Heavy Metals Contamination in Vegetables Grown in Urban and Metal Smelter Contaminated Sites in Australia

Abstract

Dietary exposure to heavy metals, namely cadmium (Cd), lead (Pb), zinc (Zn) and copper (Cu), has been identified as a risk to human health through the consumption of vegetable crops. This study investigates the source and magnitude of heavy metal contamination in soil and vegetable samples at 46 sites across four vegetable growing regions in New South Wales, Australia. The four regions Boolaroo, Port Kembla, Cowra and the Sydney Basin were a mix of commercial and residential vegetable growing areas. The extent of metal contamination in soils sampled was greatest in regions located in the vicinity of smelters, such as in Boolaroo and Port Kembla. Soil metal concentrations decreased with depth at these two sites, suggesting contamination due to anthropogenic activities. Cadmium, Pb and Zn contamination was greatest in vegetables from Boolaroo, and Cu concentrations were greatest in vegetables sampled from Port Kembla. At Boolaroo, nearly all the samples exceeded the Australian Food Standards maximum level (ML) (0.01 mg kg −1 fresh weight) of Cd and Pb in vegetables. Over 63% of samples exceeded international food standard guidelines set by the Commission of the European Communities and the Codex Alimentarius Commission. All vegetables sampled from Cowra, which is a relatively pristine site had Cd and Pb levels below the Australian and international food standards guideline values. This study suggests that the Australian guideline values are more conservative in defining the ML for Cd and Pb in vegetable crops. This investigation highlights the increased danger of growing vegetables in the vicinity of smelters.

Phytoremediation of urban soils contaminated with trace metals using Noccaea caerulescens: comparing non-metallicolous populations to the metallicolous ‘Ganges’ in field trials

“…Although Cd is generally the main target element with phytoextraction, Zn is also an element of environmental concern which should also be c o n s i d e r e d w h e n e v a l u a t i n g t h e e ff i c i e n c y o f phytoextraction with N. caerulescens. Numerous urban sites contaminated with trace metals are above thresholds for Zn in Brussels as other urban areas in the world (Imperato et al 2003;Kachenko and Singh 2006;Li et al 2001). This study has confirmed for the first time in field trials the interest of using NMET populations of N. caerulescens for Zn phytoextraction.…”

Chumbo e cádmio detectados em alimentos vegetais e gramíneas no município de Santo Amaro-Bahia

“…15 Com respeito à sua interpretação, um fator de transferência elevado expõe uma débil retenção dos contaminantes no solo e a capacidade de absorção dos metais pela espécie vegetal analisada. 16 Valores de fatores de transferência para Pb encontram-se na faixa 0,01-0,1 e no caso do Cd entre 1-10. 14 Outros estudos expõem fatores de transferência típicos ou considerados de referência para os metais Pb e Cd menores aos reportados anteriormente, os quais estão nas faixas 0,0-0,9 e 0,0-2,7 respectivamente.…”

Phytoextraction of heavy metal polluted soils using Sedum plumbizincicola inoculated with metal mobilizing Phyllobacterium myrsinacearum RC6b

“…In China, thousands of abandoned or operating metal based ore mines exist on public lands, which have generated around 1 500 000 ha of metal polluted soil and increases at a rate of 46 700 ha y À1 (MEPPRC, 2006). Results from recent studies (Kachenko and Singh, 2006;Zhuang et al, 2009) also demonstrate thatthe food crops grown in metal contaminated soils pose a major health concern. For instance, Li et al (2006) reported that Chinese cabbage and Brassica napus grown in the vicinity of a Chinese Pb/Zn mine had higher levels of heavy metals than the maximum permissible value in food proposed by food regulation.…”