Trends1114 in Biosciences 11(7), Print : ISSN 0974-8431,Trends 1114-1117, in Biosciences 2018 11 (7), 2018

Assessment of Lead Contamination in Common Tubers collected from Local Markets of Thrissur District, Kerala, India M.V. LAKSHMI1 AND NEETHU GOPALAKRISHNAN2 St. Joseph’s College (Autonomous), Irinjalakuda, Thrissur *email : [email protected]

ABSTRACT Tubers play a significant role in the human diet The present study was carried out in eight different local and they are the global sources of carbohydrates. markets of Thrissur District (Thrissur, Cherpu, Tubers are richest sources of a number of compounds Kunnamkulam,Irinjalakuda, Chalakudy, Valapad, such as phenolic compounds, saponins, phytic acids, Kodungallur, Guruvayur) to check the concentration of glycoalkaloids and carotenoids. Potatoes and yams are Lead in tubers (Potato, Tapioca and Yam). The tubers were tubers whereas cassava and sweet potatoes are also collected from farmers and Home gardens. All the storage roots. A number of species and varieties are collected samples were shade dried, powdered and digested. The concentration of Lead was found out using AAS consumed but cassava, potatoes and sweet potatoes (Atomic Absorption Spectrophotometer). Lead is a highly consist of 90% global production of root and tuber toxic metal which causes serious threats on renal, crops (Chandrasekara and Josheph Kumar, 2016). reproductive and nervous system. Exposure to Lead may The present study shows the information on the lead to severe diseases in humans and animals. It concentration of Lead in some selected tubers sold in accumulates in environment with increasing hazards due to its non-biodegradable nature. Tapioca had significant different markets of Thrissur district. It is hypothesized concentration of Lead (15 ppm) than other samples and the that the use of untreated waste water may increase content in samples were exceeded the permissible limits the levels of heavy metals in the vegetables. The of WHO and therefore it may cause deleterious effects to observed concentration of Lead was compared with the human health. Lowest Lead concentration was found WHO standards. Therefore this work was conducted in Yam (1.9 ppm). Mean± SD concentration of each heavy to reveal if the content of heavy metals in vegetables metal was calculated and data were given in ppm for each sample. The tubers show highest metal contamination is within the permissible limit or not. The main purposes because of the area that may polluted with various industrial of the present study were to investigate the activities. Highest level of Lead was reported in Thrissur concentration of Lead in the selected edible tubers market. The study concluded that the atmospheric and compare the concentration of Lead in organic and depositions and marketing systems of vegetables plays a inorganic vegetables. major role in increasing the levels of heavy metal content. So the consumers are at greater risk of using these MATERIALS AND METHODS vegetables with increased levels of heavy metals beyond The present study was carried out in eight permissible limits as defined by WHO. different markets of Thrissur district during the period, Keywords Heavy metals, Atomic Absorption April to June 2017. Tubers like Potato, Tapioca, and Spectrophotometer, Lead, WHO. Yam have been selected for the present study. Heavy metals are very harmful because of their Study area and sampling locations non-biodegradable nature and their potential to Thrissur district is located in the central part of accumulate in different body parts. Excessive Kerala; it is an important historical city known as the accumulation of heavy metals can develop systematic cultural capital of Kerala. There were a number of health problems in human body. Accumulation of heavy markets located in this district. Our study was carried metals in agricultural soil result in increased metal out in the selected markets of Thrissur district. The uptake by crops, which affects food quality and safety. major ones are as follows: ThrissurSakthanThampuran Heavy metal contamination of the food items is one market, Cherpu market, Valapad market, Irinjalakuda of the most important aspects of food quality market, Chalakudy market, Kodungallur and assurance (Marshall, 2004; Radwan and Salama, Kunnamkulam market. The organic vegetables are 2006). The analysis of heavy metal contamination collected from Velangalloor and Thrissur.All these contributes to the understanding of the potential health tubers were brought to the laboratory for further risk in environmental studies. analysis. LAKSHMI and GOPALAKRISHNAN, Assessment of Lead Contamination in Common Tubers collected from Local Markets 1115

