Metal Concentrations In Vegetables Research Articles

Elucidation of heavy metal content, phenolic profiles, and antioxidant activities of kale (Brassica oleracea L. var. acephala) and arugula (Brassica eruca L.) grown in urban gardens in Istanbul.

This study was conducted to evaluate the effect of two distances: close (0-10m) and far (60m) from the heavy traffic roadside, at three different cultivation sites (MS: Mevlanakapi-Silivrikapi, SB: Silivrikapi-Belgradkapi, and BY: Belgradkapi-Yedikule kapi) along the road line. First, the phenolic compounds, antioxidant activity, and physicochemical properties in kale and arugula vegetables were examined. Second, heavy metal concentrations in vegetables, soil, and irrigated water were investigated. In both vegetables, the highest total phenolic content was detected in samples obtained from far distance in SB site (3880.3mg/kg) for kale and in BY site (1459.9mg/kg) for arugula, whereas the lowest content was found at the close distance in MS site for both kale (448.5mg/kg) and arugula (586.4mg/kg). The antioxidant activity values [mg Trolox/kg (dw)] ranged from 366.74 to 586.10 and 2349.00 to 3757.4 for kale and from 520.00 to 945.60 and 3323.00 to 5814.70 for arugula in 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl methods, respectively. The levels of Cd and Hg in kale and arugula and Fe content in arugula exceeded FAO/WHO permissible limits, making them unsafe for human consumption. Meanwhile, the Pb content in kale and arugula and Fe content in kale were observed to be within acceptable limits set by FAO/WHO. In the irrigated water, the Pb value was below the permissible limit, whereas the Cd value was above it and no Hg and Fe were detected. In the soil samples, the Pb and Fe values were below the limit, whereas the Cd and Hg values were higher.

Statistical Analysis and Health Risk Assessment: Vegetables Irrigated with Wastewater in Kirri Shamozai, Pakistan.

One of the primary environmental routes through which humans are exposed to metals and may be exposed to health risks is the food chain's contamination with heavy metals. The study observed the risks posed by contaminants in vegetables produced in soil that received wastewater irrigation, as well as their origins and the human health impacts. Eight harmful metals (Cu, Fe, Zn, Mn, Pb, Cd, Ni, and Cr) were tested for concentration levels in water, soil, and vegetable samples using analytical techniques and an atomic absorption spectrophotometer. The present study investigated the potential health implications associated with the consumption of vegetables irrigated using wastewater containing heavy metals. The results indicated a notable accumulation of heavy metals in plant and soil samples obtained from Kirri Shamozai, Pakistan. In comparison to vegetables cultivated in soil irrigated with fresh water, the concentration levels of heavy metals in vegetables grown on soil irrigated with untreated wastewater were considerably higher at (P ≤ 0.001) and above the World Health Organization (WHO) recommended limits. The results showed that heavy metals had significantly accumulated in the soil and had permeated into the crops. Heavy metal concentrations in vegetables cultivated on land irrigated with wastewater were more significant than those grown on land irrigated with freshwater. They exceeded US EPA and World Health Organization (WHO) limits. PCA results for Pb, Cu, and Cr are the main issues impacting water quality and health hazards. The PCA results show that the soil has an extensive loading of heavy metals Cd, Ni, and Mn.

Heavy metals contamination in vegetables irrigated with wastewater: a case study of underdeveloping regions of Pakistan.

Irrigation of food crops with untreated wastewater leads to the accumulation of heavy metals in their edible parts. Exposure to toxic elements through consumption of contaminated vegetables even at very low concentration is becoming a serious problem for human health in many countries. This issue of heavy metals contamination needs great attention especially in Pakistan where irrigation by wastewater has become a common practice in urban and periurban areas. The present study was conducted to assess the contamination of different heavy metals including nickel (Ni), cadmium (Cd), lead (Pb) and chromium (Cr) in vegetables irrigated with wastewater in different districts of Punjab (Pakistan) like, Faisalabad, Lahore, Gujranwala, Sargodha, Sahiwal, Multan, Rawalpindi and Bahawalpur during years 2016-2019. The maximum contamination factor (Ni, 1.39; Cd, 5.86; Pb, 3.99; Cr, 2.24), pollution load index (2.92) and degree of contamination (13.48) were observed in wastewater irrigated agricultural soils of district Gujranwala as compared to other districts. Mean metal concentration in vegetables grown with untreated wastewater and transfer factor varied with plant type, frequency of irrigation and soils types/series of different districts of Punjab. The highest metal contamination was observed in Gujranwala where 44% vegetable samples were contaminated with Ni, 87% with Cd, 97% with Pb and 88% with Cr. Radar analysis and hierarchical cluster analysis showed that mustard leaves, spinach and lettuce were more contaminated vegetables compared to other vegetables. This study contributes to the evidence-based conclusion that cultivation of vegetable with untreated wastewater should be prohibited and required treatment of wastewater is needed.

