Heavy metals in soils

The aim of this study is to measure the levels of heavy metals (Fe, Mn, Zn, Cu, Ni, Cd and Pb) found in common vegetables (parsley, carrot, onion, lettuce, cucumber and green beans) grown in contaminated mining areas compared with those grown in reference clear area and to determine their potential detrimental effects via calculation of the daily metal intake (DImetal) and Target Hazard Quotients (THQ) for normal daily consumption of these vegetables, for male and female gender. Compared with the reference in contaminated areas, soil and plant contents of all analyzed metals are higher, usually over normally content for Mn, Zn, Cu, Cd and Pb. Particularly, in soil, higher values than intervention threshold values (ITV) were found for Cu and Pb and higher than maximum allowable limits (MAL) for Zn, Cu, Cd and Pb for parsley roots and leaves, carrot roots, cabbage, lettuce and cucumber. DImetal and THQ values for male and female were calculated for each vegetable and metal and for which oral reference doses exist. The combined THQ values calculated are concerning in that they are usually below the safe level of THQ<1 for all vegetables grown in reference area. In contaminated Moldova Noua (M) area the combined THQ exceeded the safe level only for parsley roots, while in more contaminated Ruschita (R) area combined THQ exceeded the safe level for parsley and carrot roots, lettuce and cabbage. Cd and Pb, most toxic metals to humans, have an increasing prevalence in the combined THQ for leafy (cabbage and lettuce) and fruit vegetables (cucumber). In the root vegetables only Pb has an increasing prevalence in combined THQ values. In all areas female THQ is higher than male THQ. The results of this study regarding metal contents in soils, vegetables, DImetal and THQ suggest that the consumption of some vegetables (especially parsley, carrot and cabbage and less for lettuce, cucumber and green beans) is not free of risks in these areas. The complex THQ parameter use in health risk assessment of heavy metals provides a better image than using only a simple parameter (contents of metals in soils and vegetables).

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Heavy metals health risk assessment for population via consumption of vegetables grown in old mining area; a case study: Banat County, Romania

Observing and understanding the Southeast Asian aerosol system by remote sensing: An initial review and analysis for the Seven Southeast Asian Studies (7SEAS) program

Trace elements in soil-vegetables interface: Translocation, bioaccumulation, toxicity and amelioration - A review

Practical Environmental Analysis.

The main sources of trace metals to plants are the air or soil media from which trace elements are taken up by the root or foliage. The air, soil and vegetable samples were collected from Industrial, Semi-urban and rural areas and were analysed for Pb, Zn, Ni and Cu. The rural area is free from contaminant sources and is treated as control. From each representative area composite samples of Tomato, Lady's finger, Capsicum and leafy vegetable Bimli were collected and anlysed for Pb, Zn, Ni and Cu. The air environments in Industrial and Semi-Urban areas are enriched with the four trace metals, but the concentrations were within the permissible levels. This indicates that, despite the close proximity of the agricultural lands to high emitting industrial sources, soils do not seem to have been contaminated by atmospheric deposition. Remarkable differences were observed between the trace metal content in vegetables of rural areas with semi-urban and industrial areas. In industrial area Nickel, Zinc were reported in higher concentrations in tomato and capsicum where as in semi urban area the concentration of Cu is 2-3 times higher in tomato and lady's finger on comparison with the rural vegetables. Based on the air accumulation factor and concentration factor calculations, the trace metals of Pb and Zn in industrial and semi-urban areas were found to be receiving the contributions from both atmospheric and soil inputs in all the four crops.

/pdf/trace-metal-accumulation-in-vegetables-grown-in-industrial-2iaewm7skp.pdf

S. Ramakrishna Rao

Papers

Trace metal accumulation in vegetables grown in industrial and semi-urban areas - a case study