy metals in the potatoes were all lower than the maximum permissible limit. The results show that a high As content in the soil could increase the content of Pb in potatoes, that a lower pH was beneficial to the bioaccumulation of Cr and Ni in potatoes, and that a high altitude is detrimental to the bioaccumulation of zinc and copper in potatoes. The HRI ranged between 1.12 × 10−2 and 5.92 × 10−2.

Assessment of the variation of heavy metals and pesticide residues in native and modern potato (Solanum tuberosum L.) cultivars grown at different altitudes in a typical mining region in Peru

“…Heavy metal concentrations in soils and the order in which they are found vary from one place to another because the heavy metal content of the soil depends on a wide range of factors relating to lithogenic and anthropogenic sources [45] . For example, in mining areas in Weining County in China, the soil in which potatoes are grown contains the heavy metals considered in our study, concentrated in the following order: Cr (119 mg/kg) > Pb (59.3 mg/kg) > Ni (50.8 mg/kg) > Cu (47.8 mg/kg) > As (25.8 mg/kg) [24] > Cd (2.60 mg/kg) [46] . In our study, as can be seen from Table S4 , the concentration order of heavy metals in the potato-growing soil was Al (13,127.84 mg/kg) > Mn (509.248 mg/kg) > Ba (187 mg/kg) > Cu (51.38 mg/kg) > As (23.607 mg/kg) > Pb (16.861 mg/kg) > Ni (10.199 mg/kg) > Cr (9.798 mg/kg) > Cd (0.352 mg/kg).…”

“…Few studies include altitude as a factor in the analysis of heavy metal content in potatoes, and even fewer in mining areas. In an area of abundant ore deposits in Weining County, China, altitude was found not to have a significant influence (p < 0.05) on the Pb, Cr, Ni and As concentrations in potatoes grown between 2151 and 2744 m.a.s.l., but lower altitudes favored the accumulation of Cd and Cu [24] , [46] .…”

“…Indeed, it is reported to be able to adapt to soils contaminated by heavy metals [20] and that its ability to absorb them is less than that of leafy vegetables [21] , [22] , [23] . Nevertheless, the absorption level varies from one place to another, as it depends on various factors such as metal concentration in the soil, soil pH and altitude [24] .…”

Effect of fertilization on the accumulation and health risk for heavy metals in native Andean potatoes in the highlands of Perú

“…In the present study, all the BCF values determined were below 1, and this finding indicates that the transfer of metals from the soil to native potatoes is low in the experimental area. Shi et al [64] found similar BCF values for Zn, Cu, Pb and Cr in potatoes, suggesting that the potato's ability to absorb metals is very low (BCF ≤ 1), and it does not accumulate them in its tissues [100] . The higher the BCF, the greater the transfer of heavy metals from the soil to plant tissues [66] .…”

“…The BCF was calculated using Eq. (3) [64] : where and are the content of heavy metals in potato tubers and soils (mg kg −1 ), respectively.…”