Heavy Metals in Vegetables: Screening Health Risks of Irrigation with Wastewater in Peri-Urban Areas of Bhakkar, Pakistan.

One of the key concerns in public health is food security in the food sector. Due to the large amounts of potentially hazardous metals in wastewater, this practice may pose serious environmental and health risks to neighboring residents. In this study, the health effects of heavy metals in vegetables irrigated with wastewater were studied. The findings indicated a massive accumulation of heavy metals in wastewater-irrigated soil and vegetables collected from Bhakkar, Pakistan. The current study looked at the effects of wastewater irrigation on metal buildup in the soil-plant continuum and the health hazards that come with it (Cd, Co, Ni, Mn, Pb, and Fe). Heavy metal concentrations in vegetables cultivated on soil irrigated with untreated wastewater were not significantly lower (p ≥ 0.05) than in vegetables grown on wastewater-irrigated soil and were below the World Health Organization's recommended limits. A considerable amount of the selected hazardous metals was also swallowed by adults and children who consumed these vegetables, according to the research. On soil that had received wastewater irrigation, Ni and Mn were substantially different at p ≥ 0.001 levels. Pb, Ni, and Cd had health risk scores higher than the ones in all ingested vegetables, while Mn had a health risk score greater than the ones in turnips, carrots, and lettuce. The results also showed that both adults and children who consumed these vegetables absorbed a significant amount of the chosen toxic metals. Pb and Cd were shown to be the most dangerous chemical compounds to human health, and everyday consumption of agricultural plants irrigated with wastewater may pose a health risk, according to the health risk criteria.

The Assessment of Heavy Metals (Pb, Zn, Cu, Fe, Cd) in Selected Vegetables in Kota Bharu Kelantan

Most heavy metals are naturally occurring [1] and some are derived from human activities [2]. Because of the widespread dispersion of these heavy metals in Kelantan's soil [3-8], there is a need to monitor their amounts, particularly in foods. This is due to heavy metals in soil being taken up by crops via transfusion [9]. Heavy metals are biomagnified and bioaccumulated in the bodies of humans and animals who consume heavy metal-contaminated plants [10]. Hence, this study aimed to assess the heavy metals (Pb, Zn, Cu, Fe, Cd) in chili, cucumber, round cabbage, and okra.
 The samples were transported to the Environmental and Occupational Health Laboratory in Universiti Sains Malaysia Kubang Kerian using a cold box. The samples were cut into small pieces and oven-dried at 60°C-70°C for three days. The dried samples were then crushed into powder and processed using the acid-wet digestion method. Finally, the samples were analysed for the heavy metals' concentration (Pb, Zn, Cu, Fe, and Cd) using Graphite Furnace Atomic Absorption Spectroscopy (GFAAS). A Mann-Whitney U test was used to compare the heavy metals concentration in vegetables (chili and cucumber) between Kampung Binjai and Bunut Payung.
 
 The result showed that chili in Kampung Binjai had a higher Pb (p=0.001) and Cd level (p=0.006); whereas cucumber in Bunut Payung had a higher Pb (p=0.001), Zn (p=0.002) and Cd level (p=0.002). The Kruskal Wallis test also showed that Zn (p=0.001), Cu (p=0.020), and Cd concentrations (p=0.001) were significantly different among the vegetables. A posthoc test was performed to determine further the pairs of vegetables that were significantly different from each other. The heavy metals concentrations in the vegetable samples were then compared with the permissible limit set by the Food and Agriculture Organisation (FAO)/ World Health Organisation (WHO) and Malaysian Food Regulation 1985. Among all the vegetables tested, Pb concentration (mean ± SD) in chili (0.1189 mg/kg ± 0.02), round cabbage (0.06589 mg/kg ± 0.01) in Kampung Binjai, and cucumber (0.1564 mg/kg ± 0.06) and okra (0.0677 mg/kg ± 0.02) in Bunut Payung had exceeded the permissible limit set by the FAO/ WHO. However, the heavy metals in these vegetables were within the permissible limit set by Malaysia Food Regulation 1985.
 
