*Corresponding Author ([email protected])
Study of Heavy Metals Concentration in Some Vegetables and Health Risk Assessment at Bank Town Region, Savar, Dhaka
Md. Majibar Rahman1, Md. Emadul Huda2*
1Graduate Student, Department of Environmental Sciences, Jahangirnagar University, Dhaka, Bangladesh.
2Professor, Department of Environmental Sciences, Jahangirnagar University, Dhaka, Bangladesh.
(Received: 5 April 2022, Revised: 24 June 2022, Accepted: 28 June 2022, Online: 30 June 2022)
Abstract
This study was held in Savar Bank Town Region. This study aimed to determine the toxic metal concentration among vegetables and health risk assessment in the study area. Samples were analysed by AAS. The sample’s average concentrations of Cd, Pb, Cu, Mn, and Zn were 0.59, 0.64, BDL, 3.96, 19.67, and 24.32mg/kg, respectively. The range of Cd, Pb, Cu, Mn, and Zn in vegetable species were 0.10-1.90, BDL-2.01, 1.20- 8.50, 1.60-68.05, and 6.55-60.75mg/kg in fresh weight, respectively. The lowest and highest Cadmium (Cd) level in vegetable samples was found in Papaya (0.10mg/kg) and Malabar spinach(1.90mg/kg), respectively.
The highest and lowest Lead (Pb) level was found in Lady’s finger (2.01mg/kg) and Brinjal, Papaya (BDL) gradually. The highest and lowest Manganese (Mn) level was found in Water spinach (68.05mg/kg) and Carrot (1.60mg/kg) gradually. The highest and lowest Zinc (Zn) level was found in Malabar spinach (60.75mg/kg) and Carrot (6.55mg/kg) gradually. The concentration of Cd and Pb in most vegetable species exceeds the permissible limit, indicating the unsafe for human consumption. Health risk analysis found that THQ values were higher than 1 in most vegetables, indicating there might pose a health risk due to metal exposure.
Keywords: Metal Concentration, Vegetables, Toxicity, and Health Risk.
Introduction
The human body requires at least 20 elements for optimal health (Broadley and White 2010). Many elements are essential in physiological and biological processes, such as water absorption, enzyme catalysis, and hormone functions (Gutzeit et al., 2008). Element deficiencies may result in significant debilitating effects, including reduced defense systems and reduced physical and mental development and acuity. Vegetables grown in heavy metal contaminated soils usually showed an increased metal uptake trend worldwide. Thus, crops and vegetables cultivated in contaminated soils acquire heavy metals in huge quantities causing potential health risks to consumers (Khan S, 2008). It has been reported that only 15 ppm of available arsenic is enough to create severe health risk through consuming vegetables grown in contaminated soils. Accumulation of heavy metals in the human body through consumption of cereals and vegetables created a growing concern in recent days. Several serious health problems such as kidney problems, anemia, blood disorders, stomach irritation, vomiting etc. can develop due to excessive dietary intake of heavy metals (Damek, et al., 2006; Turkdogan, et al., 2016). The daily vegetable consumption by an adult in Bangladesh is 130g
(Islam, 2014). Different kinds of vegetables are grown during the year in tropical Bangladesh, but very little is known about the metal contents of vegetables (Alam, 2003). According to naser et al.
(Naser, 2009), sporadic information regarding the accumulation of heavy metals in vegetables grown in industrially polluted soils of the country is available. Nowadays, crops and vegetables grown in contaminated soil or use of untreated industrial wastewater for irrigation is a common scenario in Bangladesh. But intake of heavy metals contaminated vegetables may pose a risk to the human health. So, heavy metal contamination of the food items is one of the most important assessment parameters of food quality assurance (WangXL, 2005), and international and national regulations on food quality have lowered the maximum permissible levels of toxic metals in food items due to an increased awareness of the risk (RadwanMA-2006). Heavy metals can accumulate and migrate in soil environments. Due to their cumulative effects and long-term interactions, accumulation of heavy metals in soil negatively affects regional eco-safety and poses a threat to relevant animals and plants. Additionally, heavy metals can enter human bodies through the food chain, leading to an increased incidence of chronic diseases such as deformity and cancer (Müller and Anke 1994; Ramadan and Al-Ashkar 2007; 2 Tembo et al., 2006). Studies have shown that fruit and vegetable consumption is the primary pathway of human exposure to heavy metals (Adamsa et al., 2004). Therefore, it is of practical significance to assess the extent of heavy metal accumulation from soil into plants such as fruits and vegetables, and relevant research has gained increasing attentions. This study investigates the concentration and health risk for consumption of Cd, Pb, Cr, Cu, Mn and Zn in the basket vegetable collected from Savar bazar, which is most popular vegetable market of Savar area. Savar area is most densely populated in the Bangladesh.
