An exploration of an integrated stochastic-fuzzy pollution assessment for heavy metals in urban topsoil based on metal enrichment and bioaccessibility

Fei Li; Jingdong Zhang; Wenchu Liu; Jiaan Liu; Jinhui Huang; Guangming Zeng

doi:10.1016/j.scitotenv.2018.06.366

An exploration of an integrated stochastic-fuzzy pollution assessment for heavy metals in urban topsoil based on metal enrichment and bioaccessibility

Sci Total Environ. 2018 Dec 10:644:649-660. doi: 10.1016/j.scitotenv.2018.06.366. Epub 2018 Jul 11.

Authors

Fei Li¹, Jingdong Zhang², Wenchu Liu², Jiaan Liu², Jinhui Huang³, Guangming Zeng⁴

Affiliations

¹ Research Center for Environment and Health, Zhongnan University of Economics and Law, Wuhan 430073, China; School of Information and Safety Engineering, Zhongnan University of Economics and Law, Wuhan 430073, China. Electronic address: lifei@zuel.edu.cn.
² Research Center for Environment and Health, Zhongnan University of Economics and Law, Wuhan 430073, China; School of Information and Safety Engineering, Zhongnan University of Economics and Law, Wuhan 430073, China.
³ College of Environmental Science and Engineering, Hunan University, Changsha 410082, China. Electronic address: huangjinhui@hnu.edu.cn.
⁴ College of Environmental Science and Engineering, Hunan University, Changsha 410082, China.

PMID: 29990913
DOI: 10.1016/j.scitotenv.2018.06.366

Abstract

An integrated stochastic-fuzzy pollution assessment method (ISFPAM) for soil heavy metal was established based on geo-accumulation index (I_geo), stochastic-fuzzy theory and double weight system under synthetical consideration of metal ecotoxicity and bioaccessibility. The pollution characteristics of the topsoil heavy metals (Cu, Zn, Cd, Pb and Cr) in Xiangjiang New District were evaluated by the widely-used Single factor index (SF), Nemerow index (NI), I_geo, Potential ecological index (PERI), Risk assessment code (RAC) and the ISFPAM. The results of SF, NI, I_geo, RI and RAC of the studied metals revealed the following orders: Cd > Zn > Cr > Cu > Pb, Cd > Zn > Pb > Cr > Cu, Cd > Cr > Cu > Zn > Pb, Cd > Cu > Pb > Cr > Zn, and Cd > Pb > Cr > Zn > Cu, respectively. The different pollution assessment methods outputted the differentiated conclusions to some extent except the judgment for Cd. Results based on ISFPAM indicated that metal pollution degrees decreased in the order of Cd (5.91, Grade 6) > Cu (2.81, Grade 3) > Pb (2.66, Grade 3) > Cr (1.58, Grade 2) > Zn (0.69, Grade 1). By detailed comparison analysis, the double weight system and stochastic-fuzzy theory made ISFPAM better resolving ability to find out priority heavy metals and areas with relatively higher enrichment, ecotoxicity and bioaccessibility under efficient parameter uncertainty control. Cd, Cu and Pb were regarded as the priority control metals, especially Cd. Simultaneously, the reliabilities of heavy metal pollution corresponding to adjacent pollution grades were quite close in some sites, which recommend recheck for avoid misleading the decision-makers.

Keywords: Chemical fractions; Double weight system; Ecotoxicity; Enrichment; Soil toxic metal.