Fig. 1. Thrissur Map

Preparation and treatment of samples: In the and the data were given in ppm for each sample. laboratory, the collected samples were washed with ANOVA and t-tests were used for comparing the tap water, and with distilled water, cut into small mean concentration between the vegetables. The piecesand then dried in an oven at 80º (Larry and criterion for significance in the procedures was set at Morgan, 1986). At the end of the drying, the oven p < 0.05 (significant). was turned off and left overnight to enable the sample RESULTS AND DISCUSSION cool to room temperature. Then each sample was grounded into fine powder using a commercial blender, The concentration of Lead was found higher in sieved and finally stored in an aluminium foil, until used Tapioca than other samples as given in table 1. for acid digestion. The level of lead in tubers is in the range -1.9 to Digestion procedure: Tri-acid mixture ( Nitric acid 15 ppm. Tapioca shows highest concentration (upto 69% , Perchloric acid 70% , Sulphuric acid 98% in 15ppm) and lowest concentration was found in Yam the ratio 5:1:1) was added to a beaker containing 1g (-1,9 ppm). High level of lead content was obtained in dry sample. The mixture was then digested at 80º till the vegetables collected from Thrissur andCherpu the transparent solution was achieved. After cooling, market. Lowest values are obtained in the the digested samples were filtered using Whatman tuberscultivated in home garden. no.42 filter paper and filtrate was diluted to 50 ml with The roots can absorb heavy metals easily and deionised water. This was then transferred into a less transported to the other edible parts such as leaves screw capped glass bottle. and shoots of many plants (Wild, 1996). As tubers are Instrumental analysis: Determination of Lead grown under the soil they are more contaminated that content in filtrate of the samples was achieved by the other vegetables. They can absorb heavy metals Atomic Absorption Spectrometer (AAS). more readily than the other plants (Divyaet al.,2015). Proper washing of vegetables is necessary to reduce Statistical analysis: Statistical analyses were carried a small amount of heavy metals. The required standard out using SPSS software version 20. The Mean and conditions of WHO have been given in Table 2. It standard deviation of each heavy metal were calculated 1116 Trends in Biosciences 11 (7), 2018

Table1. Bioaccumulation of Lead in selected vegetables of different markets

Selected Plant Sl.No. vegetables part TCR(Pb) CRP KNK IJK CKL Organic Home Average S.D 1 Potato Tuber 5.7 8.35 4.65 8.7 7.3 2.5 2 5.6 2.494136 2 Yam Tuber 10.8 10.25 5.85 6.85 -1.9 8.25 -3.1 5.285714 5.190081 3 Tapioca Tuber 15 6.55 12.55 6 2.4 0.65 5.95 7.014286 4.75978

was clearly seen that almost Lead was found in greater consuming them are in high health risks of toxic metal amounts than the maximum safe limits given by FAO/ exposure. It is therefore suggested that continuous WHO. The chief source of toxic metals is the analysis of heavy metals in vegetables should be done discharge from industries and domestic waste into to avoid maximum levels of these metals in the living sewage. Generally, agricultural soils have low beings. The ultimate solutions should be carried out in background levels of heavy metals; contaminations order to prevent maximum contamination of heavy are mainly through fertilizer application, irrigation with metals and all vegetables should be washed properly partially treated or untreated sewage (Farooq et al. before consumption, as washing can remove 2008). appropriate amount of pollutants from the vegetable The increase of Lead in the vegetables of surface. The world health organization (WHO) has Thrissur market was attributed to heavily traffic in reported that 15-18 millions are affected by lead in this area which leads to the accumulation of Lead blood. emitted from car exhaustions. The recent results CONCLUSION obtained by Divyaet al. (2015) reported that the Lead The present study provides the information on content in Tubers such as Tapioca, Sweet Potato, Yam, heavy metal contamination in selected tubers of Colocasia, Elephant Yam, Potato Collected from Thrissur district. The concentration of Lead in the different markets of Ernakulam district ranges from selected tubers and permissible levels needed for safe 2.4-26.4 mg/Kg. The lowest value was for elephant consumption stated by WHO were compared. The yam collected from Ernakulam market and highest samples collected from Thrissur market shows more value for yam collected from Tripunithara market. In concentration of heavy metals than those collected the present study, Tapioca shows the highest from other markets and lowest concentration was conecentartion of Lead (15 ppm) and the highest Lead obtained in the vegetables collected from farmers and content in Tapioca were found out by Divyaet al. those were cultivated in the Kitchen garden. The high (2015) is 14 ppm. There is lower concentration of concentration may be due to the application of polluted Lead in Yam and Potato collected from Thrissur water into the agricultural field and the application of district when compared to the Lead contcentartion in fertilizers. the same tubers collected from Ernakulam district. Vegetable species differ widely in their ability to Lead has been shown to have toxic impact on a take up and accumulate heavy metals, even among variety of metabolic processes essential to plant growth cultivars and varieties within the same species (Zhu and development, including photosynthesis, et al.,2007 ; Saumelet al.,2012). In this study, transpiration, DNA synthesis, and mitotic activity significant differences were found in the (Pehlivana et al., 2008).So these toxic elements concentrations of Lead in different markets; the transferred to our body by daily consumption that can concentrations decreased in the order of create problems in various biological systems. People