 Even though Pb concentration in some samples exceeded the standard level, most samples were safe to consume. However, traces of Pb and Cd are not supposed to be present in the vegetables. This is due to human body does not require these heavy metals, as they will harm the human body [11]. Therefore, various agencies should address this issue. Consumers should also be mindful of the consumption frequency and variation of vegetables, especially children, because they have a higher nutrient absorption capacity than adults and engage in the hand-to-mouth activity.

Assessment of Trace Metals Concentration in Vegetables from Gombe Markets, Gombe State, Nigeria

This study determined the concentration of trace metals in vegetables (lettuce, tomato and cabbage) from Gombe markets, Gombe State, Nigeria. A total of 60 samples of vegetables were analyzed for trace metals (Cd, Pb, Mn, Cr, Zn, Ni and Cu) using Atomic Absorption Spectrophotometer (AAS). The mean concentration of Cd in lettuce, tomato and cabbage samples ranged from (0.05 - 0.06 mg/kg), (0.03 - 0.07 mg/kg) and (0.08 - 0.90 mg/kg), Pb ranged from (BDL - 0.02 mg/kg), (BDL - 0.03 mg/kg) and (0.01 - 0.02 mg/kg), Mn ranged from (0.27 - 1.02 mg/kg), (0.09 - 0.12 mg/kg) and (0.25 - 0.31 mg/kg), Cr ranged from (0.05 - 0.65 mg/kg), (0.04 - 0.05 mg/kg) and (0.03 - 0.05 mg/kg), Zn ranged from (2.67 - 3.32 mg/kg), (1.93 - 2.87 mg/kg) and (2.45 - 3.26 mg/kg), Ni ranged from (0.68 - 0.77 mg/kg), (0.23 - 0.26 mg/kg) and (0.73 - 0.86 mg/kg), and Cu ranged from (0.95 - 0.97 mg/kg), (0.76 - 0.83 mg/kg) and (0.94 - 1.00 mg/kg) respectively. The abundance of trace metals was found in decreasing order: Zn > Cu > Ni > Mn > Cr > Cd > Pb in lettuce, tomato and cabbage samples. The concentration of trace metals in the different vegetables were below the World Health Organization/Food and Agriculture Organization (WHO/ FAO) standard, except Cd in all studied samples. Therefore, monitoring and strict regulation is recommended to control the safety of vegetables sold in these markets.

Monitoring of Heavy Metal Contamination in Dietary Vegetables

Reports of increasing concentrations of heavy metals in vegetables are currently a major cause of concern for human health. The samples of cauliflower and spinach were collected from different locations such as kitchen garden and local vegetable markets in and around Delhi. These vegetables were tested for the presence of heavy metals ( Pb, Cu, Cr and Zn) . Analysis was carried out using washed and unwashed samples. The concentrations of these metals were determined using Atomic Absorption Spectrophotometer. The unwashed samples showed higher concentrations of heavy metals in comparison to washed samples. Specifically, the concentrations of Cu and Cr were much higher in the vegetables procured from areas which were irrigated with polluted water as compared to vegetables grown in kitchen garden. These findings highlight the need to educate farmers on the implications of their current agricultural practices.

Health Risks Due to Metal Concentrations in Soil and Vegetables from the Six Municipalities of the Island Province in the Philippines.

This paper investigated the health risks due to metal concentrations in soil and vegetables from the island province in the Philippines and the potential ecological risks. The concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in vegetables and soil in six municipalities of the province were analyzed using the Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) Perkin Elmer Optima 8000. It was recorded that all metal concentrations in the soil, except for Cd, exceeded the soil quality standard (SQS). The concentration of Fe and Mn was highest among other metals. The Nemerow synthetical pollution index (Pn) in all soil samples was under Class V which means severe pollution level. Likewise, the risk index (RI) of soil ranged from high to very high pollution risk. Most of the metal concentrations in the vegetables analyzed also exceeded the maximum permissible limit (MPL). All health hazard indices (HHIs) were less than 1, which means potential low non-carcinogenic risk to human population by vegetable consumption. However, it was found that concentration of Cr and Ni in vegetables is a potential health hazard having concentrations exceeding the maximum threshold limit. A 75% temporary consumption reduction of bitter melon, eggplant, sweet potato tops, and string beans produced from two municipalities may be helpful in reducing exposure to target metals. Additional studies are needed to confirm this recommendation. Spatial correlation analysis showed that six out of target metals had datasets that were more spatially clustered than would be expected. The recorded data are useful for creation of research direction, and aid in developing strategies for remediation, tools, and programs for improving environmental and vegetable quality monitoring.