People of different occupations are lived here. They are constantly buying their essential vegetables from this market. Sometimes this market is called wholesale market because of many small market in Savar area are taken their vegetable from here. Toxic metal determination in the pathway i.e vegetables and their relation to human health risk is very important issues. Because sometimes their high concentration can may carcinogenic.
Materials and Methods
This study was specially analyzed 10 different types of vegetables including brinjal (Solanum melongena), Papaya (Carica papaya), malabar spinach (Basella alba), pointed gourd (Trichosanthes dioica), potato (Solanum tuberosum), bottle gour (Lagenaria siceraria), Red Amaranth (Amaranthus paniculantus), Lady’s Finger (Abelmoschus esculentus), Carrot (Daucus carota), Water Spinach (Ipomoea aquatic) which were sold in the local market of Savar, Dhaka, Bangladesh.
Sample (vegetables) ; GPS receiver; Knife; Filter paper (Whatman Grade 42 Ashless Quantitative Filter Papers ) ; Poly Bags (Zipper bag); Oven; Erlenmeyer flasks (50ml) ; Funnel and Filtration Stand ; Volumetric flasks (25ml); 70% Perchloric acid (HClO4 ) (Merck Limited, Mumbai-400018)
; 69% Nitric Acid (HNO3) ( BDH Laboratory Supplies Poole, BH15 1TD, England); Hot plate ( Lab Companion AAH35023U Model T-17S); Analytical balance (Sartorius® - CP225D); Agate Mortar With Pestle and Atomic absorption spectrophotometry (Model AA-6800, Shimadzu Corporation, Japan). All chemicals were analytical-grade reagents, and Mili-Q water was used to prepare the solution. Samples were digested with 69% nitric acid for heavy metal determination as described by (Allen et al., 1986). In this method, approximately 1 g of finely ground vegetable samples were taken into a 50 mL conical flask and di-acid mixture (conc. HNO3: HClO4 = 2:1) was added to it. At first 10 ml 69% HNO3 was mixed with weighted sample. Then the flask was placed on an electric hot plate for heating at 180-200ºC temperature until the solid particles disappeared
and white fumes were evolved from the flask. After that 5 ml 70% HClO4 were also added and again heated for 15 minutes. Then, it was cooled at room temperature, washed with distilled water and filtered into 25 mL volumetric flasks through filter paper (Whatman 42). A blank was also prepared in the same way with every batch of ten samples. The concentrations of different heavy metals in the extract were determined using an AAS (Atomic Absorption Spectroscopy). All the experiments were performed at Wazed Mia Science and Research Center Jahangirnagar University at Savar, Bangladesh.
Sample Collection and Preparation
Samples were collected from local market of Savar Upazila. Ten samples were collected from bazar Savar Upazila and carried with poly bags (zipper bag) to the lab. After collection, vegetable samples were carefully washed immediately with distilled water, and the edible part of vegetables were cut into small pieces and then oven dried at 70–80°C to attain constant weight (Tiwari et al., 2011). Sample ID-S1= Brinjal(Solanum melongena); Sample ID-S2= Papaya(Carica papaya);
Sample ID-S3= Pointed Gourd(Trichosanthes dioica); Sample ID-S4= Malabar Spinach(Basella alba); Sample ID-S5= Bottle Gourd(Lagenaria siceraria); Sample ID-S6= Potato(Solanum tuberosum); Sample ID-S7= Red Amaranth(Amaranthus paniculantus); Sample ID-S8= Ladys Finger(Abelmoschus esculentus); Sample ID-S9= Carrot (Daucus carota) and Sample ID-S10=
Water Spinach(Ipomoea aquatic).
