International Journal of Advanced Research and Publications ISSN: 2456-9992 Volume 3 Issue 10, October 2019 www.ijarp.org 7 Assessment Of Heavy Metals In Amaranthus Spinosus, Kigali, Rwanda. Protogene Hakizimana, Abias Maniragaba, Francois Xavier Nshimiyimana University of Lay Adventist of Kigali, P.O. Box : 6392, Kigali- Rwanda , +250788282971 Prokist2014@gmail.com University of Lay Adventist of Kigali, P.O. Box : 6392, Kigali- Rwanda , +250783782303 abiasrw@gmail.com University of Lay Adventist of Kigali, P.O. Box : 6392, Kigali- Rwanda , +250787435575 nshimiyimanaxavier@gmail.com Abstract: Spiny amaranths “Amaranthus spinosus” is a common leafy vegetable and is locally called dodo. It is grown both in wet and dry seasons and harvested between 30-40 days after planting. Because of its nutritional importance and demand but also less expensive it is widely cultivated especially in Kigali, Rwanda. The level of heavy metals in soil and leaf samples of Amaranthus spinosus grown in seven sites were performed by using Inductively Coupled Plasma Emission. The objective of study was to assess the level of heavy metals in soil and in leaves of amaranthus spinosus. The heavy metals that were assessed are: Manganese (Mn); Zinc (Zn); Copper (Cu); Cadmium (Cd); Iron (Fe); Nickel (Ni) and Lead (Pb). The results obtained revealed that their concentrations in soil ranged between : Mn ( 45.3-243.5); Zn (37.8-56.7) ; Cu (5.3-44.6); Cd (0.09-0.21); Fe (1789-2896); Ni (9.6-23.8) and in the leaves the concentration of some heavy metals are ranged between: Mn (0.22-0.56); Zn (0.89-1.52); Cu (0.12-0.34); Fe (66.67-92,7); Ni (0.04-3.12) in mg/kg from all sites. The Lead (Pb) was not detected in soil and in leaves samples, and cadmium “Cd” is not detected in leaves samples. The values of all heavy meta ls analyzed from in whole samples in present sites were under the threshold values established by European organization and World Health Organization (WHO for food and vegetables). The results are an indication that the spiny amaranths leaves had the potential to be used as source of nutrients in alleviating macro- and micro- nutrient deficiencies. The study will bring awareness to consumers of these items about what they are taking and the health implication as well as assist them and the farmers in taking necessary precautions towards proper care of their fruits and vegetables before consumption. This will indeed be a good way of reducing substantial quantity of contaminants from getting to the human body thereby avoiding health problems, with its attendant positive economic implications. Key words: Amaranthus Spinosus, heavy metal, soil, leave 1. Introduction Spiny amaranth (Amaranthus Spinosus) as green leafy vegetables are inexpensive, are easily and quickly cooked, and are rich in several nutrients, such as vitamins, proteins, and minerals (Gupta K, Wagle1998) .It is a terrific source of minerals (manganese and also iron, calcium, copper, magnesium, phosphorus and potassium (Thompson and Kelly, 1990 )). The originally Studies showed that optimal intake of elements, such as sodium, potassium, magnesium, calcium, manganese, copper, zinc and iodine, in amaranth could reduce individual risk factors, including those related to cardiovascular disease. Regular consumption of amaranth can help to reduce cholesterol levels and lower blood pressure (Gonor et al., 2006; Martirosyan et al., 2007). In the recent decades, the development of anthropogenic activities such as industry, agriculture and urban life has resulted in increasing of environmental pollution. According to the previous studies (Diaconu et al., 2009; Karbassi et al., 2014; F. X. Nshimiyimana and et al., 2016). Among the environmental pollutants, heavy metals represent a significant hazard to the environment, being both an ecological and health risk. The use of different chemical products such as fertilizers and pesticides in agriculture can be one of the sources for heavy metals in rural areas. These elements are highly persistent and not biodegradable contaminants, therefore, they accumulate in soil, then becoming accessible to plants or leaching to groundwater (Diaconu et al., 2009; Minkina et al., 2014; Smical et al., 2008).Therefore the heavy metals uptake by plants grown in polluted soils has been studied to a considerable extent (Wong et al., 1996 and Yusuf et al., 2003. However the human exposure to heavy metals has risen dramatically in the last 50 years, as a result of an exponential increase in the use of heavy metals in industrial processes and products(Marshall, 2004; Radwan and Salama, 2006; Wang et al., 2005; Khan et al., 2008). Even if vegetables are source of nutrients but the increase in human activities, especially with the application of modern technologies, pollution and contamination of these vegetables in their cultivated areas has become inevitable. The objective of this study was to evaluate the level of heavy metals such as Cadmium (Cd), Lead (Pb), Nickel (Ni), Copper ( Cu), Iron(Fe), Manganese( Mn), and Zinc (Zn) in topsoil, and in leaves of spiny amaranths located in Kigali City mainly at Kabuye and Nyabugogo roads then assessing if their concentrations are not high to cause potential negative effect to human health. 2. MATERIALS AND METHODS 2.1. SAMPLING SITES DESCRIPTION This study was conducted in seven sites located in Kigali City. Those sites are characterized by the combined effect of motor washing, car washing and vehicular emission from the buses roads. Vehicular emission from the bus express road which is washed by the rain and run into the soil, gasoline, heavy-duty oil and lubricating oil which are all supplemented with additives such as metallic soaps and organic metal compounds (e.g. Tetraethyl lead in gasoline) are a major