Transfer of heavy metals from soils to curly mustard (Brassica juncea (L.) Czern.) grown in an agricultural farm in Brunei Darussalam

Determination of heavy metal concentrations in vegetables and agricultural soils is crucial because high levels of heavy metals could affect soil quality, crop production and safe consumption of crops. A field study was conducted to determine the heavy metal concentrations and their transfer from agricultural soils to different parts (leaf, stem, and root) of Brassica juncea (L.) Czern. In addition, potential health risks of contamination in the vegetables grown in the field were evaluated. Acid digestion method USEPA 3050B in combination with ICP-OES were used to analyze heavy metal (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) contents in both pre- and post-harvest soils and vegetable samples. Results showed that none of the heavy metals in soils had concentrations above the maximum safety limits based on the WHO, USEPA and CCME guidelines. Calculated metal transfer factor (MTF >1) showed B. juncea accumulated Cd, Co, Ni, Pb and Zn in leaves, stems and roots, but Cu and Mn, as well as Cr were only accumulated in stems and roots, respectively. There were variations in heavy metal contents between the different parts of B. juncea, but only Cd and Pb contents were above the maximum allowable limit recommended by FAO/WHO. PCA analysis was able to identify 4 major components corresponding to 38.38%, 28.98%, 14.39% and 10.67% of the total variance and PC1 was clearly associated to leaves of B. juncea. Based on the MTF values, only Cd was found to have a value of HRI >1 compared to the other heavy metals, implying potential health risk associated with long-term ingestion of the vegetable.

HEAVY METALS IN THE FOOD CHAIN - CONSEQUENCES OF POLLUTING WATER BODIES

Purpose of the study: Heavy metals in food (vegetables, etc.) are harmful to humans due to their non-biodegradable nature, long biological half-lives, and their potential to accumulate in different body parts. Prolonged consumption of such heavy metal contaminated vegetables through foodstuffs may lead to chronic accumulation of heavy metals in human beings' kidneys and liver, disrupting numerous biochemical processes, leading to cardiovascular, neural, kidney and bone diseases. Method: The study on heavy metal concentrations in vegetables grown in the command areas of Varthur lake, Bangalore. The collected vegetable samples were analyzed using ICP-OES (Inductively Coupled Plasma-Optical Emission Spectroscopy) technique to assess the level of heavy metal in acid digested samples. Main Findings: The study has shown a significant accumulation of heavy metals in vegetables that correlated well with its concentrations in soil and lake water. The prolonged irrigation of vegetables using contaminated lake water has led to soil contamination, which ultimately resulted in contamination of vegetables due to the uptake and accumulation of heavy metals in edible portions of vegetables. Application of the Study: Urgent attention is needed to devise and implement appropriate means of regular monitoring of the toxic heavy metals from domestic sewage and industrial effluent and provide proper advice and support for the safe and productive use of wastewater for irrigation purposes to prevent excessive buildup of heavy metals in the food chain.

Effects of dust deposition from diamond mining on subarctic plant communities and barren-ground caribou forage.