Analysis of Samples
Samples were digested with 69% nitric acid for heavy metal determination as described by (Allen et al., 1986). A blank was also prepared in the same way with every batch of ten samples. An atomic absorption spectrophotometer was used for the quantification of selected heavy metals (Cd, Pb, Cr, Mn, Cu and Zn) in the vegetable samples employing the calibration line method under optimum analytical conditions. The detection limits of AAS were 25, 50, 50, 100, 25 and 25µg/L for Cd, Pb, Cr, Mn, Cu and Zn, respectively. The reagents and standard solutions used were of AAS grade with very high purity (499.99%). For excluding batch-specific errors, each sample was analyzed in double time. Standard stock solutions (1000mg/L) of each metal were used to prepare the working standards throughout this work. The accuracy of the method was evaluated using standard reference materials. The standard curve was established by using multi element standard solution. The concentrations of different heavy metals in the extract were determined by using an AAS (Atomic Absorption Spectroscopy). All the experiments were performed in Wazed Mia Science and Research Center Jahangirnagar University at Savar, Bangladesh.
Data Analysis
All data were analysis by Microsoft Excel sheet for calculating mean values, maximum, minimum, recommended daily intake, estimated daily intake, hazard index, and percentages. An atomic absorption spectrophotometer was used for the quantification of selected heavy metals (Cd, Pb, Cr, Mn, Cu and Zn) in the vegetable samples employing the calibration line method under optimum analytical conditions. The detection limits of AAS were 25, 50, 50, 100, 25, and 25 µg/L for Cd, Pb, Cr, Mn, Cu and Zn, respectively. The reagents and standard solutions used were of AAS grade with very high purity (499.99%). For excluding batch-specific errors, each sample was analyzed in double time. Standard stock solutions (1000mg/L) of each metals were used to prepare the working
standards throughout this work. The accuracy of the method was evaluated using standard reference materials. The standard curve was established by using multi element standard solution.
Estimated Daily Intake of Metals from Vegetables
Estimated daily intakes (EDIs) of heavy metals (mg/day) were calculated by following formula (FAO, 2006).
𝑬𝑫𝑰 = 𝐷𝐼𝑀𝐵𝑊
DIM = daily vegetable consumption × mean metal concentration in vegetables.;
BW= is the body weight. [The daily vegetable consumption rate for adult residents was an average of 130 g, drawing from the Report of the household income and expenditure survey 2010” (HIES 2011 and FAO, 2006). The bodyweight of an adult resident was set to 60 kg in the present study (FAO, 2006)].
Non-carcinogenic Health Hazard
For the estimation of non-carcinogenic health hazards the methodology was applied in accordance with that provided in the US Environmental Protection Agency (USEPA) Region III’s Risk based Concentration Table (USEPA 2010). The non-carcinogenic health hazards for each individual metal through vegetables consumption were assessed by the target hazard quotient (THQ) (USEPA 1989), which was ‘‘the ratio of a single substance exposure level over a specified time period (e.g., sub-chronic) to a reference dose (RfD) for that substance derived from a similar exposure period.’’
The THQ assumes a level of exposure (i.e., RfD) below which it is unlikely for even sensitive populations to experience adverse health effects. If the exposure level exceeds this threshold (i.e., if THQ = E/RfD exceeds , there may be concern for potential non-carcinogenic effects. Higher THQ values mean a higher probability of experiencing long-term non-carcinogenic effects (Islam et al., 2014). The target hazard quotient (THQ) and total target hazard quotient (TTHQ) can be calculated as (FAO/WHO, 2011).
𝑻𝑯𝑸 = 𝐸𝑓𝑟 × 𝐸𝐷 × 𝐹𝐼𝑅 × 𝐶
𝑅𝑓𝐷 × 𝐵𝑊 × 𝐴𝑇 × 𝟏𝟎−𝟑
Where THQ = is the target hazard quotient; Efr = is the exposure frequency (365 days/year); ED=
is the exposure duration (70 years) equivalent to the average human life time (USEPA 1991); FIR
=is the food ingestion rate (g/person/day); C= is the metal concentration in vegetables [(mg/kg, fw (fresh weight)], RfD = is the oral reference dose (mg/kg/day); BW= is the average body weight (adult, 60 kg); and AT= is the averaging time for non-carcinogens (365 days/ year × number of exposure years, assuming 70 years). The oral reference doses are 1.5, 0.02, 0.04, 0.3, 0.0003, 0.003, 0.0035, and 0.14 mg/kg/day for Cr, Ni, Cu, Zn, Cd, Pb, and Mn, respectively (Nadal et al., 2008;
USEPA, 2010). In order to determine the appropriate RfD for THQ, it is assumed that all chromium ions in the vegetables are trivalent (non-carcinogenic) and all arsenic ions are inorganic. If THQ <
1, the exposed population is unlikely to experience obvious adverse effects. If THQ ≥ 1, there is a potential health risk (Wang et al., 2005), and related interventions and protective measurements should be taken.
