Levels of Selected Heavy Metals in Soil, Tomatoes and Selected Vegetables from Lushoto District-Tanzania

Abstract

Abstract:This study involved the determination of heavy metals of Cd, Cr, Cu, Pb and Zn in cauliflower (Brassica oleracea L.var botrytis L.), carrot root (Daucus carota L.), tomato fruit (Lycopersicum esculentum Mill.), onion bulb (Allium cepa L.) and leafy cabbage (Brassica oleracea L. var capitata L.) and the respective soils from Lushoto District, Tanzania. Samples were collected from eight growing sites. The accumulated heavy metals were quantified and the levels compared to the FAO/WHO CODEX-STAN 179:2003 and TZS 972:2007 contamination limits for such produce. The methodology involved random sampling, extraction of the metals from the vegetable and soil and determination of heavy metals by using ICP-OES and GFAAS. The levels of Cu in all vegetables were below the FAO/WHO limit while levels of Cr and Zn in all vegetables were found to be above this limit therefore advocating a health risk for consumers. Pb was only found in carrots at 2 sites (Montisory and Resource centre) and in onions at the market all at levels above the FAO/WHO limit while Cd was only found in onions and tomatoes at 2 sites (market and Montisory) at above the FAO/WHO limits. Vegetables especially onions from the Mlalo market advocate a health risk to consumers. Levels of heavy metals in the soils were below the limits of the Tanzanian standard (TZS 972: 2007) and were lower than levels found in vegetables. However, the bioconcentration factor for Cr, Pb, Cd and Zn in all vegetables and tomatoes where they were detected except for cabbages at the Garage site were found to be above 1, an indication of high uptake of heavy metals in the vegetables from the soil. Cu at 80% of the sites had a BCF lower than 1 indicating that Cu was more abundant in the soil compared to the vegetables. These results suggest that these vegetables from Lushoto district are not safe for consumption in their raw state.

Detection of Heavy metals in Fruits and Vegetables Available in the Market of Quetta City

“…Concentration of iron in vegetables Concentration of iron in fruits & peels of fruits samplesLead: It is not essential heavy metal and is highly toxic for microorganisms, plants and animals, its use in very small quantity can cause environmental and health problems that affect the multiple body systems, Pb can enter the body through breathing in air contaminated with Pb as it gets into the lungs transported into the other parts of the body and is deposited into the bones. It affects the central nervous system, I.Q of children and behaviour, Alteration in sperms decrease the fertility in men and increase the chance of miscarriage and defects in birth in women[18].The concentration of lead in the fruit samples such as peach was observed higher than all the vegetable samples whereas other fruit samples showed no any important difference. The fruit samples such as water melon and peach indicated higher concentration of lead than the peels of all fruit samples The concentration of Pb crossed the safe values in all samples of fruits and vegetables except lady finger and cauliflower in which concentration of Pb lies in safe limits.…”

“…These are rich sources of vitamins, Fiber, minerals and also have importance as anti-oxidative effects for proper growth, body development, and maintenance of overall health [1]. Other than water and soil, foods are also contaminated with heavy metals due to the use of chemicals sprays, preservatives, industrialization, mining activities, fertilizers and use of waste water [2]. Contamination of Heavy metal in fruits and vegetables is one of the most significant aspects of food quality.…”

Determination of Essential and Non-essential Metals Concentration in Garlic (<i>Allium sativum</i> L.) Bulb and Leaf Cultivated in Ambo Woreda, Ethiopia

“…Studies have revealed that fruits and leafy vegetables are vulnerable to heavy metal contamination from soil, wastewater and air pollution. The toxicity and consequent threat to human health by heavy metals such as cadmium, copper, lead, chromium, zinc, nickel, cobalt, arsenic and mercury are a function of concentration and bioaccumulation [6,7]. The implications associated with metal contamination are of great concern, particularly in agricultural production systems due to their increasing trends in human foods and environment [8].…”

“…This fact necessitates for frequent determination of heavy metals in vegetables and soil for the safety of consumers. Fruits, vegetables and other foods are among pathways by which heavy metals enter the human tissues leading to deterioration of health [7]. Excessive amount of heavy metals in food cause a number of diseases, especially cardiovascular, renal, neurological, and bone diseases [10,11].…”

Essential and Non-Essential Elemental Composition of Five Different Major Parts of Butea monosperma (Palash) by Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES)

“…from soil, wastewater and air pollution [2,3] and as such serve as the pathways by which heavy metals enter the human tissues leading to deterioration of health [4]. Butea monosperma (family Fabaceae) commonly called Palash and "Flame of the forest" is reported in various ancient literatures to have medicinal potential.…”