VISTAS Vol. 7, No. 1, 2018, pp. 47-56 ISSN: 2319-5770, e-ISSN 2394-1138

ASSESSMENT OF LEAD AND CADMIUM CONTAMINATION IN COMMON VEGETABLES FROM LOCAL MARKETS OF DISTRICT, , Neethu Gopalakrishnan* and Lakshmi M.V* *Department of Botany, St. Joseph’s College (Autonomous) , Thrissur 680121, Kerala, India. ABSTRACT Heavy metals are very harmful due to their non-biodegradable nature and their accumulation in different body parts of human beings upon consumption. It accumulates in different levels of the ecosystems and food chain. The present investigation was conducted to screen the heavy metal contamination in some common vegetables (Tubers, Leafy vegetables and Fruity vegetables) collected from five different markets of . The vegetables were also collected from farmers and Home garden. All the collected samples were shade dried, powdered and digested. A total of 40 samples were collected and analysed for Heavy metals (Lead and Cadmium) by using AAS (Atomic Absorption Spectrometer). Distinctive accumulation of heavy metals by different vegetables was observed. Lead is a highly toxic metal which causes serious threats on renal, reproductive and nervous system. Exposure to Lead may lead to severe diseases in humans and animals. It accumulates in environment with increasing hazards due to its non-biodegradable nature. Exposure to Cadmium also leads to adverse health effects including cancer and cause severe damage to kidney, borne and lungs. Even the low concentration of Cadmium may also cause serious health hazards. The heavy metals such as Lead and Cadmium in the selected vegetables were found to be accumulated above the permissible limits of WHO and may cause deleterious effects to the human health. In this study, significant differences were found in the concentrations of heavy metals in the selected vegetable types; the concentrations decreased in the order of Tubers > fruity vegetables ~ leafy vegetables. The highest accumulation of Lead was observed in Tubers and Cadmium in Leafy vegetables. The study concludes that the atmospheric depositions and marketing systems of vegetables plays a major role in increasing the levels of heavy metal contents in vegetables and cause potential health hazards to the consumers.

Key Words: Atomic Absorption Spectrophotometer, Lead, Cadmium, WHO.

INTRODUCTION Our natural environment became polluted with heavy metals through various human activities. Heavy metals are the metals having high density and high atomic weight. The earliest known metals – common metals such as iron, cobalt and tin and precious metals such as silver, gold and platinum are heavy metals. From 1809 onwards light metals such as magnesium, aluminium and titanium were discovered, as well as less well known heavy metals including gallium, thallium and hafnium (Sharma et al., 2008). Some heavy metals are either essential (Fe, Co, Zn) or relatively harmless (ruthenium, silver &indium), but can be toxic in larger amounts or certain forms. Other heavy metals, such as cadmium, mercury and lead, are highly poisonous. Potential sources of heavy metal poisoning include mining and industrial wastes, agricultural runoff, occupational exposure and paints and treated timber.

Heavy metals are natural elements of the Earth's crust. They cannot be degraded or destroyed. They enter into our body through food, drinking water and atmospheric air. As trace elements, some heavy metals are essential to maintain the 48 ● ISSN: 2319-5770 e-ISSN 2394-1138 metabolism of the human body. But, at higher concentrations they can lead to poisoning. They are very harmful because of their non-biodegradable nature and their potential to accumulate in different body parts. Excessive accumulation of heavy metals can develop systematic health problems in human body. Accumulation of heavy metals in agricultural soils result in increased metal uptake by crops, this can affect food quality and safety. Heavy metal contamination of the food items is one of the most important aspects of food quality assurance (Marshall, 2004; Radwan and Salama, 2006). The main reason behind these is the use of a large quantity of wastewater that is used for irrigation, and it is discharged from industries, which is being taken out in several parts of the world. Wastewater used for irrigation has many contaminants mainly heavy metals depending upon the source of discharge (Huibers and Van Lier 2005; Pedrero et al., 2010). Lead, cadmium, mercury are the major heavy metals of our food supply; others like zinc, iron, copper that plays an important role in our biochemical reactions.

