Lead (Pb), cadmium (Cd), and arsenic (As) are three common non-essential heavy metals found in urban soils and can prove toxic to animals, humans, and some plants at low concentrations. The main exposure pathways of heavy metals in humans are through ingestion and inhalation of soil particles and ingestion of contaminated food. When dealing with contaminated soil in urban environments, activiti...

Thallium (Tl) is a highly toxic heavy metal that poses threat to various organisms, including human beings. In plants, Tl mostly present as the uncomplexed Tl+ species, and its uptake by plants follows similar trend of other monovalent ions such NH4+, Cs+, K+, Rb+, others. this study, we investigated relationships between concentrations in barley sunflower extractable-Tl acidic, neutral, alkali...

This article reviews recent developments in in situ bioremediation of trace metal contaminated soils, with particular reference to the microbial dynamics in the rhizospheres of plants growing on such soils and their significance in phytoremediation. In non-agricultural conditions, the natural role of plant growth promoting rhizobacteria (PGPR), P-solubilizing bacteria, mycorrhizal-helping bacte...

The major objective of this investigation was to evaluate the potential of scented geraniums, Pelargonium roseum, to uptake and accumulate heavy metals nickel (Ni), cadmium (Cd), or lead (Pb). For this, plants were grown in an artificial soil system and exposed to a range of metal concentrations over a 14-day treatment period. Then, metals from the entire biomass were extracted. The results sho...

This field-scale hydroponic experiment investigated the effects of plant density and nutrient levels on arsenic (As) removal by the As-hyperaccumulator Pteris vittata L. (Chinese brake fern). All ferns were grown in plastic tanks containing 30 L of As-contaminated groundwater (130 microg x L(-1) As) collected from South Florida. The treatments consisted of four plant densities (zero, one, two, ...

Sebertia acuminata (Sapotaceae) from New Caledonia has been shown to be a hyperaccumulator of nickel. The nickel content of the latex (25.74 percent on a dry weight basis) is easily the highest nickel concentration ever found in living material. The nickel is in the form of a low-molecular-weight, water-soluble organic complex.

We have previously identified an ecotype of the hyperaccumulator Thlaspi caerulescens (Ganges), which is far superior to other ecotypes (including Prayon) in Cd uptake. In this study, we investigated the effect of Fe status on the uptake of Cd and Zn in the Ganges and Prayon ecotypes, and the kinetics of Cd and Zn influx using radioisotopes. Furthermore, the T. caerulescens ZIP (Zn-regulated tr...

Calcium (Ca) and the toxic heavy metal cadmium (Cd) are antagonistic ions competing for uptake in plants when they co-occur in soil solutions, and high Ca concentrations can reduce the uptake of Cd in plants. However, less is known about the effects of low Ca bioavailability on Cd uptake and translocation in plants. We hypothesized that low Ca availability would enhance Cd uptake and translocat...

We compared four methods to extract arsenic (As) from three different plants containing different As levels for As speciation with the goal of developing a more efficient method, i.e., As-hyperaccumulator Pteris vittata at 459-7714mgkg(-1), rice seedling at 53.4-574mgkg(-1), and tobacco leaf at 0.32-0.35mgkg(-1). The four methods included heating with dilute HNO3, and sonication with phosphate ...