Concentration of Proximate and Heavy Metals in Four Selected Vegetables Irrigated by Municipal Wastewater

Abstract

The study was conducted to determine the level of heavy metals such as: Lead (Pb), Cadmium (Cd), Nickel (Ni), Copper (Cu), Manganese (Mn), Zinc (Zn), Iron (Fe) and Proximate such as: Moisture, Ash and Protein in four abundantly used vegetables in Quetta, Balochistan, Pakistan. The foliage and fruits of Brinjal (Solanum melongena L.), Chili (Capsicum annuum L.), Karela (Momordica charantia L.) and Khira (Cucumis sativus L.) were collected from the city areas where these were cultivated with waste and fresh (Control) waters. The food samples were digested by dry ashing procedure and their minerals were determined by atomic absorption spectrophotometer. Results exhibited that there was slightly significant variation in elemental composition of waste and control watered vegetables. The results also specified that heavy metals in vegetables irrigated with wastewater were highly significantly build-up as compared to control water vegetables. The average range of various metals in foliage and fruits of wastewater vegetables were 1.9-2.4mg/kg and1.8-2.2mg/kg for Pb, 0.14-0.25mg/kg and 0.13-0.20mg/kg meant for Cd, 0.73-1.01mg/kg and 0.70-0.91mg/kg intended for Ni, 0.86-1.20mg/kg and 0.80-1.13mg/kg for Cu, 0.16-0.24mg/kg and 0.11- 0.20mg/kg stand for Mn, 1.26-1.60 mg/kg and 1.20 - 1.50mg/kg for Zn and 1.90-2.96mg/kg and 1.50-2.90 mg/kg for Fe, respectively. Results showed that the solitary Pb and Cd concentration in waste watered vegetables were found more than the allowable limit and the foliage exhibited more accumulation of heavy metals with respect to fruit.