Vegetables are very important part of the human diet as they contain proteins, carbohydrates, vitamins, minerals and trace elements. Usually it can be categorized into Leafy vegetables, Fruity vegetables and Tubers. Tubers are the most efficient carbohydrate producers. Tuber crops have been lesser attended to by the researchers the world over, being considered inferior food stuffs (Divya et al., 2015). Vegetables, especially leafy vegetables, accumulate higher amount of heavy metals because they absorb these metals in their leaves (Neriman 2010). Fruits play a major role in providing Vitamins and Minerals such as Iron, Calcium, and Potassium that need for our Daily food as Dietary consumption. Vegetable species differ widely in their ability to take up and accumulate heavy metals. They contain both essential and toxic elements in various concentrations. Many researchers have shown that some common vegetables have ability of accumulating high level of metals from the soil. Distribution of heavy metals in plant body depends upon their concentration in soil and water as well as plant species and its population (Kailas et al., 2013). The concentration of heavy metals in vegetables may be increased by various contamination routes. Most of the Cadmium in plants originates from the soil, while Lead contamination is usually air borne (Omambia and simyu, 2014).

During the last decades, the increasing demand for food safety has stimulated research regarding the risk associated with consumption of food stuffs contaminated by pesticides, heavy metals and/or toxins (D’mello, 2003). Emission of heavy metals from the industries and vehicles may be deposited on the vegetable surfaces during their production, transport and marketing. Al jassir et al.,(2005) have reported elevated levels of heavy metals in vegetables sold in the markets at Riyadh city in Saudi Arabia due to atmospheric deposition. Recently, Sharma et al., (2008) have founded that atmospheric deposition can significantly elevate the levels of heavy metal contamination in vegetables commonly sold in the markets of Varanasi, India.

Accumulation of highly toxic metals even at low concentrations in food and water leads to the buildup of cadmium in kidneys and may likely leads to kidney diseases (Latif, 2009). Other effects of metal toxicity may include damage or reduce mental or central nervous function, lower energy levels, and damage to blood composition, lungs, kidneys, liver, and other vital organs (kihampa et al., 2003). Indeed VISTAS Vol. 6, No. 1 ● 49 it was estimated that 10% of the world population consumes food irrigated with wastewater (Finley, 2008). However these factors: climate, atmospheric deposition , the nature of the soil on which the plants are grown and the degree of maturity of plants at the time of harvesting can influence the concentration of heavy metals on and with plants (Farooq et al.,2008 , Muchuweti et al.,2005). Similarly Nasif et al.,(2006) explained that the fate and effects of pollutants discharged into particular water body will depend not only on the amount of polluting substance emitted but also on the hydrological, physical, chemical and biological conditions characterizing the water body concerned.

The present study shows the information on the concentration of Lead in some selected vegetables sold in different markets of Thrissur district. It is hypothesized that the use of untreated waste water may increase the levels of heavy metals in the vegetables. The observed concentration of Lead was compared with WHO standards. Therefore this work was conducted to reveal if the content of heavy metals in vegetables is within the permissible limit or not. The main purposes of the present study were to investigate the concentration of Lead in the selected edible tubers and compare the concentration of Lead in organic and inorganic vegetables.

MATERIALS AND METHODS The present study was carried out in different markets of Thrissur district during the period, April to June 2017. Vegetables like in Tubers (Potato, Tapioca, and Yam), Leafy (Cabbage, Spinach, Curry leaf and Coriander), and Fruits (Tomato, Bitter guard and Lady’s finger) have been selected for the present study.

Collection of samples

There were 70 samples collected from various selected markets of Thrissur district. The vegetables can be grouped into; Tubers (Potato, Yam and Tapioca), Leafy vegetables (Cabbage, Coriander, Spinach, & Curry Leaf), and Fruity vegetables (Tomato, Lady’s Finger And Bitter Guard). All these vegetables can be kept in an aluminium foil and labeled. It is then brought to the laboratory for further analysis.