Dust produced from mining has the potential to reduce plant cover, alter plant communities, and increase metal concentrations in vegetation-changes that may affect the amount, type, and quality of forage for barren-ground caribou (Rangifer tarandus groenlandicus). We quantified dust deposition from Diavik Diamond Mine (Northwest Territories, Canada) and investigated the changes on forage quality, type, and quantity for caribou. From 2002 to 2016, dust deposition was measured, and vegetation cover and richness were assessed in permanent plots established adjacent to the mine and in reference areas 1-6km from the mine. Lichen was collected from areas up to 100km from the mine to determine metal concentrations. Dust deposition rapidly decreased within 4km of the mine. Plant communities adjacent to the mine (within 500m) had disproportionately increased cover of vascular plants and decreased bryophyte and lichen cover. Lichen sampled within 4km from the mine had greater metal concentrations than those sampled farther afield. Concentrations of Al in lichen collected within 40km of the mine exceeded safe exposure limits for consumption, assuming lichen comprised 100% of caribou diet. We conclude that dust deposition from mining is altering adjacent vegetation communities but that such changes to forage are unlikely to cause negative effects to caribou due to reduced lichen intake in summer and autumn, their migratory nature, and avoidance of mine-influenced areas. However, minimization and reclamation of mine-related disturbances will be important for maintaining sufficient quality forage and available habitat or space in caribou ranges.

Heavy metals concentration in vegetables irrigated with municipal wastewater and their human daily intake in Erbil city

Assessment of heavy metals accumulation in vegetables and their levels in human is vital in countries where wastewater is used for irrigation. In this study, The aim of this research was to investigate the concentrations of highly toxic metals such as Nickel (Ni), chrome (Cr), lead (Pb), zinc (Zn), cadmium (Cd), and copper (Cu) in wastewater, farmlands soils and vegetables (chard, celery, cress and leek), and also their possible human health risk in the area of Erbil city. The heavy metals concentration in the vegetable, soil and water samples were analyzed by using an atomic absorption spectrophotometer. Bio-concentration factor (BCF), daily intake (DI) and health risk index (HRI) were calculated in order to estimate the human health risk. Overall, results indicated that the water, soil and vegetable samples were contaminated with Ni, Cd, Cr, Cu, Pb, and Zn. The trends of these metals concentrations were as follows: 0.613 > 0.316 > 0.162 > 0.065 > 0.041 > 0.028 mL/L for Ni, Cd, Pb, Cr, Cu, and Zn, respectively in the wastewater and 189.09 > 125 > 104.92 > 41.85 > 28.58 > 21.72 for Zn, Cr, Ni, Pb, Cu and Cd mgkg−1 in the soil. The mean concentrations (mg kg−1) in the vegetable samples ranged from 22.74 to 30.30, 5.18–9.19, 29.50–33.87, 39.42–64.78, 7.87–11.83 and 77.68–117.98 for Ni, Cd, Pb, Cr, Cu and Zn, respectively. In addition, the calculated BCFs value ranged from 0.21 to 71.295, with Pb having the highest BCF. The calculated DI for Ni, Cd and Pb exceeded WHO/FAW safe limits for adult and children. Furthermore, the HRI values of Cd and Pb exceeded the safe limit (1) for both adults and children, but the values for Ni (> 1) exceeded the safe limit only for children. These findings clearly indicate that the practice of irrigating the vegetables with untreated wastewater by local farmers have caused high accumulation of heavy metals in the soils and vegetables which are posing health risk to the population in the vicinity. Therefore, regular monitoring of these metals in the wastewater-irrigated vegetables is necessary.

Physiological Analysis and Contamination of Heavy Metal Contents in Vegetables and Fruits Irrigated with Wastewater

The following research work has been undertaken to examine the presence of heavy metals i.e., lead (Pb), Cadmium (Cd), Copper (Cu), Iron (Fe), Cobalt (Co) in some selected vegetables and fruits supplied in the local market. The process used to determine heavy metals is Atomic Absorption Spectrometer. Iron concentration in spinach, tomato, cauliflower and lady finger showed higher ranges which were exceeding the permissible limits. Cauliflower and spinach were within the limits specified. The pH value, ascorbic concentration and moisture content significantly decreased after oven drying of vegetables and fruits. However, the Total Soluble Solids (TSS) and ash content significantly increased after oven drying as compared with fresh vegetables and fruits. The present research data revealed that the fresh and oven dried vegetables such as Spinach, Cauliflower, Lady finger and Tomato contains 0.13-1.50%, 0.25-2.32%, 0.26-2.52% and 0.19-3.13% Titratable acidity respectively. Similarly, fresh and oven dried Guava Titratable acidity was highest 0.27 and 1.92 as compared with Water melon and Mango. The reduction in acidity may be due to catabolic activities in fruit cells and increased in pH. The pH value of vegetables and fruits dropped after oven drying. Similarly, ascorbic concentration and moisture content significantly decreased after oven drying as compared to fresh vegetables and fruits. However, the Total Soluble solids (TSS) and ash content significantly increased after oven drying as compared with fresh vegetables and fruits. Overall, from the following study we can conclude that vegetables and fruits were found to be contaminated by heavy toxic metals. Regular monitoring is required because these toxic metals will damage human body as well disturb our food chain. The main objective to conduct this study is to monitor the heavy metal toxicity and provide some recommendation, which in future will assure food safety and human health.