Target Carcinogenic Risk (TR)
The target carcinogenic risk (TR) factor (lifetime cancer risk) can be calculated as, 𝑻𝑹 = 𝐸𝑓𝑟 × 𝐸𝐷 × 𝐹𝐼𝑅 × 𝐶 × 𝐶𝑠𝑓𝑜
𝐵𝑊 × 𝐴𝑇 × 𝟏𝟎−𝟑
Where TR =represents the target cancer risk or the risk of cancer over a lifetime, AT= is the averaging time for carcinogens (365 days/ year ×ED), and Csfo =is the oral carcinogenic slope factor obtained from the Integrated Risk Information System (IRIS and USEPA, 2010) database, which was 8.5×10−3 (𝑚𝑔/𝑘𝑔/𝑑𝑎𝑦) −1 for Pb respectively.
Results and Discussion
Metal Concentrations in vegetables Chromium
In this study, all the vegetable samples Cr concentration was below detection limit (BDL) (45ppb), where the maximum allowable concentration was 2.3 mg/kg (FAO/WHO, 2011). In the literature, Cr contents were reported as 0.64 (0.35–4.48 mg/kg) (Rahman et al., 2013) and 0.76 (0.3-3.9 mg/kg) (Islam et al., 2014b). Average Cr concentration of the vegetable samples was 0.62 mg/kg (0.01- 2.50 mg/kg) in a study on 13 different species of vegetable grown beside on the Korotoa River of the Bogra district in Bangladesh (Islam et al., 2016) where mean concentration was lower than the safe recommended limits by FAO/WHO (2011). In the vegetable samples Cr content in Bangladeshi vegetables was 1.110 mg/kg and 0.296 mg/kg of bean and Carrot, respectively. Mean Cr concentrations in the vegetable samples were below the maximum permissible limit value (2.3 mg/kg) (Shaheen et al., 2016). In another study conduct on Industrial area of Dhaka city, Cr mean concentration was 1.44 mg/kg (0.61- 3.04) reported by Islam et al., (2014).
Cadmium
The concentration of Cadmium on Brinjal, Papaya, Pointed gourd, Malabar spinach, Potato, Red amaranth, Lady’s finger, Carrot, Water spinach and Bottle gourd were 0.30,0.10, 0.28, 1.90, 0.45, 0.65, 0.35, 0.45,1.11 and 0.38 mg/kg respectively (Figure 1). The average concentration of Cd in all vegetable samples was 0.59 mg/kg, higher than the maximum allowable concentration of 0.2 mg/kg set by (FAO/WHO, 2011), indicating that vegetables may be contaminated by Cd. The lowest and highest cadmium (Cd) level in vegetable samples was found in papaya (0.10 mg/kg) and Malabar spinach (1.90 mg/kg), respectively (Figure 1) . Among the vegetable samples, most of the samples Cd concentration exceeded the maximum allowable concentration (0.2 mg/kg) without Papaya. The vegetables with the highest mean Cd levels were Malabar spinach> Water spinach>
Red amaranth> Potato> Carrot> Bottle gourd> Ladys finger> Brinjal>Pointed gourd> Papaya (Figure 1).
Figure 1: Concentration of cadmium in the sample vegetables.
Copper
The concentration of Copper on Brinjal , Papaya , Pointed gourd ,Malabar spinach, Potato, Red amaranth, Ladys finger, Carrot, Water spinach and Bottle gourd were 6.50,3.50, 3.80, 5.50,1.20,3.25,3.75, 1.25,8.50 and 2.30 mg/kg respectively (Figure 2). The average concentration of Cu (3.96 mg/kg) in vegetable samples were lower than the maximum allowable concentration (40 mg/kg) as recommended by WHO/FAO, (2011). The lowest and highest Copper (Cu) concentration in vegetable samples was found in potato (1.20 mg/kg) and water spinach(8.50 mg/kg), respectively (Figure 2). Approximately the mean concentration of all vegetables was four times lower than maximum allowable concentration (MAC). The vegetables with the highest mean Cu levels were green water spinach> brinjal> malabar spinach> pointed gourd> ladys finger>
papaya> red amaranth> bottle gourd> carrot> potato (Figure 2).