Preparation and treatment of samples

In the laboratory, the collected samples were washed with tap water and thereafter with distilled water and then dried in an oven at 800 C (Larry and Morgan, 1986). At the end of the drying, the oven was turned off and left overnight to enable the sample cool to room temperature. Then each sample was grounded into a fine powder using a commercial blender, sieved and finally stored in an aluminium foil, until used for acid digestion.

Digestion procedure

Tri-acid mixture ( Nitric acid 69% , Perchloric acid 70% , Sulphuric acid 98% in the ratio 5:1:1) was added to a beaker containing 1g dry vegetable sample. The mixture was then digested at 80 degree Celsius till the transparent solution was achieved. After cooling, the digested samples were filtered using Whatman no.42 filterpaper and filtrate was diluted to 50 ml with deionised water. This was then transferred into a screw capped glass bottle. 50 ● ISSN: 2319-5770 e-ISSN 2394-1138

Instrumental analysis

Determination of heavy metals such as cadmium and lead in filtrate of the vegetables and atmospheric deposits was achieved by atomic absorption spectrometer (AAS).

RESULTS AND DISCUSSION The present study was to determine the levels of Lead and Cadmium in selected vegetables such as Leafy (Cabbage,Curry leaf, Coriander, Spinach), Fruity (Tomato, Bitterguard, Ladysfinger) and Tubers (Tapioca, Yam, Potato) collected from different markets of Thrissur district.

Heavy metal concentration in vegetables

The obtained results according to the first and second objective showed that the concentration of lead is much higher than cadmium in all the vegetables. The heavy metal contamination is much more seen in vegetables collected from the markets of Thrissur and Cherpu and low heavy metal levels are seen in organic vegetables and vegetables grown in the kitchen garden. The order of heavy metal accumulation in vegetables is as follows; Tubers > leafy vegetables ~ fruity vegetables. In the present study, the concentration of Lead is in the limit above 1 mg/kg can be considered as toxic and that might be a great threat for the consumers. Even the low concentration of Cadmium may also cause serious health hazards. The concentrations of Lead and Cadmium in each category of vegetables are as follows;

Concentration of Lead in Leafy vegetables

The concentration of lead in leafy vegetables is in the range of -0.2 to 11.25 ppm. Among leafy vegetables, lead content was highly present in Spinach (-2 to 10.1 ppm ) which was collected from the Irinjalakuda and Thrissur market. The Lead content in Cabbage is between 1.5 and 7.5 ppm. The Curry leaf shows the minimum Lead concentration(-0.3ppm) among other leafy vegetables.

Concentration of Lead in Fruity vegetables

Fruity vegetables have the maximum Lead content is in the range of -1.65 to 11.35 ppm. Among fruity vegetables, tomato from Thrissur market shows the maximum value (11.35ppm). The minimum Lead concentration was obtained in Lady’s finger collected from market. Bitter guard shows the high Lead content in Cherpu market (9.15ppm) and low in homely cultivated vegetable.

Concentration of Lead in Tubers

The level of lead in tubers is in the range -1.9 to 12.55 ppm. Yam and Tapioca shows the high range. High level of lead content was obtained in the vegetables collected from thrissur and Cherpu market. Lowest values are obtained in the vegetables collected as organic. Low Lead content was obtained in Organic Yam, i.e.,- 3.1ppm.