Heavy metal concentration in vegetables and their potential risk for human health

This study assesses heavy metal levels in the water, soil, and vegetables (swiss chard, lettuce, cabbage, collard green, tomato, green pepper, and carrot) irrigated with wastewater in Gamo, Ethiopia. The samples of soils, waters, and vegetables were randomly collected, processed, and analyzed for heavy metals using atomic absorption spectroscopy. The results obtained show that the mean concentrations of Cd, Cr, and Ni had the highest concentration, and Pb, Zn, and Cu had the lowest concentration in irrigation waters. The levels of Cd in the Kulfo river area and Chamo Lake area and Cu in most of the farm soils were also found to be higher than the guideline values. The study also revealed that the mean levels of Cd in most vegetables and Cr and Pb in some vegetables were higher than the maximum recommended limits set by the World Health Organization / Food and Agriculture Organization 2001. Among the vegetables, cabbage had the highest heavy metal content followed by Swiss-chard, carrot, tomato, collard green, green pepper, and lettuce. The Hazard quotient of Cu, and Ni of all samples of vegetables and Cd in some samples vegetables obtained exceeded unity. It signifies that there are potential health risks to the consumers. This study recommends regular monitoring of heavy metals in soils, waters, and foodstuffs to prevent excessive accrual in the food chain.

Heavy metal concentrations in vegetables cultivated and sold in Machakos Municipality, Kenya

Heavy metal contamination of vegetables is a key aspect of food quality assurance since vegetables form a substantial proportion of the daily human diet. Health risks in urban populations due to exposure to heavy metals are on the increase because of the consumption of vegetables irrigated with wastewater. This study analyzed the concentration of Cd, Cu, Pb, Zn and Cr in spinach and kales grown using contaminated water of the Mitheu urban stream and those sold within Machakos municipality. Vegetable samples were collected once per month for a period of four months starting from June to September 2019. The mean heavy metal concentrations obtained were0.013 – 3.19 mg/kg, 0.468 – 1.706 mg/kg, 0.02 – 0.368 mg/kg, 5.78 – 26.7 mg/kg, and 0.104 – 14.0 mg/kg for Cd, Cu, Pb, Zn and Cr respectively in kale samples from the different sampling sites. The heavy metal mean concentrations in spinach were 0.055 – 0.575 mg/kg, 3.79 – 5.55 mg/kg, 0.098 – 1.49 mg/kg, 8.32 – 20.7 mg/kg and 0.368 – 4.43 mg/kg for Cd, Cu, Pb, Zn and Cr respectively. The mean concentrations of Cd, Pb, Zn and Cr in both spinach and kales in some of the sampling sites were above WHO permissible levels for heavy metals in vegetables for human consumption. However, the mean concentration of Cu was below WHO recommended levels. Consumption of these vegetables therefore poses a health risk to the consumers. There is need to create public awareness on the dangers of consuming contaminated vegetables. Additionally, measures to curb heavy metal pollution in Mitheu stream should be taken by the County Government of Machakos.

Heavy metal contamination of water, soil and vegetables in urban streams in Machakos municipality, Kenya