Figure 2: Concentration of copper in the sample vegetables.
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
→ Concentration
→ Vegetables
Study of Concentration of cadmium in the sample vegetables
Brinjal Papaya P.gourd M.spinach Potato R.amaranth L.finger Carrot W.spinach B.gourd
0 2 4 6 8 10
→ Concentration(mg/kg)
→ Vegetables
Study of Concentration of cadmium in the sample vegetables
Brinjal Papaya P.gourd M.spinach Potato R.amaranth
Zinc
The concentration of Zinc on Brinjal , Papaya , Pointed gourd ,Malabar spinach, Potato, Red amaranth, Lady’s finger , Carrot, Water spinach and Bottle gourd were 15.90,13.45, 16.75, 60.75,7.01,45.03,18.20, 6.55,45.02 and 14.50 mg/kg respectively (Figure 3). The average concentration of Zn in all vegetable samples was 24.32 mg/kg, which was higher than the maximum allowable concentration 20 mg/kg set by (FAO/WHO, 2011). The lowest and highest Zinc (Zn) concentration in vegetable samples was found in carrot (6.55 mg/kg) and Malabar spinach (60.75 mg/kg), respectively(Figure 3). The vegetables with the highest mean Zn levels were Malabar spinach> red amaranth> water spinach> ladys finger> pointed gourd> brinjal> bottle gourd >
papaya> potato>carrot (Figure 3). Among the vegetable samples three samples were exceed the safe limit, where in Malabar spinach Zn concentration was approximately two times higher than the maximum allowable concentration (MAC).
Figure 3: Concentration of zinc in the sample vegetables.
Manganese
The concentration of Manganese on Brinjal , Papaya , Pointed gourd ,Malabar spinach, Potato, Red amaranth, Lady’s finger , Carrot, Water spinach and Bottle gourd were 20.40,7.50, 5.68, 65.50,1.65,8.35,4.50, 1.60,68.05 and 3.50 mg/kg respectively (Figure 4). In the vegetable samples, the lowest and highest amounts of Mn were found in carrot (1.60 mg/kg) and water spinach (68.05 mg/kg), respectively ( Figure 4). The average concentration of Mn in all vegetable samples was 19.67 mg/kg. The vegetables with the highest mean Mn levels were water spinach> Malabar spinach> brinjal> red amaranth> papaya> pointed gourd> ladysfinger > bottle gourd>
potato>carrot (Figure 4).
0 10 20 30 40 50 60 70
→ Concentration(mg/kg)
→ Vegetables
Study of Concentration of zinc in the sample vegetables
Brinjal Papaya P.gourd M.spinach Potato R.amaranth L.finger Carrot W.spinach
Figure 4: Concentration of manganese in the sample vegetables.
Lead
The concentration of Lead on Brinjal , Papaya , Pointed gourd ,Malabar spinach, Potato, Red amaranth, Lady’s finger, Carrot, Water spinach and Bottle gourd were BDL(45ppb),BDL(45ppb),0.35, BDL(45ppb), 0.60, 0.40, 2.01, 0.55, 0.65 and 1.80 mg/kg respectively(Figure 5). In vegetables, Pb was found to be the lowest in brinjal, Papaya, malabar spinach (BDL-45ppb), and highest in tomato (2.03 mg/kg) (Figure 5). The average Pb concentration of vegetable samples was 1.03 mg/kg, higher than the maximum allowable concentration 0.30 mg/kg (FAO/WHO, 2011). According to the findings of this study, Pb content in tomato was found to be approximately seven time higher than the safe limit which set by FAO/WHO, although most of the vegetables samples were higher than the permissible level value without brinjal, Papaya, and malabar spinach. The vegetables with the highest mean Pb levels were tomato> bottle gourd>
pumpkin> yardlong bean> green amaranth> potato> red amaranth> pointed gourd and some vegetable like brinjal, Papaya, malabar spinach concentrations were not showed, because of vegetables concentration was below detection limit ((45ppb) .
0 10 20 30 40 50 60 70 80
→ Concentration(mg/kg)
→ Vegetables
Study of Concentration of manganese in the sample vegetables
Brinjal Papaya P.gourd M.spinach Potato R.amaranth L.finger Carrot W.spinach
Figure 5: Concentration of lead in the sample vegetables.