Table 2: Bioaccumulation of Lead in selected vegetables of different markets VISTAS Vol. 6, No. 1 ● 51

selected plan Sl.N vegetable t TCR( CR KN CK Orga Ho Avera o. s part Pb) P K IJK L nic me ge S.D

5.9 5.2714 1.9791 1 Cabbage Leaf 7.5 7.7 5.5 5 4.7 4.05 1.5 29 52

Coriande 11. 5.0925 2 r Leaf 9.25 5.7 3.4 25 -4 -0.2 -0.2 3.6 01

9.1 10. 5.5071 4.1857 3 Spinach Leaf 10.1 5 4.4 1 4 2.8 -2 43 26

Curry 7.4 11. - 2.6642 5.2619 4 leaf Leaf 5.65 5 1 5 3.3 -3.45 -0.2 86 74

Tub 8.3 4.6 2.4941 5 Potato er 5.7 5 5 8.7 7.3 2.5 2 5.6 36

Tub 10. 5.8 6.8 - 5.2857 5.1900 6 Yam er 10.8 25 5 5 1.9 8.25 -3.1 14 81

Tub 6.5 12. 7.0142 4.7597 7 Tapioca er 15 5 55 6 2.4 0.65 5.95 86 8

- Frui 6.5 1.6 - 4.3071 4.8789 8 Tomato t 11.35 7.1 8.3 5 5 0.15 1.65 43 95

Lady'sfin Frui 5.4 - 3.2042 3.6130 9 ger t 6 5 4.1 7.9 3.8 1.5 1.28 86 47

Bittergu Frui 9.1 5.7 2.5545 10 ard t 6.65 5 5 6.8 8.1 3.15 1.28 5.84 25

Concentration of Cadmium in Leafy vegetables

Cadmium values showed low levels in leafy vegetables. Like Lead, Cadmium concentration is also highly present in the vegetables collected from Thrissur market. Cabbage and Coriander shows almost similar highest values. The lowest value was observed in vegetables collected from Home Garden, especially Spinach. Cadmium content in leafy vegetables was in the range of 0 to 1.3ppm.

Concentration of Cadmium in Fruity vegetables

Cadmium contamination was greatly present in Tomato collected from Thrissur market. It is in the range of -0.6 to 1.25 ppm. At the same time, Tomato that are collected as Organic and those grown in the Kitchen garden shows the lowest value. The maximum range of Bitter guard and Ladysfinger is 1.15 ppm.

Concentration of Cadmium in Tubers 52 ● ISSN: 2319-5770 e-ISSN 2394-1138

Tubers also show low concentration of cadmium. They have the range in between 0 to 1.4 ppm. In tubers, cadmium concentration is much more present in Yam. The highest value is 1.4 ppm and that would be collected from Thrissur market. At the same time lowest concentration was obtained in the Organic Yam and Potato.

Table 3: Bioaccumulation of Cadmium in selected vegetables of different markets

selected plan Sl.N vegetable t TCR(C CR KN IJ CK Orga Ho Averag o. s part d) P K K L nic me e S.D