Pollution of the environment by heavy metals emanating from rapid economic growth and improper waste and effluent disposal is a major concern. In this study, heavy metal concentrations (Cd, Cu, Pb, Zn and Cr) in vegetables, soil and water in two urban streams in Machakos municipality were analyzed. Physicochemical parameters; pH, temperature, total dissolved solids (TDS) and electrical conductivity (EC) were also measured on-site. One-way Analysis of variance (ANOVA) was used to test for the significant difference (p ≤ 0.05) of heavy metal concentrations in the vegetables, soil, and water across the different sampling sites. The relationship between the heavy metals in the soil, water and vegetables was investigated using Pearson correlation. Temperature (21.58 – 23.05 °C), pH (7.5 – 8.45) and TDS (577.5 – 865.83 mg/L) mean values were found to be within WHO acceptable limits for surface water while EC (864 – 1778.5 µS/cm) exceeded the set limits. Results showed that the mean concentrations (mg/kg) of Cd (BDL – 0.0011), Cu (0.0034 – 0.0055), Pb (0.0012 – 0.007), Zn (0.0232 - 0.1351), and Cr (0.0036 - 0.0292) in water and Cd (0.0058 - 0.0534), Cu (10.39 – 27.5), Pb (4.23 - 8.35), Zn (20.1 – 28.8) and Cr (8.17 – 10.03) in soil were within WHO permissible limits. Mean concentration values of (Zn (9.05 – 11.8), Pb (0.28 – 0.636), Cr (BDL – 1.002)) in spinach exceeded WHO permissible limits while Cd (BDL – 0.1285) and Cu (3.07 – 14.5) were within recommended levels. Cd (0.004 – 0.243), Cu (0.909 – 3.60) and Pb (BDL – 0.458) concentration levels in kale were within WHO safe limits for human consumption while Zn (12.06 – 18.8) and Cr (BDL – 1.62) exceeded WHO set limits. Presence of heavy metals (Zn, Pb, Cr) in the vegetables signifies a health risk hazard from consumption of these vegetables. Continuous monitoring of heavy metals in stream water, soil and vegetables is critical towards safeguarding public health.

Assessment of Some Heavy Metals in Selected Vegetables, Fruits and their Respective Soil

High concentration of heavy metal content of fruits and vegetables may reduce their antioxidant properties. Therefore, the concentration of selected heavy metals such as Cr, Ni, Mn, Fe, Mg, Cu and Pb in vegetables (Colocasia esculanta and Abelmoschus esculentus) and fruits (Psidium guajava and Pyrus) was assessed using atomic absorption spectrophotometer. The highest concentrations of heavy metals in vegetables and fruits were found 0.019, 0.008, 0.072, 0.241, 1.754, 0.107 and 0.014 mg/g for Cr, Ni, Mn, Fe, Mg, Cu and Pb, respectively. Level of Cr was found higher in Colocasia esculanta (0.011 mg/g). The highest level of Ni was found in Pyrus (0.008mg/g) while lowest in the Soil of Abelmoschus esculentus (0.003 mg/g). The highest level of Mn was observed in Soil of Colocasia esculanta (0.072 mg/g) while lowest in Abelmoschus esculentus (0.007 mg/g). Maximum level of Mg was found in Soil of Psidium guajava while minimum in Colocasia esculant. Abelmoschus esculentus showed highest level of Cu while minimum level was found in Colocasia esculanta. Pb showed maximum amount in Psidium guajava and minimum in soil of Abelmoschus esculentus. The values of Cr, Ni, Mn, Fe, Mg, Cu and Pb in all samples are in the safe limit. However the study indicates that the vegetables, fruits and soil samples are contaminated by toxic heavy metals.

Assessment of Some Heavy Metals in Selected Vegetables, Fruits and their Respective Soil

The concentration of selected heavy metals such as Cr, Ni, Mn, Fe, Mg, Cu and Pb in vegetables ( Colocasia esculanta and Abelmoschus esculentus ) and fruits ( Psidium guajava and Pyrus ) was assessed using atomic absorption spectrophotometer. The concentrations of heavy metals in vegetables and fruits were found in the range of 0.225 to 1.918 mg/L for Cr, 0.367 to 0.794 mg/L for Ni, 0.678 to 7.226 mg/L for Mn, 5.557 to 24.12 mg/L for Fe, 30.02 to 175.4 mg/L for Mg, 0.137 to 1.072 mg/L for Cu and 0.334 to 1.408 mg/L for Pb. Level of Cr was found higher in Colocasia esculanta and lowest in Pyrus (1.110- and 0.225 mg/L respectively). The highest level of Ni was found in Pyrus while lowest was in Soil of Abelmoschus esculentus (0.794 and 0.340 mg/L respectively). The highest level of Mn was observed in Soil of Colocasia esculanta while lowest in Abelmoschus esculentus vegetable (7.226 and 0.678 mg/L resoectively). Maximum level was found in Soil of Psidium guajava while minimum in Colocasia esculanta vegetable (24.07 and 5.557 mg/L. Maximum concentration appeared in Soil sample of Colocasia esculanta while minimum in Psidium guajava fruit (175.4 and 14.73 mg/L). Abelmoschus esculentus showed highest level of Cu while minimum level was found in Colocasia esculanta (1.072 and 0.137mg/L). Pb showed maximum amount in Psidium guajava and minimum in soil of Abelmoschus esculentus (1.408 and 0.334 mg/L). The values of Cr, Ni, Mn, Fe, Mg, Cu and Pb in all samples are in the safe limit. However the study indicates that the vegetables, fruits and soil samples are contaminated by toxic heavy metals. .

