Lead Bioaccumulation and Translocation in Herbaceous Plants Grown in Urban and Peri-Urban Soil and the Potential Human Health Risk

Ada Baldi,Simone Orlandini,Camillo A Zanchi,Marco Napoli,Chiara Grassi,Stefano Cecchi

doi:10.3390/agronomy11122444

Ada Baldi, Simone Orlandini + Show 4 more

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https://doi.org/10.3390/agronomy11122444

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Abstract

Lead (Pb) contamination risks to crops grown in urban and peri-urban soils is a great concern that should be better evaluated to define the Pb maximum levels in soils for safe cultivation and to identify suitable strategies to remediate Pb polluted urban soils. The objective of this work was to evaluate the potential risk for human health from the ingestion of the edible portions of barley, castor bean, common bean, Indian mustard, sorghum, spinach, and tomato grown in an unpolluted soil (initial Pb content 32.6 mg kg−1) spiked with 0, 300, 650, 1000 mg Pb kg−1, respectively. The potential possibility of using these plants to phyto-remediate the soil of Pb was also assessed. Pot trials were conducted for two years (2008 and 2009). Results highlighted that all the investigated species were able to attain growth to maturity in high Pb spiked soil, although Pb influenced dry matter accumulation. Even in soils with low Pb concentrations, Pb accumulated the edible parts. Noteworthy, even in untreated control soils, all tested species revealed a Pb concentration in the edible parts that was higher than the safe limit set by FAO/WHO. None of the investigated species were considered Pb hyperaccumulators, but all were shown to be potentially suitable for phyto-stabilization.

Highlights

Urban and peri-urban agriculture are expanding worldwide, and are emerging as an integral component of urban planning policies in both developed and developing countries, attributable to a multifunctional role [1,2,3]
One of the greatest concerns relating to urban and peri-urban agriculture is the contamination of soil with heavy metals (HM) [4,5]
Aery and Jagetiya, 1997 [39] reported a significant (p < 0.01) reduction of 70.3% in DW of roots and of 41.6% in DW of shoots of 45-day old plants of barley grown in sandy loam soil with Pb concentrations ranging from 10 to 6250 mg Pb kg−1 soil

Summary

Introduction

Urban and peri-urban agriculture are expanding worldwide, and are emerging as an integral component of urban planning policies in both developed and developing countries, attributable to a multifunctional role [1,2,3]. One of the greatest concerns relating to urban and peri-urban agriculture is the contamination of soil with heavy metals (HM) [4,5]. Inhalation and ingestion of Pb, even at low concentrations, can be very harmful to human health [8,9]. In urban and peri-urban soils, the presence of this metal was mainly shown to be dependent on the past use of Pb as an antiknock agent in gasoline and as a base for exterior paints [12]. For uncontaminated agricultural soil a Pb concentration ranging from 2 to 300 mg kg−1 was reported by Alloway (1995) [13], which designed a level of 100 mg kg−1 as a dangerous threshold for both humans and the environment. A study conducted to evaluate the HM content in agricultural soils of the European Union [11]

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