0.0 0.4214 0.6011 1 Cabbage Leaf 1.3 1.3 -0.1 0.6 5 -0.1 -0.1 29 04

- Coriande 0.3 0.4596 2 r Leaf 1.05 1.1 0.4 0.9 5 -0.2 -0.1 0.4 19

0.3 0.3 0.6 0.3357 3 Spinach Leaf 0.8 5 0.2 5 5 0 0 14 0.3283

- Curry 0.3 0.5 - 0.0857 0.3636 4 leaf Leaf 0.6 0.5 5 5 0.3 -0.2 -0.2 14 55

Tub 0.6 - 0.3785 0.6515 5 Potato er 1.3 1.2 0 5 0.2 -0.2 -0.1 71 48

Tub - 0.2142 0.8384 6 Yam er 1.4 0.5 0 0.5 0.2 -0.2 -0.5 86 27

Tub 1.0 - 0.2714 0.6919 7 Tapioca er 1.25 5 0.1 0.5 0.2 -0.4 -0.4 29 54

Frui 1.2 0.0 1.1 0.5428 0.5000 8 Tomato t 1.25 5 5 5 1.1 -0.4 -0.6 57 26

Lady'sfin Frui 1.1 0.6 - - 0.2785 0.2272 9 ger t 0.6 5 5 0.4 0.3 -0.3 0.25 71 84

Bittergua Frui 0.1 - 0.3 0.2142 0.6616 10 rd t 1.15 1.1 5 0.2 5 -0.45 -0.6 86 5

According to the Table 2 and 3, Tubers that shows the highest metal contamination. The reason behind these was roots can absorb heavy metals easily and less transported to the other edible parts such as leaves and shoots of many plants. As tubers are grown under the soil they are more contaminated that the other vegetables. They can absorb heavy metals more readily than the other plants (Divya et al.,2015). Proper washing of vegetables is necessary to reduce a small amount of heavy metals. VISTAS Vol. 6, No. 1 ● 53

The elevated concentration levels of heavy metals and the strong ability for heavy metal accumulation in leafy vegetables were possibly due to the leaves being the main parts of the vegetables used for photosynthesis, because metal content is highly flowed to the leaves due to higher transpiration.

The required standard conditions of WHO have been given in Table 4. It was clearly seen that almost both the metals Lead and Cadmium were found in greater amounts than the maximum safe limits given by FAO/WHO. The chief source of toxic metals is the discharge from industries and domestic waste into sewage. Generally, agricultural soils have low background levels of heavy metals; contaminations are mainly through fertilizer application, irrigation with partially treated or untreated sewage (Farooq et al. 2008).

Table 4: WHO maximum permissible level of heavy metals in vegetables found in mg/kg

Maximum permissible level of heavy metals Sl.No. Heavy metals according to WHO(mg /kg)

1 Lead (Pb) 0.3

2 Cadmium (Cd) 0.1

The increase of Lead in the vegetables of Thrissur market was attributed to heavily traffic in this area which Lead to the accumulation of Lead emitted from cars exhaustions. The recent results obtained by Sharma et al., (2006) who reported the Pb concentration (17.54–25.00 mg kg−1) in vegetables grown in industrial areas. Muchuweti et al., (2006) reported the level of Lead (6.77 mg kg−1) in vegetables irrigated with mixtures of wastewater and sewage from Zimbabwe to be higher than WHO safe limit (2 mg kg−1). Al Jassir et al., (2005) studied six washed and unwashed green leafy vegetables from Saudi Arabia and noted the highest concentrations of Lead in coriander and purslane. Lead has been shown to have toxic impact on a variety of metabolic processes essential to plant growth and development, including photosynthesis, transpiration, DNA synthesis, and mitotic activity (Pehlivana et al., 2008).

Cadmium values showed low levels in Tubers, Leafy and Fruity vegetables as compared with other metals, since the lowest value was recorded in vegetables collected as organic and were cultivated in the Kitchen garden. The highest contents of cadmium found in Tomato, Tapioca and Cabbage, collected from Thrissur market. However, there was insignificant difference between tubers, leafy and fruity vegetables with regard to Cadmium content. The cadmium uptake in human beings can be up to 10-20 µg but it can be up to 0.9 -2.8 mg/day in smokers. Epidemiological studies have 54 ● ISSN: 2319-5770 e-ISSN 2394-1138 revealed that cadmium may be a contributing factor in some forms of cancer in humans (Sobukola, 2010).

Fytianos et al. (2001) reported that spinach and lettuce grown in the soil of industrial area of Greece are enriched in Cadmium. Al Jassir et al. (2005) reported that levels of Cadmium were higher in the garden rocket vegetable species for both washed and unwashed samples. In our study, concentration of Cadmium was noted to be above the critical level of 0.1 mg kg−1 as reported by WHO and thus might be a great threat for the human consumers.

CONCLUSION The present study provides the information on heavy metal contamination in selected vegetables of Thrissur district. The concentration of heavy metals in the selected vegetables and permissible levels needed for safe consumption stated by WHO were compared. The samples collected from Thrissur market shows more concentration of heavy metals than those collected from other markets and lowest concentration was obtained in the vegetables collected as Organic and those were cultivated in the Kitchen garden. The high concentration may be due to the application of polluted water into the agricultural field and the application of fertilizers.

