Uptake effects of toxic heavy metals from growth soils into jujube and persimmon of China

Abstract

Compared with other agricultural plants, information about uptake effects of toxic heavy metals from growth soils into persimmon and jujube are scarce. In this study, the single and comprehensive uptake effects of five toxic heavy metals (Pb, As, Cd, Cr, and Hg) between the two fruits and their growth soils were investigated. The results showed that the average concentrations of heavy metals in the two fruits were found to be 30 (Pb), 6.6 (As), 2.3 (Cd), 38 (Cr), and 0.33 (Hg) μg/kg, respectively. The average concentrations of heavy metals in their growth soils were 26.31 (Pb), 9.63 (As), 0.12 (Cd), 57.6 (Cr), and 0.049 (Hg) mg/kg, respectively. An uptake effect was observed for the two fruits. The values of Nemerow pollution index (NPI) in the two fruits and their growth soils were 0.10 and 0.55, respectively. The average bioconcentration factor (BCF) values of Pb, As, Cd, Cr, and Hg in the two fruits were 0.0012, 0.00075, 0.021, 0.00077, and 0.012, respectively. Based on the residue levels of toxic heavy metals in the growth soils and soil parameters, the prediction models for NPI and BCF were established, with the adjusted regression coefficients of 0.65 (NPI) and 0.81 (BCF). The contribution rates of different soil parameters to NPI were 21.7% (OC), 16.1% (Pb), 17.1% (Cr), 19.8% (Cd), and 25.4% (As), respectively. The contribution rates of different soil parameters to BCF were 10.2% (OC), 9.4% (Cr), and 80.4% (Cd), respectively.

Risk assessment and prediction for toxic heavy metals in chestnut and growth soil from China

“…In some previous reports, the single element prediction model of Cd could be draw in spinach plants ( R 2 = 0.89) and cereals ( R 2 = 0.76) . Additionally, Cd content in growth soils was taken for comprehensive prediction models of jujubes and persimmons in our previous study . Total Cd content might be a key factor for the establishment of BCF prediction model, which should be paid more attention in the future model studies.…”

“…Total Cd content in growth soils was the most crucial factor, which accounted for nearly half of the total contribution for BCF. A similar result showed the contribution rate of soil Cd content to BCF was over 76.0% in jujube and persimmon . However, soil pH was the primary factor to BCF in wheat plants, vegetables for 68.1% and grains for 52.0% .…”

“…The result was caused by different transport mechanisms and accumulation ability of THMs in plants. For environmental risk of THMs, the contribution rates of different soil parameters to NPIs in jujube were 25.0% (OC), 21.8% (Pb), 17.5% (Cd) and 35.7% (As), respectively . However, contribution rate of soil Cr and soil pH in chestnuts each account for about 50% while soil OC, soil Cd and Pb content did not play any roles in our predictions.…”

“…SFPI avg is the mean single factor pollution index. According to the SFPI class: ≤ 1, non‐pollution; 1–2, minor pollution; 2–3, light pollution; 3–5, medium pollution; ≥ 5, heavy pollution. NPI classes: ≤ 0.7, pollution‐free.…”

“…42 Additionally, Cd content in growth soils was taken for comprehensive prediction models of jujubes and persimmons in our previous study. 23 Total Cd content might be a key factor for the establishment of BCF prediction model, which should be paid more attention in the future model studies. For the prediction model of NPI, only two soil parameters (total Cr content and pH) were introduced in the model with the adjusted regression coefficients of 0.40 (P < 0.0001).…”