Abstract
Accumulation of heavy metals in agricultural soils tends to increase crop uptake of heavy metals, and can adversely impact human health through food chains. This study assessed the heavy metal pollution status and the potential ecological risk of tea plantation soils in southern Shaanxi Province, China. A total of 330 topsoil samples were collected to analyze the concentrations of seven heavy metals (Pb, Zn, Cu, Cr, Hg, As and Cd) and the pH level. The Hakanson potential ecological risk index was used based on the background levels of soil heavy metals in Shaanxi. Results showed that the averaged concentrations of soil Pb, Zn, Cu, Cr, Hg, As, and Cd were 10.0, 87.6, 16.4, 12.4, 0.2, 6.9 and 0.1 mg/kg, respectively. Cd and Hg concentrations exceeded level II of China’s Soil Environment Quality Standard (GB 15618–2009) in 9.3% and 7.0% of the total samples, respectively. The coefficient of variation ranged from 29.2% to 52.2% for different elements, and was 49.3% for Cd and 48.6% for Hg. The averaged comprehensive potential ecological risk index was 95.4, and the overall potential ecological risk was low, with 82.4% of the total samples at a low level of potential ecological risk. Cd and Hg contributed most to the potential ecological risk (35.5% and 46.5%, respectively), and the risks associated with other elements were relatively minor. This study suggested that soil Cd and Hg pollution should be controlled to ensure the safe production of tea in the study area. Keywords: ecological risk, heavy metal, soil pollution, tea plantation DOI: 10.25165/j.ijabe.20191206.4363 Citation: Zhao Z P, Yan S, Duan M, Fu J, Wang Q, Liu Z F, et al. Assessing heavy metal pollution and potential ecological risk of tea plantation soils. Int J Agric & Biol Eng, 2019; 12(6): 185–191.
Highlights
In recent decades, urban and rural planning process has accelerated, while industry and agriculture have developed rapidly
As the soil background levels of heavy metals vary across different regions, there may be a risk of pollution in some areas with low soil background level based on the national standard, the critical value for heavy metal pollution is not reached after years of accumulation
The Hakanson potential ecological risk index was used for assessment of soil pollution risk in tea plantations based on the background levels of soil heavy metals in Shaanxi Province
Summary
Urban and rural planning process has accelerated, while industry and agriculture have developed rapidly. Problems resulted from soil heavy metal pollution have drawn widespread attention from researchers[1,2,3]. Soil heavy metal pollution is cumulative, complex, concealed, irreversible, hysteretic, and severe. Once heavy metals enter the soil environment, they can accumulate in agricultural products and endanger human health through food chains[5]. Assessment of soil heavy metal pollution and the ecological risk in agricultural areas have become increasingly important. Numerous studies have been conducted to assess heavy metal levels and soil quality in vegetable-producing areas[6,7], farmlands[8,9,10], production areas of economic crops[11,12], and wastewater irrigation and mining areas[13,14]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call