Vegetable species differ widely in their ability to take up and accumulate heavy metals, even among cultivars and varieties within the same species (Zhu et al.,2007 ; Saumel et al.,2012). In this study, significant differences were found in the concentrations of heavy metals in the selected vegetable types; the concentrations decreased in the order of Tubers > fruity vegetables ~ leafy vegetables. And also the significant differences were found in the concentrations of heavy metals in different markets; the concentrations decreased in the order of Thrissur > Cherpu > Irinjalakuda > > Chalakudy. In addition, the ability for heavy metal uptake and accumulation of Tubers was higher than for the other vegetable types, Furthermore; the concentrations of most studied metals are above the standard permissible levels thus might be in concern for the human consumers especially in middle and eastern districts.

This study further confirms the increased danger of growing vegetables on soils irrigated with contaminated industrial and domestic wastewaters. However, the levels of the metals are currently within the FAO/WHO safe limits guidelines. But, if the practice of treating the soils in the irrigation gardens with contaminated waters is not controlled, it may lead to health hazard on the part of consumers of the vegetables on the long term. Therefore, there is the need to continually monitor, control and take necessary policy decisions so as to limit and ultimately prevent these avoidable problems. However, in the meantime, farmers from the study areas are hereby encouraged to use well water for irrigation in their gardens instead of contaminated streams.

Urbanization and industrialization are the main causes of heavy metal pollution. The present study “Assessment of heavy metal contamination in Vegetables from Local Markets of Thrissur district, Kerala, India” revealed the presence of Lead and Cadmium in the selected vegetables of Thrissur District. It concludes that transportation and marketing of vegetables shows a considerable role in heavy metal VISTAS Vol. 6, No. 1 ● 55 contamination. The usage of purified water from various industries for irrigation purposes may also elevate the levels of heavy metals in the samples. The prolonged consumption of these vegetables leads to dangerous accumulation of toxic heavy metals in the kidney and liver and ultimately leads to many diseases in human. The results of the present study showed that consumers are at greater risk of purchasing fresh vegetables with high levels of heavy metals beyond permissible limits as defined by WHO. Regarding the first objective we can conclude that there is high accumulation of lead in Tubers and cadmium in leafy and fruity vegetables. It will negatively influence the health systems of human. Regarding the second objective we can conclude that the accumulation of heavy metals is very high in the vegetables of our daily usage. So the government and industries should take necessary actions to avoid the heavy metal pollution in our environment.

REFERENCES • Al jassir MS, Shaker A, Khaliq MA (2005) Deposition of heavy metals on green leafy vegetables sold on roadsides of Riyad city, Saudi Arabia. Bulletin of environment contamination and toxicology 75(2): 1020 – 1027. • Charles Kihampa (2013) Heavy metal contamination in water and sediment downstream of municipal wastewater treatment plants, Dares Salaam,Tanzania. International Journal of Environmental Sciences 3(1): 1407-1415. • Divya L, Jessen George, Midhun G (2015) Heavy Metal Contamination of Some Common Tubers Sold in Local Markets of Ernakulam District, Kerala, India. International Research Journal of Biological Sciences 4(3): 49-52. • D’mello JPF (2003) Food safety:contaminants and toxins,London. Oxford university press • Farooq M, Anvar F, Rashid U (2008) Appraisal of heavy metal contents in different vegetables grown in the vicinity of an industrial area 40 (5): 2099-2106. • Finley SD, Broadbelt L.J and Hatzimanikatis V (2010) In silico feasibility of novel biodegradation pathways for 1, 2, 4-trichlorobenzene. BioMed Central Systems Biology 4(1): 1-14. • Fytianos K, Katsianis G, Triantafyllou P, Zachariadis G (2001) Accumulation of heavy metals in vegetables grown in an industrial area in relation to soil. Bulletin of environment contamination and toxicology 16(2): 423-430. • Huibers FP, Van Lier JB (2005) Use of wastewater in agriculture: the water chain approach. Irrig Drain 54 (51): 3–9. • Ina Saumel, Iryna Kotsyuk, Marie Holscher, Ingo Kowarik (2012) How healthy is urban horticulture in high traffic areas? Trace metal concentrations in vegetable crops from plantings within inner city neighbourhoods in Berlin, Germany. Journal of environmental pollution 165(4): 124-132. • Kailas R labhade (2013) Assessment of Heavy Metal Contamination in Vegetables Grown in and Around Nashik City, Maharashtra State, India. IOSR Journal of Applied Chemistry (IOSR-JAC) 5(3): 09-14. • Larry RW, Morgan JT (1986) Determination of Plant Iron, Manganese and Zinc by wet digestion procedures. J. Food Agric. 37(2): 839-844. • Latif MI (2009) Quantitative assessment of heavy metals in soils and vegetables irrigation with sewage in Rawalpindi area, unpublished thesis partial fulfillment of the requirements for the degree of doctor of philosophy in soil science. Dept.of 56 ● ISSN: 2319-5770 e-ISSN 2394-1138

