Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
CHEN Tong-bin, SONG Bo, ZHENG Yuan-ming, HUANG Ze-chun, ZHENG Guo-di, LEI Mei, CHEN Huang
In order to assess healthy risk of nickel in vegetables and to select vegetable variety with high pollutant-resistance,a large scale survey on nickel concentrations in vegetable lands and vegetables planted or sold in Beijing,were carried out.A total of 54 soil samples were collected from vegetable lands and their nickel concentrations were determined using Graphite Furnace Atomic Absorption Spectrometry(GF-AAS).In addition,97 varieties with 412 fresh samples of vegetables were obtained from vegetable bases,supermarkets and wholesale markets,with sampling principle of taking both consumption and diversity of vegetables into account.The results showed that the nickel concentrations in vegetable lands ranged from2.8 to 46.5mg·kg-1,with median,arithmetical means(AM)and arithmetical standard deviation(SD)of 25.75,25.89 and 7.33mg·kg-1,respectively.Compared with the background concentrations of soil nickel in Beijing,nickel was found to be accumulated not significantly in the vegetable lands.Nickel concentrations in the vegetables ranged from 0.7 to 1689.0μg·kg-1 fresh weight,with arithmetical and geometrical and Box-Cox means of 91.3μg·kg-1,53.0μg·kg-1 and 55.4μg·kg-1 fresh weight,respectively.Nickel in most of the samples(97.38%)was below the limit,3.0mg·kg-1 and 0.3mg·kg-1 fresh weight pulse vegetables and other vegetables,respectively,set by Tolerance Limit of Nickel in Foods for the maximum permissible concentration of nickel in vegetables.The highest nickel concentration,1689.0μg·kg-1,was found in a green soybean(maodou)sample,followed by a cowpea(Vigna unguic-ulata)and soybean sprouts sample,992.7 and 965.8μg·kg-1,respectively,and then pea(Pisum sativum),celery(Apium graveolens)and horse bean(Vicia faba),745.3,704.3 and 697.4μg·kg-1,respectively.The nickel concentration of vegetables planted in the open field was significantly higher than those planted in greenhouse.Results of hierarchical cluster analysis on bioconcentration factor(BCF)of nickel in vegetables showed that beans round trellis(Vigna unguiculata)can be classified into one group with higher bioconcentration factors of nickel,and hence its nickel-resistant was lower;followed by cucumber(Cucumis sativus),pakchoi(Brassica chinensis),Chinese cabbage(Brassica pekinensis),radish(Raphanus),cabbage(Brassica oleracea),chili(Capsicum annuum)and wax gourd(Beninacasa hispida),which can be classified into one group;and the others were clustered to be a group with the lowest bioconcentration factor of nickel,including eggplant(Sola-num),welsh onion(Allium fistulosum),swiss chard(Beta vulgaris)and tomato(Lycopersicon esculentum).The average intake of nickel from vegetables was 99.5μg/individual/day for people of Beijing,and some vegetables with high nickel concentration may lead to a little of healthy risk for local people.