Journal of Zhejiang University SCIENCE B

, Volume 8, Issue 1, pp 1–13

Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops

  • Islam Ejaz ul 
  • Yang Xiao-e 
  • He Zhen-li 
  • Mahmood Qaisar 
Review

DOI: 10.1631/jzus.2007.B0001

Cite this article as:
Islam, E.u., Yang, X., He, Z. et al. J. Zhejiang Univ. - Sci. B (2007) 8: 1. doi:10.1631/jzus.2007.B0001

Abstract

Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary toxicity.

Key words

Heavy metalsDietary toxicityVegetablesFood crops

CLC number

X5

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Islam Ejaz ul 
    • 1
  • Yang Xiao-e 
    • 1
  • He Zhen-li 
    • 1
    • 2
  • Mahmood Qaisar 
    • 3
  1. 1.MOE Key Lab of Environment Remediation and Ecosystem Health, School of Natural Resources and Environment SciencesZhejiang UniversityHangzhouChina
  2. 2.Institute of Food and Agricultural Sciences, Indian River Research and Education CenterUniversity of FloridaUSA
  3. 3.Department of Environmental Engineering, School of Natural Resources and Environment SciencesZhejiang UniversityHangzhouChina