International Journal of Engineering Research and Development e-ISSN: 2278-067X, p-ISSN: 2278-800X, www.ijerd.com Volume 7, Issue 3 (May 2013), PP. 01-05 1 Determination of Heavy Metal Contaminants in Leafy Vegetables Cultivated By the Road Side Surukite O. Oluwole 1 , Olubunmi Makinde S.C. 2 , Kafeelah A. Yusuf 3, Olusegun O. Fajana 4 , Ayobami O. Odumosu 5 1,2,5 Department of Botany, Lagos State University Ojo, PMB 0001, Lagos State University Post Office Ojo Lagos, Nigeria, 3 Department of Chemistry, Lagos State University,Ojo, PMB 0001, Lagos State Unive4rsity Post Office Ojo , Laghos Nigeria. 4 Department of Biochemistry Lagos State University Ojo, PMB 0001 , Lagos State University, Post Office Ojo, Lagos Nigeria Abstract:- A study was conducted to analyze the heavy metals in some leafy vegetable cultivated by roadside including Talium triangulare, Amaranthus hybridus and Telfairia occidentalis. The vegetables were sampled from different areas of Ojo local goverment. The vegetables were digested using 98% nitric acid (HN0 3 ) and analyzed with the aid of Atomic Absorption Spectrophotometer(AAS) to determine heavy metals. The mean concentration for each heavy metal in the samples gotten from each sites were calculated and the comparison of these data was done amongst the three differnt locations. These were compared with the permissible levels set by the FAO and WHO. Results showed that the levels of Copper and Cadmium for the leafy vegetables ranged from 0.3944 ± 0.159 to 1.6559 ± 0.919 and from 0.0854 ± 0.043 to 0.2563 ± 0.249mg/kg dry weight respectively. While that of Zinc and Lead was 1.8028 ± 0.111 to 6.2267 ± 1.572 and 0.0856 ± 0.040 to 2.104 ± 1.490mg/kg . When compared with standards, heavy metal levels were found to be within safe limit which is an indicator that the leafy vegetable in Ojo local government area are safe for consumption without the risk of environmental toxicants. Keywords:- Heavy metals, Leafy vegetables, Environmental pollutants, Road side, Atomic absorption spectrometer I. INTRODUCTION Air pollution of the natural environment by heavy metals is a universal problem because these metals are indestructible and most of them have toxic effect on living organisms, when permissible concentration levels are exceeded. Heavy metals frequently reported in literature with regards to potential hazards and occurrences in contaminated soil are cadmium, copper, zinc and lead (Akoto et al., 2008., Alloway, 1995). The vehicular exhausts, as well as several industrial activities emit these heavy metals so that soils, plants and even residents along roads with heavy traffic loads are subjected to increasing levels of contamination with heavy metals (Ghrefat and Yusuf, 2006). However, heavy metals are natural components of the earth’s crust and cannot be degraded nor destroyed. They enter the human body through food, water and air. Heavy metals are ubiquitous; therefore they tend to bio accumulate, thus causing an increase in their concentration in a biological system. Chronic heavy metal toxicity has been the result of long term low level exposure to pollutants and is associated with many chronic diseases. Heavy metals are given significant interest throughout the globe due to their toxic, mutagenic and teratogenic effects even at very low concentrations. Vegetables constitute an important part of the human diet since they are rich in carbohydrates, proteins as well as vitamins, minerals and trace elements however; they contain both essential and toxic elements over a wide range of concentrations. Metals accumulation in vegetables may pose a direct threat to human health. Heavy metals are one of a range of important types of contaminants that can be found on the surface and in tissue of dry vegetables. Vegetables are also part of daily diets in many households forming an important source of vitamins and minerals required for human health. They are made up of chiefly cellulose, hemi-cellulose and pectin substances that give them their texture and firmness (Sobukola and Sairo 2007). Vegetables takes up metals by absorbing them from contaminated soils, as well as from deposits on different parts of the vegetables exposed to the air from polluted environments (Sobukola et al., 2010). Vegetable plants growing on heavy metal contaminated medium can accumulate high concentrations of trace elements to cause serious health risk of consumers. Regular monitoring of these heavy metals from effluents, sewage, in vegetables and in other food materials is essential for preventing excessive buildup of the metals in the food chain. Heavy metals depositions are associated with a wide range of sources such as small scale industries (including battery production, metal