Assessment of Some Heavy Metals in Selected Vegetables, Fruits and their Respective Soil

The concentration of selected heavy metals such as Cr, Ni, Mn, Fe, Mg, Cu and Pb in vegetables ( Colocasia esculanta and Abelmoschus esculentus ) and fruits ( Psidium guajava and Pyrus ) was assessed using atomic absorption spectrophotometer. The concentrations of heavy metals in vegetables and fruits were found in the range of 0.225 to 1.918 mg/L for Cr, 0.367 to 0.794 mg/L for Ni, 0.678 to 7.226 mg/L for Mn, 5.557 to 24.12 mg/L for Fe, 30.02 to 175.4 mg/L for Mg, 0.137 to 1.072 mg/L for Cu and 0.334 to 1.408 mg/L for Pb. Level of Cr was found higher in Colocasia esculanta and lowest in Pyrus (1.110- and 0.225 mg/L respectively). The highest level of Ni was found in Pyrus while lowest was in Soil of Abelmoschus esculentus (0.794 and 0.340 mg/L respectively). The highest level of Mn was observed in Soil of Colocasia esculanta while lowest in Abelmoschus esculentus vegetable (7.226 and 0.678 mg/L resoectively). Maximum level was found in Soil of Psidium guajava while minimum in Colocasia esculanta vegetable (24.07 and 5.557 mg/L. Maximum concentration appeared in Soil sample of Colocasia esculanta while minimum in Psidium guajava fruit (175.4 and 14.73 mg/L). Abelmoschus esculentus showed highest level of Cu while minimum level was found in Colocasia esculanta (1.072 and 0.137mg/L). Pb showed maximum amount in Psidium guajava and minimum in soil of Abelmoschus esculentus (1.408 and 0.334 mg/L). The values of Cr, Ni, Mn, Fe, Mg, Cu and Pb in all samples are in the safe limit. However the study indicates that the vegetables, fruits and soil samples are contaminated by toxic heavy metals. .

Monitoring and modeling of heavy metal contents in vegetables collected from markets in Imo State, Nigeria.

Vegetable consumption is one major exposure route of heavy metals to humans, but few data exist for Imo State, Nigeria. We assessed the contamination levels and associated health risk of cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) in vegetables (Telfairia occidentalis, Pterocarpus mildbraedii, Gongronenina latifolium and Vernonia amygdalina) that are consumed frequently from markets (n=16) in three zones of Imo State, Nigeria. After wet-digestion of samples, the supernatant were analyzed using atomic absorption spectrophotometry. The mean concentrations in the four vegetables ranged from 0.006±0.003 mg/kg to 0.011±0.007 mg/kg for Cd, 0.064±0.012 mg/kg to 1.225±0.226 mg/kg for Co, 10.711±1.968 mg/kg to 25.088±13.975 mg/kg for Cu, 0.062±0.013 mg/kg to 0.307±0.210 mg/kg for Ni, 0.006±0.005 mg/kg to 0.012±0.002 mg/kg for Pb and 63.55±4.055 mg/kg to 104.126±24.080 mg/kg for Zn. Except for Zn, all heavy metals in the various vegetables were below the joint standard of Food and Agriculture Organization and World Health Organization. Although, overall load of heavy metal was very low, Zn had the highest contamination factor in vegetables. Heavy metals concentrations in vegetables generally showed low to high variations and statistically different (p<0.05). Average daily intake was below the provisional tolerance limit except for Zn. The target hazard quotient of metals in vegetables for both children and adults were below 1, indicating no potential risk to the public. Overall, heavy metals hazard index were below 1, indicating acceptable level of non-carcinogenic adverse health effect. However, potential multi-element contamination from ingestion is possible as revealed by the correlation profiling of heavy metals.