Welcome to Chinese Journal of Ecology! Today is Share:

cje

Previous Articles     Next Articles

Characteristics and source identification of heavy metal pollution in agricultural soils and vegetables in Wuqing District, Tianjin City, China.

PENG Hao1,2, MA Jie2, MA Yu-ling2, CHEN Ya-li2*   

  1. (1College of Resources and Environmental Science, Jilin Agricultural University, Changchun 130118, China; 2AgroEnvironmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China).
  • Online:2019-07-10 Published:2019-07-10

Abstract: To evaluate heavy metal pollution in agricultural soils and vegetables in North China, 45 surface agricultural soil samples and corresponding vegetable samples, 32 livestock manure samples, and four soil profiles were collected in Wuqing District, Tianjin City. For all samples, heavy metal (Cd, Cr, Cu, Ni, Pb, Zn) concentrations and their fractions were analyzed. The correlation analysis and principal component analysis were used to determine the potential pollution sources. The results showed that the accumulation (relative to soil background value) of heavy metals in surface soils decreased in the order of Cd>Cr>Cu>Zn>Pb>Ni. The concentration of Cd in 26.7% of samples exceeded the Second Standards of Soil Environment (GB 15618-2018). Heavy metal concentrations in vegetable roots were relatively enriched (especially for Cd), while those in leaves did not exceed the standards (GB 2762-2017). In the study area, 16% of samples for Cd in applied livestock manures exceeded the industry standards of organic fertilizer of China (NY 525-2012), which could lead to the accumulation of heavy metals in surface soils after longterm application. Relatively high proportion of exchangeable Cd, Cu and Zn in the surface soil might increase the potential risk of heavy metals absorbed by crops and lead to the accumulation of heavy metals in roots and leaves of vegetables. Results from the principal component analysis showed that Cr and Ni may derive from soil parent material, Zn from agricultural activities (such as the application of livestock manures), Cd and Pb from industrial activities, and Cu from both agricultural and industrial activities. In summary, Cd in some soil and livestock manure samples exceeded the standard in this area. More attention should be paid to control or reduce the impacts of agricultural and industrial pollution on metal concentrations in soils and vegetables, although no heavy metal concentrations in leaves exceed the limit of stan dards at present.