Estimated Daily Intake (EDI) of Metals
The dietary exposure approach of vegetables consumption is a reliable tool for investigating a population’s diet in terms of intake levels of nutrients, bioactive compounds, and contaminants, providing important information about the potential nutritional deficiencies or exposure to food contaminants (WHO, 1985). The intake data can then be used to examine a specific element of interest. This study provides an estimate of the dietary intake and examines the dietary exposure to six heavy metals through consumption of vegetables in the population’s daily diet. Data are then compared to those provided by studies conducted worldwide.
The EDI of five metals (Cd, Pb, Cu, Mn and Zn) was calculated according to the mean concentration of each metal in each food and the respective consumption rates. The EDI and maximum tolerable daily intake (MTDI) of studied metals from consumption of vegetables are also shown in Table 4.3.
Total daily intake of Cd, Pb, Ni, Cu, Mn and Zn were 1.45×10-2, 1.79×10-2, 0.153, 0.116, 0.645, 0.902 mg/day, respectively. Daily intakes of all the metals were less than the MTDI. In vegetable samples, mean values of EDI decreased in the following order: Zn> Mn> Cu> Pb> Cd. According to Shaheen et al., (2016) the estimated daily intake of Cd, Pb, Cr, Mn, Cu, and Zn were 3E-04, 7E- 04, 0.008, 0.184, 0.077, and 0.023 mg/day, respectively. Which was also less than the MTDI value.
Another study showed that, the estimated daily intake of metal (EDI) values of Cr, Cu, Zn, Cd and Pb were, 0.004, 0.05, 0.14, 0.0006 and 0.0021 mg/kg /body weight, respectively.(Islam et al., 2014a) ,which result was very similar to this study.
Non-carcinogenic Risk
The health risk from consumption of contaminated vegetables by adult populations was assessed based on THQ which is the ratio of determined dose of a pollutant to a reference dose level. If THQ
>1, the exposed population will likely to experience a detrimental effect (Wang et al.,2005).THQ values in the studied samples are in table-.THQ >1 was observed for Cd, Pb and Mn in few
0 0.5 1 1.5 2 2.5
1
→ Concentration(mg/kg)
→ Vegetables
Study of Concentration of lead in the sample vegetables
Brinjal Papaya P.gourd M.spinach Potato R.amaranth L.finger Carrot W.spinach
vegetables for adults. It indicates the take of these heavy metal through vegetables had non cancer risk. On the other hand, intake of Cu and Zinc through vegetables was safe (THQ<1).THQ for Cd and Mn were 1.37 and 1.02 gradually for Malabar Spinach (Table-1). Ladys finger and bottle gourd had to non-cancer risk because Pb values were 1.24 and 1.12 respectively (Table-1). THQ values of Red amaranth was-1.24for Mn, water spinach was-1.05 for Mn. The rank of TTHQ were Malabar spinach >Red amaranth>Bottle gourd> Ladys finger Water spinach> Pointed gourd>Potato>Brinjal> Papaya respectively (Table 1).
Table 1: THQ and TTHQ values on the study samples
Vegetables Target Hazard Quotient(THQ) TTHQ
Cd Pb Cu Mn Zn
Brinjal 0.216 - 0.352 0.315 0.114 0.997
papaya 0.072 - 0.189 0.116 0.097 0.474
Pointed Gourd
0.202 0.216 0.205 0.087 0.120 0.83
Malabar spinach
1.372 - 0.297 0.013 0.438 2.48
Bottle Gourd 0.274 1.114 0.124 0.054 0.054 1.62
Potato 0.325 0.371 0.065 0.024 0.050 0.835
Red Amaranth
0.469 0.247 0.176 1.243 0.325 2.46
Ladys Finger 0.252 1.244 0.203 0.069 0.131 1.899
Carrot 0.325 0.340 0.067 0.024 0.047 0.803
Water spinach 0.801 0.402 0.460 1.053 0.325 3.041
Conclusion
This study provides an estimate of the dietary intake and examines the dietary exposure to six heavy metals through consumption of vegetables in the population’s daily diet. The daily intake of heavy metals was estimated according to the average vegetable consumption. The EDI of five metals (Cd, Pb, Cu, Mn and Zn) was calculated according to the mean concentration of each metal in each food and the respective consumption rates. In vegetable samples, mean values of EDI decreased in the following order: Zn> Mn> Cu> Pb> Cd, which was less than the MTDI(Maximum Tolerable Daily Intake) value. The results of this study showed that the potential health risk, due to metal exposure through vegetables consumption could not be neglected.
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