27 research outputs found
Heavy metals in the irrigation water, soils and vegetables in the Philippi horticultural area in the Western Cape Province of South Africa
The aims of this study were to investigate the
extent of heavy metal contamination in the Philippi
horticultural area in the Western Cape Province, South
Africa. Concentrations of Cd, Cr, Cu, Mn, Ni, Pb and Zn
were determined in the irrigation water, soils and vegetables
in both winter and summer cropping seasons with
an ICP-AES and tested against certified standards.
Differences were found in heavy metal concentrations
between the winter and summer cropping seasons in the
irrigation water, soils and vegetables. Certain heavy
metals exceeded the maximum permissible concentrations
in the irrigation water, soils and vegetables produced
in South Africa. These toxic concentrations were
predominantly found in the summer cropping season for
the soils and in the crops produced in winter. It is thus
suggested that further studies are carried out in the
Philippi horticultural area to determine the sources of
the heavy metals to try and mitigate the inputs thereof
and therefore reduce the amount of heavy metals entering
the human food chain.ISI & Scopu
Toxicity assessment of two soils from Jales mine (Portugal) using plants: Growth and biochemical parameters
Contaminants in soils can enter food chains through primary producers. Bioavailable contaminants can induce growth, and reproductive or biochemical changes in plants. To evaluate the bioavailability of heavy metals in two soils from Jales mine surroundings, bioassays with the plants Brassica rapa (RCBr) and Avena sativa were performed. Biochemical parameters (protein and malondialdehyde [MDA] content, and catalase and peroxidase activities) were also measured. The soils had different heavy metal contents: JNC soil contained low heavy metal concentrations, whereas JC soil had high heavy metal contents. Results stressed the difference between species sensitivity, with A. sativa showing no toxicity effects when exposed to both soils. On the other hand, B. rapa presented a decrease in growth parameters when exposed to JNC soil and no changes when exposed to JC soil. A Life Cycle Bioassay confirmed this trend for B. rapa exposed to JNC soil, but also evidenced that JC soil was affecting B. rapa in terms of flower and seed pod production. Biochemical assays showed that plants affected by heavy metals also displayed oxidative stress, with an increase in MDA production, reduction of protein content, and reduction of catalase and peroxidase activities. All bioassays revealed that JNC soil, although with a lower heavy metal content, had a higher bioavailable fraction when compared to JC soil, which consequently increased its toxicity to plants.FCTERAS Project - POTI-MGS-34782-200