soil science and water conservation, pir mehrali shah,arid agriculture university Rawalpindi, Pakistan 40(5): 389-445. • Marshall (2004) Enhancing food chain integrity: quality assurance mechanism for air pollution impacts on fruits and vegetables systems. Crop Post Harvest Program, Final Technical Report 5(1): 124-130. • Muchuweti M, Birkett JW, Chinyanga E, Zvauya R, Scrimshaw MD, Lester JN (2006) Heavy metal content of vegetables irrigated with mixtures of wastewater and sewage sludge in Zimbabwe. Implications for human health Agriculture, Ecosystems & Environment 112(1): 41-48. • Nasif perveen W, Shah AS (2006) Evaluation of irrigation water for heavy metals of akburpura area. Journal of agriculture and biological science 1(1): 51-54. • Neriman Bagdatlioglu, Cevdet Nergiz, Pelin Gunc Ergonul (2010) Heavy metal levels in leafy vegetables and some selected fruits. Journal of Consumer Protection and Food Safety 5(1): 421-428. • Omambia BM, Simyu GM (2014) Heavy metals (Cu,Zn, Cd and Pb) contamination of indigenous green vegetables in eldoret town and their health implications to consumers. Baraton interdisciplinary research journal 4(4): 1-4. • Pedrero F, Kalavrouziotis I, Alarcón JJ, Koukoulakis P, Asano T (2010) Use of treated municipal wastewater in irrigated agriculture. Review of some practices in Spain and Greece. Agric Water Manag 97(2): 1233–1241. • Pehlivana EGA, Fethiye G, Turkan A and Ozcand MM (2008) Determination of some inorganic metals in edible vegetable oils by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Grasas Y Aceites 53(3): 239-244. • Radwan MA, Salama AK (2006) Market basket survey for some heavy metals in Egyptian fruits and vegetables. Food and Chemical Toxicology 44(1): 1273–1278. • Sharma, Agrawal M, Marshall FM (2008) Heavy metals (Cu, Cd, Zn and Pb) contamination of vegetables in Urban India: a case Study in Varanasi Environmental Pollution 154(2): 254–263. • Sobukola OP, Adeniran OM, Odedairo AA, Kajihausa OE(2010) Heavy metal levels of some fruits and leafy vegetables from selected markets in Lagos, Nigeria. African Journal of Food Science 4(2): 389-393. • Zhu Y, Yu H, Wang J, Fang W, Yuan J, Yang Z (2007) Heavy metal accumulations of 24 asparagus bean cultivars grown in soil contaminated with Cd alone and with multiple metals (Cd, Pb, and Zn). J. Agric. Food Chem. 55(3): 1045–1052. • Zurera C, Moreno R, Salmeron E and Lora R (1989) Heavy metal uptake from green border soils for edible vegetables. J. Sci. Food Agric. 49(3): 309 – 314.