Table 2. WHO maximum permissible level of heavy metals in vegetables found in mg/kg

Sl.No. Heavy metals Maximum permissible level of heavy metals according to WHO(mg /kg) 1 Lead (Pb) 0.3 2 Cadmium (Cd) 0.1

LAKSHMI and GOPALAKRISHNAN, Assessment of Lead Contamination in Common Tubers collected from Local Markets 1117

Thrissur>Cherpu>Irinjalakuda>Kunnamkulam>Chalakudy. leads to many diseases in human. The results of the Lead is a serious cumulative body poison, which present study showed that consumers are at greater enters into the body system through air, water and risk of purchasing fresh vegetables with high levels of food and cannot be removed by washing fruits and heavy metals beyond permissible limits as defined by vegetables (Chove et al., 2003). Lead has been WHO. It will negatively influence the health systems shown to have toxic impact on a variety of metabolic of human. So the government and industries should processes essential to plant growth and development, take necessary actions to avoid the heavy metal including photosynthesis, transpiration, DNA synthesis, pollution in our environment. and mitotic activity (Pehlivana et al, 2008).The Potato LITERATURE CITED and Tapioca samples had Lead content that was higher than the FAO standard of 0.3 mg/kg. The high Chandrasekara, A .V., and Josheph Kumar, T. 2016. Roots and Tuber Crops as Functional Foods: A Review on Phytochemical concentration of Lead in these tubers may probably Constituents and Their Potential Health Benefits. due to the use of untreated industrial waste water for International Journal of Food Science: Article ID 3631647, irrigation, pollutants from soil or due to cultivation of http://dx.doi.org/10.1155/2016/3631647 the vegetables near the industrial area. It can be stated Chove, B.E., Ballegu, W.R. and Chove, L.M. 2006. Copper and that the field of cultivation noticeably influences the Lead levels in two popular leafy vegetables grown around heavy metal uptake by vegetables. Morogoro Municipality, TanzaniA. Tanzania Health Research Bulletin 8(1): 168-169. This study further confirms the increased danger Divya, L., Jessen George and Midhun, G. 2015. Heavy Metal of growing tubers on soils irrigated with contaminated Contamination of Some Common Tubers Sold in Local industrial and domestic wastewaters. However, the Markets of Ernakulam District, Kerala, India. International levels of the metals are currently within the FAO/WHO Research Journal of Biological Sciences 4(3): 49-52. safe limits guidelines. But, if the practice of treating Farooq, M., Anvar, F. and Rashid, U. 2008. Appraisal of heavy metal contents in different vegetables grown in the vicinity of the soils in the irrigation gardens with contaminated an industrial area 40 (5): 2099-2106. waters is not controlled, it may lead to health hazard Larry, R.W. and Morgan, J.T. 1986. Determination of Plant Iron, on the part of consumers of the vegetables on the Manganese and Zinc by wet digestion procedures. J. Food long term. Therefore, there is the need to continually Agric. 37(2): 839-844. monitor, control and take necessary policy decisions Marshall. 2004. Enhancing food chain integrity: quality assurance so as to limit and ultimately prevent these avoidable mechanism for air pollution impacts on fruits and vegetables problems. However, in the meantime, farmers from systems. Crop Post Harvest Program, Final Technical Report 5(1): 124-130. the study areas are hereby encouraged to use well Pehlivana, E.G.A., Fethiye, G., Turkan, A. and Ozcand, M.M. water for irrigation in their gardens instead of 2008. Determination of some inorganic metals in edible contaminated streams. vegetable oils by inductively coupled plasma atomic emission Urbanization and industrialization are the main spectroscopy (ICP-AES). Grasas Y Aceites 53(3): 239-244. causes of heavy metal pollution. It concludes that Radwan, M.A. and Salama, A.K .2006. Market basket survey for some heavy metals in Egyptian fruits and vegetables. Food transportation and marketing of tubers shows a and Chemical Toxicology 44(1): 1273–1278. considerable role in heavy metal contamination. The Wild, A. 1996. Soils and the Environment: An Introduction, usage of purified water from various industries for Cambridge University Press, 1:189-203. irrigation purposes may also elevate the levels of heavy Zhu, Y., Yu, H., Wang, J., Fang, W., Yuan, J. and Yang, Z. 2007. metals in the samples. The prolonged consumption of Heavy metal accumulations of 24 asparagus bean cultivars these tubers leads to dangerous accumulation of toxic grown in soil contaminated with Cd alone and with multiple heavy metals in the kidney and liver and ultimately metals (Cd, Pb, and Zn). J. Agric. Food Chem. 55(3): 1045– 1052.

Received on 11-02-2018 Accepted on 15-02-2018